Reference: MSEgui

│ English (en) │

Widgets

TSimpleWidget

see also Reference:_MSEgui/TSimpleWidget

TMseFormWidget

Use it in order to insert a tcustomform descendant into another widget at designtime. Does not try to load resources in "create".

        tmseform descendants ( MainForm, SimpleForm,.. )

	Client area of the form & parent of its widgets ( against which the widgets 
	are placed and colored ) is presented by the "container" property 
	not "container.frame.clientarea"

	CanClose is called :

		- on receiving "ek_close" by window
		- for modal window, on focus change

		- within parent window's "CanClose"	where all nested windows are  
		checked for OnCloseQuery & OnClose - if any sets "mr_none" then the parent window 
		can't close as well
			
		- from nested window's "CanParentClose"
		- from own "CanParentClose"

		- some componnets build oneself in own "Loaded" procedure :
			= widget grids
			= database access components
			= ...

	The "form.show" has parameter "transientfor".
	The window Z-order is above the "transientfor" window. The exact behaviour
	depends on the window manager.
        
        caption
		- run-time caption on the title bar

	color
		- color behind the client ( contaner ) area

	container
		- the real parent of form's widgets, <see "tformscrollbox">

	cursor
		- the mouse over cursor shape

	enabled - "false" disables all child widgets

	face
		<see "tfacecomp"> + some more options

	font
		<see "tfont">

	frame
		<see "tframecomp"> + some more options
		
	icon 
		<see "timage">

	mainmenu
		<see tmainmenu>

	name
		- name to refer when programming

	options:

		fo_main 
			- assigns this from as the aplication GUI-face & event receiver
			- causes the icon of this form to be icon of the application 

		fo_terminateonclose
			- causes the application to terminate once the form has closed ( doesn't depend on "fo_main" )


		fo_freeonclose
			- causes the form (even being modal) to release its memory on closure or OK-return from "CanClose"

		fo_defaultpos
			- lets the WM to position the form initially

		fo_screencentered
			- causes the form initially to show in center of the apllication work area

		fo_closeonesc
			- causes the form to close on "Esc" key pressed ( with MR_ESCAPE & "OnCloseQuery" firing )

		fo_cancelonesc
			- causes the form to close on "Esc" key pressed ( with MR_CANCEL & "OnCloseQuery" firing )

		fo_closeonenter
			- causes the form to close on "Enter" key pressed ( with MR_OK & "OnCloseQuery" firing )

		fo_closeonf10
			- causes the form to close on "F10" key pressed ( with MR_F10 & "OnCloseQuery" firing )

		fo_globalshortcuts
			- allows on-this-form "ao_globalshortcut" actions to trigger

			  Notes :
				= shortcuts for modal not "fo_localshortcut" forms are processed by app
				= shortcuts for "fo_globalshorcut" forms are processed by the owning window 

		fo_localshortcuts
			- disables triggering shortcuts of on-this-form actions

		fo_autoreadstat
			- for "cs_ismodule" forms, before "OnLoaded" fires, rereads all statvars from the bound stafile/memorystream

		fo_autowritestat
			- in "CanClose", after "OnClose" fires [ and before app termination for "fo_terminateonlose" form ], 
			rewrites all statvars to the stafile/memorystream
			- for datamodules, does this before "OnDestroy" fires

		fo_savepos
			- saves/restores Z-order, size & scree coordinates of the form 
			as soon as the stat data are ready

		fo_savestate
			- for top-level form, saves/restores "VSize", "Active" & "Visible" 
			as soon as the stat data are ready

	optionswidget
		<see "any widget">
	optionswindow
		<see "any window">
	popupmenu
		<see "tpopupmenu">
	stafile
		<see "tstafile">
	stavarname
	taborder
	tag

	visible - for a form, only affects its childs widgets

	Events:

		activate = to set focused & redraw the invalidated area

		oncreate
			- fires before "Loaded" procedure is called
			- fires after creating the widget & its subwidgets but before the final arrangement
			- forms arent' yet visible on return

		  Since "Loaded" procedure hasn't yet worked at this point then 
			database contents, values of widget grid's subwidgets 
			are invalid in this event ***

		onloaded
			- fires once "Loaded" procedure of owns & all form's widgets finishes
			- processed  after "OnCreate"
			- on finishing, forms aren't yet visible

		oneventloopstart ( main forms only )
			- only applicable to main forms
			- fires once all application GUI is built and shown 
			( and ready to user's interaction )
			
		onactivate 
			- see {any_widget.OnActivate}

		onenter
			= see {any_widget.OnEnter}

		onfocus
			- see {any_widget.OnFocus}
			

		onwindowactivechanged
			- fires on :
				= touching another window even on clicking in a behind-modal window ( or its title bar )
				= 1-st showing the window
				- reactivating the window

		onbeforepaint
			- fires at the very beginning of "paint", before drawing canvas

		onpaint
			- fires in "paint" procedure, between drawing canvas and contained widgets

		onafterpaint (doafterpaint)
			- fires just on return from "paint" procedure

        	onapplicationactivechanged 
			- fires :
				= if the application gets/looses input focus

		onasyncevent (doasyncevent)
			- fires on calling {this_form}.asyncevent(atag) from any place of the application
			once delivered by the app even queue

			 "atag" set by caller(s) helps to branch within "onasyncevent", to identify the caller, etc ***
			 generally, doesn't fire instantly because these events are delivered through the app event queue ***


		onchildmouseevent
			- fires on any mouse activity over its child widget(s) not the (containing) widget oneself

		      for forms, it even fires on enetering "container" therefore it appears as if to be the form itself ***

		onchildscaled
			- see {any_widget.OnChildScaled}

		onclientmouseevent
			- fires on any mouse activity over areas expecting user's mouse input (not titlebars/frames/...)

		onclose
			- fires in "CanClose" if "modalresult <> mr_none"

		onclosequery
			- fires in "CanClose" before "OnClose"
			- "mr_none" set on return prevents the window (and its parent) from closing 
			( "OnClose" is also bypassed )


		ondeactivate
			- see {any_widget.OnDeactivate}

		ondefocus
			- see {any_widget.OnDeFocus}
			
		ondestroy
			- fires on in-code calling "BeforeDestruction"

		ondestroyed
			- fires on return from the form's destructor ( when all resources are freed )

		onterminatequery
			- fires on an attempt to terminate the app
			- by setting "var terminate:= false", allows to cancel termination 

			 Termination by debugger/OS facilities can't be blocked this way ( win32 )***

		onterminated
			- fires for not-yet-destroyed forms, once the app event loop finishes 
			- may be caused by any closure of the main app form 
			( app termination, WM/OS facilities, )


		onwindowdestroyed
			- fires once a descendant window is destroyed 
			( for a main form, when a modal simple form is closed by any way,.. )

		onevent
			- fires on receiving an event 
				= for simple forms, it's only "ek_loaded"

			There can be more if the form is connected to object_event sending
			components or if the application uses object events, for example by calling
			tguicomponent.postcomponentevent. ****

		onexit
			- see {any_widget.OnExit}

		onfocusedwidgetchanged
			- for a "prev-new" parent-wide focused wigdets pair, fires once installing new focus has finished, 
			after "OnFocus"
			- resends for all contained widgets
			- doesn't fire if the "prev-new" pair don't really change

		onfontheightdelta
			- see {any_widget.OnFontHeightDelta}

		onhide
			- fires at beginnig of own/parent's 
				= hide
				= hidden
				= destroying
				= setting "visible:= false"
				= closing the window ( receiving event "ek_close",.. )
				= calling "window.close" 
				
		onidle
			- fires everytime when the app GUI event queue gets empty
			- to stop calling for a while, set "again" parameter to "false" (the initial value );
			
			 DON'T DO ANYTHING AFFECTING THE APP EVENT QUEUE ( MODAL WINDOWS, "ShowMessage", Sleep(N),... ) IN THIS HANDLER. 
				MODAL WINDOWS CAUSE RECURSION ! 
			
			A code fragment:

				again:= i < 5;
				if not again then exit;

		onkeydown
			- fires on pressing down a keyboard key over the client area when none of child widgets is focused

		onkeyup
			- fires on releasing a keyboard key over the client area when none of child widgets is focused

		onmouseevent
			- fires on any mouse activity over the client area

		onmove
			- see {any_window.OnMove}

		onpopup
			- see {any_widget.OnPopup}

		onresize
			- see {any_widget.OnResize}

		onshortcut
			- fires before built-in shorcut processing
			- "info.eventstate=es_processed" set in "OnShortcut" prevents 
			the event from further auto-processing

			The app 
				- recognizes & takes registered shortcuts from app event queue
				- passes the shocrcut event to each of its windows until the event 
				is processed otherwise processes it by oneself 
			

		onshow
			- fires if the widget is visible:
				= on calling "Show" method
				= on return from "Loaded" procedure
				= on showing the parent widget
			- since called at end, allows to adjust the default behavior

		onshowhint
			- see {any_widget.OnShowHint}

		onstatbeforeread 
			- fires before loading statvars  from the disk file

		onstatafterread
			- fires once statvars are loaded from the disk file

		onstatupdate 
			- fires at 1-st stage before updating GUI "state/pos" for read statvars
			or 
			- fires at pre-last stage before saving GUI "state/pos"

		onstatread 
			- fires at 2-nd stage before updating GUI "state/pos" for read statvars

		onstatwrite
			- fires at last stage before saving GUI "state/pos"

		pon stat reading, non-minimized visible windows are shown, 
		the active window is activated 

TPaintbox

How to draw line (or circle) on tpaintbox? In event onpaint:

 
 procedure tmainfo.paintboxonpaint(const sender: twidget; const canvas: tcanvas); 
 begin 
  with sender,canvas do begin 
   drawline(nullpoint,pointty(size),cl_yellow);  
   //diagonal line across widget 
   drawellipse(makerect(makepoint(bounds_cx div 2,bounds_cy div 2), size),cl_red); 
   //circle (or ellipse) centered in widget                             
  end; 
 end;

Makepoint and makerect are in msegraphutils.

TEventWidget

A widget which publishes all possible events of a twidget. Normally it is better to implement your own specialized descendant of an existing widget instead to use teventwidget.

TButton

• A rectangular clickable area that can show text/bitmap.

- Main properties:

Caption: read/write the text that appear on top of it.
onexecute: read/write the address of a procedure (event handler) to be executed when clicked.

TLabel

• Draws a piece of text on the given surface (canvas: screen/printer/bitmap).

- Main properties:

Caption: read/write the piece of text.

See also TLabel

TStringDisp

• A read only version of TStringEdit, difference from TLabel: has a frame around it.

-Main properties:

Value: read/write the text that are showed.
Caption: A label normally describing the purpose or meaning of the presented text, it can be positioned around the frame.

TSpliter

	       A widget very similar to "tspacer" but :
		- designed to rearrange areas occupied by adjacent widgets
		- a linked widget may only enlarge by "eating" the opposite one, 
		so the summary area of both widgets don't change
		- has GUI look ( hatched grip, color etc) switched on by default
		- facilitates run-time repositioning oneself and linked widgets
		- linked widgets may even be other splitters, spacers (with their linked widgets ),..
	
        Properties:

	- color
		= see {any_widget.color}

	- cursor
		= see {any_widget.cursor}

	- enabled
		= "false" stops user interaction

	- face
		= see {any_face}

	- frame
		= see {any_frame}

	- colorgrip
		= color of grip hatching

	- grip
		= defines hatching pattern of the grip

			* stb_dens(N) : the pattern is of rhombuses, the painted rhombs occupy "N" persents of the grip

			* stb_block(N) : the pattern is of squares, painted & unpainted squares are equally sized and 
			both have "N" pixels sides
			
			* stb_hatchup(N) : the pattern is of right-tilted lines of 1 pixel width,
			each "N"-th pixel forms these lines

			* stb_hatchdown(N) : the pattern is of left-tilted lines of 1 pixel width,
			each "N"-th pixel forms these lines

			* stb_crosshatch(N) : the pattern is of crossing (left & right) tilted lines of 1 pixel width,
			each "N"-th pixel forms these lines


	- linkbottom/linkleft/linkright/linktop 
		= see {tspacer.*}

	- options

		= spo_hmove
			* "true" allows the spliter to move horizontally

		= spo_hprop
			* "true" : keep the left position proportional ( on the ratio of creation time ) 
			to weigth of the client area of parent

		= spo_hsizeprop
			* "true" : keep width of the spacer proportional ( on the ratio of creation time ) 
			to weigth of the client area of parent
			* the width stops shrinking on one set in design time

		= spo_vmove
			* "true" allows the spliter to move vertically

		= spo_vprop
			* "true" : keep the top position proportional ( on the ratio of creation time ) 
			to height of the client area of parent

		= spo_vsizeprop
			* "true" : keep height of the spacer proportional ( on the ratio of creation time ) 
			to height of the client area of parent
			* the height stops shrinking on one set in design time

		= spo_dockleft
			* causes the "linkleft" widget to dock to the left border of splitter
			* make sence only if linkleft "widget.bounds_x" less than "splitter.bounds_x"

		= spo_docktop
			* causes the "linktop" widget to dock to the top border of splitter
			* make sence only if linktop "widget.bounds_y" less than "splitter.bounds_y"

		= spo_dockright
			* causes the "linkright" widget to dock to the right border of splitter
			* make sence only if linkright "widget.(bounds_x+bounds_cx)" more than "splitter.(bounds_x+bounds_cx)"

		= spo_dockbottom
			* causes the "linkbottom" widget to dock to the bottom border of splitter
			* make sence only if linkbottom "widget.(bounds_y+bounds_cy)" more than "splitter.(bounds_y+bounds_cy)"

		!!! Two special cases :

		1. (spo_dockleft = spo_dockright = TRUE) && (linkleft = linkright = the_same_widget) : 
			causes the "linkleft" widget to adjust to h-positiion & width of the splitter, 
			it's even possible that the widget doesn't touch the splitter

			(spo_docktop = spo_dockbottom = TRUE) && (linktop = linkbottom = the_same_widget) : 
			causes the "linktop" widget to adjust to v-position & height of the splitter, 

			It's even possible in these cases that the widget doesn't touch the splitter

	- optionsscale
		= see {tscalingwidget.optionsscale}

	- optionswidget
		= see {anywidget.optionswidget}

	- onactivate, onchildscaled, ondeactivate, ondefocus, onenter, onexit, onfocus,
	  onfontheightdelta, onmove, onpopup, onresize, onshowhint
		= see "tspacer"

	- onupdatelayout
		fires :
		
		= on creating the splitter
		= on any reposition of the linked widgets 
		( due to moving the splitter, resizing the parent,.. )

TSpacer

* a regular widget which creates a kind of positional link between surrounding widgets
* designed to maintain distances between widgets
* may have GUI look, caption etc switched off by default
* resizing a spacer repositions its linked widgets

Properties:

- anchors = see {any_widget.anchors}

- bounds = see {any_widget.bounds}

- color = see {any_widget.color}

- enabled = "false" turns color of the caption to gray

- visible = "true" allows displayable settings (caption text, face, frame etc) to take effect in run-time as well

- <face> = see {any face}

- <frame> = see {any frame}

- linkbottom = widget linked down to most outer edge (incl. frame[.caption]) of the spacer - linkleft = widget linked left to most outer edge of the spacer - linkright = widget linked right to most outer edge of the spacer - linktop = widget linked up to most outer edge of the spacer

- dist_bottom, dist_left, dist_right, dist_top : = margins between most outer edge the spacer and the corresponding linked widget

- options :

= spao_glueright

- if "false"

h-repositioning or h-resizing the linkleft widget shifts the whole linked construction, it becomes the only way to h-shift

if {an_right IN linkright_widget.anchors} then the spacer may be right-resized with auto h-resizing the linkright widget so that the right margin of that widget is kept

if NOT {an_right IN linkright_widget.anchors} then the spacer may be right-resized with auto h-shifting the linkright widget so that width of that widget is kept

- if "true"

h-repositioning or h-resizing the linkright widget shifts the whole linked construction, it becomes the only way to h-shift

if {an_left IN linkleft_widget.anchors} then the spacer may be h-resized with auto h-resizing the linkleft widget so that the left margin of that widget is kept

if NOT {an_left IN linkleft_widget.anchors} then the spacer may be h-resized with auto h-shifting the linkleft widget so that width of that widget is kept

= spao_gluebottom

- if "false"

v-repositioning or v-resizing the linktop widget shifts the whole linked construction, it becomes the only way to v-shift

if {an_bottom IN linkbottom_widget.anchors} then the spacer may be v-resized with auto v-resizing the linkbottom widget so that the bottom margin of that widget is kept

if NOT {an_bottom IN linkbottom_widget.anchors} then the spacer may be v-resized with auto v-shifting the linkbottom widget so that height of that widget is kept

- if "true"

v-repositioning or v-resizing the linkbottom widget shifts the whole linked construction, it becomes the only way to v-shift

if {an_top IN linktop_widget.anchors} then the spacer may be v-resized with auto v-resizing the linktop widget so that the top margin of that widget is kept

if NOT {an_top IN linktop_widget.anchors} then the spacer may be v-resized with auto v-shifting the linktop widget so that height of that widget is kept

- optionsscale = see {tscalingwidget.optionsscale}

- optionswidget = see {anywidget.optionswidget}

- onactivate, onchildscaled, ondeactivate, ondefocus, onenter, onexit, onfocus, onfontheightdelta, onpopup, onresize, onshowhint = see {any_widget.*}

- onmove = see {any_window.OnMove}

any "link*" option set disables the spacer to reposition solely, repositioning is only controlled by a "glued" widget since then

TLayouter

• a tspacer descendant designed to (auto)resize or/and move its contained widgets acc to some size/positon dependencies
• may have GUI look, frame caption etc switched off by default
• layouters may be nested to achieve complex layouts

Each layout change/assignment is divided into performing 3 consequent stages :

Stage 1

Widgets auto resized using the following options:

- if {lao_placex OR lao_placey} :

		= if {plo_scalesize in optionslayout}  then
			* widgets with "osk_nopropwith" unset in their "optionsskin" are h-scaled 
		  	  in the proportion of change of tlayouter's clientwidth
			* widgets with "osk_nopropheight" unset in their "optionsskin" are v-scaled 
		  	  in the proportion  of change of tlayouter's clientheight

			For h-resized layouter, the effect looks like :

		 	 |--Widget__1---Widget__2--|		=> the initial look

		  	 |--Widget_1--Widget_2--|			=> the layouter gets narrower

		  	 |---Widget___1---Widget___2---|	=> the layouter gets wider

			*** both widget sizes & margins are affected ***
			*** Widget_N may generally situate on different y-levels *** 
		  	
	otherwise :

		= if lao_scalewidth in optionslayout :
			* widgets with "osk_nopropwith" unset in their "optionsskin" enters in the mode 
		 	  ( not applied until the layouter resizes! ) when they are h-scaled in the proportion 
		 	  as far as clientwidth of the tlayouter changes, then stages 2 & 3 are reapplied

			For h-resized layouter, the effect looks like :

			  |--Single____widget????|		=> the initial look

			  |--Single__widget???|			=> the layouter gets narrower

			  |--Single_______widget?????|	=> the layouter gets wider

			* also, if {lao_scaleleft in optionslayout} then left margins of the widgets 
			  with unset "optionsskin.osk_nopropleft" resize too otherwise retain

		= if lao_scaleheight in optionslayout :
			* widgets with "osk_nopropheight" unset in their "optionsskin" enters in the mode 
		 	  ( not applied until the layouter resizes! ) when they are v-scaled in the proportion 
		  	  as far as clientheight of the tlayouter changes, then stages 2 & 3 are reapplied

			* also, if {lao_scaletop in optionslayout} then top margins of the widgets 
			  with unset "optionsskin.osk_noproptop" resize too otherwise retain

			*** only widget sizes & margins not distances between them are affected ***

Stage 2

Widgets may be auto resized in 5 consequent steps using the following options:

1. if plo_syncmaxautosize in place_options :
   = all widgets are autosized then their client areas are synchronised to the
     clientareas of the highest and the widest of the widget
   * calls "msegui.syncmaxautosize"

2. if plo_syncpaintwidth in place_options :
   = the paintwidths of all widgets are synchronized to the widget with the
     widest outer frame width ( ex. width of "frame.caption" )
   * mainly makes sense if "lao_alignx" set and {align_glue = wam_start or wam_end}
     ( see below ) when the widgets will be adjusted in order to fit into the
     inner client width of tlayouter:

                                   x-align level           
                                         V                 
                        +----------------------------------+
                        | Widget_1 the_widest_frame_caption|
                        | Widget_2 frame_caption2          |
                        | Widget_N wider_frame_captionN    |
                        +----------------------------------+

   here, the effect is shown for "cp_right" frame captions
     // otherwise syncronizes to the outer ( of the frame except its caption ) width 
     // of the Z-top widget
   * calls "msegui.syncpaintwidth"
   * paintwidth is the outer width

3. if plo_syncpaintheight in place_options :
   = the paintheights of all widgets are synchronized to the widget with the
     highest outer frame width ( ex. width of "frame.caption" ).
   * mainly makes sense if lao_aligny set and {align_glue = wam_start or wam_end}
     ( see below ) the widgets will be adjusted in order to fit into the inner
     client height of tlayouter :

                        +------------------------------+
                        | The_                         |
                        | tallest_            taller_  |
                        | frame_    frame_    frame_   |
                        | caption   caption2  captionN |  
                        |                              |
                        | Widget1   Widget_2  Widget_N |<== y-align level 
                        +------------------------------+     		

  here, the effect is shown for "cp_topleft" frame captions
    // otherwise syncronizes to the outer ( of the frame except its caption ) 
    // height of the Z-top widget
  * calls "msegui.syncpaintheight"
 
4. plo_synccaptiondistx in place_options :
   = causes all widgets to have the widest common room for their cp_(left/right)* frame captions
   * calls "msegui.synccaptiondistx"
 
5. plo_synccaptiondisty in place_options :
   = causes all widgets to have the highest common room for their cp_(top/bottom)* frame captions
   * calls "msegui.synccaptiondisty"

Stage 3

The widgets may be (re)arranged within the layouter.

There're 2 modes of such (re)arrangement which can be partially (orthogonally)
combined (see later):

1) The place(ment) mode ( lao_place* in optionslayout ) :

- widgets are placed at some distances between each other, possibly with some
  margins, rooms of invisible widgets ( having visible=false) are also allocated
  unless "plo_noinvisible in place_options"

  * the widgets are placed in the order of decreasing their "widgetrect.x"
	coordinates before alignment
  
  * the inter-widget distances and the side margins ( if apllied ) in both
	dimentions are identical and limited between "place_mindist" and
	"place_maxdist"
  
  = if {lao_placex in optionslayout} and {place_mode <> wam_none} then the
	following relevant settings apply:
  
	* non-limiting value of "place_maxdist" :
	
		# |Widget_1------Widget_2------Widget_3| 
	
	* non-limiting value of "place_maxdist" and {plo_propmargin in place_options} :
	
		# |---Widget_1---Widget_2---Widget_3---|
		
	* limiting value of "place_maxdist" and {place_mode = wam_start} :
	
		# |Widget_1----Widget_2----Widget_3????|
		
	* limiting value of "place_maxdist" and {place_mode = wam_start} and
	  {plo_propmargin in place_options} :
	
		# |---Widget_1---Widget_2---Widget_3???|
		
	* limiting value of "place_maxdist" and {place_mode = wam_end} :
	
		# |??????Widget_1---Widget_2---Widget_3|
		
	* limiting value of "place_maxdist" and {place_mode = wam_end} and
	  {plo_propmargin in place_options} :
	
		# |???Widget_1---Widget_2---Widget_3---|
		
	* limiting value of "place_maxdist" and {place_mode = wam_center} :
	
		# |???Widget_1---Widget_2---Widget_3???|
		
	* limiting value of "place_maxdist" and {plo_endmargin in place_options} :
	
		# |Widget_1----Widget_2----Widget_____3|, or
		
		# |Widget_1----Widget_____2----Widget_3|, or
		
		# |Widget_____1----Widget_2----Widget_3|, here, the most left amongst
		widgets having both [an_left,an_right] set is expanded otherwise the most
		right widget ( Widget_3 in the example )
		
	* limiting value of "place_maxdist" and {place_mode = wam_end} and
	  {plo_propmargin in place_options} and {plo_endmargin in place_options} :
	  
		# |--Widget_1--Widget_____2--Widget_3--|,
		  
	The Legend:
	===========
	limiting value of "place_maxdist" : such value which produce some visual
	effect on the layouter
	
	  "----" :           distance ( = number of minuses, limited by place_maxdis )
	  "????" :           some remaining space ( = number of questmarks )
	  "Widget_1" :       widget of the original size
	  "Widget__..__1" : (auto)resized widget
  
  = if {lao_placey in optionslayout} and {place_mode <> wam_none} then the things
	are handled in the same manner as with "lao_placex" but for the vertical
	"top2bottom" direction of placement instead of the horizontal "left2right" one.

2) the align(ment) mode ( optionslayout.lao_align* ) :

- widgets are gathered into a visual group to a dedicated "leader" widget of
  the layout ( set by "align_leader" and defaults to the lowest in
  Z-Order = twidget.widgets[0] ) the leader stays in place while the others :

  = if lao_alignx in optionslayout ( the hor alignment mode ):
	  * if align_mode = wam_start :
		snap their left borders to the left border of leader
	  * else if align_mode = wam_end :
		snap their right borders to the right border of leader
	  * else if align_mode = wam_center :
		snap their v-axes to the v-axis of leader after that,
  = if lao_aligny in optionslayout ( the vert alignment mode ):
	  * if align_mode = wam_start :
		snap their top borders to the top border of leader
	  * else if align_mode = wam_end :
		snap their bottom borders to the bottom border of leader
	  * else if align_mode = wam_center :
		snap their h-axes to the h-axis of leader

- after that, the whole widget group can be aligned within the layouter:

  = if align_glue =  wam_start
	  * if lao_alignx in optionslayout:
		the left extent of group snaps to the left border of layouter
	  * if lao_aligny in optionslayout:
		the top extent of group snaps to the top border of layouter
  = else if align_glue = wam_end
	  * if lao_alignx in optionslayout:
		the right extent of group snaps to the right border of layouter
	  * if lao_aligny in optionslayout:
		the bottom extent of group snaps to the bottom border of layouter
  = else if align_glue =  wam_center
	  * if lao_alignx in optionslayout:
		the v-axis of group snaps to the v-axis of layouter
	  * if lao_aligny in optionslayout:
		the h-axis of group snaps to the h-axis of layouter

Mutually exclusive settings:
* only one of "align_mode" can be choosen
* only one of  "glue_mode" can be choosen
* "optionslayout.lao_alignx" & 	"optionslayout.lao_placex"
* "optionslayout.lao_aligny" & 	"optionslayout.lao_placey"

V-alignment ( optionslayout.lao_aligny ) may be combined with h-placement
( optionslayout.lao_placex ), and h-alignment ( optionslayout.lao_alignx ) may
be combined with v-placement ( optionslayout.lao_placey )

NOTE:
  The effects of the above described { resizing / placement / alignment } are
  irreversible. So, the only way to revert is to set "wan_none" then to revert
  manually.

TImage

<any image>

	*** Note that switch to the monochrome mode is irerreversible ! ***

	alignment:

		By default, images are top-left aligned, with the original size preserved.

		al_xcentered = centers the image horizontally
		al_ycentered = centers the image vertically

		al_right = docks the image to the right border of placeholder
		al_bottom = docks the image to the bottom border of placeholder

		al_grayed = fills non-transparent areas with the selected color

		al_stretchx = adjusts size so that to fill the placeholder in width
		al_stretchy = adjusts size so that to fill the placeholder in height
		al_fit = adjusts size so that to fill the placeholder in both width & height

		al_tiled = spawns the image & tile the whole  placeholder with the copies 

		Interpolation mode while stretching

			al_intpol =	antialiases as far as the size changes 
						(the only working in Linux)
			al_or = interpolation pixel operation is "or" -> 1's are extended
			al_and = interpolation pixel operation is "and" -> 0's are extended
		( al_or and al_and only on win32, mainly useful for stretching of monochrome bitmaps) :

	colorbackground = color of image transparent ( masked ) areas in monochrome 
						non-masked mode 
	colorforeground = color of non-transparent areas in monochrome mode  

	options:

		bmo_monochrome = fills non-transparent areas with "colorforeground", 
						also, in non-masked mode, fills transparent areas 
						with "colorbackground"

		bmo_masked = activates built-in image transparency {it "hides" transparent (masked) areas}
		bmo_colormask = applies faded edge transparency on the color masked areas in the image

	transparency = makes the image transparent as long as enlights areas behind 
					the image with the selected color

	transparentcolor = for a non-masked image, assigns a color indicate transparency areas
					( on matching areas, the image will be seen through )

TChart

There are demos here:

https://github.com/mse-org/mseuniverse/tree/master/attic/msedocumenting/mse/trunk/help/tutorials/widgets/charts

Edit

TDropdownListEdit

A tstringedit with a dropdownlist to choose text values. Important dropdown.options members:
- deo_autodropdown dropdown on keypress
- deo_selectonly don't allow entering arbitrary text.
- deo_forceselect don't allow entering empty text.

THistoryEdit

A tstringedit which shows the previously entered values in a dropdownlist for selection.

TKeyStringEdit

Maps string to string.

TEnumEdit

Maps integer to string, zero based and sequencial (first item 0, next 1, ...).

TEnumTypeEdit

A TEnumEdit which maps Pascal enums to their names. Use OnInit event to store the typeinfo pointer of the enum type into sender.typeinfopo.

 
procedure tmainfo.enumtypeeditinit(const sender: tenumtypeedit);
begin
  sender.typeinfopo := PTypeInfo(TypeInfo(TMyEnumeratedType));
end;

TSelector

TSelector is the most specialized widget of the dropdown editwidget group, it is based on tenumedit (tenumedit maps an integer to a string) and uses for the dropdownlist a second map which must be created on the fly in ongetdropdowninfo. An example is tcommselector where the enumedit maps commnrty to commname and the dropdownlist shows the available RS232 ports only.

TEdit

MSEgui counterpart of Delphi TEdit. You will never use it.

TDropDownItemEdit

A tstringedit with a dropdownlist to choose text values. Important dropdown.options members:
- deo_autodropdown dropdown on keypress
- deo_selectonly don't allow entering arbitrary text.
- deo_forceselect don't allow entering empty text.

TRecordFieldEdit

Used in twidgetgrid in order to edit fields of a ttreeitemedit. Example is MSEide projecttreeform.pas.

TDialogStringEdit

A tstringedit with an ellipse button. Use "onexecute" to show the dialog.

TDataButton

A button with an integer value. Clicking increments the value until "max", then it restarts with "min". Can be inserted into a twidgetgrid. The current value selects the showed image and face by the items of "imagenums" and "valuefaces".

TDataIcon

Shows an imagelist item by lookup from "value" to "imagenums". Clicking increments value until "max" then it restarts with "min". Can be inserted into a twidgetgrid.

TTextEdit

Only useful if inserted into a twidgetgrid, builds a text editor, used in MSEide source editor.

TDataImage

A pixmap display widget which can be inserted into twidgetgrid.

TTerminal

Only useful if inserted into a twidgetgrid, builds a very simple terminal emulator. Used in MSEide target console.

NoGui

TAction

	Shortcut processing order :

	- the smallest piece of processing is "doshortcut" procedure which 
	is called until processed:
		= starting from the sender up to the toplevel widget
		= then by all child widgets with non-set "ow_noparentshortcut" 
		= then, if "ow_nochildshortcut" isn't set, by the parent widget
		= then by the widget oneself
	
	- "doshortcut" is checked in the following order:
		= starting from form's main menu
		= then from the owning window ( the widget oneself ) 
		= then from the application


		*** A shortcut is bound to a widget by :
			- placing an action component on the widget ***
			- direct assigning the shortcut to the widget (menus,..) 
	---------------------------

		caption, color, colorglyph, helpcontext, hint, imagecheckedoffset,
		imagelist <see "timagelist">, imagenr, imagenrdisabled

			- sets look of "clients" (buttons, menu/toolbar items,..), unless 
			these clients have "state.as_local*" set :

		*** For meaning of these options, see help on the "client" widgets ***

	group
		- default value for one-named property of the bound widgets
		( menu items,... )

	options :
		ao_updateonidle
			- runs this action in cycle, waiting for no gui events everytime

		ao_globalshortcut 
			- allows the action to trigger on a non-main form
			  (the shortcut is triggered whatever form of the applicatin it was pressed on, 
			  otherwise only when the form where the aption is placed on is focused )

		ao_nocandefocus 
			- causes the action not to call "CanDefocus" for focused edit widget of active form
			  before executing own code
			  ( it helps to avoid the effect of cancelling changes in these widgets 
			  on activating the bound shortcut )

	shortcut
		- keyboard combination triggering the action

	shortcut
		- alternative "shortcut" and handled identically

	state :

		as_disabled
			- prevents the action from triggering, also puts the bound widgets to "disabled" look

		as_invisible
			- in run-time, hides the bound widget, still reacting on the shortcut or direct call

		as_checked
			- selects the bound menu item if it has "mao_checkbox" option set

		as_default
		as_local*

	statfile	
		<see "tstatfile">

	stavarname

	
	tagaction
	onasyncevent
	onchange
	onexecute
	onupdate

TCustomLookupbuffer

	-	provides a group of parallel arrays of float(=datetime), integer and widestring types,
		and facilities to :
			= search in any array
			= on found position, quickly obtain corresponding value in another array
	-	for each type, several arrays  may be kept
	- 	each array is integer-indexed, even string ones ( case[in]sensitive )
	-	uses two way of accessing arrays data, through :
			= physic : array storage index ( row number ) directly
			= logical : the integer index ( see above ):
				first, physic row number is known for the logical index then the data 
				are accessed with the found number

			*** logical index values are built automatically based on array values, 
			on updating its data ***
	- dont' have interface to load data ( see its descendants for that )
	
	fieldcountfloat - number of float arrays
	fieldcountinteger - number of integer arrays
	fieldcounttext - number of widestring arrays

	Event handlers:
		- onchange

	Public interface:

   		procedure beginupdate; - marks beginning of "update"
   		procedure endupdate; - if all "update" finished, fires "onchange" event
	 	procedure clearbuffer; - clears all arrays then fires "onchange"

   		procedure checkbuffer; 
   			- [re]loads the arrays with most actual data
   			- just a stub here since doesn't have a data source

   		function find(const fieldno: integer; const avalue: integer/realty/msestring;
         	out aindex: integer; const filter: lbfiltereventty = nil): boolean;
			- applies external filtering ("filter" procedure) then incrementally searches integer/realty(datetime) array "fieldno" 
			for value "avalue" starting from logical index "aindex", returns "true" and the updated logical index 
			if found else next bigger; 

   		function find(const fieldno: integer; const avalue: msestring;
                 out aindex: integer;
                 const caseinsensitive: boolean;
                 const filter: lbfiltereventty = nil): boolean; overload;
			- applies external filtering ("filter" procedure) then incrementally searches widestring array "fieldno" for value "avalue", 
			in "caseinsensitive" manner, starting from logical index "aindex", returns "true" and the updated logical index 
			if found else next bigger;

   		function findphys(const fieldno: integer; const avalue: integer;
         	out aindex: integer; const filter: lbfiltereventty = nil): boolean; overload;
			- applies external filtering ("filter" procedure) then incrementally searches integer/realty(datetime) array "fieldno" 
			for value "avalue" starting from row number "aindex", returns "true" and the updated row number 
			if found else next bigger; 

		function findphys(const fieldno: integer; const avalue: msestring;  out aindex: integer; const caseinsensitive: boolean;
                 const filter: lbfiltereventty = nil): boolean; overload;
			- applies external filtering ("filter" procedure) then incrementally searches widestring array "fieldno" for value "avalue", 
			in "caseinsensitive" manner, starting from row number "aindex", returns "true" and the updated row number  
			if found else next bigger;

			The external filtering ("filter") procedure takes the arguments of the caller 
			togehther with physical row number found in the caller which allows 
			to check several values at once for that number, within the filter
			
		function integervaluephys(const fieldno,aindex: integer): integer;
			-  returns value of integer array "fieldno" at row number "aindex" 
              
		function integervaluelog(const fieldno,aindex: integer): integer;
			-  returns value of integer array "fieldno" where the array index equals to "aindex" 

		function integerindex(const fieldno,aindex: integer): integer;
			- returns row number of integer array "fieldno" where the array index equals to "aindex"

		function integerindexar(const fieldno: integer): integerarty;
			- returns all bunch of indexes of integer array "fiedlno"

		function integerar(const fieldno: integer): integerarty;
			- returns all bunch of data of integer array "fiedlno"
   
		function floatvaluephys(const fieldno,aindex: integer): realty;
			-  returns value of real/datetime array "fieldno" at row number "aindex" 

		function floatvaluelog(const fieldno,aindex: integer): realty;
			-  returns value of real/datetime array "fieldno" where the array index equals to "aindex" 

		function floatindex(const fieldno,aindex: integer): integer;
			- returns row number of real/datetime array "fieldno" where the array index equals to "aindex"

		function floatindexar(const fieldno: integer): integerarty;
			- returns all bunch of indexes of real/datetime array "fiedlno"

		function floatar(const fieldno: integer): realarty;
			- returns all bunch of data of real/datetime array "fiedlno"   

		function textvaluephys(const fieldno,aindex: integer): msestring;
			-  returns value of widestring array "fieldno" at row number "aindex" 

		function textvaluelog(const fieldno,aindex: integer;
                       const caseinsensitive: boolean): msestring;
			-  returns value of widestring array "fieldno" where the array index equals to "aindex" 

		function textindex(const fieldno,aindex: integer;
                      const caseinsensitive: boolean): integer;
			- returns row number of widestring array "fieldno" where the array index equals to "aindex"

		function textindexar(const fieldno: integer;
                            const caseinsensitive: boolean): integerarty;
			- returns all bunch of indexes of widestring array "fiedlno"

		function textar(const fieldno: integer): msestringarty;
			- returns all bunch of data of widestring array "fiedlno"   

   
		function lookupinteger(const integerkeyfieldno,integerfieldno,
                                keyvalue: integer): integer; overload;
			- returns value of integer array "integerfieldno" at position where
				value of parallel integer array "integerkeyfieldno" equals to "keyvalue"
                ( 0 if not found )

		function lookupinteger(const stringkeyfieldno,integerfieldno: integer;
                         const keyvalue: msestring): integer; overload;
			- returns value of integer array "integerfieldno" at position where
				value of parallel widestring array "stringkeyfieldno" equals to "keyvalue"
                ( 0 if not found )

		function lookuptext(const integerkeyfieldno,textfieldno,
                                keyvalue: integer): msestring; overload;
			- returns value of integer array "textfieldno" at position where
				value of parallel integer array "integerkeyfieldno" equals to "keyvalue"
                ( '' if not found )

		function lookuptext(const stringkeyfieldno,textfieldno: integer;
                      const keyvalue: msestring): msestring; overload;
			- returns value of integer array "textfieldno" at position where
				value of parallel integer array "integerkeyfieldno" equals to "keyvalue"
                ( '' if not found )


		function lookupfloat(const integerkeyfieldno,floatfieldno,
                                keyvalue: integer): realty; overload;
			- returns value of real/datetime array "floatfieldno" at position where
				value of parallel integer array "integerkeyfieldno" equals to "keyvalue"
                ( emptyreal if not found )

		function lookupfloat(const stringkeyfieldno,floatfieldno: integer;
                                keyvalue: msestring): realty; overload;

			- returns value of real/datetime array "floatfieldno" at position where
				value of parallel widestring array "stringkeyfieldno" equals to "keyvalue"
                ( emptyreal if not found )

		function count: integer; - returns number of data rows

		property fieldcounttext: integer; -  returns/sets number of widestring arrays
		property fieldcountfloat: integer; - returns/sets number of real/datetime arrays
		property fieldcountinteger: integer; - returns/sets number of integer arrays

		 the above "fieldcount*" props clear the buffer on setting a value 

		property integervalue[const fieldno,aindex: integer]: integer; - a shortcut to "integervaluephys"
		property floatvalue[const fieldno,aindex: integer]: realty; - a shortcut to "floatvaluephys"
		property textvalue[const fieldno,aindex: integer]: msestring; - a shortcut to "textvaluephys"

		property onchange: notifyeventty; 
			- called in "changed" wich in turn is called in :
				= clearbuffer
				= endupdate
				= doasyncevent
				= loaded
				= tlookupbuffer.addrow

TLookupBuffer

tlookupbuffer = class(tcustomlookupbuffer)

	- extends "tcustomlookupbuffer" with methods of run-time data filling

	- see <tcustomlookupbuffer>

	+= Extentions to the public interface:

		procedure addrow(const integervalues: array of integer;
                    const textvalues: array of msestring;
                    const floatvalues: array of realty);

			- adds one row to each of widestring arrays, integer arrays and real/datetime arrays,
			array size of  "{type}values" equals to number of {type} arrays

   		procedure addrows(const integervalues: array of integerarty;
                    const textvalues: array of msestringarty;
                    const floatvalues: array of realarty);

			- adds many data rows  to each of widestring arrays, integer arrays and real/datetime arrays, 
			only min length of the input data arrays are inserted, longer data are truncated
			array size of  "{type}values" equals to number of {type} arrays and the size of "{type}values[i]"
			describes number od data elements in the array
		

TDBLookupBuffer

tdblookupbuffer = class(tcustomdblookupbuffer -> tcustomlookupbuffer)

	- extends "tcustomlookupbuffer" with interface to fill arrays with DB-data
	- see <tcustomlookupbuffer> & <tcustomdblookupbuffer>

	 Extentions to the public interface:

   		procedure checkbuffer; - if data obsolete ("invalid") then reloads them from "datasource"
   
		property datasource: tdatasource; - sets/returns DB data source where to load data from
		property textfields: tdbfieldnamearrayprop; - allows to assign a {datasource:datafield} to each of widestring arrays
		property integerfields: tdbfieldnamearrayprop; - allows to assign a {datasource:datafield} to each of integer arrays
		property floatfields: tdbfieldnamearrayprop; - allows to assign a {datasource:datafield} to each of real/datetime arrays

		property optionsdb: lbdboptionsty; - tunes some DB behaviour apects
			-	olbdb_closedataset : 
				= once data obsolete, opens (if needed) the supplier dataset (disabling its bound controls) 
				then [re]loads data from it then closes it

			-	olbdb_invalidateifmodified :
				= gets marked "invalid" once contents of the bound dataset change, 
				it signals to reload the buffer with the new data just before next accessing 
				( for any purpose - searching, lookuping, getting value/(array of values),..)

TDBmemoLookupbuffer

- allows to use  for lookup-ing any text-convertable DB-fields
	- an analog of tdblookupbuffer, but :
		- "integerfields" may be names of any integer-convertable DB-fields
		- "floatfields" may be names of any (real/datetime)-convertable DB-fields
		- "textfields"  may be names of any text-presentable DB-fields

		- each DB-field value ( presenting a memo generally of many lines ) may supply many data rows at once 
		to the bound array of the buffer, since this value will be internally splitted & turned into native array values,
		and the resulting "count" (arrays row count) of the whole buffer will be the minimal rows count amongst arrays 
		of the buffer, the rest data are truncated 

		- when loading widestring arrays, also checks for & performs "utf8-to-widestring" conversion of values of 
		the bound DB-fields so that these arrays always store widestrings

TStatFile

- so that to be in effect, it should also be assigned to the form where the widget using the stafile is placed on
- in design, if "onstatwrite" is set and "filedir" is not yet created,	deactivate exception "ECreateError" in project settings ( "Debugger" tab )
- "filedir" may contain "~/" indicating the user's home directory
- options "oe_savestate" & "oe_savevalue" of "client" widgets define what to store to the file 
- position etc changes or/and value changes 
- in case when a main form shares its stafile with non-main forms, on creating non-main ones, just edited not saved data of the main form ( bound to vars of the statfile) are reset to values read from the statfile upon creating the form; for "sfo_memory", this effect absents unless widgets on the concurring forms share same variable[s]; to avoid this behaviour, disable "fo_autoreadstat" & "fo_autowritestat" of the non-main forms
- each "tstafile" owns:
 = tstatwriter:
* provides methods of writing sections & statvars to a memory/file stream
- tstatreader:
* holds list of sections with statvars each
* provides search & check & reading interface to the statvars
* provides reading statvars from a memory/file stream

Positioning to a section speeds up accessing its statvars

- there also is "tstatfiler" ( exposed by some "tstatfile" events ) which:
= may present or "tstatwriter" or "tstatreader" ( there's a check method )
= provides directionless "update" methods with internal switch to needed direction of processing 
- "reading" or "writing" statvars on per-section basis


	activator :
		<see tactivator> : NOT YET DONE		

	encoding = "en_utf8" selected here, allows to store non-Latin text in the file
       filedir = directory where to keep the file ( by default - the current working directory )
	filename = name of the file

	options:
		sfo_memory = reads & writes not from a disk file but from a named memory stream 
					( there's an exclusion - see below "sfo_savedata" ),
					mostly useful for presenting last used values on recalling 
					non-main forms etc ( data even survive recreating forms),
					or even for data "exchange" between non-main modal( non-concurring ) forms 
					in case of the target widgets share same statvarnames

		sfo_createpath = creates "filedir" if necessary
		sfo_savedata =	used only with "sfo_memory", commands to save 
						the memory data to the master statfile (see below)						

	sfo_activatorread = activator activate triggers reading ???
	sfo_activatorwrite = activator deactivate triggers writing ???

	statfile = a master statfile
	statvarname = name of section of this file in the upper statfile
	Tag = an integer property for misc purposes

	Event handlers:
		onstatafterread - fires on return from "readstat"
		onstatafterwrite - fires on return from "writestat"
		onstatbeforeread - fires on beginning of "readstat"
		onstatbeforewrite - fires on beginning of "writestat"
		onstatread = fires after reading state data
		onstatwrite = fires after writing state data
		onstatupdate = fires after reading/writing state data just before 
					"onstatread" & "onstatwrite"

	Public methods:

   		procedure initnewcomponent(const ascale: real); override;
   			- does nothing but fixes the default file name as the statfile default
   
   		procedure readstat(stream: ttextstream = nil); overload;
   			- rereads all statvars of the stafile/memorystream
   
   		procedure readstat(const aname: msestring; const statreader: tstatreader); overload;
   			- rereads "aname" statvar of the statfile

   		procedure writestat(const stream: ttextstream = nil); overload;
		   	- rewrites all statvars to the stafile/memorystream
			  (if neccessary, prepares to writting - creates "filedir", stafile,...)
   
   		procedure writestat(const aname: msestring; const statwriter: tstatwriter); overload;
   			- overwrites "aname" statvar of the statfile
   		
   		procedure updatestat(const aname: msestring; const statfiler: tstatfiler);
   			- depending on kind of "statfiler" ( writer/reader ), writes/reads 
   			  the most up-to-date stat data

Font

See also : Reference:_MSEgui/TFont

Any Font

    	charset { ANSI/ DEFAULT/ SYMBOL /SHIFTJIS /HANGEUL /GB2312 /CHINESEBIG5 /OEM 
		/JOHAB / HEBREW/ ARABIC/ GREEK/ TURKISH/ VIETNAMESE/ THAI/ EASTEUROPE/
		RUSSIAN/ MAC/ BALTIC }
		- changes the font to the nearest containing the selected encoding(charset)
		- no font change made if the supplied encoding doesn't match any font
	color
		- color of the glyphs contours
	colorbackground
		- fill color of the glyph cells ( not including extraspace )
	colorshadow
		- color of SE glyph "edges" ( if not "cl_none", deactivates "colorbackground" )
	extraspace
		- v-space between glyph cells of adjacent text rows (negative values cause the cells to overlap )
	height
		- v-size of glyph cells, in pixels
	name
		- initially, font is choosen by { "family" = this name }
	options:
		foo_fixed
			- changes the font to the nearest "mono" spaced (usually = Courier)
		foo_proportional
			- changes the font to the nearest "proportionally" spaced (usually = Helvetica)
		foo_helvetica
			- changes the font to the nearest in "sans" category (usually = Helvetica)
		foo_roman
			- changes the font to the nearest in "serif" category (usually = Times[ New Roman])
		foo_script
			- Win32 only, changes the font to the nearest in "script" category
		foo_decorative
			- Win32 only, changes the font to the nearest in "decorative" category
		foo_antialiased
			- Linux-only, enables antialiasing (if disabled by Xft globally)
		foo_nonantialiased
			- Linux-only, disables antialiasing (if enabled by Xft globally) 
			usually making glyph extents (not cells !) a bit wider
	style:
		fs_bold
			- gives the font a "bold" look
		fs_italic
			- gives the font an "italic" look
		fs_underline
			- gives the font an "underlined" look
		fs_strikeout
			- gives the font a "striked out" look
		fs_selected
			- "TRUE" here combined with {tf_noselect:=FALSE}, causes the text described by this font 
			to be initially selected ( with the clipboard operations available ), 
			currently applicable only to richstrings

	width
		- 10*{ glyph cell width, average in pixels }, 0 = {font default}

	xscale
		- width ratio of each glyph {cell & contour}, the effect is similar to "width"

		*** "foo_*" font selection overrides one made with "name" 

		*** if change with "foo_*" is unsuccessful then the nearest "sans" font is usually chosen

		*** The categories :

			sans		=> have no serifs and have strokes of even thickness
			serif		=> have serifs at glyph contours and made up of strokes of varying thickness
			script		=> resemble handwriting
			decorative	=> flashy styles to be used sparingly in headlines or posters

GUI

TWindow

twindow = class(teventobject,icanvas)
  public

	// releases mouse, unlinks from the canvas, processes all pending events of the window
	// if called from within main thread then destroys the window directly
	// otherwise posts a window destroy event for oneself and waits for it to be processed
	procedure destroywindow;

	// registers the instance of onself in the "owner" widget, allocates the canvas, 
	// adds a reference to oneself,
	// then prepares the "owner" hierarchy to be invalidated ( "owner.rootchanged" )
	// since now, the window is allocated and belongs to the "aowner" widget 
	constructor create(aowner: twidget);

	destructor destroy; override;

	// adds "method" to the internal list of scroll dependants
	procedure registeronscroll(const method: notifyeventty);

	// removes "method" from the internal list of scroll dependants
	procedure unregisteronscroll(const method: notifyeventty);

	// releases mouse if captured, resets the cursor, then enters an event loop for the window,
	// TRUE on return if the window is destroyed
	function beginmodal: boolean;
 
	  * checks if the "sender" window is already modal to avoid circularity, 
	    if not then starts an event loop  for the "sender" where the "sender" is a receiver of GUI events,
   	    once the loop is terminated reactivates the previously active window if it was,
	    TRUE if modalwindow destroyed  

	  function tinternalapplication.beginmodal(const sender: twindow): boolean;

	// removes the internal stuff which indicates the modal state
	procedure endmodal;

	// if the window is visible, 
	// deactivates the previously active window, shows the window (see below),
	// if no active window in the app or the window or its Z-predecessor is modal and 
	// the app has no focused widget then prepares the bound widget to be focused,
	// then addresses the WM to put the window to foreground
	procedure activate;

	  // if the bound widget has visible=true then:
	  //  - if NOT windowevent then :
	  //    = address the WM to set size of the window acc to window opts 
	  //      wp_maximized, wp_fullscreen or normal size otherwise
	  //	= if the window is normally sized, moves it to its default position is specified ( screen centered etc )
	  // - unhides/unminimizes the window if needed
	  // - shows other windows of the applications acc to state of the window group 
	  // ( in normal size or minimized )

	  private 
		procedure twindow.show(windowevent: boolean);

	// TRUE if this window currently grabs user input
	( a widget drawn within the window(=form) is in focus,.. )
	function active: boolean;

	// if the window was active then deactivates the window  & remembers it as the previous active ( to restore leater if requested ),
	// returns TRUE if that storage occurred
	function deactivateintermediate: boolean; 

	// makes the window active & clears the above app reference to it ( "active before deactivating" )
	procedure reactivate; //clears app.finactivewindow

	// scans the app event queue for "ek_expose" event[s] addressed to the window,
	// if found then redraws that part of the window which the event describes
	// ( processed events are then deleted )
	procedure update;

	// TRUE if the window :
	// 1) doesn't have an inner widget grabbing input focus
	// or
	// 2) has such widget, and this widget ( and all its descendants ) 
	//    pass "CanClose" check
	//
	// *** see also "twidget.CanClose" ***
	//
	function candefocus: boolean;

	// tries to defocus the currently focused widget if it belongs to the window,
	// if succeeds then executes code of virtual "DoDefocus" of the widget descessor
	// ( this code defines behaviour & look of the widget on defocusing );
	//
	// no defocusing is done if the focused widget ( or its descendants ) 
	// doesn't pass "CanClose" check
	//
	procedure nofocus;
   
   	// setfocusedwidget(widget)
   
   property focuscount: cardinal read ffocuscount;
   function close: boolean; //true if ok
   procedure beginmoving; //lock window rect modification
   procedure endmoving;
   procedure bringtofront;
   procedure sendtoback;
   procedure stackunder(const predecessor: twindow);
       //stacking is performed in mainloop idle, nil means top
   procedure stackover(const predecessor: twindow);
       //stacking is performed in mainloop idle, nil means bottom
   function stackedunder: twindow; //nil if top
   function stackedover: twindow;  //nil if bottom
   function hastransientfor: boolean;

   procedure capturemouse;
   procedure releasemouse;
   procedure postkeyevent(const akey: keyty; 
        const ashiftstate: shiftstatesty = []; const release: boolean = false;
                  const achars: msestring = '');

   function winid: winidty;
   function haswinid: boolean;
   function state: windowstatesty;
   function visible: boolean;
   function activating: boolean; //in internalactivate proc
   function normalwindowrect: rectty;
   property updateregion: regionty read fupdateregion;
   function updaterect: rectty;

   procedure registermovenotification(sender: iobjectlink);
   procedure unregistermovenotification(sender: iobjectlink);

   property options: windowoptionsty read foptions;

	// widget 
	property owner: twidget read fowner;

   property focusedwidget: twidget read ffocusedwidget;
   property transientfor: twindow read ftransientfor;
   property modalresult: modalresultty read fmodalresult write setmodalresult;
   property buttonendmodal: boolean read getbuttonendmodal write setbuttonendmodal;
   property globalshortcuts: boolean read getglobalshortcuts write setglobalshortcuts;
   property localshortcuts: boolean read getlocalshortcuts write setlocalshortcuts;
   property windowpos: windowposty read getwindowpos write setwindowpos;
   property caption: msestring read fcaption write setcaption;


 windowoptionty = (wo_popup,wo_message,wo_buttonendmodal,wo_groupleader,
                   wo_windowcentermessage); //showmessage centered in window


	optionswindow:
		wo_popup 
			- in run-time, hides all OS windows-manager ( WM ) decorations (title bar, buttons "Close/Resize,Min/Max" etc),
			letting only its client area to appear
			so :
				= the window should have own facilities to replace the deactivated WM functionality if needed
				= can't be resized/maximize/minimized/moved
		wo_message
			- similar to "wo_popup" but allows WM to close ( with "Close" button ) & move the window

		wo_groupleader
			- keeps on the WM taskbar a shortcut to the window 
			( if the parent window is a groupleader too then displays a step upper in its group )

	Event handlers:

	 - onmove
		= fires once the (window/widget) is created/moved ( with check if really moved by a distance)

TFormScrollbox

- presents client area of form & parent of its widgets, 
	initially stretched to fit the form & bound with anchoring 
	but may be adjusted with "bounds" & "anchors"
   
    Properties:
                
	anchors
	bounds
	
	color
		- color of the whole container area ( except its frame ) & form widgets 
		if their color is "cl_parent"

	name = container

	cursor,	enabled, face, frame, helpcontext, hint, optionswidget, popupmenu,
	taborder, tag, visible, onactivate, onafterpaint, onbeforepaint, 
	onchildmouseevent, onclientmouseevent, ondeativate, ondefocus, onenter,
	onexit, onfocus, onfontheightdelta, onmouseevent, onpaint, onpopup
	onresize, onshowhint
		- the same meaning as for the served form


	oncalcminscrollsize	
	onscroll
	onchildscaled	

TFrameComp

See also here: Reference:_MSEgui/TFrame.

	Terminology :

	{client area = area of the widget which interacts with a user}

	{bevelling = additional facets rising/sinking frame & client area, 
		constists of two parts - 
			- external: between frame and widget
			- internal: between frame and client area
	}

	{frame=	flat space between external & internal facets,
			floats at the inner level of the external facet
 	}

	*** Both frame & bevelling affect the client area ***

	--------------------------
	template:

		colorclient	=	color of the client area

		colorframe =	color of the frame
		colorframeactive =	used instead of colorframe if the widget is
							active; "cl_default" means same as colorframe.

		works if (leveli/levelo <> 0 that's the facets exist :

			colorshadow = color of facets screened from the NW light source
			colordkshadow =	color of shadows dropped by the NW light source
        	        colordkwidth =	width of the shadows in pixel, -1=default

			colorlight = color of facets exposed to the NW light source
			colorhighlight = color of brighter edges of the facets
                 	colorhlwidth = width of the brighter edges in pixel, -1=default

		        extraspace = if applied to menu items, adds more space between these items

		framei_:
			(for extendable widgets like menus, these settings widen the widget,
			for non-extendable like buttons - they squeeze the text area )

			bottom=	lower margin of text to the client area
			left =	left margin of text to the client area
			right =	margin of text to the client area
			top =	upper margin of text to the client area

		framewidth=	width of the frame
	leveli = {width=height} of the internal facet, positive -> raised, negative -> sunken
	levelo = {width=height} of the external facet, positive -> raised, negative -> sunken

<any frame>

	*** extends & customizes "tframecomp" ***

	template
		- "tframecomp" supplying the initial settings

	colorclient,colordkshadow,colordkwidth,colorframe,colorframeactive,
	colorhighlight,colorhlwidth,colorlight,colorshadow,framewidth, 
	leveli, levelo, framei_*,

		<see "tframecomp">

	font
		<see "tfont">

	caption	
		- some descriptive text( function name, user prompt,...) placed 
		in a N/W/S/E-combination to the widget's client area

		*** 
		non-empty caption if (captionpos <> cp_center) & (captiondistouter=false & captiondist>0) enlarges the framed widget 
		by the corresponding size of caption

		***

	captiondist - margin between the caption & the client area

	captiondistouter :

	- if "false"(by default), the distance is measured between 
		the inner (facing the client area) extent of the caption 
		and the client area outward the area, 
		the caption is placed outside of the client area

	- if "true", the caption is mirrored against the edge of client area as 
		to the position when "false"

		*** nagative values of "captiondist" visually inverse "out of" and within ***

       captionnoclip - do not clip frame and client area for caption background 
					( the client area preserves own background under the caption text)

	captionnooffset - shift orthogonal to "captiondist"

	captionpos - "corner" where to place the caption

	localprops :

		frl_levelo - "levelo" overrides "template.levelo"
		frl_leveli - "leveli" overrides "template.leveli"
		frl_framewidth - "framewidth" overrides "template.framewidth"
		frl_colorclient - "colorclient" overrides "template.colorclient"
		frl_colorframe - "colorframe" overrides "template.colorframe"
		frl_colorframeactive - "colorframeactive" overrides "template.colorframeactive"
		frl_colordkshadow - "colordkshadow" overrides "template.colordkshadow"
		frl_colorshadow - "colorshadow" overrides "template.colorshadow"
		frl_colorlight - "colorlight" overrides "template.colorlight"
		frl_colorhighlight - "colorhighlight" overrides "template.colorhighlight"
		frl_colordkwidth - "colordkwidth" overrides "template.colordkwidth"
		frl_colorhlwidth - "colorhlwidth" overrides "template.colorhlwidth"
		frl_fileft - "framei_left" overrides "template.framei_left"
		frl_firight - "framei_right" overrides "template.framei_right"
		frl_fitop - "framei_top" overrides "template.framei_top"
		frl_fibottom - "framei_bottom" overrides "template.framei_bottom"

		frl_nodisable

TFaceComp

See also here: https://wiki.freepascal.org/Reference:_MSEgui/TFace

	- doesn't affect the widget frame but client area of the frame


	template:
		fade:
			color[i]: = colors forming the fade
			direction: = direction where the fade grows to
			gd_(right/up/left/down)

		pos[i]: = relational position of color[i] on the direction (0.0..1.0) extent

			transparency = 	makes the face half-transparent and enlighten the underlying widget  
							with a light source of the selected color 
							( in this case, colors of the face & the widget & the light source 
							simply summarize to higher brightness )

		image:
			see <any image>

		options:

        	*** The fade colors are used not as colors but RGB alpha values ($00 -> opaque, $ff -> transparent) 
			if fao_alpha* are set *** :

				fao_alphafadeall = applies blending to the widget & all its children
				fao_alphafadenochildren = preserves child widgets from blending
		                fao_alphafadeimage = applies blending to "face.image" 


<any face>

	*** extends & customizes "tfacecomp" ***

	fade, image, option
		- see "tfacecomp"
	
	template
		- "tfacecomp" supplying the initial settings

	localprops :
		fal_options - "options" overrides "template.options"
		fal_fadirection - "fade.direction" overrides "template.fade.direction"
		fal_image - "image" overrides "template.image"
		fal_fapos - "fade.pos[i]" overrides "template.fade.pos[i]"
		fal_facolor - "fade.color[i]" overrides "template.fade.color[i]"
		fal_fatransparency - "fade.transparency" overrides "template.fade.transparency"

TScalingwidget

   optionsscale : 
		autosizing to provide room for :
		= {"frame.caption" + "offset_*"}
		= "offset_*" if "frame.caption" is unset and "osc_shrink*" is set
	
		= osc_expandx 
			- makes the widget wider to fit the caption if needed

		= osc_shrinkx
			- makes the widget narrower to have no space left & right to the "frame.caption"

		= osc_expandy
			- makes the widget taller to fit the caption if needed

		= osc_shrinky
			- makes the widget lower to have no space up & down to the "frame.caption"

		= osc_invisishrinkx
			- fully h-collapses if "visible=false" ( run-time only )

		= osc_invisishrinky
			- fully v-collapses if "visible=false" ( run-time only )

Application

TGuiApplication

 tguiapplication = class(tcustomapplication)
  public

   // [re]starts the system timer with the new period and 
   // subscribes the application to be a receiver of the modified "ek_timer" event 
   // ( can check for it in the event queue )
   procedure settimer(const us: integer);

   // finds a window by its winID
   function findwindow(id: winidty; out window: twindow): boolean;

   // finds a window by its ID & adjusts "rect" so that it 
   // fits "bounds_minc*" & "bounds_maxc*" of the found window
   procedure checkwindowrect(winid: winidty; var rect: rectty);

   // initialises the timer and "megraphics"
   procedure initialize;

   // frees the allocated system resources (GDI, event subscription, the timer)
   procedure deinitialize;

   // creates a form instance, it will be shown in "application.run"
   procedure createform(instanceclass: widgetclassty; var reference);

   // invalidates all registered forms ( all their widgets will be redrawn )
   procedure invalidate; 
   
   // calls a nested main event loop, forces processing any pending messages,
   procedure processmessages; override; //handle with care!

   // TRUE if no pending events to process for the application
   function idle: boolean; override;
   
   // requests to indicate waiting ( to show the "watches" cursors )
   procedure beginwait; override;

   // removes the "watches" if no unclosed requests for displaying them,
   // otherwise closes the currently active request
   procedure endwait; override;

   // TRUE if there are unclosed requests for displaying "watches"
   function waiting: boolean;

   // TRUE if ESC has just been pressed
   //  - if all requests for displaying "watches" are closed then refreshes 
   //    the internal list of events ( the GUI-queue -> the app event list)
   function waitescaped: boolean; //true if escape pressed while waiting

   // sets state of the current wait dialogue ( but doesn't close one ) to undefined
   procedure resetwaitdialog;   

   // runs "aexecuteaction" in the main thread in OnIdle mode,
   // then shows a cancellable message,
   // if the one is cancelled then runs "acancelaction" then 
   // either fully clears (if exceptions occur ) 
   // or terminates the execution otherwise,
   // true if not cancelled;
   // "application.processmessages" must be called regularly if "aexecuteaction" is used here,
   // alternatively "aidleaction" can be used, call sleep ( some time ) in order to minimize
   // processor load. 
   // If athread <> nil the function starts and terminates the thread    
   function waitdialog(const athread: tthreadcomp = nil; const atext: msestring = '';
                   const caption: msestring = '';
                   const acancelaction: notifyeventty = nil;
                   const aexecuteaction: notifyeventty = nil): boolean; override;

   // closes the currently modal waitdialogue with "cancelled" state
   procedure cancelwait;

   // closes the currently modal waitdialogue with "ok" state
   procedure terminatewait;

   function waitstarted: boolean;   // the last waitdialogue is currently showing for some requests
   function waitcanceled: boolean;  // the last waitdialogue has been cancelled for some request (but can be shown fot others ?)
   function waitterminated: boolean; // the last waitdialogue has been terminated for some request (but can be shown fot others ?) 

   // if called from the main app thread then shows as a modal message describing the exception 
   // otherwise posts an async event for which the message will be called
   procedure showexception(e: exception; const leadingtext: string = ''); override;

   // posts an async event for which the message describing the exception will be called
   procedure showasyncexception(e: exception; const leadingtext: string = '');

   // "application.errormessage" shows standard error message ( with "ERROR" title ) 
   procedure errormessage(const amessage: msestring); override;

   // [re]calculates timings & position of hint for "ahintedwidget"
   // if "ow_timedhint" in "ahintedwidget.foptionswidget" then iys showtime will be 
   // "defaulthintshowtime" ( an app wide setting, 3sec by default)   
   procedure inithintinfo(var info: hintinfoty; const ahintedwidget: twidget);


   // shows the supplied hint text within "aposrect" with alignment "aplacement" during "ashowtime",
   // the avail ( but not used currenly ) flags are : hfl_show,hfl_custom,hfl_noautohidemove,hfl_noautohidemove   
   procedure showhint(const sender: twidget; const hint: msestring;
              const aposrect: rectty; const aplacement: captionposty = cp_bottomleft;
              const ashowtime: integer = defaulthintshowtime; //0 -> inifinite,
                 // -1 defaultshowtime if ow_timedhint in sender.optionswidget
              const aflags: hintflagsty = defaulthintflags
                      ); overload;

   // shows the supplied hint text at left-top position"apos" during "ashowtime",
   // the avail ( but not used currenly ) flags are : hfl_show,hfl_custom,hfl_noautohidemove,hfl_noautohidemove   
   procedure showhint(const sender: twidget; const hint: msestring;
              const apos: pointty;
              const ashowtime: integer = defaulthintshowtime; //0 -> inifinite,
                 // -1 defaultshowtime if ow_timedhint in sender.optionswidget
              const aflags: hintflagsty = defaulthintflags
                      ); overload;

   // shows the hint fully defined in "info" for the widget "sender"
   procedure showhint(const sender: twidget; const info: hintinfoty); overload;

   // removes the current hint widget & frees its resources & stops its stop timer
   procedure hidehint;

   // restarts the current hint and its stop timer
   procedure restarthint(const sender: twidget);

   function hintedwidget: twidget; //last hinted widget
   function activehintedwidget: twidget; //nil if no hint active

   // returns helpcontext of active widget, '' if none;   
   function activehelpcontext: msestring;

   // returns helpcontext of the widget under mouse, '' if none;
   function mousehelpcontext: msestring;

   // TRUE if one of the app's window/console is in input focus
   function active: boolean;

   // returns the desktop resolution ( or the virtual one if used )
   function screensize: sizety;

   // returns the (virtual) desktop resolution except the tray area,
   // nil -> current active window
   function workarea(const awindow: twindow = nil): rectty;

   // returns which application window ( a form not an eventwidget, an openglwidget or a windowwidget !) 
   // is active ( provides the input focus ),
   // it's same for all widgets of the form served by this window
   function activewindow: twindow;

/ * A transient window is a descendant of ( "transientfor" ) another window in the stacking order hierarchy */

   // returns a first non-transient ( on top of the app stacking order ) window upward 
   // from the currently active window of the application.
   // or that active window if no such
   function regularactivewindow: twindow;

   // same as "activewindow" but the window must not be released (?)
   function unreleasedactivewindow: twindow;

   // returns the focused widget of the currently active window if one exists
   function activewidget: twidget;

   // returns the widget presenteing the currently active window
   function activerootwidget: twidget;
   
   // returns the window ( not hidden or disabled !) under the screen point "pos"
   function windowatpos(const pos: pointty): twindow;

   // puts to "awidget" the container of widget pointed by "namepath"
   // ( finalizing "." is discarded if found ) ,
   // FALSE if not found, and NIL and TRUE if "namepath" = ''
   function findwidget(const namepath: string; out awidget: twidget): boolean;

   // rebuilds the application's window list accorrding to the current on-screen Z-order of its windows;
   // window list is ordered by "z" - bottom first & top last;
   // invisibles first
   procedure sortzorder;

   // returns a copy of the internal window list of application
   function windowar: windowarty;

   // returns the list of application window winIDs
   function winidar: winidarty;

   // returns the count of the application windows    
   function windowcount: integer;

   // returns the window by its number ( "index" >= 0) in the application window list
   property windows[const index: integer]: twindow read getwindows;

   // returns the lowest visible window in stackorder, 
   // calls "sortzorder" within
   function bottomwindow: twindow;

   // returns the highest visible window in stackorder, 
   // calls "sortzorder" within
   function topwindow: twindow;


   // TRUE if all owned windows pass "CanClose" check or 
   // don't have focused widgets
   function candefocus: boolean;

   // subscribes the handler "method" to receive keyboard events
   procedure registeronkeypress(const method: keyeventty);

   // unsubscribes the handler "method" from receiving keyboard events
   procedure unregisteronkeypress(const method: keyeventty);

   // subscribes the handler "method" to receive shortcut events
   procedure registeronshortcut(const method: keyeventty);

   // unsubscribes the handler "method" from receiving shortcut events
   procedure unregisteronshortcut(const method: keyeventty);

   // subscribes the handler "method" to receive "OnWindowActiveChanged" event ( form-wide )
   procedure registeronactivechanged(const method: activechangeeventty);

   // unsubscribes the handler "method" from receiving "OnWindowActiveChanged" event ( form-wide )
   procedure unregisteronactivechanged(const method: activechangeeventty);

   // subscribes the handler "method" to receive "OnDestroyed" events ( form-wide )
   procedure registeronwindowdestroyed(const method: windoweventty);

   // unsubscribes the handler "method" from receiving "OnDestroyed" events ( form-wide )
   procedure unregisteronwindowdestroyed(const method: windoweventty);

   // subscribes the handler "method" to receive "OnWindowDestroyed" events ( form-wide )
   procedure registeronwiniddestroyed(const method: winideventty);

   // unsubscribes the handler "method" form receiving "OnWindowDestroyed" events ( form-wide )
   procedure unregisteronwiniddestroyed(const method: winideventty);

   // subscribes the handler "method" to receive "ApplicationActiveChanged" events ( form-wide )
   procedure registeronapplicationactivechanged(const method: booleaneventty);

   // unsubscribes the handler "method" from receiving "ApplicationActiveChanged" events ( form-wide )
   procedure unregisteronapplicationactivechanged(const method: booleaneventty);

// tcustomapplication

   // subscribes the handler "method" to receive "OnTerminated" event ( form-wide )
   procedure registeronterminated(const method: notifyeventty);

   // unsubscribes the handler "method" from receiving "OnTerminated" events ( form-wide )
   procedure unregisteronterminated(const method: notifyeventty);

   // subscribes the handler "method" to receive "OnTerminateQuery" event ( form-wide )
   procedure registeronterminate(const method: terminatequeryeventty);

   // unsubscribes the handler "method" from receiving "OnTerminateQuery" event ( form-wide )
   procedure unregisteronterminate(const method: terminatequeryeventty);

   // subscribes the handler "method" to receive "OnIdle" event ( form-wide )
   procedure registeronidle(const method: idleeventty);

   // unsubscribes the handler "method" from receiving "OnIdle" events ( form-wide )
   procedure unregisteronidle(const method: idleeventty);

   // calls "canclose" of all application windows except the "sender" window 
   // if all "canclose"are TRUE then checks "OnTerminateQuery" 
   // for all its subscribers ( usually forms of the application )
   procedure terminate(const sender: twindow = nil); 

   // TRUE as long as a "terminate" call is in progress
   function terminating: boolean;

   // TRUE as long as a "deinitialize" call is in progress
   function deinitializing: boolean;
   
   // returns the current caret object ( the text input focus indicator ) of the application
   / ( this object provides facilities to control position & appearance & visibility & timings of the caret )
   property caret: tcaret read fcaret;

   // returns the current mouse object of the application
   / ( this object provides facitities to control position & appearance of the mouse )   
   property mouse: tmouse read fmouse;

   // simulates mouseparkevent 
   // ( an adjusting mouse movement without user intervention - grid snapping, docking etc ?)
   procedure mouseparkevent;

   // sets mouse position correction for further mouse events,
   // the real position is less the visual one by the supplied shift
   procedure delayedmouseshift(const ashift: pointty);

   // returns/sets a cursor shape used for widgets having their cursor shape set to "cr_default";
   // setting it to "cr_default" restores the individual widget cursor(s)
   property widgetcursorshape: cursorshapety read fwidgetcursorshape write
                                        fwidgetcursorshape;

   // returns/sets the current application-wide cursor shape ( not "watches" if a waiting dialog is currently displayed ! )
   // or request to set a new cursor shape ( app-wide );
   // doesn't change when changing mouse widgets
   // 
   // if called from a non-main app thread & no waiting dialogue displayed then redraws 
   // the cursor immediately;
   // set it to "cr_default" to restore the shape to one set by "widgetcursorshape"
   //
   property cursorshape: cursorshapety; // cr_arrow, cr_*

   // assures the displayed mouse cursor shape to be the shape assigned to the currently under-mouse widget,
   // otherwise "cr_default" 
   procedure updatecursorshape; //restores cursorshape of mousewidget

   // returns a widget of the application where the mouse is currently positioned over
   property mousewidget: twidget read fmousewidget;

   // returns a widget of the application currently "owning" the mouse ( grabbing all mouse input )
   property mousecapturewidget: twidget read fmousecapturewidget;


   // returns/sets a window to become the main window of the application
   // then resets all other application windows to the window group it belongs to ( Linux only );
   //
   // the main window minimizes all windows if minimized;
   property mainwindow: twindow read fmainwindow write setmainwindow;

   // returns which system thread was allocated to the application on its start
   // ( the main thread )
   property thread: threadty read fthread;

   // returns teh widget where a mouse button click occured last time 
   // ( to compare with when determinibg whether another widget is clicked )
   property buttonpresswidgetbefore: twidget read fbuttonpresswidgetbefore;

   // returns teh widget where a mouse button release occured last time 
   // ( to compare with when determinibg whether another widget is clicked )
   property buttonreleasewidgetbefore: twidget read fbuttonreleasewidgetbefore;


   // returns/sets the interval of mouse double click recognition ( in microsecs ),
   // defaults to 0.4 sec
   property dblclicktime: integer read fdblclicktime write fdblclicktime default
                 defaultdblclicktime; //us

// tcustomapplication

   // creates a datamodule instance ( its startup code including "OnLoaded" is executed )
   procedure createdatamodule(instanceclass: msecomponentclassty; var reference);


   // enters the application event loop;
   //
   // once the loop finishes, performs "OnTerminated" for all its subscribers,
   // destroys all application forms ( components & windows )
   procedure run;

   // TRUE if the eventloop is entered
   function running: boolean;

   // returns/sets the application name 
   // ( defaults to the full path to application executable in the native OS format );
   // currently, only for informatiion query purposes
   property applicationname: msestring read fapplicationname write fapplicationname;
   

   // if exclusive "rights" are satisfied for the main thread ( a mutex lock is OK )  & the event loop is in progress 
   // then posts the "event" to the main application thread for asyc processing,
   // otherwise adds the event to the internal list for further handling as soon as the above conditions meet
   procedure postevent(event: tevent);

   // TRUE if never idle since last call,
   // unlocks the application and calls sleep if not mainthread and asleepus >= 0
   function checkoverload(const asleepus: integer = 100000): boolean;

   // returns/sets the application exception handler
   property onexception: exceptioneventty read fonexception write fonexception;

   // if not "eabort" & no unhandled exceptions, 
   // executes the above "OnException" code if assigned 
   // or shows an exception message otherwise;
   procedure handleexception(sender: tobject = nil; 
                                       const leadingtext: string = '');

   // synchronizes the calling thread with the main event loop ( via a mutex),
   // TRUE if the calling thread allready holds the mutex,
   // the mutex is recursive
   function lock: boolean;

   // tries to synchronize the calling thread with the main event loop ( via a mutex)
   function trylock: boolean;

   // releases the mutex if the calling thread holds the mutex,
   // TRUE if no unlock done
   function unlock: boolean;

   // releases the mutex recursively if the calling thread holds the mutex,
   // returns "count" for the below "relockall"
   function unlockall: integer;

   // regains the mutex to serve "count" locks
   procedure relockall(count: integer);

   // creates a syncronize event ( which will fire asyncronously then waits for another thread will allow it to finish ), assigns "proc" to it as the event handler, 
   // then frees all locks temporarily then posts the event to the app event queue & waits fot it to be processed the resores the locks;
   // 
   // TRUE if not aborted, quiet -> shows no exceptions if occurs
   //
   // the "syncronize event" is an event owning a semaphore which can be touched by another thread 
   // thus causing "event.waitfo" to return & to exec the event handler code
   //
   function synchronize(const proc: objectprocty;
                       const quite: boolean = false): boolean;

   // TRUE if the calling ( this function ) thread is the application main thread
   function ismainthread: boolean;

   // TRUE if the currently locked thread is the application main thread
   function islockthread: boolean;

   // waith for "athread" to terminate,
   // does "unlock-relock" around waiting
   procedure waitforthread(athread: tmsethread);

   // post a "nothing-to-do" event for asynchronous processing in the main thread 
   procedure wakeupmainthread;

   // invalidates all registered forms of the application so that their widgets redraw land-specific captions 
   // ( changed by "mseconsts.setlangconsts" ),
   // called internally in "setlangconsts" before return
   procedure langchanged; virtual;

   // returns/sets "aps_terminated" state flag ( no actions ? )
   // this flag is also set internally by "terminate" if not cancelled
   property terminated: boolean read getterminated write setterminated;

   // returns the number of "handleexception" calls having an effect ( a message or the handler code )
   property exceptioncount: longword read fexceptioncount;


private
 // function tinternalapplication.beginmodal(const sender: twindow): boolean;

DB

TDBwidgetgrid

  Properties:

        anchors - ...
	bounds - ...

	color 
		- color of the grid's client area
	cursor 
		- cursor shape when the mouse is over the client area

	datacols
		colorselect
		linecolor
		linecolorfix
		linewidth
		newrowcol

		options
			co_readonly
			co_nofocus
			co_invisible
			co_disabled
			co_drawfocus
			co_mousemovefocus
			co_lefbuttonfocusonly
			co_focusselect
			co_mouseselect
			co_keyselect
			co_multiselect
			co_resetselectionexit
			co_rowselect
			co_fixwidth
			co_fixpos
			co_fill
			co_proportional
			co_nohscroll
			co_savevalue
			co_savestate
			co_rowfont
			co_rowcolor
			co_zebracolor
			co_nosort
			co_sortdescent
			co_norearrange
			co_cancopy
			co_canpaste
			co_mousescrollrow
			co_rowdatachange

		sortcol
		width

		items[N]
			color
			colorselect
			datalist - ???
			face - see <any face>
			fontselect - see <any font>
			frame - see <any frame>
			linecolor
			linecolorfix
			linewidth
			name
			
			options
	

General stuff

Properties for all widgets

	name

	anchors

		-----------

		- they control of design/runtime sticking widgets to their parents

		- dimention pair ( top/bottom or left/right ) both set to "false" cause 
		the widget to fit the parent's client area in that dimention;
		this effect may be partial in case of "bounds_c*max" settings limit the extents

		*** Return to the look "before dimention fit" is only possible by manual resizing or setting "bounds_*"
		-----------
		an_left 
			- on run-time, resizes/shifts left the widget to keep the design-set distance 
			between the widget's left border and the left side of parent's client area 
			as the parent resizes, until scrolling begins

		an_top
			- on run-time, resizes/shifts up the widget to keep the design-set distance 
			between the widget's top border and the upper side of parent's client area 
			as the parent resizes, until scrolling begins

		an_right
			- on run-time, resizes/shifts right the widget to keep the design-set distance 
			between the widget's right border and the right side of parent's client area 
			as the parent resizes, until scrolling begins

		an_bottom
			- on run-time, resizes/shifts down the widget to keep the design-set distance 
			between the widget's bottom border and the lower side of parent's client area 
			as the parent resizes, until scrolling begins

	bounds

		cx	- width of the widget
		cxmax, cxmin - design/runtime width of the widget is enforced between "cxmax" and "cxmin"
		cy	- height of the widget
		cymax, cymin - design/runtime height of the widget is enforced between "cymax" and "cymin"
		x	- distance between the widget's left border and the left side of parent's client area 
		y	- distance between the widget's top border and the upper side of parent's client area 


	autosize

		-----------
		- only applicable to widgets with "ow_autosize" set
		- the effect may be partial in case when "bounds_c*max" settings limit the extents
		-----------

		cx - addition to width of the widget (with h-centering post applied)
		cy - addition to height of the widget (with v-centering post applied)

	- color
		= the default color of client area & caption text background
		= may be overwritten:
			* the client area - with "frame.colorclient"
			* the caption BG - with "frame.font.colorbackground"

	- font
		= see {any font}

	- frame
		= see {any frame}

	- face
		= see {any face}

	- hint
		= descriptive text appearing when mouse pointer enters the widget

	- cursor
		= shape of the mouse pointer over the client area of widget (run-time only)

	- visible
		= "true" allow the widget to appear ( run-time only )

	- enabled
		= "true" allows the widget to participate in GUI interaction
		= "false" disallows the widget & its children :
			* processing all events & shortcuts & menu calls
			* auto "CanClose" check

			Also "false" usually paints the widget in color marking 
			the "disabled" state ( usually light gray font color )

	- popupmenu
		= reference to a preset tpopupmenu widget serving the right-click menu

	- taborder
		- {0..N} order number when TAB-key cycling through widgets in the container 

	- tag
		- an integer value bound to this widget instance

	- helpcontext
		= a string returned by "(active/mouse)helpcontext" methods of the owning form 
		  when this widget is focused or under mouse in the active window

	- zorder
		= reading: finds the current Z-order of the widget's window
		= setting: if the value = 0 then lowers the widget's window in the stacking hierarchy, otherwise rises


	optionswidget:

		ow_background
			- keeps the window/widget on bottom of the Z-order stack.

		ow_top
			- keeps the window/widget in foreground

		ow_noautosizing
			- when docking, not to resize for the docking area

		ow_mousefocus
			- "false" here disables focusing the widget with mouse
			  ( and "OnFocus" doesn't fire on mouse clicks )

		ow_tabfocus
			- "false" here disables focusing the widget with "TAB" key
			  ( and "OnFocus" doesn't fire on TAB pressed )

		ow_parenttabfocus
			- enters the childs on TAB-focusing then returns to the widget after 
			sequential TAB-ing through its child widgets,
			otherwise TAB-ing cycles on the children if entered

		ow_arrowfocus
			- allows the widget ( and its children in turn ) to be focused with 
			the arrow keys 

		ow_subfocus, ow_arrowfocusin, ow_arrowfocusout
			- in case of arrow keys focusing enabled for child-containing widget, 
			determine behaviour on entering & leaving the widget, see the below table:

			ow_subfocus	| ow_arrowfocusin |	ow_arrowfocusout | effect

			   FALSE           FALSE             FALSE         entering-/leaving-
			   FALSE           FALSE             TRUE          entering-/leaving+
			   FALSE           TRUE              FALSE         entering(nearest)+/leaving-
			   FALSE           TRUE              TRUE          entering(nearest)+/leaving+
			   TRUE            FALSE             FALSE         entering(last focused)+/leaving-
			   TRUE            FALSE             TRUE          entering(last focused)+/leaving+
			   TRUE            TRUE              FALSE         entering(nearest)+/leaving-
			   TRUE            TRUE              TRUE          entering(nearest)+/leaving+

			- "entering" is focusing on a child within the widget
			- "leaving"  is return from last child onto the widget's level
			- "nearest" is the child closest on the arrow direction
			- "last focused" is the child focused on last leaving the widget
 
			*** The Up/Down arrow keys can leave from the children circle, 
				but Left/Right can only toggle between the children ***

			*** mouse entering/leaving isn't controllable by these options


		ow_focusbackonesc 
			- on pressing "Esc", returns input focus to the previously focused widget

		ow_noparentshortcut

			*** disables processing of delegated ( from the parent ) shortcuts *** 

			- "true" here disables processing shortcuts	if they're delegated 
			from the parent widget ( obviously, not processed by the parent )

		ow_nochildshortcut

			*** disables delegating shortcuts to the parent for taking decision *** 

			- if "true" then the widget tries to process it by oneself 
			otherwise it's passed to the parent widget for further chaining

			*** A shortcut can only be processed once ( by one widget ) ***

		ow_canclosenil
			- "true" here allows to continue even if there's contained widget(s) 
			not passing "CanClose" check

		ow_mousetransparent
			- "true" here causes the widget oneself ( not its contained ones ) 
			not to react to mouse events ( just allow them through to the children )

		ow_mousewheel
			- enables/disables {scrolling/navigating} with wheel of ImPS/2 etc mouse

		ow_noscroll
			- don't use screen image scrolling for twidget.scrollrect, 
			redraw the whole scrolled widget rectangle instead;
			sometimes needed with background fades.

		ow_nochildpaintclip
			- 

		ow_destroywidgets
			- "true" here causes calling "free" for all containing widgets as well

		ow_hinton
			- to show the hint even in case of hinting is disabled on the parent
			( "parent.ow_hintoff= true & parent.ow_hinton= false" )

		ow_hintoff 
			- "true" here combined with "ow_hinton=false" fully disables displaying the hint

		ow_multiplehint 
			- "true" here causes the widget to redisplay its hint on each {>3px} move within the widget oneself

        	ow_timedhint 
			- "true" here causes hint of the widget to disappear after a timed inteval (about 2 secs by default)

		ow_fontlineheight (design-time only)
			- causes "extraspace" of the last text line to be drawn, 
			in turn it causes adjustment of widget height if "ow_autoscale" is set
			
			*** makes sence only if "ow_autoscale=true" & ow_autosize=false & "extraspace <> 0" ***

		ow_fontglyphheight (design-time only)
			- causes only interline "extraspace"-s to be drawn, opposite to "ow_fontlineheight" 

		ow_autoscale (design-time only)
			- causes that if the contents change (design OR run-time) so that its' height changes 
			then the widget will be v-scaled as well

		ow_autosize (design-time only)
			- causes that widget's height & width & client area adjust so that to provide space for contents of the client area
			- no design-time change of height/width are possible as long as this option is in effect

		ow_autosizeanright
			- when autosizing & {an_right isn't set}, the design-set right margin against the parent is preserved

		ow_autosizeanbottom
			- when autosizing & {an_bottom isn't set}, the design-set bottom margin against the parent is preserved

	optionsskin:

		- osc_noskin
		- osc_framebuttononly
		- osc_container


	Methods:

	  // tmsecomponent

		// (re)draws the widget according to the related skin if apllicable;
		//
		// also called internally by "loaded" procedure ( before "OnLoaded" code ),
		// by ShowMessage ( for the internal widgets of the message dialogue ), 
		// when creating tab & form & menu widgets
		procedure updateskin(const recursive: boolean = false);

		// TRUE if the instance is created but not yet ready 
		// for interaction & accessing data & appearance change & receiving events etc
		// ( the stage between firing "OnCreate" & "OnLoaded" )
		function loading: boolean;
	
	 {$ifdef FPC}
		procedure setinline(value: boolean); // ?
		procedure setancestor(value: boolean); // ?
	 {$endif}

		// TRUE if all conditios are OK for executing the code of "event" ( a handler must be assigned to the event )
		function canevent(const event: tmethod): boolean;


		// Shortly, replaces the persistent storage of the widget
		//
		// if {value <> nil} then 
		//	- if "instance" is nil then calls "createproc" to create the instance,
		//    then assigns the instance's value:= "value" 
		// otherwise frees "instance"
		procedure setoptionalobject(const value: tpersistent; var instance;
                        createproc: createprocty);

		// creates the persistent storage of the widget via calling "createproc"
		procedure getoptionalobject(const instance: tobject; createproc: createprocty);

		// obtains & puts to "obj" a CORBA interface entry for "aintf" (GUID,...)
		function getcorbainterface(const aintf: ptypeinfo; out obj) : boolean;

        // TRUE if the widget is owned, or "self" otherwise
		function checkowned(component: tcomponent): boolean; 

        // TRUE if the widget is owner, or "self" otherwise
		function checkowner(component: tcomponent): boolean; 

		// return the top-most widget in owner chain starting from this widget
		function rootowner: tcomponent;

		// return the array of owning widgets starting from this widget
		// componentarty[0] is the widget oneself
		function getrootcomponentpath: componentarty;

        // returns items of objeclinker ( which notify this widget )
        // and free notify list ( which are notified by this widget ),
        // duplicates are removed.
        //	
        // Notifies mainly relate to insertion/removal operation on widgets
        // The notify list is maintained by FreeNotification & RemoveFreeNotification
		function linkedobjects: objectarty;

		// sends "event" recursively to child widgets until no more children or 
		// the event is processed ( cea_processed ) by one of the children,
		// "event" will be destroyed if destroyevent= true and not async
		procedure sendcomponentevent(const event: tcomponentevent; 
                                        const destroyevent: boolean = true);

		// sends "event" to each of owning widgets downward from the root owner,
		// "event" will be destroyed if destroyevent= true and not async
		procedure sendrootcomponentevent(const event: tcomponentevent;
                                        const destroyevent: boolean = true);

		// posts an async "atag"-ged event to be handled by oneself
		procedure asyncevent(atag: integer = 0);

		// posts a "tcomponentevent" instance from sender=self, 
		// "kind" is defined when creating the event, 
		// and "tag" may be adjusted after creation
		procedure postcomponentevent(const event: tcomponentevent);

		// returns the classname of the widget if the widget is toplevel, 
		// and "tmsecomponent" otherwise )
		property moduleclassname: string read getmoduleclassname;

		// returns the classname of the widget as the entry of its constructor
		// ( button => tbutton, datamodule => tdm1mo, form => ttstfo, dbstringedit => tdbstringedit,.. )
		property actualclassname: string read getactualclassname;

		// returns "fmsecomponentstate"
		// ( a set of cs_ismodule,cs_endreadproc,cs_loadedproc,cs_noload, cs_hasskin,cs_noskin )
		property msecomponentstate: msecomponentstatesty read fmsecomponentstate;

		// returns/sets a pointer associated with the widget
		// ( contrary to the integer "tag", allows to use an arbitary data type 
		// for associating data )
		property tagpo: pointer read ftagpo write ftagpo;

		// returns/sets a string identifying the widget in the help system
		property helpcontext: msestring read gethelpcontext write fhelpcontext;

	// twidget

		// creates an instance of the widget, owned by "aowner" if not NIL
		constructor create(aowner: tcomponent); override;

		destructor destroy; override;

		// ??
		procedure afterconstruction; override;

		// rescales the widget frame ( if assigned ) then owned widgets ( if exist, recursively ) then bounds_* then the font ( if assigned )
		// called before inserting in parentwidget,
		// calls "scale(ascale)",
		// no visual repainting
		procedure initnewcomponent(const ascale: real); virtual;

 		// restores the "fontheight" to "font.glyphheight" if "ow_fontglyphheight" or
 		// to "font.lineheight" if "ow_fontlineheight" otherwise,
		// ascale is ignored ?
		// calls "synctofontheight->setfontheight",
		// called after inserting in parentwidget,
		// no visual repainting
		procedure initnewwidget(const ascale: real); virtual;

		// creates the widget frame if not yet created
		procedure createframe;

		// creates the widget face if not yet  created
		procedure createface;

		// creates the widget font if not yet  created
		procedure createfont;

		// checks ws_loadlock and csdestroing too
		function isloading: boolean;

		// returns "widgetstatety" - a set of (
		// ws_visible,ws_enabled,ws_active,ws_entered,ws_entering,ws_exiting,
		// ws_focused,ws_mouseinclient,ws_wantmousebutton,ws_wantmousemove,
		// ws_wantmousefocus,ws_iswidget,ws_opaque,ws_nopaint,
		// ws_clicked,ws_mousecaptured,ws_clientmousecaptured,
		// ws_loadlock,ws_loadedproc,ws_showproc,ws_minclientsizevalid,
		// ws_showed,ws_hidden, //used in tcustomeventwidget
		// ws_destroying,ws_staticframe,ws_staticface,ws_isvisible
		//
		// iframe
		function widgetstate: widgetstatesty;

		// returns "widgetstate1ty" - a set of (
		// (ws1_childscaled,ws1_fontheightlock,
		// ws1_widgetregionvalid,ws1_rootvalid,
		// ws1_anchorsizing,ws1_isstreamed,
		// ws1_scaled, //used in tcustomscalingwidget
		// ws1_noclipchildren,
		// ws1_nodesignvisible,ws1_nodesignframe,ws1_nodesignhandles,
		// ws1_nodesigndelete,ws1_designactive,
		// ws1_fakevisible,ws1_nominsize //used for report size calculations
		// )
		property widgetstate1: widgetstates1ty read fwidgetstate1;
		
			* this set of states is needed because the max FPC set size is 32 
			  thus "widgetstate1ty" can't fit all states

		// TRUE if the widget is contained within another widget
		// ( tcomponent stuff )
		function hasparent: boolean; override;               

		// returns the parent component if it's a widget or the grandparent otherwise
		function getparentcomponent: tcomponent; override;   // tcomponent

		// TRUE if "awidget" is an ascendant or the widget or they are the same widget
		function checkdescendent(awidget: twidget): boolean;
		
		// TRUE if app is running and the widget owns the caret or the caret widget
		function hascaret: boolean;

        // TRUE if "winid" allocated and not loading and not destroying,
        // all widgets on a form have "winid" of this form ( a real window allocated by the OS )
        // thus have this function TRUE
		function windowallocated: boolean;

		// TRUE if presents a valid toplevelwindow with assigned "winid"
		function ownswindow: boolean;

		// invalidated area of the widget, the origin is "clientpos" against the roor widget
		function updaterect: rectty; 

		// calls recursively "canclose" for all contained widgets ( the widget oneself excluded! ),
		// TRUE if none of the widgets return FALSE
		//
		// more specialized widgets may have "canclose" overridden 
		// to perform more work than just this call recursion
		// ( not null or range check,.. )
		//
		// "onclosequery" must also pass the check if assigned, for the function to succeed
		function canclose(const newfocus: twidget = nil): boolean; virtual;

        // checks "canclose" first for focused widget of the window ( form,.. ) 
        // if it is a descendant of the widget or the widget oneself,
        // then continues with subwidgets of the widget;
        // also - finishes editing ( snapshots "value" ) in the focused widget before checking
		function canparentclose(const newfocus: twidget): boolean; overload;

		// the above function but with the preserved focus
		function canparentclose: boolean; overload;
                   //newfocus = window.focusedwidget      

		function canfocus: boolean; virtual;
		function setfocus(aactivate: boolean = true): boolean; virtual;//true if ok
		procedure nextfocus; //sets inputfocus to then next appropriate widget

		function findtabfocus(const ataborder: integer): twidget;
                       //nil if cannot focus

		function firsttabfocus: twidget;
		function lasttabfocus: twidget;
		function nexttaborder(const down: boolean = false): twidget;

		function focusback(const aactivate: boolean = true): boolean;
                               //false if focus not changed

		function parentcolor: colorty;
		function actualcolor: colorty; virtual;
		function actualopaquecolor: colorty;
		function backgroundcolor: colorty;
		function translatecolor(const acolor: colorty): colorty;

		procedure widgetevent(const event: twidgetevent); virtual;

		procedure sendwidgetevent(const event: twidgetevent);
                              //event will be destroyed

		procedure release; override;

		function show(const modal: boolean = false; const transientfor: twindow = nil): modalresultty; virtual;

		procedure hide;
		procedure activate(const abringtofront: boolean = true); virtual;
                             //show and setfocus

		procedure bringtofront;
		procedure sendtoback;
		procedure stackunder(const predecessor: twidget);

		procedure paint(const canvas: tcanvas); virtual;
		procedure update; virtual;
		procedure scrollwidgets(const dist: pointty);

		procedure scrollrect(const dist: pointty; const rect: rectty; scrollcaret: boolean);
                             //origin = paintrect.pos

		procedure scroll(const dist: pointty);
                            //scrolls paintrect and widgets

		procedure getcaret;
		procedure scrollcaret(const dist: pointty);
		function mousecaptured: boolean;
		procedure capturemouse(grab: boolean = true);
		procedure releasemouse;
		procedure capturekeyboard;
		procedure releasekeyboard;
		procedure synctofontheight; virtual;

		procedure dragevent(var info: draginfoty); virtual;
		procedure dochildscaled(const sender: twidget); virtual;

		procedure invalidatewidget;     //invalidates whole widget
		procedure invalidate;           //invalidates clientrect
		procedure invalidaterect(const rect: rectty; org: originty = org_client);
		procedure invalidateframestate;

		procedure invalidateframestaterect(const rect: rectty; 
                                        const org: originty = org_client);   
		function hasoverlappingsiblings(arect: rectty): boolean; //origin = pos

		function window: twindow;
		function rootwidget: twidget;

		function parentofcontainer: twidget;
            //parentwidget.parentwidget if parentwidget has not ws_iswidget,
            //parentwidget otherwise

		property parentwidget: twidget read fparentwidget write setparentwidget;
		function getrootwidgetpath: widgetarty; //root widget is last

		// number of contained widgets ( the widget oneself excluded ! )
		function widgetcount: integer;

		function parentwidgetindex: integer; //index in parentwidget.widgets, -1 if none
		property widgets[const index: integer]: twidget read getwidgets;
		function widgetatpos(var info: widgetatposinfoty): twidget; overload;
		function widgetatpos(const pos: pointty): twidget; overload;

		function widgetatpos(const pos: pointty; 
                   const state: widgetstatesty): twidget; overload;

		property taborderedwidgets: widgetarty read gettaborderedwidgets;

		function findtagwidget(const atag: integer; const aclass: widgetclassty): twidget;
              //returns first matching descendent

		property container: twidget read getcontainer;
		function containeroffset: pointty;
		function childrencount: integer; virtual;
		property children[const index: integer]: twidget read getchildwidgets; default;

		function childatpos(const pos: pointty; 
                   const clientorigin: boolean = true): twidget; virtual;

		function getsortxchildren: widgetarty;
		function getsortychildren: widgetarty;
		property focusedchild: twidget read ffocusedchild;
		property focusedchildbefore: twidget read ffocusedchildbefore;

		function mouseeventwidget(const info: mouseeventinfoty): twidget;

		function checkdescendent(widget: twidget): boolean;
                    //true if widget is descendent or self

		function checkancestor(widget: twidget): boolean;
                    //true if widget is ancestor or self

		function containswidget(awidget: twidget): boolean;

		procedure insertwidget(const awidget: twidget); overload;

		procedure insertwidget(const awidget: twidget; const apos: pointty); overload; virtual;
                 //widget can be child

		function iswidgetclick(const info: mouseeventinfoty; const caption: boolean = false): boolean;
		//true if eventtype = et_butonrelease, button is mb_left, clicked and pos in clientrect
 		//or in frame.caption if caption = true, origin = pos

		function isclick(const info: mouseeventinfoty): boolean;
		//true if eventtype = et_butonrelease, button is mb_left, clicked and pos in clientrect

		function isdblclick(const info: mouseeventinfoty): boolean;
		//true if eventtype = et_butonpress, button is mb_left, pos in clientrect
		// and timedlay to last buttonpress is short

		function isdblclicked(const info: mouseeventinfoty): boolean;
		//true if eventtype in [et_buttonpress,et_butonrelease], button is mb_left,
		// and timedlay to last same buttonevent is short

		function isleftbuttondown(const info: mouseeventinfoty): boolean;
		//true if eventtype = et_butonpress, button is mb_left, pos in clientrect
		//origin = paintrect.pos

		widgetrect: the widget on-screen area including its frame & frame caption

			paintrect: the widget on-screen area except its frame & frame caption

			clientrect: virtual area which 
				- for non-scrolling widgets, equals to "paintrect", with its "pos:= (0,0)"
				- for scrolling widgets, may be bigger than "paintrect", 
				  also may shift ( change its "pos" ) when scrolling
		
	// the coord of outer top-left corner against the toplevel form = the window owner,
	// including the frame & frame caption 
		function rootpos: pointty; 

	// the coord of the outer top-left corner against the screen ( the WM decorations aren't counted in )
	// includes the frame & frame caption 
		property screenpos: pointty; 

	//  the coord of the outer top-left corner against the parent widget,
	// including the frame & frame caption 
		property widgetrect: rectty; 
		property pos: pointty; // =widgetrect.pos
		property size: sizety; // =widgetrect.size
		property left: integer; // =bounds_x
		property right: integer; //widgetrect.x + widgetrect.cx, sets cx;
		property top: integer;  // =bounds_y
		property bottom: integer; //widgetrect.y + widgetrect.cy, sets cy;
		property width: integer; // =bounds_cx
		property height: integer; // =bounds_cy
		function widgetsizerect: rectty;          //pos = nullpoint

    // the coord of the paint area ( paintrect ) against own outer top-left corner ( against "widgetrect=pos" )
    //  except the frame & frame caption 
		function paintrect: rectty;
		function paintpos: pointty;
		function paintsize: sizety;
		function innerpaintrect: rectty; // mainly equals to paintrect
		function clientwidgetrect: rectty; // mainly equals to paintrect
		function clientwidgetpos: pointty;
		function clippedpaintrect: rectty; // mainly equals to  but clipped by all parentpaintrects
		function innerwidgetrect: rectty;     // mainly equals to paintrect
		function innerclientwidgetpos: pointty;

    // the coord of the paint area ( paintrect ) against own outer top-left corner ( against "widgetrect=pos" )
    //  except the frame caption 
		function framerect: rectty; // =paintrect except the frame caption area
		function framepos: pointty;
		function framesize: sizety;

    // the coord of the client area ( clientrect )  against the paint area ( paintrect )
    //  usually these areas match
		function clientrect: rectty;
		property clientsize: sizety;
		property clientwidth: integer;
		property clientheight: integer;
		property clientpos: pointty;

    // the coord of the paint area of the parent against the paint area of this widget
		function paintrectparent: rectty; //nullrect if parent = nil,

    // the coord of the client area of the parent against the paint area of this widget
		function clientrectparent: rectty; //nullrect if parent = nil,

	// the coord of the inner area against the client area ( clientrect )
		function innerclientrect: rectty;  // mainly equals to clientrect
		function innerclientsize: sizety;
		function innerclientpos: pointty;

		function framewidth: sizety;              //widgetrect.size - paintrect.size
		function clientframewidth: sizety;        //widgetrect.size - clientrect.size
		function innerclientframewidth: sizety;   //widgetrect.size - innerclientrect.size
		function innerframewidth: sizety;         //clientrect.size - innerclientrect.size  

    // the coord of the paint area against the widgetrect(pos) of the parent
		function paintparentpos: pointty;    //origin = parentwidget.pos

    // the coord of the client area against the widgetrect(pos) of the parent
		function clientparentpos: pointty;   //origin = parentwidget.pos

    // the coord of the widgetrect(pos) against the client area of parent
		property parentclientpos: pointty;


		function clientpostowidgetpos(const apos: pointty): pointty;
		function widgetpostoclientpos(const apos: pointty): pointty;
		function widgetpostopaintpos(const apos: pointty): pointty;
		function paintpostowidgetpos(const apos: pointty): pointty;
		procedure scale(const ascale: real); virtual;


		property minsize: sizety read fminsize write setminsize;
		property maxsize: sizety read fmaxsize write setmaxsize;
		function maxclientsize: sizety; virtual;


		property anchors: anchorsty read fanchors write setanchors default defaultanchors;
		property defaultfocuschild: twidget read getdefaultfocuschild write setdefaultfocuschild;


		procedure changeclientsize(const delta: sizety); //asynchronous

		function getcanvas(aorigin: originty = org_client): tcanvas;

		function showing: boolean;
               //true if self and all ancestors visible and window allocated

		function isenabled: boolean;
               //true if self and all ancestors enabled

		function active: boolean;
		function entered: boolean;

		function activeentered: boolean; 
			//true if entered and window is regularactivewindow or inactivated

		function focused: boolean;
		function clicked: boolean;

		function indexofwidget(const awidget: twidget): integer;

		procedure changedirection(const avalue: graphicdirectionty;
                                            var dest: graphicdirectionty); virtual;

		// (re)arranges "awidgets" horizontally within the parent's client area 
		// so that awidget[i] were placed next each other 
		// at h-space dist[i], starting from "startx" with the right margin "endmargin";
		// 
		// if the number of "dist" is fewer than the number of "awidgets" then the remaining h-spaces are taken 
		// as the last "dist[i]" or "0" if none;
		// if the number of "dist" is more than the number of "awidgets" then the extra dist[i] are discarded
		// 
		// non-zero "endmargin" causes one of awdidget[i] to h-resize to provide the margin :
		//  - if one or more of awidgets[i] have [an_left,an_right] set then the first of such is resized
		//    otherwise the last awidgets[i] is h-resized 
		// 
		procedure placexorder(
				const startx: integer; 
				const dist: array of integer;
                const awidgets: array of twidget;
                const endmargin: integer = minint);

		// (re)arranges "awidgets" vertically within the parent's client area 
		// so that awidget[i] were placed upper/lower each other 
		// at v-space dist[i], starting from "starty" with the bottom margin "endmargin";
		// 
		// if the number of "dist" is fewer than the number of "awidgets" then the remaining v-spaces are taken 
		// as the last "dist[i]" or "0" if none;
		// if the number of "dist" is more than the number of "awidgets" then the extra dist[i] are discarded
		// 
		// non-zero "endmargin" causes one of awdidget[i] to v-resize to provide the margin :
		//  - if one or more of awidgets[i] have [an_top,an_bottom] set then the first of such is resized
		//    otherwise the last awidgets[i] is v-resized 
		// 
		procedure placeyorder(
				const starty: integer; 
				const dist: array of integer;
                const awidgets: array of twidget;
                const endmargin: integer = minint);
               //origin = clientpos, endmargin by size adjust of widgets 
               //with [an_top,an_bottom], minint -> no change

		// if {mode <> wam_none} then (re)arranges "awidgets" horizontally  within the parent's client area so that 
		// awidgets[0] stays on its place but awidgets[1..N] :
		// - if {mode = wam_end} then awidgets[i>=1] move or resize ( if "anchors.al_left" set ) so that they right borders match the right border of awidgets[0]
		// - if {mode = wam_start} then awidgets[i>=1] move or resize ( if "anchors.al_right" set ) so that they left borders match the left border of awidgets[0]
		// - if {mode = wam_center} then awidgets[i>=1] move so that they Y-axes match the Y-axe of awidgets[0]
		//
		// mainly applicable for v-stacked widgets since h-stacked may overlap after such alignment
		//
        // returns the reference point ( the coord of awidgets[0] )
		function alignx(const mode: widgetalignmodety;
                        const awidgets: array of twidget): integer;


		// if {mode <> wam_none} then (re)arranges "awidgets" vertically within the parent's client area so that 
		// awidgets[0] stays on its place but awidgets[1..N] : 
		// - if {mode = wam_end} then awidgets[i>=1] move or resize ( if "anchors.al_top" set ) so that they bottom borders match the bottom border of awidgets[0]
		// - if {mode = wam_start} then awidgets[i>=1] move or resize ( if "anchors.al_bottom" set ) so that they top borders match the top border of awidgets[0]
		// - if {mode = wam_center} then awidgets[i>=1] move so that they X-axes match the X-axe of awidgets[0]
		//
		// mainly applicable for h-stacked widgets since v-stacked may overlap after such alignment
		//
        // returns the reference point ( the coord of awidgets[0] )
		function aligny(const mode: widgetalignmodety;
                        const awidgets: array of twidget): integer;

		function actualcursor: cursorshapety; virtual;


	Event handlers:

	- onactivate

		 fires :

		= on receiving input focus, just before "OnFocus"
			
		= forms specific :
			* on 1-st display of the form after "OnLoaded" ( from "Loaded" procedure)
			* on switch back from another apllication/WM ( "oe_activate" event )
			* after closure of a descendant form
			* on minimizing/maximizing the form

	- onchildscaled

		 fires :

		= on child/children resizing due to font height change

		= form widget: once "form.container" {scrolling widget} is loaded

	- ondeactivate
		 fires 
			= form widget: when the form looses input focus
			= non-form widget: when the widget looses input focus

	- ondefocus

		fires 
		= on disabling the widget

	= form widget: if another form is focused
		= non-form widget: if another widget is focused

	- onenter
		= fires on any way of taking parent-wide focus as soon as 
		the parent stores the new child's order, before "OnActivate" & "OnFocus"

	- onexit
		= fires last on parent-wide lossing focus, after "OnDefocus" & "OnDeactivate"
		= for top-level ( not in a container ) forms, doesn't fire

	- onfocus
		fires 
			= once the existing widget takes the focus 
			= on showing the widget's form if the widget has the lowest "TabOrder"

	- onfontheightdelta
		fires
			= if [ow_fontglyphheight OR ow_fontlineheight ] AND {the
			new font height differs from the previos one}
			= before the parent redraws this widget

	- onpopup
		fires :
			= on calling a popup-menu ( with "RightClick" ), once the menu items of the current level are loaded
			( before building the submenus ) 

	- onresize

		= fires on creating/(changing size)/(min-max restoring) of widget, 
		before actual redrawing

		= rechecks if there's real work to do

	- onshowhint
		= fires when a installed hint is activated or on "aplication.showint" called
		= since called last, allows to adjust the default behavior

	- onbeforeupdateskin
		= fires in "updateskin" ( the widget is loaded etc ) before applying the skin

	- onafterupdateskin
		= fires in "updateskin" ( the widget is loaded etc ) once the skin is applied

TWidget stuff

   Properties:    
		- name
		- anchors
		- bounds
		- color
		- enabled
		- visible
		- <face> : see {any face}
		- <frame> : see {any frame}
	    - hint
	    - helpcontext
	    - tag
	    - taborder
	    - cursor
	    - optionswidget
	    - optionsskin
	    - popupmenu
    
		twidget's event handlers:
    
			- on(de)activate
			- onbeforeupdateskin
			- onafterupdateskin
			- onchildscaled
			- onfontheightdelta
			- on(de)focus
			- onenter
			- onmove
			- onpopup
			- onresize
			- onshowhint
      
	align_glue : 
	  ( outer anchoring mode for widget group, in the align mode )
		- wam_none
		- wam_start
		- wan_center
		- wm_end

	align_leader : 
		the widget ( incl another spacer, splitter or layouter ) against which the alignment applies ( the reference widget )

	align_mode : 
	  ( inner anchoring mode within widget group, in the align mode )
		- wam_none
		- wam_start
		- wan_center
		- wm_end

// Place mode:

      
	place_mindist, place_maxdist:
		- in the place(ment) mode, limits distance between widgets
		  ( these distance once calculated also define side margins if applicable )

	place_mode: 
	  ( outer anchoring mode for widget group, in the place mode )
		- wam_none
		- wam_start
		- wan_center
		- wm_end

	place_options:
		- plo_endmargin
			= to resize a widget so that it "eats" extra space if it occurs
			
			* only applicable in the place mode, with a limiting value of "place_maxdist" and:

			  1) {place_mode <> wam_none}
			or
			  2) {place_mode = wam_end} and {plo_propmargin in place_options}

			For the exact look, see above


		- plo_propmargin
			= виджеты расставляются теснее так, чтобы образовались отступы перед и после,
			  причем расстояние между центрами виджетов было бы таким же, 
			  как и растояние между серединами крайних виджетов и соотв. границами зоны расстановки

		- plo_syncmaxautosize
			= see above

		- plo_synccaptiondistx
			= see above

			  * affects widgets with opposite cp_left/right set as well	
			  * the minimal before-adjustment "captiondist" among all widgets limits "captiondist" for each of the widget
              * don't set cfo_captiondistouter here !

		- plo_synccaptiondisty
			= see above

			  * affects also widgets with opposite cp_top/bottom set	
			  * the minimal before-adjustment "captiondist" amongst all widgets limits "captiondist" for each of the widget

              ! here, don't set "cfo_captiondistouter" for affected widgets !

		- plo_syncpaintwidth
			= see above

		- plo_syncpaintheight
			= see above

		- plo_scalesize
			= see above


	dist_left, dist_right, dist_top, dist_bottom : 
		= margins between most outer edge the layouter and 
		  the corresponding linked widget

		* see "tspacer" for detail

	linkleft,linkright,linktop,linkbottom : see "tspacer"

	options:
		- spao_glueright, spao_gluebottom: 
			= set the adjustment dependencies between the layouter and its link_* widgets

			* see "tspacer" for more details

	// which mode of widget placement to apply - see above
	optionslayout: 
		- lao_alignx
		- lao_aligny
		- lao_placex
		- lao_placey
		- lao_scalewidth
		- lao_scaleheight
		- lao_scaleleft
		- lao_scaletop
		
		* lao_place* & lao_align* can't be combined for one direction

	optionsscale: 
	  
	  * cause the layouter to provide full space for the widgets as long as they expand/shrink/move

		- osc_expandx 
			= allocates more h-space if needed

		- osc_shrinkx
			= removes extra h-space if occurred

		- osc_expandy
			= allocates more v-space if needed

		- osc_shrinky
			= removes extra v-space if occurred

		- osc_invisishrinkx
			= fully h-collapses the layouter if "visible=false" ( run-time only )

		- osc_invisishrinky
			= fully v-collapses the layoter if "visible=false" ( run-time only )

	optionsskin:
		= see <any widget>


	Methods:

		constructor create(aowner: tcomponent); override;

Public stuff

	(f)window: 
		the OS-allocated ( root = toplevel ) window common for all widgets of this window
		
		* "widget.fwindow.fowner = widget.self" in case of the widget present the root "fwindow" 
		  ( owns the window )

	(f)rootpos: 
		position of the widget in the coord of toplevel window not the nearest parent widget alone,
		calculated as sum of such positions ( fwidgetrect.pos ) starting from the toplevel through the
                chain of all parents up to the current widget;
		"nullpoint" (0,0) for toplevel widgets ( window-owning forms,..)

	screenpos:
		- coord aginst the top-left corner of screen
		- WM decoration & title aren't parts of the widget !

	widgetrect: 
		the widget on-screen area including its frame & frame caption

	paintrect: 
		the widget on-screen area except its frame & frame caption

	clientrect: 
		virtual area which 
			- for non-scrolling widgets, equals to "paintrect", with its "pos:= (0,0)"
			- for scrolling widgets, may be bigger than "paintrect", 
		 	  also may shift ( change its "pos" ) when scrolling

			* "t*grid" aren't such scrollable widgets since their virtual height would be limited by 
			  the X11 "+-32000" limitation, 
			  so example of such widgets are tscrollbox, "tform.container" etc

	framerect: 
		the widget on-screen area except its frame caption but including inner & outer frame

	****************

	// releases all thread locks then post the event to the app event queue and
	// waits for the event handler finishes ( signalled by "sye_ok on a semaphore )
	// finally restores the locks
    // true if the handler is not aborted
	function synchronizeevent(const aevent: tsynchronizeevent): boolean;

    // translates "point" coord against "source" widgetrect to "dest" widgetrect
	//
	//   * nil "source" = from screen coord 
	//   * nil "dest" = to screen coord
	procedure translatewidgetpoint1(var point: pointty; const source,dest: twidget);

	// the function-framed version of "translatewidgetpoint1"
	function translatewidgetpoint(const point: pointty; const source,dest: twidget): pointty;

	// rect isntead of point, 
	// if dest = nil then to screen 
    // if source = nil then against screen
	function translatewidgetrect(const rect: rectty; const source,dest: twidget): rectty;
	//-----------------
    // translates "point" coord against "source" paintrect to "dest" paintrect
	//   * nil "source" = from screen coord 
	//   * nil "dest" = to screen coord
	procedure translatepaintpoint1(var point: pointty; const source,dest: twidget);

	// the function-framed version of "translatepaintpoint1"
	function translatepaintpoint(const point: pointty; const source,dest: twidget): pointty;

	// rect isntead of point, 
	// if dest = nil then to screen 
    // if source = nil then against screen
	function translatepaintrect(const rect: rectty;const source,dest: twidget): rectty;
    //-----------------
    // translates "point" coord against "source" clientrect to "dest" clienttrect
	//   * nil "source" = from screen coord 
	//   * nil "dest" = to screen coord
	procedure translateclientpoint1(var point: pointty;
                    const source,dest: twidget);

	// the function-framed version of "translateclientpoint1"
	function translateclientpoint(const point: pointty; const source,dest: twidget): pointty;

	// rect isntead of point, 
	// if dest = nil then to screen 
    // if source = nil then against screen
	function translateclientrect(const rect: rectty; const source,dest: twidget): rectty;
    //-----------------

	// (re)sorts "awidgets" in order of increasing their "widgetrect.x" coords
	//   - if parent = nil then the coords are against individual parent of each of "awidgets"
	//   - if parent is supplied then the coords are against this parent
	procedure sortwidgetsxorder(var awidgets: widgetarty; const parent: twidget = nil);

	// (re)sorts "awidgets" in order of increasing their "widgetrect.y" coords
	//   - if parent = nil then the coords are against individual parent of each of "awidgets"
	//   - if parent is supplied then the coords are against this parent
	procedure sortwidgetsyorder(var awidgets: widgetarty; const parent: twidget = nil);

	// for each  of "widgets", calculates its autosized client area ( min size rect to fit the caption, etc )
    //   - both hor & ver sizes of client area of each of "widgets" are adjusted to the max of the above calculated areas,
	//	   as the result - client areas of all widgets become identically v+h sized
    // 
    //   * right & bottom anchored margins of each widget are preserved
	procedure syncmaxautosize(const widgets: array of twidget);

	// for each  of "widgets", width of client area of each of "widgets" is adjusted so that 
    // external ( by the outer border of frame ) widths of all widgets become identical 
    // to the external widht of the widest widget
    //    
    //   * if "awidth" >= 0 then no determining the widest widget is taken and
    //     "awidth" is adjusted to instead, for all widgets
    //   * right anchored margins of each widget are lost
	procedure syncminframewidth(const awidgets: array of twidget;
                               const awidth: integer = -1);

	// for each  of "widgets", height of client area of each of "widgets" is adjusted so that 
    // external ( by the outer border of frame ) heights of all widgets become identical 
    // to the external height of the highest widget
    //    
    //   * if "aheight" >= 0 then no determining the highest widget is taken and
    //     "aheight" is adjusted to instead, for all widgets
    //   * bottom anchored margins of each widget are lost
	procedure syncminframeheight(const awidgets: array of twidget; const aheight: integer = -1);

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