ExCtrls is a collection of controls which try to overcome limitations posed by the widgetset. Moreover, some missing controls are added.
The package is written by Werner Pamler, but re-uses a lot of code of the LCL components written by the Lazarus team. The TColumnComboBoxEx was contributed by Howard Page-Clark.
Modified LGPL (with linking exception, like Lazarus LCL)
Download and Installation
Use an svn client to download the current trunk version from svn://svn.code.sf.net/p/lazarus-ccr/svn/components/exctrls. Alternatively download the zipped snapshot from https://sourceforge.net/p/lazarus-ccr/svn/HEAD/tree/components/exctrls/ and unzip it to some folder.
There is no release version, yet.
In Lazarus, go to "Package" > "Open Package File .lpk". Navigate to the folder with the ExCtrls sources, and select exctrlspkg.lkp. Click "Compile", then "Use" > "Install". This will rebuild the IDE (it may take some time). When the process is finished the IDE will restart, and you'll find the components on the palettes ExCtrls and LazControls.
The application of each component is demonstrated by a project in the folder examples coming along with the component code.
TRadioButtonEx, TCheckBoxEx, TRadioGroupEx and TCheckGroupEx
These components re-implement the standard TRadioButton, TCheckBox, TRadioGroup and TCheckGroup, but inherit from TCustomControl and thus are not drawn by the widgetset but by the ThemeServices. As a consequence there are less widgetset related restrictions although the components look and behave like their original LCL counter-parts.
- Wordwrapped captions: If the new property WordWrap is set to true, long captions are word-wrapped to fit into the width of the control. Note that when AutoSize is active before WordWrap is activated the caption is not wrapped initially and all the text is placed into a single line. Turn AutoSize off and reduce the width of the control. Once the text is wrapped AutoSize may be switche on again to adjust the height.
- Vertical layout: ButtonLayout and TextLayout control the vertical positioning of checkbox/radiobutton and caption, respectively. Default is tlCenter, i.e. the corresponding element is centered vertically within the bounds of the control; other values are tlTop and tlBottom. Normally ButtonLayout and TextLayout are changed in pairs.
- User provided check images: The checkboxes and radiobuttons are normally drawn by the ThemeServices, but it is possible to provide dedicated bitmaps which can be used instead. The bitmaps must be stored in a TImageList attached to property Images. The corresponding image index must be assigned in a handler of the event OnGetImageIndex which has appropriate parameters to distinguishe between mouse-over, pressed, enabled/disabled and checked/unchecked states.
- Custom caption colors and font settings: The font of the caption can be changed when the property ThemedCaption is switched to false. In case of TRadioGroupEx the font of individual items can only be changed at runtime by accessing the RadioGroup1.Buttons[Andex] property pointing to the TRadioButtonEx at the given index in the groupbox. The same is possible also with the TCheckGroupEx.
The default LazControls palette contains already extended spin edit controls for integers and floating point numbers (TSpinEditEx and TFloatSpinEditEx, respectively). The missing edit for currency values is implemented in package ExCtrls.
New and modified properties
- Value: The data type of the control is currency.
- CurrencyString: The currency name, for example '$' or '€', is added to the numeric value in the edit box. The default value is taken from the DefaultFormatSettings provided by the SysUtils unit.
- CurrencyFormat: Defines the order of (positive) numeric value and currency name in the edit field:
- secfCurrVal: currency string first, no space (e.g. '$1')
- secfValCurr: value first, no space (e.g. '1$')
- secfCurrSpaceVal: currency string first, space to value (e.g. '$ 1');
- secfValSpaceCurr: value first, space to currency string (e.g. '1 $');
- NegCurrencyFormat: Like CurrencyFormat, but now for negative values:
- sencfParCurrValPar: currency string first, no space, the entire string is put in parenthesis (e.g. '($1)')
- sencfMinusCurrVal: currency string first with leading '-' character, no space (e.g. '-1$')
- sencfCurrMinusVal: currency string first, no space, '-' at value (e.g. '$-1')
- sencfCurrValMinus: currency string first, value with appended '-' (eg. '$1-')
- etc... Other allowed values are sencfParValCurrPar ('1$'), sencfMinusValCurr ('-1$'), sencfValMinusCurr ('1-$'), sencfValCurrMinus ('1$-'), sencfMinusValSpaceCurr ('-1 $'), sencfMinusCurrSpaceVal ('-$ 1'), sencfValSpaceCurrMinus ('1 $-'), sencfCurrSpaceValMinus ('$ 1-'), sencfCurrSpaceMinusVal ('$ -1'), sencfValMinusSpaceCurr ('1- $'), sencfParCurrSpaceValPar ('($ 1)'), sencfParValSpaceCurrPar ('(1 $)')
- DecimalSeparator: Character used to separate decimals from the integer part. Defaults to the value defined by the DefaultFormatSettings.
- ThousandSeparator:If not empty (i.e. not #0) the integer part of the Value is formatted with a thousand separator for better readability. Note that the control does not allow DecimalSeparator and ThousandSeparator to be equal.
This is an extended version of TFloatSpinEditEx which accepts scientific multiplier suffixes, e.g. k for "kilo" or the factor 1000; the user can input the text '1.23k' and the Value of the component is 1230.
TColumnComboBoxEx, written by Howard Page-Clark, is a text-only combobox that displays its dropdown items list in single phrase columns, which are parsed according to the delimiter property. The column width in the dropdown is adjusted automatically to accomomodate the longest word/phrase in each column. The number of columns shown depends entirely on the number of delimiters found in each listed item, hence is an unpublished read-only property.
- Delimiter: the char value which separates the columns in each combobox item. The default is the comma.
- ShowColSeparators: a boolean display property which activates the display of vertical dividing lines between the columns. Default: false.
- ColSeparatorColor (TColor): defines the color of the vertical dividing lines between the columns. Default: clSilver.
- ColumnMargin (Integer): allows for adjustment of all column widths by a fixed amount.
TCheckComboBoxEx overcomes some annoyances of the TCheckComboBox which comes with the Lazarus IDE:
- Incidentally checking an item by selecting an item is no longer possible
- The item list stays in the dropped state until ENTER, ESC, ALT-UP or ALT-DOWN are pressed, or another control is selected. This way several items can be checked without having to drop down the list multiple times. The easiest way to do this is by the UP/DOWN arrow keys and pressing the SPACE bar for checking/unchecking items.
- The main field of the control lists all checked items rather than only the selected item.
Although the control inherits from TGroupedEdit rather than from TCustomComboBox, many its properties and events are based on TComboBox; other properties were added to achieve the unique behaviour of the component:
- AllowGrayed (boolean): if false (default), the items in the dropdown list can either be checked or not. If true, the items can also be switched to a third, "grayed" state.
- AutoDropDown (boolean): if true, the list window drops down automatically when the control is focused. Otherwise the arrow icon at the right must be clicked, or the key ALT-DOWN must be pressed.
- Delimiter (char): character separating the items in the list of checked items in the main control field.
- DropDownCount (integer): maximum count of lines shown in the dropdown list
- EscCancels (boolean): when true and the dropdown list is closed by pressing the ESC key the changes in the list are cancelled and all items have their checked states as when the list had dropped down initially.
- HintMode (enumeration of cbhmDefault, cbhmItems):
- cbhmDefault: the default hint is shown as specified by the Hint property
- cbhmItems: the hint is composed of the checked items.
- Items (TStrings): list of the items names shown in the dropdown window.
- ItemIndex (integer): Index of the selected (= highlighted) item in the dropdown window
- Sorted (boolean): the items in the dropdown window are sorted alphabetically, when true.
- Checked[AIndex] (boolean): it true when the item at the given index is checked
- State[AIndex] (boolean): depending on the checked state of the item at the given index the property can have three values: cbUnchecked, cbChecked, or cbGrayed. AllowGrayed must be true to use this option.
- Enabled[AIndex] (boolean): when false, the checked state of the item at the given index cannot be changed by the user.
- OnDropDown: this event fires when the dropdown windows is dropping down
- OnCloseUp: this event is generated when the dropdown window closes
- OnItemChange: when an item is checked, either by the user or by code, this event is triggered.
- OnItemClick: this event is fired when the user clicks on a checkbox in the dropdown list or when he presses the SPACE bar. It is not fired when the item is checked by code.
- OnChange: In addition to changes of inidividual items, this event fires when all items are changes (methods Clear(), CheckAll).
The most important methods:
- function AddItem(AText: String; AChecked: Boolean = false; AEnabled: Boolean = true): Integer; - Adds a new item to the combobox list and sets is Checked and Enabled states.
- procedure CheckAll(AState: TCheckBoxState; aAllowGrayed: Boolean = true; aAllowDisabled: Boolean = true); - Sets all existing items to the given state. When aAllowGrayed is false the cbGrayed state is not applied. When aAllowDisabled is false then only enabled items are changed.
- procedure Clear - removes all items from the dropdown list.
- procedure Toggle(AIndex: Integer) - toggle the list item at the given index between checked and unchecked.