Difference between revisions of "How to use a TrayIcon"
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And on Lazaurs 0.9.23 or superior it is automatically installed with LCL | And on Lazaurs 0.9.23 or superior it is automatically installed with LCL | ||
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=== Demonstration program 1 === | === Demonstration program 1 === |
Revision as of 22:56, 9 December 2008
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English (en) │
About
TrayIcon is a multiplatform System Tray component. You can find TrayIcon on the Addition tab of components on recent versions of Lazarus (0.9.23+).
TrayIcon used to be an optional component, but is part of LCL since Lazarus 0.9.23
To start quickly, please read the demonstration program.
Documentation
Bellow is a list of all methods, properties and events of the component. They have the same names and work the same way on the visual component and on the non-visual object.
A function works on all target platforms unless written otherwise.
Methods
Show
procedure Show;
Shows the icon on the system tray.
Hide
procedure Hide;
Removes the icon from the system tray.
GetPosition
function GetPosition: TPoint;
Returns the position of the tray icon on the display. This function is utilized to show message boxes near the icon. Currently it´s only a stub, no implementations are available and TPoint(0, 0) is returned.
Properties
Hint
property Hint: string;
A Hint will be shown the string isn't empty
PopUpMenu
property PopUpMenu: TPopUpMenu;
A PopUp menu that appears when the user right-clicks the tray icon.
Events
OnPaint
property OnPaint: TNotifyEvent;
Use this to implement custom drawing to the icon. Draw using the canvas property of the icon.
Note: Does not work on win32.
OnClick
property OnClick: TNotifyEvent;
OnDblClick
property OnDblClick: TNotifyEvent;
OnMouseDown
property OnMouseDown: TMouseEvent;
OnMouseUp
property OnMouseUp: TMouseEvent;
OnMouseMove
property OnMouseMove: TMouseMoveEvent;
Screenshot
Authors
- Windows Notes: Ozz Nixon
License
Modified LGPL.
Download
Status: Stable
Can be located at Lazarus 0.9.22 or inferior at the directory: lazarus/components/trayicon
And on Lazaurs 0.9.23 or superior it is automatically installed with LCL
Demonstration program 1
As of Lazarus 0.9.26 TIcon has been fully implemented and it is no longer necessary to load the icon from a resource file on Windows. The icon can be loaded in the IDE or with usual code.
Go to the Additional tab of components, and add a TTrayIcon to your form. Then change it's Name property to SystrayIcon
Next add a button to the form. Double click the button and add this code to it:
procedure MyForm.Button1Click(Sender: TObject); begin SystrayIcon.Icon.LoadFromFile('/path_to_icon/icon.ico'); SystrayIcon.ShowHint := True; SystrayIcon.Hint := 'my tool tip'; SystrayIcon.PopUpMenu := MyPopUpMenu; SystrayIcon.Show; end;
Subversion
Located under components/trayicon/ on the latest subversion Lazarus.
Help, Bug Reporting and Feature Request
Please, post Bug Reports and Feature Requests on the Lazarus Bugtracker.
Help requests can be posted on the Lazarus mailling list or on the Lazarus Forum.
Change Log
- 17/01/2006 - Available as a preview on the Lazarus subversion. Still under heavy construction, however.
- 24/01/2006 - Stable under win32, gnome and gtk1, but still waiting for gtk2 support. Lazarus 0.9.12 was release with this version.
- 17/02/2006 - Added support for gtk2 on subversion.
Technical Details
A difficulty on the development of this component was the many differences on the system tray implementation on various OSes and even Window Managers on Linux. To solve this, the component tries to implement the minimal set of features common to all target platforms. Below is a list of the features implemented on each platform:
Windows - Multiple system tray icons per application are supported. The image of the icon can be altered using a HICON handle. Events to the icon are sent via a special message on the user reserved space of messages (>= WM_USER) to the Window which owns the Icon. No paint events are sent to the Window.
- NOTE * for some odd reason the environment by default does not support WM_USER+ messages, you will need to add "-dPassWin32MessagesToLCL" (without quotations) to support the messaging code. The steps are, click Tools -> Configure "Build Lazarus"..., and add that compiler option to "Options". If you have any existing options, they are "space" delimited.
Linux (Gnome, KDE, IceWM, etc) - Multiple system tray icons per application are supported. The image of the icon is actually a very small Window, and can be painted and receive events just like any other TForm descendant.
Linux (WindowMaker, Openbox, etc) - Does not support system tray icons out-of-the-box. However, There are at least two softwares that provides support for it: Docker and WMSystray
Mac OS X - This system does not really have System Tray icons in the way Linux and Windows have them. This component attempts to use tray-like features of Mac OS X to implement a tray icon. Every application on Mac OS X has a Dock icon. The software can assign a popup menu for this Dock, and this is probably how TrayIcon for Mac OS will work in the future. One compatibility problem is that only one Dock per application can exist.
You can see here is how it will look like: http://developer.apple.com/documentation/UserExperience/Conceptual/OSXHIGuidelines/XHIGMenus/chapter_16_section_6.html
With this in mind a approach which supports all Platforms was created:
- Only one Systray Icon is supported per application, and all applications that use the component have it initialized on the startup of the program. This way you will use the SystrayIcon object, and not it´s class. (Required by Mac OS X)
- Painting is done via a TIcon object. (Required by Windows)
The following extra features are already available or will be, but they won´t work on all platforms.
- Multiple Systray Icons. Won´t work on Mac OS X.
- OnPaint event and Canvas property to draw the icon freely. Won´t work on Windows.
External Links
- http://www.codeproject.com/shell/ctrayiconposition.asp - Code and theory to find the tray icon position under Windows
- http://cvs.gnome.org/viewcvs/gtk%2B/gtk/gtkstatusicon.c?rev=1.23&view=markup - Gtk2 code that implements gtkstatusicon