Theme library

From Free Pascal wiki

What is a Theme manager?

The Theme manager was originally created by Mike Lischke (see http://www.soft-gems.net/) to enable Windows XP theme painting in Borland Delphi and Borland C++ Builder applications.

Why do we need a Theme manager?

It gives the ability to have ownerdraw controls with the same look and feel as native controls.

What ownerdraw controls do we have?

  1. TCustomSpeedButton descendants (TSpeedButton)
  2. TCustomSplitter descendants (TSplitter)
  3. TCustomGrid descendants (TStringGrid, TDBGrid)
  4. TCustomUpDown descendants (TUpDown)
  5. ...

What is the current state of implementation?

Windows XP and Vista applications with manifest - fully implemented since theme manager originally created for Windows XP.

Element default gtk gtk2 carbon qt Used in components
teButton Partially Implemented Partially Implemented Partially Implemented Partially Implemented Partially Implemented TSpeedButton
teHeader Partially Implemented Partially Implemented Partially Implemented Not Implemented Partially Implemented TCustomGrid
teRebar Partially Implemented Partially Implemented Partially Implemented Partially Implemented Not Implemented TSplitter
teToolBar Partially Implemented Partially Implemented Partially Implemented Partially Implemented Partially Implemented TSpeedButton

How to use ThemeServices class for painting?

Simply proceed as follows. Create an empty form and paint a push button on it with normal state.

 unit Unit1; 
 {$mode objfpc}{$H+}
 
 interface
 uses
   Classes, SysUtils, LResources, Forms, Controls, Graphics;
 
 type
   TForm1 = class(TForm)
   private
     { private declarations }
   public
     procedure Paint; override;
   end;
 
 var
   Form1: TForm1; 
 
 implementation
 {$R manifest.res}
 
 uses
   LCLType, Themes;
   
 procedure TForm1.Paint;
 var
   Details: TThemedElementDetails;
   PaintRect: TRect;
 begin
   inherited Paint;
   PaintRect := Rect(10, 10, 80, 50);
   Details := ThemeServices.GetElementDetails(tbPushButtonNormal);
   ThemeServices.DrawElement(Canvas.Handle, Details, PaintRect, nil);
   PaintRect := ThemeServices.ContentRect(Canvas.Handle, Details, PaintRect);
   ThemeServices.DrawText(Canvas, Details, 'Test caption', PaintRect,
     DT_CENTER or DT_VCENTER or DT_SINGLELINE, 0);
 end;
 
 initialization
   {$I unit1.lrs}
 end.

And the result will look so:

theme painting.png

--Paul Ishenin 20:31, 9 June 2007 (CEST)