Cross-Platform Development

This is my collection:

• Get Win4Lin and install it, then:
  1. Install Delphi
  2. Re-boot Win4Lin.
  3. Run Win4Lin and run Regedit.exe within it.
  4. Change HK_CURRENT_USER\Software\Borland\Debugging\Evaluators\UseCount from "1" to "0".
  5. Start Delphi. It complains about the JIT debugging being set to ".". Just click on "Don't ask again" then "No" (I don't want to change it).
  6. Delphi should then start.
  7. Don't believe me ? Then check out this screenshot of Delphi and Kylix running simultaneously.

• You can use the same source code for both Delphi® and Kylix. Just make sure that:
  1. You change {$R *.DFM} to {$R *.dfm}.
  2. You ensure that the unit names in the uses clause exactly match, including case, those of the actual files.
  3. Beware of access rights ! *nix's are much more picky about who owns what file. Learn how to use "su root" and running konqueror in SuperUser mode.
  4. Use $IFDEFs to define the units in the uses clause. A good example is Normal1.pas, which is in the TPlot distribution.
  5. Many of the standard VCL units simply have a "Q" pre-pended in VisualClx. Again, see the code in Normal1.pas.
  6. Kylix supports 8, 16 and 32 bit color. 24 bit color images are not supported, particularly in resources.
  7. TForm.Color: the default in Delphi is clBtnFace. Kylix understands that this really means clBackground. But Delphi thinks that clBackground really means what it says. This is also fixed in cleandfm.dpr.
  8. Resources work almost the same as in Delphi, except:
     1. there's a bug in TheBitmap.LoadFromResourceID which is fixed in FreeClx on SourceForge.
     2. and another in LoadStr, which is also fixed in FreeClx on SourceForge.
  9. Form layout is a bugger. TForm.PixelsPerInch and TForms.Scaled are the recommended solutions, but I've had severe problems with them. Instead, I use a method based on the position of the bottom-right control:

     				
     procedure SetDialogGeometry(AForm: TForm; AButton: TControl; BorderWidth: Integer);
     begin
     {$IFDEF MSWINDOWS}
       AForm.BorderStyle := bsDialog;
     {$ENDIF}
     {$IFDEF LINUX}
       AForm.BorderStyle := fbsDialog;
     {$ENDIF}
       AForm.Scaled := FALSE;
       AForm.HorzScrollBar.Visible := FALSE;
       AForm.VertScrollBar.Visible := FALSE;
     
       AForm.Left := 10;
       AForm.Top := 10;
       AForm.ClientHeight := AButton.Top + 3 * AButton.Height div 2;
       AForm.ClientWidth := AButton.Left + AButton.Width + BorderWidth;
     end;
     
     				

  10. Some properties are not common: HelpType, CharSet, Font.Weight, and so on. When you open a Delphi form in Kylix, it will complain about these properties, and vice-versa. Just "Ignore" the complaints.
  11. This becomes a more severe problem if you compile a program without opening and re-saving each and every form, so ...
  12. The cleandfm.dpr program is useful for automatically fixing or removing these problem properties.