PB5.2 : set windows transparency (cross-platform)

[eddy]

This function makes your window transparent.
It returns #TRUE if windows opacity has been changed.

I aggregate some past tips into a function source1 + source2

@Fred
It could be a futur PB command

Code: Select all

; PB 5.2 - set windows transparency (Mac,Linux,Windows)
CompilerIf #PB_Compiler_OS=#PB_OS_Linux
   ImportC "-gtk"
      gtk_window_set_opacity(*Window.i, Opacity.d);
      gtk_widget_is_composited(*Widget)
   EndImport
   
   Procedure.i SetWindowTransparency(Window, Transparency=255)
      Protected *windowID=WindowID(Window), alpha.d=Transparency/255.0
      If Transparency>=0 And Transparency<=255
         If gtk_widget_is_composited(*windowID)
            gtk_window_set_opacity(*windowID, alpha.d)
            ProcedureReturn #True
         EndIf
      EndIf
   EndProcedure
CompilerElseIf #PB_Compiler_OS=#PB_OS_MacOS
   Procedure.i SetWindowTransparency(Window, Transparency=255)
      Protected *windowID=WindowID(Window), alpha.CGFloat=Transparency/255.0
      If Transparency>=0 And Transparency<=255
         CocoaMessage(0, *windowID, "setOpaque:", #NO)
         If CocoaMessage(0, *windowID, "isOpaque")=#NO
            CocoaMessage(0, *windowID, "setAlphaValue:@", @alpha)
            ProcedureReturn #True
         EndIf
      EndIf
   EndProcedure
CompilerElseIf #PB_Compiler_OS=#PB_OS_Windows
   Procedure.i SetWindowTransparency(Window, Transparency=255)
      Protected *windowID=WindowID(Window), exStyle=GetWindowLongPtr_(*windowID, #GWL_EXSTYLE)
      If Transparency>=0 And Transparency<=255
         SetWindowLongPtr_(*windowID, #GWL_EXSTYLE, exStyle | #WS_EX_LAYERED)
         SetLayeredWindowAttributes_(*windowID, 0, Transparency, #LWA_ALPHA)
         
         ProcedureReturn #True
      EndIf
   EndProcedure
CompilerEndIf

[flaith]

Thanks eddy

[eddy]

updated
- fix window specific code (remove one useless "if" ...)

[Little John]

Smart, thank you!

//edit:
Better use Procedure.i

[eddy]

Smart, thank you!
//edit:
Better use Procedure.i

Updated

[eddy]

updated
- fix linux : gtk_window_set_opacity(*windowID, alpha.d)
- fix mac : alpha.CGFloat