Change transparency of window

[Shardik]

On MacOS X 10.0 and later it is very easy to change the transparency of your window:

Code: Select all

ImportC ""
  SetWindowAlpha(WindowRef.L, AlphaValue.F)
EndImport

OpenWindow(0, 200, 100, 300, 60, "Change window's transparency")
TrackBarGadget(0, 10, 10, 280, 20, 0, 100)
SetGadgetState(0, 0)
TextGadget(1, 15, 35, 40, 20, "0%")
TextGadget(2, 260, 35, 40, 20, "100%")

Repeat
  Select WaitWindowEvent()
    Case #PB_Event_CloseWindow
      Break
    Case #PB_Event_Gadget
      If EventGadget() = 0
        SetWindowAlpha(WindowID(0), 1.0 - GetGadgetState(0) / 100.0)
      EndIf
  EndSelect
ForEver

[delikanli_19_82]

very good solution. thank you shardik.

thx

kurt

[WilliamL]

That's pretty neat but what would you use it for?

[delikanli_19_82]

i am working on an own cross-platform toolkit for purebasic. and the forms (windows) shell be able to transparent also.

[vwidmer]

Sorry if this is stupid but using the code posted above I am getting this error.

Code: Select all

Undefined symbols for architecture x86_64:
  "_SetWindowAlpha", referenced from:
      _Case1 in purebasic.o
      PStub_SetWindowAlpha in purebasic.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Am I doing something wrong? I am on a MBP runing 10.9.2

[Mindphazer]

I think this code was using carbon, which is not supported anymore.

Maybe this could help : http://www.purebasic.fr/english/viewtop ... 52#p393352

[Shardik]

Mindphaser is right. My code example runs only with the Carbon framework. At the time of my posting the only available framework was Carbon. With PB 5.00 the default framework changed to Cocoa. So to run my above code example you have to use PB 5.11 or older. In PB 5.00 to 5.11 you have to set the "Library Subsystem:" to "Carbon" in "Compiler/Compiler options...". In PB 4.61 or older the code example runs without anything to change (even on OS X 10.9.2 Mavericks).

Beginning with PB 5.20 the subsystem Carbon was removed...

For your conveniance I have ported the code example to Cocoa:

Code: Select all

Define Alpha.CGFloat

OpenWindow(0, 200, 100, 300, 60, "Change window's transparency")
TrackBarGadget(0, 10, 10, 280, 20, 0, 100)
SetGadgetState(0, 0)
TextGadget(1, 15, 35, 40, 20, "0%")
TextGadget(2, 260, 35, 40, 20, "100%")

Repeat
  Select WaitWindowEvent()
    Case #PB_Event_CloseWindow
      Break
    Case #PB_Event_Gadget
      If EventGadget() = 0
        Alpha = 1.0 - GetGadgetState(0) / 100.0
        CocoaMessage(0, WindowID(0), "setAlphaValue:@", @Alpha)
      EndIf
  EndSelect
ForEver

[Mindphazer]

Nice example Shardik

Thank you

[Shardik]

Nice example Shardik

Thank you

You are welcome.


Here is an improved example which uses BindEvent() for a real time change of the transparency while dragging the trackbar knob:

Code: Select all

Procedure TrackBarChangedCallback()
  Protected Alpha.CGFloat = 1.0 - GetGadgetState(0) / 100.0
  CocoaMessage(0, WindowID(0), "setAlphaValue:@", @Alpha)
EndProcedure

OpenWindow(0, 200, 100, 300, 60, "Change window's transparency")
TrackBarGadget(0, 10, 10, 280, 20, 0, 100)
SetGadgetState(0, 0)
BindEvent(#PB_Event_Gadget, @TrackBarChangedCallback(), 0, 0)
TextGadget(1, 15, 35, 40, 20, "0%")
TextGadget(2, 260, 35, 40, 20, "100%")

Repeat
Until WaitWindowEvent() = #PB_Event_CloseWindow