Canvas and transparent background gadgets

FlatEarth · **Joined:** Tue Jan 28, 2020 10:17 am **Posts:** 69

Hi
Why is the background of the checkbox, option, panel and ... transparent when added to the canvas container?
Is there an easy way to prevent this? like window.

Code:

If OpenWindow(0, 0, 0, 600, 600, "CanvasGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  
  SetWindowColor(0,RGB(80,255,255))
  
  ;CheckBoxGadget(1,30,30,100,30,"chk") 
  OptionGadget(1,30,30,100,30,"Opt")
  
  
  CanvasGadget(0, 200, 200, 200, 200,#PB_Canvas_Container|#PB_Canvas_Border)
  If StartDrawing(CanvasOutput(0))
    Box(0,0,200,200,RGB(80,255,255))
    StopDrawing()
  EndIf  
  
  ;CheckBoxGadget(2,30,30,100,30,"chk") 
  OptionGadget(2,30,30,100,30,"Opt")
  
  CloseGadgetList()
  
  Repeat
    
  Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf

IdeasVacuum · **Posted:** Fri Apr 17, 2020 12:55 pm

Tested on PB5.72x64, Windows7

You are right FlatEarth! I hope this is intentional because it is of course what we want

FlatEarth · **Joined:** Tue Jan 28, 2020 10:17 am **Posts:** 69

Thanks IdeasVacuum,
It could be a bug for CanvasGadget? because it works properly in ContainerGadget.

Code:

If OpenWindow(0, 0, 0, 600, 600, "CanvasGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
 
  SetWindowColor(0,RGB(80,255,255))
 
  ;CheckBoxGadget(1,30,30,100,30,"chk")
  OptionGadget(1,30,30,100,30,"Opt")
 
 
  ContainerGadget(0, 200, 200, 200, 200)
  
  ;CheckBoxGadget(2,30,30,100,30,"chk")
  OptionGadget(2,30,30,100,30,"Opt")
 
  CloseGadgetList()
  
  SetGadgetColor(0,#PB_Gadget_BackColor, RGB(80,255,255))
  Repeat
   
  Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf

Derren · **Posted:** Fri Apr 17, 2020 2:36 pm

You really want a non-transparent background for gadgets on Canvas?
Or are you looking for a way to have transparent gadgets on a window?

For the canvas you simply need to draw a box before you place your gadget.

Code:

If OpenWindow(0, 0, 0, 600, 600, "CanvasGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
 
  SetWindowColor(0,RGB(80,255,255))
 
  ;CheckBoxGadget(1,30,30,100,30,"chk")
  OptionGadget(1,30,30,100,30,"Opt")
 
  CanvasGadget(0, 200, 200, 200, 200,#PB_Canvas_Container|#PB_Canvas_Border)
  If StartDrawing(CanvasOutput(0))
        Box(0,0,200,200,RGB(80,255,255))
        
        Box(30,30,100,30,$FFFFFF) ; <-- you would need to get the default window color somehow, if that's what you want.
        
    StopDrawing()
  EndIf 
 
  ;CheckBoxGadget(2,30,30,100,30,"chk")
  
  OptionGadget(2,30,30,100,30,"Opt")
 
  CloseGadgetList()
 
  Repeat
   
  Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf

FlatEarth · **Joined:** Tue Jan 28, 2020 10:17 am **Posts:** 69

I found this way and it is more suitable for me.

Code:

If OpenWindow(0, 0, 0, 600, 600, "CanvasGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
  
  SetWindowColor(0,RGB(80,255,255))
  
  CheckBoxGadget(1,30,30,100,30,"chk")
  OptionGadget(2,30,70,100,30,"Opt")

  CanvasGadget(0, 200, 200, 200, 200,#PB_Canvas_Container|#PB_Canvas_Border)
  If StartDrawing(CanvasOutput(0))
    Box(0,0,200,200,RGB(80,255,255))        
    StopDrawing()
  EndIf
  
  CheckBoxGadget(3,30,30,100,30,"chk")
  OptionGadget(4,30,70,100,30,"Opt")
  
  SetWindowTheme_(GadgetID(3),0,@"")
  SetWindowTheme_(GadgetID(4),0,@"") 
  
  CloseGadgetList()
  
  Repeat
    
  Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf

@Derren : Thanks for your idea.

IdeasVacuum · **Posted:** Fri Apr 17, 2020 4:25 pm

With my brief test, the TrackBar Gadget is an obstacle. The Help lists Frame, Checkbox and Option Gadgets as being opaque (Windows OS) but they are not. It also lists Text and Hyperlink Gadgets, but you can change their background colour anyway.

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Canvas and transparent background gadgets

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