[Done] Canvas gadget / #PB_EventType_Resize

srod · **Posted:** Thu Aug 09, 2018 6:51 pm

Purebasic 5.70 Beta 1x64. Ubuntu 18.04.

qt subsystem.

The following shows that when using a #PB_EventType_Resize bound event with a canvas gadget, the underlying bitmap has not been resized prior to the event procedure firing. GadgetWidth() and GadgetHeight() seem correct. We had a similar problem under Windows before PB 5.70 beta 1.

This problem can hide itself within the StartDrawing() bug reported previously since if we are drawing within the resize event procedure, the StartDrawing() can fail if the bitmap still has 0 width, for example, because of this resizing issue; and the StartDrawing() bug then kicks in. Two bugs for the price of one!

Run the code and resize the window.

Code:

Procedure winSize()
  ResizeGadget(0, #PB_Ignore, #PB_Ignore, 100, WindowHeight(0)-20)
EndProcedure

Procedure ResizeOne()
  If StartDrawing (CanvasOutput(0))
    Debug "Drawing output width = " + Str(OutputWidth()) + ", SHOULD BE 100!"
    Debug "Canvas gadget width = " + Str(GadgetWidth(0))
    Debug "Canvas gadget height = " + Str(GadgetHeight(0))
    StopDrawing()
    End  
  EndIf
 
EndProcedure


If OpenWindow(0, 0, 0, 220, 220, "Canvas example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered | #PB_Window_SizeGadget)
  CanvasGadget(0, 10, 10, 50, 200)
  
  BindEvent(#PB_Event_SizeWindow, @winSize(), 0)
  BindGadgetEvent(0, @ResizeOne(), #PB_EventType_Resize)
  
  Repeat
    Event = WaitWindowEvent()
  Until Event = #PB_Event_CloseWindow
EndIf

Fred · **Posted:** Sun Sep 16, 2018 8:40 pm

Fixed.

srod · **Posted:** Sun Nov 25, 2018 6:26 pm

There is another problem with Canvas gadget and redrawing in response to event type resize (I think also reported by mk-soft).

The following should fill the canvas with red on resize.

Code:

Declare winSize()
Declare CanvasEventHandler()


If OpenWindow(0, 0, 0, 220, 220, "CanvasGadget", #PB_Window_SystemMenu | #PB_Window_SizeGadget | #PB_Window_ScreenCentered)
  CanvasGadget(0, 0, 10, 220, 220)
  BindEvent(#PB_Event_SizeWindow, @winSize(), 0)
  BindGadgetEvent(0, @CanvasEventHandler(), #PB_EventType_Resize)

  Repeat
    Event = WaitWindowEvent()
  Until Event = #PB_Event_CloseWindow
EndIf
  
  
Procedure winSize()
  ResizeGadget(0, #PB_Ignore, #PB_Ignore, WindowWidth(0), WindowHeight(0))
EndProcedure

Procedure CanvasEventHandler()
  If StartDrawing(CanvasOutput(0))
    Box(0, 0, GadgetWidth(0), GadgetHeight(0), $FF)
    StopDrawing()
  EndIf
EndProcedure

mk-soft · **Posted:** Sun Nov 25, 2018 7:15 pm

Yes, is not Fixed

Link to Bugreport: viewtopic.php?f=23&t=71638

The problem is that the gadgets at the event resize are not yet valid data stored, and therefore the query of the sizes are not correct...
Only in the next event are the sizes valid.

Here's another code so you can see the error.

Code:

Declare winSize()
Declare CanvasEventHandler()


If OpenWindow(0, 0, 0, 220, 220, "CanvasGadget", #PB_Window_SystemMenu | #PB_Window_SizeGadget | #PB_Window_ScreenCentered)
  CanvasGadget(0, 5, 5, 210, 210)
  BindEvent(#PB_Event_SizeWindow, @winSize(), 0)
  BindGadgetEvent(0, @CanvasEventHandler(), #PB_EventType_Resize)

  Repeat
    Event = WaitWindowEvent()
  Until Event = #PB_Event_CloseWindow
EndIf

  
Procedure winSize()
  ResizeGadget(0, #PB_Ignore, #PB_Ignore, WindowWidth(0) - 10, WindowHeight(0) - 10)
  ;PostEvent(#PB_Event_Gadget, EventWindow(), 0, #PB_EventType_Resize, 2)
EndProcedure

Procedure CanvasEventHandler()
  Select EventType()
    Case #PB_EventType_Resize
      If EventData() = 2
        Debug "PostEvent Resize Data 2"
      Else
        Debug "PB Event Resize"
      EndIf
      If StartDrawing(CanvasOutput(0))
        Box(0, 0, GadgetWidth(0), GadgetHeight(0), $FF0000)
        StopDrawing()
      EndIf
    
  EndSelect
EndProcedure

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[Done] Canvas gadget / #PB_EventType_Resize

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