PureBasic Forums - English

Posted: **Wed Oct 30, 2013 8:20 pm**

Would be useful to add a Destroy Gadget Event so when a window is closed the event can fire
so custom gadget can clean up eg free heap memory.

Posted: **Wed Oct 30, 2013 11:35 pm**

If you have custom gadgetdata stored in a list/map you may use

Code: Select all

Procedure EventCloseWindow()
  
  Protected Window = EventWindow()
  
  If WindowInMyList
    ; free gadgets memory etc
    ; maybe a map/list hold the data
    ; UnBindGadgetEvents.... etc

    UnbindEvent(#PB_Event_CloseWindow, @EventCloseWindow(), Window)
  EndIf

EndProcedure

Or miss I something ?

I wish a command to send an event directly to a gadget...
With PostEvent() I can only send an event to a window...

Posted: **Thu Oct 31, 2013 2:58 am**

Yes you can do it like that but we shouldn't have to store custom gadgets in a list or map
and should be free to heap allocate them and set a callback to clean them up

Posted: **Thu Oct 31, 2013 11:50 am**

Why can't you just watch for #PB_Event_CloseWindow and then execute your cleanup code?

Posted: **Thu Oct 31, 2013 6:19 pm**

PB wrote:Why can't you just watch for #PB_Event_CloseWindow and then execute your cleanup code?

FreeGadget() does not fire #PB_Event_CloseWindow event. Gadgets are also freed/destroyed automatically
when the parent of the gadget (ContainerGadget(), PanelGadget() etc.) is freed, see help for FreeGadget().

So #PB_EventType_Destroy should be send for:

Code: Select all

- FreeGadget() is used with the gadget
- The window that contains the gadget is closed. 
- The parent of the gadget (ContainerGadget(), PanelGadget() etc.) is freed. 
- The program ends.

Posted: **Thu Oct 31, 2013 7:19 pm**

i have a little workaround

Code: Select all

Structure GadgetVT Align 4
  GadgetType.l  
  SizeOf.l    
  GadgetCallback.i
  FreeGadget.i
EndStructure

Structure Gadget
  Gadget.i
  *vt.GadgetVT
EndStructure  

Prototype CallFreeProc(Gadget)

Structure FreeProcInfo
  OldProc.CallFreeProc
  NewProc.CallFreeProc
  GadgedNR.i
EndStructure

Global NewMap OldFreeProc.FreeProcInfo()

;-------------------------------------------
Procedure FreeProc(Gadget)
  Protected GadgedNR
  
  If Gadget
    
    GadgedNR    = OldFreeProc(Str(gadget))\GadgedNR
    
    OldFreeProc(Str(gadget))\NewProc(GadgedNR)
    
    DeleteMapElement(OldFreeProc(), Str(gadget))    
    
    If OldFreeProc(Str(gadget))\OldProc
      ProcedureReturn OldFreeProc(Str(gadget))\OldProc(GadgedNR)
    EndIf    
    
  EndIf    
  
EndProcedure

;-------------------------------------------
Procedure SetFreeProc(Gadget, Proc)
  Protected *g.Gadget
  
  *g = IsGadget(gadget)
  
  If *g

    OldFreeProc(Str(*g))\GadgedNR = Gadget
    OldFreeProc(Str(*g))\OldProc  = *g\vt\FreeGadget
    OldFreeProc(Str(*g))\NewProc  = Proc          
    
    *g\vt\FreeGadget = @FreeProc()
  EndIf
  
EndProcedure
;######################################################

Procedure FreeButton(Gadget)
  Debug "Free ButtonGadget"
EndProcedure

Procedure FreeString(Gadget)
  Debug "Free StringGadget"
EndProcedure


Procedure Main()
  Protected event
  
  If OpenWindow(0, #PB_Ignore, #PB_Ignore, 300, 300, "") And InitScintilla()
    
    ButtonGadget(0, 0, 0, 100, 25, "Blub")
    ButtonGadget(1, 0, 0, 100, 25, "Blub")
    StringGadget(2, 0, 30, 100, 25, "Blub")
    ButtonGadget(3, 0, 0, 100, 25, "Blub")
    ButtonGadget(4, 0, 0, 100, 25, "Blub")
    CanvasGadget(5, 0, 30, 100, 25)    
    
    SetFreeProc(0, @FreeButton())
    SetFreeProc(1, @FreeButton())
    SetFreeProc(2, @FreeString())
    SetFreeProc(3, @FreeString())
    SetFreeProc(4, @FreeString())
    SetFreeProc(5, @FreeButton())
    
    Repeat
      event = WaitWindowEvent()
      
      If event = #PB_Event_CloseWindow
        Break
      EndIf
      
    ForEver 
        
  EndIf  
  
EndProcedure: End main()

Posted: **Thu Oct 31, 2013 8:09 pm**

@hallodri

crashes on line 37 with x64 compiler!

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DestroyGadget Event

DestroyGadget Event

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Re: DestroyGadget Event