[MaxGUI] Setting the maximum window size

Try something like this

Function MyHook:Object( id:Int,data:Object,context:Object )
	Local ev:TEvent=TEvent(data)
	If ev.source=Win And ev.id=EVENT_WINDOWSIZE
		SetGadgetShape win,0,0,640,480
	End If
	Return Data
End Function


Global win:TGadget
win=CreateWindow( "A window!",0,0,640,480, Null, WINDOW_TITLEBAR | WINDOW_RESIZABLE )

AddHook EmitEventHook,MyHook
While True
	WaitEvent
Wend

To handle the canvas (which I have taken out to make the program simpler) you have to trap an EVENT_GADGETPAINT as well.

See my tutorial to understand how eventhook works.