Menus on windows with canvases

One way is to use eventhook like so:-

Const MENU_NEW=101
Const MENU_OPEN=102
Const MENU_SAVE=103
Const MENU_CLOSE=104
Const MENU_EXIT=105

Const MENU_CUT=106
Const MENU_COPY=107
Const MENU_PASTE=108

Const MENU_ABOUT=109

window=CreateWindow("My Window",40,40,320,240)
Global canvas:TGadget=CreateCanvas(0,0,320,240,window)'<---GLOBAL


filemenu=CreateMenu("&File",0,WindowMenu(window))
CreateMenu"&New",MENU_NEW,filemenu,KEY_N,MODIFIER_COMMAND
CreateMenu"&Open",MENU_OPEN,filemenu,KEY_O,MODIFIER_COMMAND
CreateMenu"&Close",MENU_CLOSE,filemenu,KEY_W,MODIFIER_COMMAND
CreateMenu"",0,filemenu
CreateMenu"&Save",MENU_SAVE,filemenu,KEY_S,MODIFIER_COMMAND
CreateMenu"",0,filemenu
CreateMenu"E&xit",MENU_EXIT,filemenu,KEY_F4,MODIFIER_COMMAND

editmenu=CreateMenu("&Edit",0,WindowMenu(window))
CreateMenu "Cu&t",MENU_CUT,editmenu,KEY_X,MODIFIER_COMMAND
CreateMenu "&Copy",MENU_COPY,editmenu,KEY_C,MODIFIER_COMMAND
CreateMenu "&Paste",MENU_PASTE,editmenu,KEY_V,MODIFIER_COMMAND

helpmenu=CreateMenu("&Help",0,WindowMenu(window))
CreateMenu "&About",MENU_ABOUT,helpmenu

UpdateWindowMenu window'<---NEW
AddHook EmitEventHook, MyHook

While True
	WaitEvent 
	Select EventID()
	Case EVENT_WINDOWCLOSE
		End
	Case EVENT_MENUACTION
	Select EventData()
		Case MENU_EXIT
			End
		Case MENU_ABOUT
			Notify "Incrediabler~n(C)2005 Incredible Software"
	End Select
	RedrawGadget(canvas)'<---NEW
	Case EVENT_GADGETPAINT '<---NEW
		UpdateCanvas()'<---NEW
	End Select
Wend

End

'-----------------NEW---------------------------------------
Function MyHook:Object(iId:Int,tData:Object,tContext:Object)
  Local Event:TEvent=TEvent(tData)

  If Event.source=Canvas 'And Event.ID=EVENT_GADGETPAINT
     UpdateCanvas()
     Return Null
  EndIf

  Return tData
End Function

Function UpdateCanvas:Int()
     SetGraphics CanvasGraphics(Canvas)
     Cls
     Flip
End Function
'-----------------------------------------------------------

see tutorial here if you want to learn more