Event Questions

BlitzMax Forums/BlitzMax Beginners Area/Event Questions

Jean-Marie

(Posted 2009) [#1]

For trial I try to write a very simple drawing program.

For reasons mentioned in another post ( http://www.blitzbasic.com/Community/posts.php?topic=86218 ), I've currently my main loop like:

Repeat
  Select WaitEvent()
  Case KEY_ESCAPE
     ...
  End Select

  X=MouseX()
  Y=MouseY()
  If drawing mode, draw
  If delete mode, delete
  If something changed, flip
Until false

First, is it ok to mix Events and polled events? For example, I read the mouse pos with mousex(); is there any reason why I should use the CurrentEvent info instead?

Then: because of this construct, partially hiding the window with another one will garbage the display (which is not refreshed, as no event came). Is there an event code like WINDOW_SHOW for this?

jsp	(Posted 2009) [#2]

Then: because of this construct, partially hiding the window with another one will garbage the display (which is not refreshed, as no event came). Is there an event code like WINDOW_SHOW for this?

Check out the events below. Best to put some of them in a hook function for immediate effect.

EVENT_GADGETPAINT
A Canvas Gadget needs to be redrawn
EVENT_WINDOWMOVE
Window has been moved
EVENT_WINDOWSIZE
Window has been resized
EVENT_APPRESUME
Application resumed

And for your first question i would do it event based, but that's probably just me:)
The advantage is that no cpu power is consumed when nothing happens...

Jean-Marie

(Posted 2009) [#3]

hmmm, none of those worked for my repaint problem. Looks anyway bad for simple repaint: I tried following:

Repeat
	WaitEvent()
	Print CurrentEvent.id
        Select CurrentEvent.id
           ...

No event id is displayed for repaint (e.g. when another window is moved over my app window)

Anotherone: EVENT_WINDOWCLOSE doesn't react when I press the window-close-cross in the window bar. Why? instead, EVENT_APPTERMINATE does.

jsp	(Posted 2009) [#4]

Quick example:
Draw something and move windows on top. Resize will clear the window.

'Source Code created on 09 Aug 2009 00:40:52 with Logic Gui Version 5.0 Build 404
'Start of external Header File
SuperStrict

Import MaxGui.Drivers

Global MouseIsDown:Int

'End of Header File



Global	Canvas1:TGadget

Local Window1:TGadget = CreateWindow("Window1",201,84,438,265,Null,WINDOW_TITLEBAR|WINDOW_RESIZABLE |WINDOW_STATUS |WINDOW_CLIENTCOORDS )
	Local BorderPanel2:TGadget = CreatePanel(2,5,356,259,Window1,PANEL_BORDER,"BorderPanel2")
		SetGadgetLayout( BorderPanel2,EDGE_ALIGNED,EDGE_ALIGNED,EDGE_ALIGNED,EDGE_ALIGNED )
		Canvas1 = CreateCanvas(0,0,352,255,BorderPanel2,Null)
			SetGadgetLayout( Canvas1,EDGE_ALIGNED,EDGE_ALIGNED,EDGE_ALIGNED,EDGE_ALIGNED )
	Local Group_Colors:TGadget = CreatePanel(362,0,73,263,Window1,PANEL_GROUP,"Colors")
		SetGadgetLayout( Group_Colors,EDGE_CENTERED,EDGE_ALIGNED,EDGE_ALIGNED,EDGE_ALIGNED )
		Local Button_Green:TGadget = CreateButton("Green",1,47,64,23,Group_Colors,BUTTON_PUSH)
			SetGadgetLayout( Button_Green,EDGE_ALIGNED,EDGE_CENTERED,EDGE_ALIGNED,EDGE_CENTERED )
			SetGadgetColor( Button_Green,128,255,0, True )
		Local Button_Blue:TGadget = CreateButton("Blue",1,24,64,23,Group_Colors,BUTTON_PUSH)
			SetGadgetLayout( Button_Blue,EDGE_ALIGNED,EDGE_CENTERED,EDGE_ALIGNED,EDGE_CENTERED )
			SetGadgetColor( Button_Blue,0,0,255, True )
		Local Button_Red:TGadget = CreateButton("Red",1,1,64,23,Group_Colors,BUTTON_PUSH)
			SetGadgetLayout( Button_Red,EDGE_ALIGNED,EDGE_CENTERED,EDGE_ALIGNED,EDGE_CENTERED )
			SetGadgetColor( Button_Red,255,0,0, True )
		Local Button_Yellow:TGadget = CreateButton("Yellow",1,70,64,23,Group_Colors,BUTTON_PUSH)
			SetGadgetLayout( Button_Yellow,EDGE_ALIGNED,EDGE_CENTERED,EDGE_ALIGNED,EDGE_CENTERED )
			SetGadgetColor( Button_Yellow,255,255,0, True )
		Local Button_Pink:TGadget = CreateButton("Pink",1,93,64,23,Group_Colors,BUTTON_PUSH)
			SetGadgetLayout( Button_Pink,EDGE_ALIGNED,EDGE_CENTERED,EDGE_ALIGNED,EDGE_CENTERED )
			SetGadgetColor( Button_Pink,255,0,255, True )
		Local Button_Clear:TGadget = CreateButton("Clear",1,218,64,23,Group_Colors,BUTTON_PUSH)
			SetGadgetLayout( Button_Clear,EDGE_CENTERED,EDGE_ALIGNED,EDGE_CENTERED,EDGE_ALIGNED )

AddHook EmitEventHook , MyHook



Repeat
	WaitEvent()
	Select EventID()
		Case EVENT_WINDOWCLOSE
			Select EventSource()
				Case Window1	Window1_WC( Window1 )
			End Select

		Case EVENT_GADGETACTION
			Select EventSource()
				Case Button_Green	Button_Green_GA( Button_Green )
				Case Button_Blue	Button_Blue_GA( Button_Blue )
				Case Button_Red	Button_Red_GA( Button_Red )
				Case Button_Yellow	Button_Yellow_GA( Button_Yellow )
				Case Button_Pink	Button_Pink_GA( Button_Pink )
				Case Button_Clear	Button_Clear_GA( Button_Clear )
			End Select

		Case EVENT_MOUSEDOWN
			Select EventSource()
				Case Canvas1	Canvas1_MD( Canvas1 , EventData() , Window1 )
			End Select

		Case EVENT_MOUSEUP
			Select EventSource()
				Case Canvas1	Canvas1_MU( Canvas1 , EventData() )
			End Select

		Case EVENT_MOUSEMOVE
			Select EventSource()
				Case Canvas1	Canvas1_MM( Canvas1 , EventX() , EventY() )
			End Select

	End Select
Forever

Function Window1_WC( Window:TGadget )
	DebugLog "Window Window1 wants to be closed"

	End
End Function

Function Button_Green_GA( Button:TGadget )
	DebugLog "Button Button_Green was pressed"
	SetColor(0,255,0)
End Function

Function Button_Blue_GA( Button:TGadget )
	DebugLog "Button Button_Blue was pressed"
	SetColor(0,0,255)
End Function

Function Button_Red_GA( Button:TGadget )
	DebugLog "Button Button_Red was pressed"
	SetColor(255,0,0)
	
End Function

Function Button_Yellow_GA( Button:TGadget )
	DebugLog "Button Button_Yellow was pressed"
	SetColor(255,255,0)
End Function

Function Button_Pink_GA( Button:TGadget )
	DebugLog "Button Button_Pink was pressed"
	SetColor(255,0,255)
End Function

Function Button_Clear_GA( Button:TGadget )
	DebugLog "Button Button_Clear was pressed"
	Redraw(True)
End Function

Function Canvas1_MD( Canvas:TGadget , MouseButton:Int , Window:TGadget=Null )
	DebugLog "Canvas Canvas1 detected Mouse Button "+ MouseButton +" pressed down"
	DrawSomething(EventX(),EventY(),3,3)
	MouseIsDown=True
End Function

Function Canvas1_MU( Canvas:TGadget , MouseButton:Int )
	DebugLog "Canvas Canvas1 detected Mouse Button "+ MouseButton +" released"
	MouseIsDown=False
End Function

Function Canvas1_MM( Canvas:TGadget , x:Int , y:Int )
	If MouseIsDown Then DrawSomething(x,y,3,3)
	
	
End Function

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

	If event=Null Return Null
	
	Select Event.ID 
		Case EVENT_WINDOWSIZE 
			Redraw(True)
	
		Case EVENT_WINDOWMOVE ,EVENT_APPRESUME ,EVENT_GADGETPAINT
			Redraw()
	End Select
	
	Return tData
End Function


Function Redraw(Clear:Int=False)
	SetGraphics CanvasGraphics ( Canvas1 )
	SetViewport 0,0,GadgetWidth( Canvas1 ),GadgetHeight( Canvas1 )
	If Clear Then Cls
	Flip
End Function

Function DrawSomething(x:Int,y:Int,w:Int,h:Int)
	DrawRect(x,y,w,h)
	Redraw()
End Function