Windows / GUI Functionality in Blitz+

I'd say that the code could be organised somewhat better ..

Anyway.. try to study this map-editor example below.. I think I broke my record in fast-map-editor-coding :)

It doesn't save the maps, but that's easy to implement..

; miniminiminiminiminiminiminiminiminiminiminiminiminiminimap-editor - by CS^TBL
app=CreateWindow("blah",0,0,640,480)

Global c1=CreateCanvas(8,8,32,256,app)
Global c2=CreateCanvas(56,8,512,256,app)
Global img,currentpalette=0,maplmd=False

Dim map(32,16)

loadimg=CreateButton("IMG",8,8+256+4,32,24,app)

UpdatePalette(True)

quit=False
;------------------------------------------------------------------------
Repeat
	WaitEvent()
	If EventID()=$803 quit=True ; window-close / alt-f4
	


	If EventID()=$401 ; generic gadget action.. like a buttonpress
	
		If EventSource()=loadimg
			; request a file
			whichfile$=RequestFile$("load image..","jpg")
			
			If whichfile$<>"" ; did we succeed?
				If img FreeImage img ; first get rid of the old image
				img=LoadImage(whichfile$)
				UpdatePalette(True)
			EndIf
			
		EndIf
	EndIf
	
	If EventSource()=c1 ; the palette? ------------------------------------------------

		If EventID()=$203 ; mousemove
			x=EventX()/16
			y=EventY()/16
			
			UpdatePalette(False)
				Color 255,255,255:Rect x*16,y*16,16,16,False
				Color 0,0,0:Rect 1+x*16,1+y*16,14,14,False
			FlipCanvas c1
		EndIf

		If EventID()=$206 ; mouseleave
			UpdatePalette(True)
		EndIf

		If EventID()=$201 ; mouseclick
			x=EventX()/16
			y=EventY()/16
			currentpalette=(x Mod 2)+y*2
			UpdatePalette(True)
		EndIf

	EndIf



	If EventSource()=c2 ; the map? ------------------------------------------------

		If EventID()=$203 ; mousemove
			x=EventX()/16
			y=EventY()/16
			UpdateMap(False)
				Color 255,255,255:Rect x*16,y*16,16,16,False
				Color 0,0,0:Rect 1+x*16,1+y*16,14,14,False
			FlipCanvas c2
		EndIf

		If EventID()=$206 ; mouseleave
			UpdateMap(True)
		EndIf

		If EventID()=$201 ; mouseclick
			maplmd=True
		EndIf

		If EventID()=$202 ; mouseclick
			maplmd=False
		EndIf
		
		If maplmd
			x=EventX()/16
			y=EventY()/16
			
			If x<0 x=0  ; make sure you clip! otherwise you'll get errors!
			If y<0 y=0
			If x>31 x=31
			If y>15 y=15
			
			map(x,y)=currentpalette
		
			UpdateMap(False)
			Color 255,255,255:Rect x*16,y*16,16,16,False
			Color 0,0,0:Rect 1+x*16,1+y*16,14,14,False
			FlipCanvas c2

		EndIf

	EndIf



Until quit

FreeImage img

End

;------------------------------------------------------------------------
Function UpdatePalette(swap)

	SetBuffer CanvasBuffer(c1)
		Cls
		If img DrawBlock img,0,0
		
		x=currentpalette Mod 2
		y=currentpalette /2
		
		Color 255,255,255:Rect x*16,y*16,16,16,False
		Color 0,0,0:Rect 1+x*16,1+y*16,14,14,False
		
	If swap FlipCanvas c1

End Function

;------------------------------------------------------------------------
Function UpdateMap(swap)

	SetBuffer CanvasBuffer(c2)
		Cls

		For y=0 To 15
			For x=0 To 31
			
				tile=map(x,y)
				px=tile Mod 2
				py=tile / 2
				
				If img DrawBlockRect img,x*16,y*16,px*16,py*16,16,16
				
			Next
		Next

	If swap FlipCanvas c2

End Function