GUI.SetXORPart of GUI module

Syntax   GUI.SetXOR (widgetID : int, xor : boolean)

Description   Sets the "xor mode" of the canvas specified by widgetID. If the xor parmeter is set to true, the canvas is set to xor mode. When in xor mode, all the Draw... procedures of a canvas are treated as if the View.Set ("xor") statement had been executed before the Draw procedure.

Example   See GUI.SetDisplayWhenCreated for an example of GUI.Show.

        import GUI in "%oot/lib/GUI"
        View.Set ("graphics:400;300")
        var canvas1, label1, canvas2, label2 : int
        canvas1 := GUI.CreateCanvas (10, 20, maxx div 2  20, maxy  30)
        label1 := GUI.CreateLabelFull (10, 2, "XOR", maxx div 2  20, 0,
            GUI.CENTER, 0)
        canvas2 := GUI.CreateCanvas (maxx div 2 + 10, 20, 
            maxx div 2  20, maxy  30)
        label2 := GUI.CreateLabelFull (maxx div 2 + 10, 2, "Normal", 
            maxx div 2  20, 0, GUI.CENTER, 0)
        
        GUI.SetXOR (canvas1, true)
        for i : 1 .. 20
            var x : int := Rand.Int (0, maxx div 2  20)
            var y : int := Rand.Int (0, maxy  20)
            var c : int := Rand.Int (1, 15)
            GUI.DrawFillStar (canvas1, x  20, y  20, x + 20, y + 20, c)
        end for
        
        GUI.SetXOR (canvas2, false)
        for i : 1 .. 20
            var x : int := Rand.Int (0, maxx div 2  20)
            var y : int := Rand.Int (0, maxy  20)
            var c : int := Rand.Int (1, 15)
            GUI.DrawFillStar (canvas2, x  20, y  20, x + 20, y + 20, c)
        end for
Status   Exported qualified.

This means that you can only call the function by calling GUI.SetXOR, not by calling SetXOR.

See also   GUI.CreateCanvas.