[Lazarus] Paintbox complete redraw

[Howard Page-Clark]

Benito van der Zander wrote:

> So how can you redraw the paintbox complete in OnPaint?

This is a hack, so I hope another may show you how to do it properly.

Add a boolean flag to your form class thus:

type
  TForm1 = class( TForm )
    ...
    private
    FOnPaintCalled: boolean;
    ...
end;

and a Formcreate event handler to initialise FOnPaintCalled:

PROCEDURE Tform1 .Formcreate ( Sender : Tobject ) ;
BEGIN
  inherited;
  FOnPaintCalled := false;
End; 

and write the OnPaint handler as follows:

PROCEDURE Tform1 .Paintbox1paint ( Sender : Tobject ) ;
BEGIN
  PaintBox1.Canvas.brush.Color:=rgb( random(255), random(255), random(255) );
  PaintBox1.Canvas.Rectangle(0, 0, 100, 100);
  if not FOnPaintCalled then Paintbox1.Invalidate;
  FOnPaintCalled := not FOnPaintCalled;
End;

Regards

Howard