public override void Redo()
{
int swap_width = PintaCore.Workspace.ImageSize.X;
int swap_height = PintaCore.Workspace.ImageSize.Y;
PintaCore.Workspace.ImageSize = new Cairo.Point (old_width, old_height);
PintaCore.Workspace.CanvasSize = new Cairo.Point (old_width, old_height);
old_width = swap_width;
old_height = swap_height;
base.Redo ();
PintaCore.Layers.ResetSelectionPath ();
PintaCore.Workspace.Invalidate ();
}