// The App class accepts its commands via constructor-injection
public App(CircleCommand circleCommand, TriangleCommand triangleCommand, SquareCommand squareCommand, NoneCommand noneCommand)
{
_circleCommand = circleCommand;
_triangleCommand = triangleCommand;
_squareCommand = squareCommand;
_noneCommand = noneCommand;
}
private void Canvas_MouseDown(object sender, MouseEventArgs e)
{
// Each mouse down creates a new command class instance
ICommand command = null;
if (_activeShape == ShapeEnum.Square)
{
command = new SquareCommand(_bitmap, _activeColor, e.X, e.Y);
}
else if (_activeShape == ShapeEnum.Rectangle)
{
command = new RectangleCommand(_bitmap, _activeColor, e.X, e.Y);
}
command.Do();
_commandStack.Push(command);
RefreshUI();
}