private void btnTool_Click(object sender, EventArgs e)
        {
            Button button = sender as Button;

            ToolType             = button?.Text;
            sizeTrackBar.Enabled = true;
            ToolAction?.Invoke();
        }
        private void btnBrush_Click(object sender, EventArgs e)
        {
            Button button = sender as Button;

            BrushType            = button?.Name;
            sizeTrackBar.Enabled = false;
            BrushAction?.Invoke();
            ToolAction?.Invoke();
        }