* 鼠标绘图和键盘绘图。鼠标事件和键盘事件 * 提示： 鼠标拖动绘图，响应 mouseDragged 事件 * 方向键绘图，响应 keyPressed 事件-mouse and keyboard mapping. The mouse and keyboard events events * Tip : Drag the mouse drawings, mouseDragged response to the incident direction of bond * mapping, in