drawroundal.java

用JAVA写的画图软件

// 触发面板画圆事件
package graphInterface;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class DrawRoundAL implements ActionListener {
	private JPanel sourcePanel;

	private JPanel infoPanel;

	public DrawRoundAL(JPanel sp, JPanel ip) {
		sourcePanel = sp;
		infoPanel = ip;
	}

	public void actionPerformed(ActionEvent ae) {
		Graphics infoGra = infoPanel.getGraphics();
		// 清除信息面板内容
		infoGra.fillRect(0, 0, 1000, 1000);
		// 提供画圆方法提示信息
		infoGra.setColor(Color.magenta);
		infoGra.drawString("拖拽鼠标即可画圆", 12, 202);
		// 清除原先的鼠标监听
		MouseListener[] al = sourcePanel.getMouseListeners();
		for (int i = 0; i < al.length; ++i) {
			sourcePanel.removeMouseListener(sourcePanel.getMouseListeners()[i]);
			sourcePanel.removeMouseMotionListener(sourcePanel
					.getMouseMotionListeners()[i]);
		}
		// 建立新的鼠标监听
		sourcePanel.addMouseListener(new DrawRoundML(sourcePanel, infoPanel));
		sourcePanel.addMouseMotionListener(new DrawRoundML(sourcePanel,
				infoPanel));
	}
}