Swing中按ctrl键同时移动鼠标拖动组件（类中多借口共享同一数据）_JAVA_编程开发_程序员俱乐部

? ? ? ? 都知道java中类只能单继承，但可以实现多个接口，但我发现实现多个接口之后，多个接口却不能共享同一个数据，应用开发中想实现：当用户按着ctrl键时，可以用鼠标点击拖动组件，比如说文本框。

编写一个监听实现KeyListener,NouseListener,MouseMotionListener三个接口，重写方法。定义一个全局变量boolean ctrlPressed;

@Override

public void keyPressed(KeyEvent e) {

if(e.getModifiers()==InputEvent.CTRL_MASK)

? {

? ctrlPressed=true;

? System.out.println("ctrl is pressed");

? }

}class="Apple-tab-span" style="white-space: pre;">@Override

public void keyReleased(KeyEvent e) {

ctrlPressed=false;

System.out.println("ctrl release");

}

用户在按下ctrl的时候为true,在MouseMotionListener接口的方法中判断ctrlPressed是否为真。

public void mouseDragged(MouseEvent e) {

if(ctrlPressed)

{

...........//实现拖动

}

}

这么写也不会报错，结果呢，mouseDragged方法中ctrlPressed却一直是false,按照逻辑来说用户按着ctrl,在keyPressed已经更改了ctrlPressed=true了呀！所以咯，不同的接口的方法是不能共用同一个变量的，全局变量，ctrlPressed,在不同的监听域中创建了不同的存储单元，也可以说是私有化了!我的解决办法是，创建一个类SharedData,创建静态变量ctrlPressed,而在keyPressed,和MouseDagged方法中都是用这个静态变量就能共用了！但是由于静态变量很多地方都是用，所以在特殊的地方需要恢复初始化，不然很容易出现问题。下面是我的具体实现代码，这个监听类，这个类可以实现选中组件中间移动组件，四周放大缩小组件，用的时候只需要添加监听即可，三个都要加哦

diamend.addMouseMotionListener(new PainRectListener(mJFrame,diamend));

diamend.addMouseListener(new PainRectListener(mJFrame,diamend));

diamend.addKeyListener(new PainRectListener(mJFrame,diamend));

package com.msi.frame;

import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextPane;
import javax.swing.KeyStroke;
/**
 * 組件拖動事件的監聽，任意組件都可以使用這個方法
 * @author sharkliu
 *
 */
public class PainRectListener implements KeyListener,MouseListener,MouseMotionListener{
	private JFrame mJFrame;
	private JTextPane panel;
	//private boolean ctrlPressed=false;
    public PainRectListener(JFrame mJFrame,JTextPane panel)
    {
    	this.mJFrame=mJFrame;
    	this.panel=panel;
    }
    
    /**当前是否操作图片**/
  	private boolean isContains(Point point){
  		Rectangle rectangle = new Rectangle();
  		rectangle.x=0;
  		rectangle.y = 0;
  		rectangle.width = ShareData.componentSize[0];
  		rectangle.height = ShareData.componentSize[1];
  		return rectangle.contains(point);
  	}
  	
  	/**得到是否是点击的4个边中的1个(0,1,2,3,4)**/
  	private int getPressSide(Point point){
  		int side = 0;
  		Rectangle rectTop = new Rectangle(0,0,ShareData.componentSize[0],8);
  		Rectangle rectBottom = new Rectangle(0,ShareData.componentSize[1]-8,ShareData.componentSize[0],8);
  		Rectangle rectLeft =  new Rectangle(0,8,8,ShareData.componentSize[1]-8); 
  		Rectangle rectRight = new Rectangle(ShareData.componentSize[0]-8,8,8,ShareData.componentSize[1]-8);
  		if(rectTop.contains(point)){
  			return 1;		//上
  		}else if(rectBottom.contains(point)){
  			System.out.println("下");
  			return 2;		//下
  		}else if(rectLeft.contains(point)){
  			System.out.println("左");
  			return 3; 		//左
  		}else if(rectRight.contains(point)){
  			System.out.println("右");
  			return 4;		//右
  		}
  		return side;		//中间
  	}
  	public void mouseDragged(MouseEvent e) {
  		System.out.println(ctrlPressed);
				if(ShareData.isPressComponent&&ShareData.ctrlPressed){
					System.out.println("mouseDragged ininin");
					Point nowPoint = e.getPoint();		//当前鼠标拖拽到的鼠标位置
					int diffX = nowPoint.x - ShareData.pressPoint.x;
					int diffY = nowPoint.y - ShareData.pressPoint.y;
					/**移动**/
					if(ShareData.moveSide == 0){	
						ShareData.componentPoint.x += diffX;
						ShareData.componentPoint.y += diffY;
					}
					/**收缩**/
					else{
						//收缩 下和右时
						if(ShareData.moveSide == 2 || ShareData.moveSide == 4){
							if(ShareData.moveSide == 2)			//拉下（只能拉长拉短）
								ShareData.componentSize[1] += diffY; 
							else						//拉右（只能拉宽拉窄）
								ShareData.componentSize[0] += diffX;
							
						}
						//收缩 上和左时
						else if(ShareData.moveSide == 1 || ShareData.moveSide == 3){
							if(ShareData.moveSide == 1){			//拉上边（只能拉长拉短）
								ShareData.componentPoint.y += diffY;
								ShareData.componentSize[1] -= diffY;
							}else{						//拉左边（只能拉宽拉窄）
								ShareData.componentPoint.x += diffX;
								ShareData.componentSize[0] -= diffX;
							}
							
						}
						        ShareData.pressPoint = nowPoint;
					}
					//拖動組件改變組件的的寬不能超出黑框區域，以及防止拖動時把組件給拖沒了當size小於0組件無法匯出，便消失了
					if( (ShareData.componentSize[0]>=20)&&(ShareData.componentSize[1]>=20))
					{
						System.out.println("e"+e.getComponent());
						
						
						
						panel.setBounds(ShareData.componentPoint.x, ShareData.componentPoint.y, ShareData.componentSize[0], ShareData.componentSize[1]);
						panel.setPreferredSize(new Dimension(ShareData.componentSize[0],ShareData.componentSize[1]));
						panel.setSize(ShareData.componentSize[0], ShareData.componentSize[1]);
						
						mJFrame.validate();// 重构内容面板  
  				 	    mJFrame.repaint();// 重绘内容面板 
						
				}
				}
	}
	private void paintRect(Graphics graphics) {
		graphics.drawLine(1, ShareData.componentSize[1]/2-1, ShareData.componentSize[0]/2-1, 1);
		graphics.drawLine(ShareData.componentSize[0]/2-1,2, ShareData.componentSize[0]-1, ShareData.componentSize[1]/2-1);
		graphics.drawLine(ShareData.componentSize[0]-1, ShareData.componentSize[1]/2-1, ShareData.componentSize[0]/2-1, ShareData.componentSize[1]-1);
		graphics.drawLine(ShareData.componentSize[0]/2-1, ShareData.componentSize[1]-1, 1, ShareData.componentSize[1]/2-1);
	}

	public void mouseMoved(MouseEvent e) {
		
        Rectangle rectTop = new Rectangle(0,0,ShareData.componentSize[0],8);
 		
 		Rectangle rectBottom = new Rectangle(0,ShareData.componentSize[1]-8,ShareData.componentSize[0],8);
 		
 		Rectangle rectLeft =  new Rectangle(0,8,8,ShareData.componentSize[1]-8);
 		
 		Rectangle rectRight = new Rectangle(ShareData.componentSize[0]-8,8,8,ShareData.componentSize[1]-8);
 			
 					if(rectTop.contains(e.getPoint())){
 			 			e.getComponent().setCursor(new Cursor(Cursor.N_RESIZE_CURSOR));
 			 		}else if(rectBottom.contains(e.getPoint())){
 			 			System.out.println("下");
 			 			e.getComponent().setCursor(new Cursor(Cursor.S_RESIZE_CURSOR));
 			 		}else if(rectLeft.contains(e.getPoint())){
 			 			e.getComponent().setCursor(new Cursor(Cursor.W_RESIZE_CURSOR));
 			 		}else if(rectRight.contains(e.getPoint())){
 			 			e.getComponent().setCursor(new Cursor(Cursor.E_RESIZE_CURSOR));
 			 		} 	
 			 		else{
 					e.getComponent().setCursor(new Cursor(Cursor.MOVE_CURSOR));
 			 		}
 			
	}
	public void mouseClicked(MouseEvent e) {	
	}

	/**把組件所占的矩阵用变量表示出来(便于判断是否操作图片)**/
	/**
	 * 
	 * 跟新初始化數
	 * */
	public void mousePressed(MouseEvent e) {
                ShareData.ctrlPressed=false;
		ShareData.componentPoint=e.getComponent().getLocation();
		ShareData.componentSize[0]=e.getComponent().getSize().width;
		ShareData.componentSize[1]=e.getComponent().getSize().height;
		//這是爲了區分對待圖片和文本，圖片隨時可以拖動，不受管控
				if(isContains(new Point(e.getPoint().x, e.getPoint().y))){
					ShareData.moveSide = getPressSide(new Point(e.getPoint().x, e.getPoint().y));		//记录操作图片的边
					ShareData.isPressComponent = true;
					ShareData.pressPoint = e.getPoint();
				}else{
					ShareData.isPressComponent = false;
				}
		}
	public void mouseReleased(MouseEvent e) {
		ShareData.isPressComponent = false;
		ShareData.pressPoint = null;
	}
	public void mouseEntered(MouseEvent e) {}
	 public void mouseExited(MouseEvent e) {}

	@Override
	public void keyTyped(KeyEvent e) {}

	@Override
	public void keyPressed(KeyEvent e) {
		if(e.getModifiers()==InputEvent.CTRL_MASK)
  		{
  			ShareData.ctrlPressed=true;
  			System.out.println("ctrl is pressed");
  		}
	}

	@Override
	public void keyReleased(KeyEvent e) {
		ShareData.ctrlPressed=false;
		System.out.println("ctrl release");
	}
	}	   

?

package com.msi.frame;

import java.awt.Component;
import java.awt.Point;

import javax.swing.JComponent;

/**
 * 名字為共享數據，專門記錄工具欄點擊了那些屬性，
 * 在版面繪製的時候，可先查看這個類中有哪些動作
 * @author sharkliu
 *
 */
public class ShareData {
public static int textFont=12;
public static int textStyle;

public static boolean dragable=false;//可拖動
public static boolean editable=true;//可編輯
public static Component selectCompoment=null;
public static int layer=1000;//

/*
 * 控制組件移動、變形等需要共用到的數據
 */
public static int[]componentSize=new int[]{1,1};//組件大小
public static boolean isPressComponent=false;		//是否操作組件、圖片或者文本框

public static int moveSide=0;		//拉升的边(0:移动 1:上 2：下 3：左 4：右)

public static Point componentPoint;		//組件（圖片或者文本框）位置

public static Point pressPoint;		//press組件时的鼠标位置
//控制文字樣式的按鈕背景變換
public static boolean isBorder=false;
public static boolean isItalic=false;
public static boolean isUnderline=false;
public static String CMD="";
public static boolean ctrlPressed=false;
	
}

?