drawfigurepanel.java

java实现的版画图程序

package drawfigure;

import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.*;

import javax.swing.JPanel;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: </p>
 * @author 孙明辉
 * @version 1.0
 */

public class DrawFigurePanel extends JPanel {
  //atribuits
  public static final int SELECT=0;
  public static final int LINE=1;
  public static final int RECTANGLE=2;
  public static final int OVAL=3;
  /**
  * 当前工具类型，它可能和当前的图形（currFigure）不一致，比如：用SELECT工具选中一个RectangleFigure
  * 那么，当前工具类型=SELECT,而当前图形=RectangleFigure
  */
  private int currToolType=-1;
  private Figure currFigure=null;
  private Figures figures=new Figures();
  
  private Point dragStartPoint, dragEndPoint; //拖放图形时的起始坐标和终止坐标
  
  public void setCurrentToolType(int type){
    currToolType=type;
  }
  public int getCurrentToolType(){
    return currToolType;
  }
  
  public void setCurrentFigure(Figure figure){
    currFigure=figure;
  }
  public Figure getCurrentFigure(){
    return currFigure;
  }
  public Figures getFigures(){
    return figures;
  }
  public void setFigures(Figures f){
    figures=f;
  }
  //public Document document;
  //methods
  public DrawFigurePanel() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }

  }
  private void jbInit() throws Exception {
    this.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
      public void mouseDragged(MouseEvent e) {
        this_mouseDragged(e);
      }
      public void mouseMoved(MouseEvent e){
      	this_mouseMoved(e);
      }
    });
    this.addMouseListener(new java.awt.event.MouseAdapter() {
      public void mouseClicked(MouseEvent e) {
        this_mouseClicked(e);
      }
      public void mousePressed(MouseEvent e) {
        this_mousePressed(e);
      }
      public void mouseReleased(MouseEvent e) {
        this_mouseReleased(e);
      }
    });
    
   ////通常按键的时候焦点在其他控件上，而不是在本Panel上，所以此代码基本没有用 
   //this_keyPressed(e)方法被frame的key事件调用才能生效
   this.addKeyListener(new KeyAdapter(){   	
	public void keyPressed(KeyEvent e){
   	  this_keyPressed(e);
   	}     
   });
   ////
  }//end jbIni()

  //鼠标单击
  void this_mouseClicked(MouseEvent e) {
  //
  }


  //拖动鼠标的时候
  void this_mouseDragged(MouseEvent e) {
    if(currFigure==null){return;}
    
    Graphics g=this.getGraphics();
    g.setXORMode(this.getBackground());
    
    //System.out.println(currFigure+"\nismoving="+currFigure.isMoving()+"@mouseDrag");
    
    //如果是选择工具
    if(currToolType==SELECT){	    	    
	    dragEndPoint=e.getPoint();		
		if(currFigure.isMoving()){//如果当前图形可以移动，说明在移动图形	      
		 	currFigure.move(g,dragEndPoint.x-dragStartPoint.x,dragEndPoint.y-dragStartPoint.y);
		}else if(currFigure.isResizing()){//如果当前图形可以变形，说明在变形
			currFigure.resize(g,dragEndPoint.x-dragStartPoint.x,dragEndPoint.y-dragStartPoint.y);
		}
		dragStartPoint=dragEndPoint;
		return;
	}else{
	    //如果是画图
	    if(currFigure.isFirstDraw()){
	      currFigure.draw(g);
	      currFigure.setFirstDraw(false);
	      if(!(currFigure instanceof SelectFigure)){figures.add(currFigure);}//在此处加进去是否合适？
	    }else{
			currFigure.draw(g);
			currFigure.setEndPoint(e.getPoint());
			currFigure.draw(g);          
	    }
	}
	//g.setPaintMode();
  }
//鼠标移动的时候
  void this_mouseMoved(MouseEvent e){
  	this.setCursor(figures.getCursor(e.getPoint()));
  	
  }


//按下鼠标的时候
  void this_mousePressed(MouseEvent e) {
  	//如此多的重复代码，有待改进===
      switch(currToolType){
        case LINE: currFigure=new LineFigure(e.getPoint());
	         currFigure.setDrawing(true);
	         //currFigure.setStartEndPoint(e.getPoint(),e.getPoint());//鼠标按下时起点=终点
	         currFigure.setFirstDraw(true);
        	 break; 
        case RECTANGLE: currFigure=new RectangleFigure(e.getPoint());
        	 currFigure.setDrawing(true);
	         //currFigure.setStartEndPoint(e.getPoint(),e.getPoint());//鼠标按下时起点=终点
	         currFigure.setFirstDraw(true);
        	 break;
        case OVAL:currFigure=new OvalFigure();
        	 currFigure.setDrawing(true);
	         currFigure.setStartEndPoint(e.getPoint(),e.getPoint());//鼠标按下时起点=终点
	         currFigure.setFirstDraw(true);
             break;
        case SELECT:
        	 Figure tmpFigure=figures.getFigureFromPoint(e.getPoint());
        	 
        	 //如果没有选中了图形，把上次选中的图形设置为未选中
        	 if(tmpFigure==null){
        	 	System.out.println("select none!:(");
        	   if((currFigure!=null)&&(currFigure.isSelected())){
        	   		currFigure.unSelected();
        	   		repaint();
        	   	}
        	 }else{
        	 	//如果选中一个图形，但是不是当前图形（上次选中的，或者上次画的），则把这次选中的设置为当前图形
        	 	if(!tmpFigure.equals(currFigure)){
        	   		currFigure.unSelected();        	   		
        	   		currFigure=tmpFigure;
        	 	}
        	 	currFigure.selected();        	 	        	    
        	 	repaint();
        	 	//如果鼠标在控制块内，则要改变图形,否则是移动图形
				ControlRect ctrl;
        	 	if((ctrl=currFigure.getControlRect(e.getPoint()))!=null){
        	 	  	currFigure.setResizing(true,ctrl.getPosition());
        	 	}else{        	 					
					currFigure.setMoving(true);
        	 	}
        	 	
        	 	dragStartPoint=e.getPoint();
        	 }//end if
        	  //end SELECT case
      	}//end switch
 }
//释放鼠标的时候
  void this_mouseReleased(MouseEvent e) {
    if(currFigure!=null){
    	currFigure.setFirstDraw(false);
    	currFigure.setDrawing(false);
    	currFigure.setMoving(false);
    	currFigure.setResizing(false);
    }    
  }

  protected void paintComponent(Graphics g) {
    /**@todo Override this javax.swing.JComponent method*/
    super.paintComponent(g);
    g.setXORMode(this.getBackground());
    if(figures!=null)
    for(int i=0;i<figures.size();i++){
      Object x=figures.get(i);
      if(x instanceof LineFigure){
        LineFigure lineFigure=(LineFigure)x;
        lineFigure.draw(g);
      }
      if(x instanceof RectangleFigure){
        RectangleFigure recFigure=(RectangleFigure)x;
        recFigure.draw(g);
      }
      if(x instanceof OvalFigure){
        OvalFigure ovalFigure=(OvalFigure)x;
        ovalFigure.draw(g);
      }
    }
    
    //System.out.println("figures number="+figures.size());
    //figures.printAllFigures();
  }
  
  public void this_keyPressed(KeyEvent e){
    if(e.getKeyCode()==KeyEvent.VK_DELETE){
      if((currFigure!=null)&&(currFigure.isSelected())){
		figures.remove(currFigure);
		repaint();	
      }      
    }
  }

}