outermonitor.java

来自「由浅入深的介绍JAVAse的基本编程思想」· Java 代码 · 共 62 行

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

public class OuterMonitor extends MouseMotionAdapter implements ActionListener{
	private TextArea msgBoard;
	private Button[] buttons;
	private String clipBoard = "";
	
	public OuterMonitor(TextArea msgBoard,Button[] buttons){
		this.msgBoard = msgBoard;
		this.buttons = buttons;	
	}	
	public void setClipBoard(String text){
		this.clipBoard = text;	
	}
	public String getClipBoard(){
		return this.clipBoard;	
	}	
	@Override
	public void actionPerformed(ActionEvent e){
		int positon = msgBoard.getSelectionStart();
		String s = e.getActionCommand();
		if(s.equals("RESET")){
			msgBoard.setText("");
		}else if(s.equals("SUBMIT") ){
			System.out.println("你的留言为：\n  " + msgBoard.getText());	
		}else if(s.equals("COPY")){
			clipBoard = msgBoard.getSelectedText();
			msgBoard.setSelectionStart(msgBoard.getSelectionEnd());
		}else if(s.equals("CUT")){
			clipBoard = msgBoard.getSelectedText();
			this.delete();
		}else if(s.equals("PASTE")){
			//msgBoard.insert(clipBoard,msgBoard.getCaretPosition());			
			String content = msgBoard.getText();
			String alter = content.substring(0,positon) + clipBoard + content.substring(positon);
			msgBoard.setText(alter);
		}else if(s.equals("DELETE")){
			this.delete();	
		}	
		this.switchButtons();
	}	
	public void delete(){
			int start = msgBoard.getSelectionStart();
			int end = msgBoard.getSelectionEnd();
			String content = msgBoard.getText();
			String alter = content.substring(0,start) + content.substring(end);
			msgBoard.setText(alter); 	
	}
	public void switchButtons(){
		boolean clipped = (clipBoard!=null) && (clipBoard.length()>0);
		buttons[2].setEnabled(clipped);
		boolean selected = msgBoard.getSelectionEnd() != msgBoard.getSelectionStart();	
		buttons[0].setEnabled(selected);	
		buttons[1].setEnabled(selected);	
		buttons[3].setEnabled(selected);	
	}
	@Override
	public void mouseDragged(MouseEvent te){
		this.switchButtons();	
	}	
}