drawplat.java

用JAVA实现。一个简单的画图软件。可以进行简单的操作。还可以实现简单的图形绘画。如三角形等。

		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			for(int j = 3; j < choices.length; j++) {
				if(e.getSource() == choices[j]) {
					currentChoice = j;
					createNewItem();
					repaint();
				}
			}
		}
		
		
	}
	
	
//按钮侦听器ButtonHandler1类，用来侦听颜色选择，画笔粗细设置，文字输入按钮的操作
	public class ButtonHandler1 implements ActionListener {

		@Override
		public void actionPerformed(ActionEvent e) {
			// TODO Auto-generated method stub
			if(e.getSource() == choices[choices.length-2]) 
				{
				System.out.println("chooseColor");
				chooseColor();}
			if(e.getSource() == choices[choices.length-1])
				{
				System.out.println("stroke");
				setStroke();}

		}
		
	}
	

	 
	 
	 
	 


//新建一个画图基本单元对象的程序段
	void createNewItem() {
		if(currentChoice == 14) // 进行相应的游标设置
			drawingArea.setCursor(Cursor.getPredefinedCursor(Cursor.TEXT_CURSOR));
		else
			drawingArea.setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
		
		switch(currentChoice) {
			case 3:
				itemList[index] = new Pencil();
				break;
			case 4:
				itemList[index] = new Line();
				break;
			case 5:
				itemList[index] = new Rect();
				break;
			case 6:
				itemList[index] = new fillRect();
				break;
			case 7:
				itemList[index] = new Oval();
				break;
			case 8:
				itemList[index] = new fillOval();
				break;
			case 9:
				itemList[index] = new Circle();
				break;
			case 10:
				itemList[index] = new fillCircle();
				break;
			case 11:
				itemList[index] = new RoundRect();
				break;
			case 12:
				itemList[index] = new fillRoundRect();
				break;
			case 13:
				itemList[index] = new Rubber();
				break;


								
		}
		itemList[index].type = currentChoice;
		itemList[index].R = R;
		itemList[index].G = G;
		itemList[index].B = B;
		itemList[index].stroke = stroke;
		
	}//createNewItem()
	

//选择当前颜色程序段
	public void chooseColor() {
		color = JColorChooser.showDialog(DrawPlat.this, "Choose a Color", color);
		R = color.getRed();
		G = color.getGreen();
		B = color.getBlue();
		itemList[index].R = R;
		itemList[index].G = G;
		itemList[index].B = B;
	} //chooseColor
	
//选择当前线条粗细程度段
	public void setStroke() {
		String input;
		input = JOptionPane.showInputDialog(
				"Please input a float stroke value!( > 0 )"		
			);
		stroke = Float.parseFloat(input);
		itemList[index].stroke = stroke;
	}
	
	
//保存图形文件程序段，saveFile（）函数通过建立类FileOutputStream对象保存文件
	public void saveFile() {
		JFileChooser fileChooser = new JFileChooser();
		fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
		int result = fileChooser.showSaveDialog(this);
		if(result == JFileChooser.CANCEL_OPTION)
			return;
		File fileName = fileChooser.getSelectedFile();
		fileName.canWrite();
		
		if(fileName == null || fileName.getName().equals(""))
			JOptionPane.showMessageDialog(fileChooser,
					"Invalid File Name",
					"Invalid File Name",
					JOptionPane.ERROR_MESSAGE);
		else {
			
			try{
				fileName.delete();
				FileOutputStream fos = new FileOutputStream(fileName);
				
				output = new ObjectOutputStream(fos);
				drawings record;
				
				
				output.writeInt(itemList.length);
				
				for(int i = 0; i < itemList.length; i++ ) {
					record = itemList[i];
					output.writeObject(record);
					output.flush(); //将所有图形信息强制转换成父类线性化存储到文件中
				}//for
				output.close();
				fos.close();
				
			} catch(IOException ioe) {
				ioe.printStackTrace();
				
			} //catch
			
			
		} // else
		
	} //saveFile()
	
	
//打开一个图形文件程序段，loadFile函数通过建立FileInputStream对象读入文件
	public void loadFile() {
		
		JFileChooser fileChooser = new JFileChooser();
		fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
		int result = fileChooser.showOpenDialog(this);
		if(result == JFileChooser.CANCEL_OPTION)
			return;
		File fileName = fileChooser.getSelectedFile();
		fileName.canRead();
		if(fileName == null || fileName.getName().equals(""))
			JOptionPane.showMessageDialog(fileChooser,
					"Invalid File Name",
					"Invalid File Name",
					JOptionPane.ERROR_MESSAGE);
		else{
			try{
				FileInputStream fis = new FileInputStream(fileName);
				input = new ObjectInputStream(fis);
				drawings inputRecord;
				int countNumber = 0;
				countNumber = input.readInt();
				for(index = 0 ; index < countNumber ; index++ ){
					inputRecord = (drawings)input.readObject();
					itemList[index] = inputRecord;
				}//for
//				createNewItem();
				input.close();
				repaint();
			}catch(EOFException endofFileException) {
				JOptionPane.showMessageDialog(this,
						"no more record in file",
						"class not found",
						JOptionPane.ERROR_MESSAGE);
			} //catch endofFileException
			catch(ClassNotFoundException classNotFoundException) {
				JOptionPane.showMessageDialog(this,
						"Unable to Create Object",
						"End of file",
						JOptionPane.ERROR_MESSAGE);
			} //catch classNotFoundException
			catch(IOException ioException) {
				JOptionPane.showMessageDialog(this,
						"error during read from file",
						"read Error",
						JOptionPane.ERROR_MESSAGE);
			} 
			
			
		} 
		
		
	}//loadFile
	
	
//新建一个文件程序段
	public void newFile() {
		index = 0;
		currentChoice = 3 ;
		color = Color.black;
		stroke = 1.0f;
		createNewItem();
		repaint(); //将有关值设置为初始状态，并且重画
	}
	


	public void update(Graphics g) {
     	
		if(offScreenImage == null ) {
     		offScreenImage = this.createImage(width , height);
     	}
		
     	Graphics gOffScreen = offScreenImage.getGraphics();  //虚拟背景画的画笔
     	Color c = gOffScreen.getColor();
    	gOffScreen.setColor(Color.white);
     	gOffScreen.fillRect(0, 100,width , height);
     	gOffScreen.setColor(c);
       	paint(gOffScreen);
		g.drawImage(offScreenImage, 0, 0, null);
     	
	}	

	
/*

	public void repaint() {
	
		Graphics2D g2d = (Graphics2D)this.getGraphics(); 
		g2d.setColor(Color.white);
		g2d.drawRect(0, 100, width, height);
		int j = 0;
		int i = 0;
		if(itemList.length >= 0 )
			while(j < itemList.length-1) {
				if( j ==  records[i]) {
					itemList[records[i]].draw(g2d);
					i++;
					j++;
					continue;
				}


				itemList[j].draw(g2d);
				j++;
			


			}
		


	}//repaint
	*/



	public void paint(Graphics g) {

Graphics2D g2d = (Graphics2D)g; //定义画笔
		g2d.setBackground(Color.white);
		g2d.setColor(Color.white);
		g2d.drawRect(0, 100, width, height);
		int j = 0;
		int i = 0;
		if(itemList.length >= 0 )
			while(j < itemList.length-1) {
				if(records.length >= 0) {
					itemList[records[i]].draw(g2d);
					i++;
					j++;
					continue;
				}
				
			}
	}


	//主程序段
	public static void main(String[] args) {
		try{
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		
			DrawPlat newPad = new DrawPlat(); //创建MiniDrawPad实例
		newPad.addWindowListener(
				new WindowAdapter() {			
					public void windowClosing(WindowEvent e) {
					
						System.exit(0);
					}
					
				} 
			);
		} catch(Exception e) {
			e.printStackTrace();
		}
		
	} 
	
} //DrawPlat