JAVA画图板
import java.awt.BasicStroke; import java.awt.BorderLayout; import java.awt.Button; import java.awt.Color; import java.awt.Cursor; import java.awt.Dimension; import java.awt.Frame; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.Label; import java.awt.Panel; import java.awt.RenderingHints; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.image.BufferedImage; /** * 简单画图板程序 * * @author 何青松 * @version 1.0 */ public class UI extends Frame { // 画板 private Palette palette = null; // 显示当前颜色的面板 private Panel nonceColor = null; // 画笔粗细 private Label drawWidth = null; // 画笔端点的装饰 private Label drawCap = null; // 选取颜色按钮的监听事件类 private ButtonColorAction buttonColorAction = null; // 鼠标进入按钮后光标样式的监听事件类 private ButtonCursor buttonCursor = null; // 画笔样式的监听事件 private ButtonStrokeAction buttonStrokeAction = null; /** * 构造方法 * */ public UI() { // 设置标题栏文字 super("画图板"); // 构造一个画图板 palette = new Palette(); Panel pane = new Panel(new GridLayout(2, 1)); // 画笔颜色选择器 Panel paneColor = new Panel(new GridLayout(1, 13)); // 12 个颜色选择按钮 Button [] buttonColor = new Button[12]; Color [] color = {Color.black, Color.blue, Color.cyan, Color.darkGray, Color.gray, Color.green, Color.magenta, Color.orange, Color.pink, Color.red, Color.white, Color.yellow}; // 显示当前颜色的面板 nonceColor = new Panel(); nonceColor.setBackground(Color.black); paneColor.add(nonceColor); buttonColorAction = new ButtonColorAction(); buttonCursor = new ButtonCursor(); for(int i = 0; i < buttonColor.length; i++){ buttonColor[i] = new Button(); buttonColor[i].setBackground(color[i]); buttonColor[i].addActionListener(buttonColorAction); buttonColor[i].addMouseListener(buttonCursor); paneColor.add(buttonColor[i]); } pane.add(paneColor); // 画笔颜色选择器 Panel paneStroke = new Panel(new GridLayout(1, 13)); // 控制画笔样式 buttonStrokeAction = new ButtonStrokeAction(); Button [] buttonStroke = new Button[11]; buttonStroke[0] = new Button("1"); buttonStroke[1] = new Button("3"); buttonStroke[2] = new Button("5"); buttonStroke[3] = new Button("7"); buttonStroke[4] = new Button("9"); buttonStroke[5] = new Button("11"); buttonStroke[6] = new Button("13"); buttonStroke[7] = new Button("15"); buttonStroke[8] = new Button("17"); buttonStroke[9] = new Button("■"); buttonStroke[10] = new Button("●"); drawWidth = new Label("3", Label.CENTER); drawCap = new Label("●", Label.CENTER); drawWidth.setBackground(Color.lightGray); drawCap.setBackground(Color.lightGray); paneStroke.add(drawWidth); for(int i = 0; i < buttonStroke.length; i++){ paneStroke.add(buttonStroke[i]); buttonStroke[i].addMouseListener(buttonCursor); buttonStroke[i].addActionListener(buttonStrokeAction); if(i <= 8){ buttonStroke[i].setName("width"); }else{ buttonStroke[i].setName("cap"); } if(i == 8){ paneStroke.add(drawCap); } } pane.add(paneStroke); // 将画笔颜色选择器添加到窗体中 this.add(pane, BorderLayout.NORTH); // 将画图板添加到窗体中 this.add(palette); // 添加窗口监听，点击关闭按钮时退出程序 this.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); // 设置窗体 ICON 图标 this.setIconImage(Toolkit.getDefaultToolkit().createImage("images/palette.png")); // 设置窗口的大小 this.setSize(new Dimension(400, 430)); // 设置窗口位置，处于屏幕正中央 this.setLocationRelativeTo(null); // 显示窗口 this.setVisible(true); } /** * 程序入口 * * @param args * 字符串数组参数 */ public static void main(String[] args) { new UI(); } /** * 选取颜色按钮的监听事件类 * @author 何青松 * */ class ButtonColorAction implements ActionListener { public void actionPerformed(ActionEvent e) { Color color_temp = ((Button)e.getSource()).getBackground(); nonceColor.setBackground(color_temp); palette.setColor(color_temp); } } /** * 鼠标进入按钮变换光标样式监听事件类 * @author 何青松 * */ class ButtonCursor extends MouseAdapter { public void mouseEntered(MouseEvent e) { ((Button)e.getSource()).setCursor(new Cursor(Cursor.HAND_CURSOR)); } public void mouseExited(MouseEvent e) { ((Button)e.getSource()).setCursor(new Cursor(Cursor.DEFAULT_CURSOR)); } } /** * 设置画笔的监听事件类 * @author 何青松 * */ class ButtonStrokeAction implements ActionListener { public void actionPerformed(ActionEvent e) { Button button_temp = (Button) e.getSource(); String name = button_temp.getName(); if(name.equalsIgnoreCase("width")){ drawWidth.setText(button_temp.getLabel()); palette.setStroke(Float.parseFloat(button_temp.getLabel())); }else if(name.equalsIgnoreCase("cap")){ drawCap.setText(button_temp.getLabel()); if(button_temp.getLabel().equals("■")){ palette.setStroke(BasicStroke.CAP_SQUARE); }else if(button_temp.getLabel().equals("●")){ palette.setStroke(BasicStroke.CAP_ROUND); } } } } } /** * 画板类 * * @author 何青松 * */ class Palette extends Panel implements MouseListener, MouseMotionListener { // 鼠标 X 坐标的位置 private int mouseX = 0; // 上一次 X 坐标位置 private int oldMouseX = 0; // 鼠标 Y 坐标的位置 private int mouseY = 0; // 上一次 Y 坐标位置 private int oldMouseY = 0; // 画图颜色 private Color color = null; // 画笔样式 private BasicStroke stroke = null; // 缓存图形 private BufferedImage image = null; /** * 构造一个画板类 * */ public Palette() { this.addMouseListener(this); this.addMouseMotionListener(this); // 默认黑色画笔 color = new Color(0, 0, 0); // 设置默认画笔样式 stroke = new BasicStroke(3.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND); // 建立 1280 * 1024 的 RGB 缓存图象 image = new BufferedImage(1280, 1024, BufferedImage.TYPE_INT_RGB); // 设置颜色 image.getGraphics().setColor(Color.white); // 画背景 image.getGraphics().fillRect(0, 0, 1280, 1024); } /** * 重写 paint 绘图方法 */ public void paint(Graphics g) { super.paint(g); // 转换为 Graphics2D Graphics2D g2d = (Graphics2D) g; // 获取缓存图形 Graphics2D Graphics2D bg = image.createGraphics(); // 图形抗锯齿 bg.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); // 设置绘图颜色 bg.setColor(color); // 设置画笔样式 bg.setStroke(stroke); // 画线，从上一个点到新的点 bg.drawLine(oldMouseX, oldMouseY, mouseX, mouseY); // 将缓存中的图形画到画板上 g2d.drawImage(image, 0, 0, this); } /** * 重写 update 方法 */ public void update(Graphics g) { this.paint(g); } /** * @return stroke */ public BasicStroke getStroke() { return stroke; } /** * @param stroke 要设置的 stroke */ public void setStroke(BasicStroke stroke) { this.stroke = stroke; } /** * 设置画笔粗细 * @param width */ public void setStroke(float width) { this.stroke = new BasicStroke(width, stroke.getEndCap(), stroke.getLineJoin()); } /** * 设置画笔端点的装饰 * @param cap 参考 java.awt.BasicStroke 类静态字段 */ public void setStroke(int cap) { this.stroke = new BasicStroke(stroke.getLineWidth(), cap, stroke.getLineJoin()); } /** * @return color */ public Color getColor() { return color; } /** * @param color 要设置的 color */ public void setColor(Color color) { this.color = color; } public void mouseClicked(MouseEvent mouseEvent) { } /** * 鼠标按下 */ public void mousePressed(MouseEvent mouseEvent) { this.oldMouseX = this.mouseX = mouseEvent.getX(); this.oldMouseY = this.mouseY = mouseEvent.getY(); repaint(); } public void mouseReleased(MouseEvent mouseEvent) { } /** * 鼠标进入棋盘 */ public void mouseEntered(MouseEvent mouseEvent) { this.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR)); } /** * 鼠标退出棋盘 */ public void mouseExited(MouseEvent mouseEvent) { this.setCursor(new Cursor(Cursor.DEFAULT_CURSOR)); } /** * 鼠标拖动 */ public void mouseDragged(MouseEvent mouseEvent) { this.oldMouseX = this.mouseX; this.oldMouseY = this.mouseY; this.mouseX = mouseEvent.getX(); this.mouseY = mouseEvent.getY(); repaint(); } public void mouseMoved(MouseEvent mouseEvent) { } } }
