我被赋予了创建自定义swing组件的任务。我的组件在测试应用程序中正常运行，其中包括用于放大和缩小Image的JSlider。但是我需要以Model，UIDelegate和Component类格式呈现我的自定义组件，我完全迷失了如何转换代码以使其遵循这种格式。这是我的测试应用程序的代码。
package test;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.swing.event.*;
import java.io.File;
import java.net.URL;
import javax.imageio.ImageIO;
public class ZoomDemo extends JComponent implements ChangeListener {
JPanel gui;
/**
* Displays the image.
*/
JLabel imageCanvas;
Dimension size;
double scale = 1.0;
private BufferedImage image;
public ZoomDemo() {
size = new Dimension(10, 10);
setBackground(Color.black);
try {
image = ImageIO.read(new File("car.jpg"));
} catch (Exception ex) {
ex.printStackTrace();
}
}
public void setImage(Image image) {
imageCanvas.setIcon(new ImageIcon(image));
}
public void initComponents() {
if (gui == null) {
gui = new JPanel(new BorderLayout());
gui.setBorder(new EmptyBorder(5, 5, 5, 5));
imageCanvas = new JLabel();
JPanel imageCenter = new JPanel(new GridBagLayout());
imageCenter.add(imageCanvas);
JScrollPane imageScroll = new JScrollPane(imageCenter);
imageScroll.setPreferredSize(new Dimension(300, 100));
gui.add(imageScroll, BorderLayout.CENTER);
}
}
public Container getGui() {
initComponents();
return gui;
}
public void stateChanged(ChangeEvent e) {
int value = ((JSlider) e.getSource()).getValue();
scale = value / 100.0;
paintImage();
}
protected void paintImage() {
int imageWidth = image.getWidth();
int imageHeight = image.getHeight();
BufferedImage bi = new BufferedImage(
(int)(imageWidth*scale),
(int)(imageHeight*scale),
image.getType());
Graphics2D g2 = bi.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
AffineTransform at = AffineTransform.getTranslateInstance(0, 0);
at.scale(scale, scale);
g2.drawRenderedImage(image, at);
setImage(bi);
}
public Dimension getPreferredSize() {
int w = (int) (scale * size.width);
int h = (int) (scale * size.height);
return new Dimension(w, h);
}
private JSlider getControl() {
JSlider slider = new JSlider(JSlider.HORIZONTAL, 1, 500, 50);
slider.setMajorTickSpacing(50);
slider.setMinorTickSpacing(25);
slider.setPaintTicks(true);
slider.setPaintLabels(true);
slider.addChangeListener(this);
return slider;
}
public static void main(String[] args) {
ZoomDemo app = new ZoomDemo();
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(app.getGui());
app.setImage(app.image);
// frame.getContentPane().add(new JScrollPane(app));
frame.getContentPane().add(app.getControl(), "Last");
frame.setSize(700, 500);
frame.setLocation(200, 200);
frame.setVisible(true);
}
}
以下代码是我需要遵循的类格式
组件类
package component;
import javax.swing.JComponent;
import javax.swing.JSlider;
import javax.swing.plaf.ComponentUI;
public class ProgressBar extends JComponent {
public static ComponentUI createUI(JComponent c) {
return new ZoomUI();
}
public void installUI(JComponent c){
}
public void uninstallUI (JComponent c){
}
}
模型CLass
public class ZoomModel extends JSLider {
}
UIDelegate Class
public class ZoomUI extends ComponentUI implements ChangeListener{
}
如何以这种格式实现我的自定义组件的任何帮助将不胜感激。我对Swing非常陌生，我在自定义组件上找到的文档非常令人困惑并且帮助不大。
测试申请
package test;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
import javax.swing.event.*;
import java.io.File;
import java.net.URL;
import javax.imageio.ImageIO;
import component.ZoomComponent;
public class ZoomDemo extends JPanel implements PropertyChangeListener, ActionListener {
ZoomComponent zoomer;
JPanel board;
private BufferedImage image;
public ZoomDemo( ) {
super(true);
setLayout(new BorderLayout( ));
board = new JPanel(true);
board.setPreferredSize(new Dimension(300, 300));
board.setBorder(new LineBorder(Color.black, 5));
zoomer = new ZoomComponent();
add(board, BorderLayout.NORTH);
add(zoomer, BorderLayout.SOUTH);
}
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void propertyChange(PropertyChangeEvent arg0) {
// TODO Auto-generated method stub
}
public static void main(String[] args) {
UIManager.getDefaults().put("ZoomComponentUI", "component.BasicZoomUI");
ZoomDemo s= new ZoomDemo();
JFrame frame = new JFrame("Sample Sketch Application");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(s);
frame.pack( );
frame.setVisible(true);
}
}
答案 0 :(得分：6)
好的，这是一个有趣的冒险，我不使用的部分API :)，首先阅读How to Write a Custom Swing Component及其相关链接，这将为您提供理解什么的基础工作即将发生...
就个人而言，我总是从界面开始，接口生活更好，它给你更多的灵活性。现在，你应该扩展哪种模式（根据你的要求）......？
嗯，我能找到的最佳选择是BoundedRangeModel，它也被JSlider使用......这实际上意味着我不仅可以将此模型传递给视图，而且还可以一个JSlider，没有任何额外的工作，让滑块改变图像!!双赢
import java.awt.Dimension;
import java.awt.Image;
import javax.swing.BoundedRangeModel;
public interface ZoomModel extends BoundedRangeModel {
public Image getImage();
public Dimension getScaledSize();
}
接下来，我想制作一个抽象版本，这是我放置“常用”功能的地方，对于大多数实现来说可能是相同的，在这种情况下，它可能不是必需的，但我很喜欢此...
import java.awt.Dimension;
import java.awt.Image;
import javax.swing.DefaultBoundedRangeModel;
public abstract class AbstractZoomModel extends DefaultBoundedRangeModel implements ZoomModel {
public AbstractZoomModel() {
super(100, 0, 0, 200);
}
@Override
public Dimension getScaledSize() {
Dimension size = new Dimension(0, 0);
Image image = getImage();
if (image != null) {
double scale = getValue() / 100d;
size.width = (int) Math.round(image.getWidth(null) * scale);
size.height = (int) Math.round(image.getHeight(null) * scale);
}
return size;
}
}
所以，你可以在这里看到，我已经定义了一些基本属性，起始缩放级别为100，最高级别为200，最低级别为0，另外还有我实现了getScaledSize，使用了一点，让生活更轻松......
现在，因为我们很喜欢，我们提供模型的“默认”实现。这是非常基本的，只需要参考图像......
import java.awt.Image;
public class DefaultZoomModel extends AbstractZoomModel {
Image image;
public DefaultZoomModel(Image image) {
this.image = image;
}
@Override
public Image getImage() {
return image;
}
}
您可以创建从URL下载图像的实现，例如......
好的，这是实际的组件本身，它会被添加到您的UI中。它包含构建和准备UI委托以及管理模型所需的基本功能。这里感兴趣的关键是使用属性更改支持来提供模型更改的通知，这很重要，因为您将看到......
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JComponent;
import javax.swing.UIManager;
public class ZoomComponent extends JComponent {
private static final String uiClassID = "ZoomComponentUI";
private ZoomModel model;
public ZoomComponent() {
setBackground(Color.black);
setFocusable(true);
updateUI();
}
public void setModel(ZoomModel newModel) {
if (model != newModel) {
ZoomModel old = model;
this.model = newModel;
firePropertyChange("model", old, newModel);
}
}
public ZoomModel getModel() {
return model;
}
@Override
public Dimension getPreferredSize() {
ZoomModel model = getModel();
Dimension size = new Dimension(100, 100);
if (model != null) {
size = model.getScaledSize();
}
return size;
}
public void setUI(BasicZoomUI ui) {
super.setUI(ui);
}
@Override
public void updateUI() {
if (UIManager.get(getUIClassID()) != null) {
ZoomUI ui = (ZoomUI) UIManager.getUI(this);
setUI(ui);
} else {
setUI(new BasicZoomUI());
}
}
public BasicZoomUI getUI() {
return (BasicZoomUI) ui;
}
@Override
public String getUIClassID() {
return uiClassID;
}
}
现在其他有趣的东西......如果我们遵循标准惯例，您通常会提供UI委托的abstract概念，例如......
import javax.swing.plaf.ComponentUI;
public abstract class ZoomUI extends ComponentUI {
}
由此，其他代表将成长......
惯例通常会建议你提供一个“基本”实现，做很多繁重的工作，但允许其他实现有机会跳转到那里的东西
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseWheelEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.ComponentUI;
public class BasicZoomUI extends ZoomUI {
private ZoomComponent zoomComponent;
private MouseAdapter mouseHandler;
private ChangeListener changeHandler;
private Action zoomIn;
private Action zoomOut;
private PropertyChangeListener propertyChangeHandler;
protected ChangeListener getChangeHandler() {
if (changeHandler == null) {
changeHandler = new ChangeHandler();
}
return changeHandler;
}
protected void installMouseListener() {
mouseHandler = new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
zoomComponent.requestFocusInWindow();
}
@Override
public void mouseWheelMoved(MouseWheelEvent e) {
int amount = e.getWheelRotation();
ZoomModel model = zoomComponent.getModel();
if (model != null) {
int value = model.getValue();
model.setValue(value + amount);
}
}
};
zoomComponent.addMouseListener(mouseHandler);
zoomComponent.addMouseWheelListener(mouseHandler);
}
protected void installModelPropertyChangeListener() {
propertyChangeHandler = new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
ZoomModel old = (ZoomModel) evt.getOldValue();
if (old != null) {
old.removeChangeListener(getChangeHandler());
}
ZoomModel newValue = (ZoomModel) evt.getNewValue();
if (newValue != null) {
newValue.addChangeListener(getChangeHandler());
}
}
};
zoomComponent.addPropertyChangeListener("model", propertyChangeHandler);
}
protected void installKeyBindings() {
zoomIn = new ZoomInAction();
zoomOut = new ZoomOutAction();
InputMap inputMap = zoomComponent.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, 0), "zoomIn");
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, 0), "zoomOut");
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_PLUS, 0), "zoomIn");
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_MINUS, 0), "zoomOut");
ActionMap actionMap = zoomComponent.getActionMap();
actionMap.put("zoomIn", zoomIn);
actionMap.put("zoomOut", zoomOut);
}
protected void installModelChangeListener() {
ZoomModel model = getModel();
if (model != null) {
model.addChangeListener(getChangeHandler());
}
}
@Override
public void installUI(JComponent c) {
zoomComponent = (ZoomComponent) c;
installMouseListener();
installModelPropertyChangeListener();
installKeyBindings();
installModelChangeListener();
}
protected void uninstallModelChangeListener() {
getModel().removeChangeListener(getChangeHandler());
}
protected void uninstallKeyBindings() {
InputMap inputMap = zoomComponent.getInputMap(JComponent.WHEN_FOCUSED);
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, 0), "donothing");
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, 0), "donothing");
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_PLUS, 0), "donothing");
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_MINUS, 0), "donothing");
AbstractAction blank = new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
}
};
ActionMap actionMap = zoomComponent.getActionMap();
actionMap.put("zoomIn", blank);
actionMap.put("zoomOut", blank);
}
protected void uninstallModelPropertyChangeListener() {
zoomComponent.removePropertyChangeListener(propertyChangeHandler);
propertyChangeHandler = null;
}
protected void uninstallMouseListener() {
zoomComponent.removeMouseWheelListener(mouseHandler);
mouseHandler = null;
}
@Override
public void uninstallUI(JComponent c) {
uninstallModelChangeListener();
uninstallModelPropertyChangeListener();
uninstallKeyBindings();
uninstallMouseListener();
mouseHandler = null;
zoomComponent = null;
}
@Override
public void paint(Graphics g, JComponent c) {
super.paint(g, c);
paintImage(g);
}
protected void paintImage(Graphics g) {
if (zoomComponent != null) {
ZoomModel model = zoomComponent.getModel();
Image image = model.getImage();
Dimension size = model.getScaledSize();
int x = (zoomComponent.getWidth() - size.width) / 2;
int y = (zoomComponent.getHeight() - size.height) / 2;
g.drawImage(image, x, y, size.width, size.height, zoomComponent);
}
}
public static ComponentUI createUI(JComponent c) {
return new BasicZoomUI();
}
protected ZoomModel getModel() {
return zoomComponent == null ? null : zoomComponent.getModel();
}
protected class ChangeHandler implements ChangeListener {
@Override
public void stateChanged(ChangeEvent e) {
zoomComponent.revalidate();
zoomComponent.repaint();
}
}
protected class ZoomAction extends AbstractAction {
private int delta;
public ZoomAction(int delta) {
this.delta = delta;
}
@Override
public void actionPerformed(ActionEvent e) {
ZoomModel model = getModel();
if (model != null) {
model.setValue(model.getValue() + delta);
}
}
}
protected class ZoomOutAction extends ZoomAction {
public ZoomOutAction() {
super(-5);
}
}
protected class ZoomInAction extends ZoomAction {
public ZoomInAction() {
super(5);
}
}
}
从这里你可以去设计特定于平台的实现，但我决定坚持使用基本的代理......
如果这还不够，那么在使用任何一个之前，你必须安装代理......
UIManager.getDefaults().put("ZoomComponentUI", "your.awesome.package.name.BasicZoomUI");
nb：更改your.awesome.package.name以反映您的实际包名......
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestZoom100 {
public static void main(String[] args) {
new TestZoom100();
}
public TestZoom100() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
UIManager.getDefaults().put("ZoomComponentUI", "your.awesome.package.name.BasicZoomUI");
try {
DefaultZoomModel model = new DefaultZoomModel(ImageIO.read(new File("/your/awesome/image.jpg")));
model.setValue(50);
ZoomComponent zoomComp = new ZoomComponent();
zoomComp.setModel(model);
JSlider slider = new JSlider(model);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new JScrollPane(zoomComp));
frame.add(slider, BorderLayout.SOUTH);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (IOException exp) {
exp.printStackTrace();
}
}
});
}
}
不要忘记将BasicZoomUI的包名更改为您存储的包名，并实际指定图像文件;）