s16.htm

java图形设计卷2 swing

            <p align="center"><b>例子 16-8 JFileChooser动作事件</b></p>
            <hr size="1">
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.io.File;<br>
            import javax.swing.*;
            <p>public class Test extends JFrame {<br>
              JFileChooser chooser = new JFileChooser();<br>
              JDialog dialog;<br>
              JButton button = new JButton(&quot;show file chooser ...&quot;);</p>
            <p> public Test() {<br>
              super(&quot;Simple File Chooser Application&quot;);<br>
              Container contentPane = getContentPane();</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(button); </p>
            <p> button.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              String title = chooser.getDialogTitle();</p>
            <p> if(title == null)<br>
              chooser.getUI().getDialogTitle(chooser);</p>
            <p> dialog = new JDialog((Frame)null, title, false);<br>
              <br>
              Container dialogContentPane = <br>
              dialog.getContentPane();</p>
            <p> dialogContentPane.setLayout(new BorderLayout());<br>
              dialogContentPane.add(chooser, <br>
              BorderLayout.CENTER);<br>
              <br>
              dialog.setTitle(&quot;Non-Modal File Chooser&quot;);</p>
            <p> dialog.pack();<br>
              dialog.setLocationRelativeTo(Test.this);<br>
              <br>
              dialog.setVisible(true); <br>
              }<br>
              });<br>
              chooser.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              String state = (String)e.getActionCommand();</p>
            <p> if(state.equals(JFileChooser.APPROVE_SELECTION)) {<br>
              File file = chooser.getSelectedFile();</p>
            <p> JOptionPane.showMessageDialog(<br>
              null, file.getPath());<br>
              }<br>
              else if(<br>
              state.equals(JFileChooser.CANCEL_SELECTION)) {<br>
              JOptionPane.showMessageDialog(<br>
              null, &quot;Canceled&quot;);<br>
              }<br>
              // JFileChooser action listeners are notified<br>
              // when one either the approve button or<br>
              // cancel button is activated<br>
              dialog.setVisible(false);</p>
            <p> }<br>
              });<br>
              }<br>
              public static void main(String args[]) {<br>
              JFrame f = new Test();<br>
              f.setBounds(300,300,350,100);<br>
              f.setVisible(true);</p>
            <p> f.setDefaultCloseOperation(<br>
              WindowConstants.DISPOSE_ON_CLOSE);<br>
              <br>
              f.addWindowListener(new WindowAdapter() {<br>
              public void windowClosed(WindowEvent e) {<br>
              System.exit(0); <br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 16.1.8 JFileChooser类总结</p>
            <p>&nbsp;</p>
            <p> 16.1.9 AWT兼容</p>
            <p>&nbsp;</p>
            <p align="center">&nbsp; </p>
            <p> 16.2 JColorChooser</p>
            <p>&nbsp;</p>
            <p align="center"><b>例16-9 在一个小应用程序中显示的颜色选取器</b></p>
            <hr size="1">
            import javax.swing.*;<br>
            import javax.swing.colorchooser.*;<br>
            import javax.swing.event.*;<br>
            import java.awt.*;
            <p>public class Test extends JApplet {<br>
              JColorChooser chooser = new JColorChooser();<br>
              ColorSelectionModel model = chooser.getSelectionModel();</p>
            <p> public void init() {<br>
              getContentPane().add(chooser, BorderLayout.CENTER);</p>
            <p> model.addChangeListener(new ChangeListener() {<br>
              public void stateChanged(ChangeEvent e) {<br>
              showStatus(&quot;Color: &quot; + chooser.getColor());<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 16.2.1 在对话框中显示颜色选取器</p>
            <p>&nbsp;</p>
            <p align="center"><b>例16-10 在对话框中显示的颜色选取器</b></p>
            <hr size="1">
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class Test extends JApplet {<br>
              public void init() {<br>
              getContentPane().add(new Palette(), BorderLayout.CENTER);<br>
              }<br>
              }<br>
              class Palette extends JPanel {<br>
              private Color[] defaultColors = new Color[] {<br>
              Color.blue, Color.red, Color.yellow, Color.green,<br>
              Color.magenta, Color.darkGray, Color.white, Color.orange,<br>
              Color.pink, Color.cyan, Color.lightGray, Color.gray,<br>
              };</p>
            <p> public Palette() {<br>
              int columns = 3;</p>
            <p> setBorder(<br>
              BorderFactory.createTitledBorder(&quot;Color Palette&quot;));</p>
            <p> setLayout(new GridLayout(columns,0,1,1));</p>
            <p> for(int i=0; i &lt; defaultColors.length; ++i)<br>
              add(new ColorPatch(defaultColors[i]));<br>
              } <br>
              }<br>
              class ColorPatch extends JPanel {<br>
              JApplet applet;<br>
              Color selectedColor;</p>
            <p> public ColorPatch(Color color) {<br>
              setBorder(BorderFactory.createEtchedBorder());<br>
              setBackground(color);</p>
            <p> addMouseListener(new MouseAdapter() {<br>
              public void mousePressed(MouseEvent e) {<br>
              selectedColor = JColorChooser.showDialog(<br>
              ColorPatch.this, // parent comp<br>
              &quot;Pick A Color&quot;, // dialog title<br>
              getBackground()); // initial color</p>
            <p> if(selectedColor == null) {<br>
              JOptionPane.showMessageDialog(ColorPatch.this,<br>
              &quot;ColorChooser Canceled&quot;);<br>
              }<br>
              else {<br>
              setBackground(selectedColor);<br>
              repaint();</p>
            <p> JOptionPane.showMessageDialog(ColorPatch.this,<br>
              &quot;Color Selected: &quot; + selectedColor);<br>
              }<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 16.2.2 定制颜色选取器</p>
            <p>&nbsp;</p>
            <p align="center"><b>例16-11 颜色选取器中的一个定制预览</b></p>
            <hr size="1">
            import javax.swing.*;<br>
            import javax.swing.colorchooser.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class Test extends JApplet {<br>
              private JColorChooser chooser = new JColorChooser();<br>
              private JButton button = new JButton(&quot;Show Color Chooser&quot;);<br>
              private JDialog dialog;</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(button, BorderLayout.CENTER);</p>
            <p> chooser.setPreviewPanel(new PreviewPanel());</p>
            <p> button.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {</p>
            <p> if(dialog == null) <br>
              dialog = JColorChooser.createDialog(<br>
              Test.this, // parent comp<br>
              &quot;Pick A Color&quot;, // dialog title<br>
              false, // modality<br>
              chooser, <br>
              null, null);</p>
            <p> dialog.setVisible(true);<br>
              }<br>
              });<br>
              }<br>
              class PreviewPanel extends JPanel {<br>
              public PreviewPanel() {<br>
              setPreferredSize(new Dimension(0,100));<br>
              setBorder(BorderFactory.createRaisedBevelBorder());<br>
              }<br>
              public void paintComponent(Graphics g) {<br>
              Dimension size = getSize();</p>
            <p> g.setColor(getForeground());<br>
              g.fillRect(0,0,size.width,size.height);<br>
              }<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p align="center"><b>例16-12 实现一个定制颜色选取器面板</b></p>
            <hr size="1">
            import javax.swing.*;<br>
            import javax.swing.event.*;<br>
            import javax.swing.colorchooser.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class Test extends JApplet {<br>
              private JColorChooser chooser = new JColorChooser();<br>
              private AbstractColorChooserPanel colorPanels[] =<br>
              new AbstractColorChooserPanel[] {<br>
              new ListPanel(),<br>
              };<br>
              private JButton button = new JButton(&quot;Show Color Chooser&quot;);<br>
              private JDialog dialog;</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(button, BorderLayout.CENTER);</p>
            <p> chooser.setChooserPanels(colorPanels);</p>
            <p> button.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              if(dialog == null) <br>
              dialog = JColorChooser.createDialog(<br>
              Test.this, // parent comp<br>
              &quot;Pick A Color&quot;, // dialog title<br>
              false, // modality<br>
              chooser, <br>
              null, null);</p>
            <p> dialog.setVisible(true);<br>
              }<br>
              });<br>
              }<br>
              }<br>
              class ListPanel extends AbstractColorChooserPanel <br>
              implements ListSelectionListener {<br>
              private JPanel labelPanel = new JPanel(),<br>
              listPanel = new JPanel();</p>
            <p> private JList redList = new JList(), blueList = new JList(), <br>
              greenList = new JList();</p>
            <p> private DefaultListModel redModel = new DefaultListModel(),<br>
              blueModel = new DefaultListModel(),<br>
              greenModel = new DefaultListModel();</p>
            <p> private boolean isAdjusting = false;</p>
            <p> public void updateChooser() {<br>
              if( ! isAdjusting) {<br>
              isAdjusting = true;</p>
            <p> Color color = getColorFromModel();<br>
              int r = color.getRed(), g = color.getGreen(), <br>
              b = color.getBlue();</p>
            <p> redList.setSelectedIndex(r);<br>
              redList.ensureIndexIsVisible(r);</p>
            <p> blueList.setSelectedIndex(b);<br>
              blueList.ensureIndexIsVisible(b);</p>
            <p> greenList.setSelectedIndex(g);<br>
              greenList.ensureIndexIsVisible(g);</p>
            <p> isAdjusting = false;<br>
              }<br>
              }<br>
              protected void buildChooser() {<br>
              redList.setFixedCellWidth(50);<br>
              greenList.setFixedCellWidth(50);<br>
              blueList.setFixedCellWidth(50);</p>
            <p> for(int i=0; i &lt; 256; ++i) {<br>
              redModel.addElement(Integer.toString(i));<br>
              greenModel.addElement(Integer.toString(i));<br>
              blueModel.addElement(Integer.toString(i));<br>
              }</p>
            <p> redList.setModel(redModel);<br>
              greenList.setModel(greenModel);<br>
              blueList.setModel(blueModel);</p>
            <p> listPanel.setLayout(new GridLayout(0,3,10,0));</p>
            <p> listPanel.add(new JScrollPane(redList));<br>
              listPanel.add(new JScrollPane(blueList));<br>
              listPanel.add(new JScrollPane(greenList));</p>
            <p> labelPanel.setLayout(new GridLayout(0,3,10,0));</p>
            <p> labelPanel.add(new JLabel(&quot;Red&quot;));<br>
              labelPanel.add(new JLabel(&quot;Blue&quot;));<br>
              labelPanel.add(new JLabel(&quot;Green&quot;));</p>
            <p> setLayout(new BorderLayout());<br>
              add(labelPanel, BorderLayout.NORTH);<br>
              add(listPanel, BorderLayout.CENTER);</p>
            <p> redList.addListSelectionListener(this);<br>
              greenList.addListSelectionListener(this);<br>
              blueList.addListSelectionListener(this);<br>
              }<br>
              public void valueChanged(ListSelectionEvent e) {<br>
              int r = redList.getSelectedIndex(),<br>
              b = blueList.getSelectedIndex(),<br>
              g = greenList.getSelectedIndex();</p>
            <p> if(r != -1 &amp;&amp; g != -1 &amp;&amp; b != -1)<br>
              getColorSelectionModel().setSelectedColor(<br>
              new Color(r,g,b));<br>
              }<br>
              public String getDisplayName() {<br>
              return &quot;display name&quot;;<br>
              }<br>
              public Icon getSmallDisplayIcon() {<br>
              return null;<br>
              }<br>
              public Icon getLargeDisplayIcon() {<br>
              return null;<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p>&nbsp;</p>
            <p> 16.2.3 JColorChooser属性</p>
            <p>&nbsp;</p>
            <p> 16.2.4 JColorChooser事件</p>
            <p>&nbsp;</p>
            <p> 16.2.5 JColorChooser类总结</p>
            <p>&nbsp;</p>
            <p> 16.2.6 AWT兼容</p>
            <p>&nbsp;</p>
            <p> 16.3 本章回顾</p>
            <p>&nbsp;</p>
            <p>&nbsp;</p>
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            <p>&nbsp; </p>
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