s20.htm

Java2Swingt界面设计

              <br>
              filename.substring(index+1) : <br>
              filename;<br>
              }<br>
              public void explore(boolean force) {<br>
              if(!isExplored() || force) {<br>
              File file = getFile();<br>
              File[] children = file.listFiles();</p>
            <p> for(int i=0; i &lt; children.length; ++i) <br>
              add(new FileNode(children[i]));</p>
            <p> explored = true;<br>
              }<br>
              }<br>
              }<br>
              class FileNodeRenderer extends DefaultTreeCellRenderer {<br>
              protected JCheckBox checkBox = new JCheckBox(&quot;backup&quot;);<br>
              private Component strut = Box.createHorizontalStrut(5);<br>
              private JPanel panel = new JPanel();</p>
            <p> public FileNodeRenderer() {<br>
              panel.setBackground(<br>
              UIManager.getColor(&quot;Tree.textBackground&quot;));<br>
              <br>
              setOpaque(false);<br>
              checkBox.setOpaque(false);<br>
              panel.setOpaque(false);</p>
            <p> panel.setLayout(new FlowLayout(FlowLayout.CENTER,0,0));<br>
              panel.add(this);<br>
              panel.add(strut);<br>
              panel.add(checkBox);</p>
            <p> } <br>
              public Component getTreeCellRendererComponent(<br>
              JTree tree, Object value, <br>
              boolean selected, boolean expanded,<br>
              boolean leaf, int row, <br>
              boolean hasFocus) {<br>
              FileNode node = (FileNode)value;<br>
              String s = tree.convertValueToText(value, selected,<br>
              expanded, leaf, row, hasFocus);</p>
            <p> super.getTreeCellRendererComponent(<br>
              tree, value, selected, expanded,<br>
              leaf, row, hasFocus);</p>
            <p> checkBox.setVisible(node.isDirectory());<br>
              checkBox.setSelected(node.isSelected());</p>
            <p> return panel;<br>
              }<br>
              }<br>
              class GJApp extends WindowAdapter {<br>
              static private JPanel statusArea = new JPanel();<br>
              static private JLabel status = new JLabel(&quot; &quot;);</p>
            <p> public static void launch(final JFrame f, String title,<br>
              final int x, final int y, <br>
              final int w, int h) {<br>
              f.setTitle(title);<br>
              f.setBounds(x,y,w,h);<br>
              f.setVisible(true);</p>
            <p> statusArea.setBorder(BorderFactory.createEtchedBorder());<br>
              statusArea.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));<br>
              statusArea.add(status);<br>
              status.setHorizontalAlignment(JLabel.LEFT);</p>
            <p> f.setDefaultCloseOperation(<br>
              WindowConstants.DISPOSE_ON_CLOSE);</p>
            <p> f.addWindowListener(new WindowAdapter() {<br>
              public void windowClosed(WindowEvent e) {<br>
              System.exit(0);<br>
              }<br>
              });<br>
              }<br>
              static public JPanel getStatusArea() {<br>
              return statusArea;<br>
              }<br>
              static public void updateStatus(String s) {<br>
              status.setText(s);<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p align="center"><b>例20-11 把用户对象设置为货币模式</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import javax.swing.tree.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.text.*;
            <p>public class Test extends JApplet {<br>
              public void init() {<br>
              JTree tree = new JTree();<br>
              JScrollPane scrollPane = new JScrollPane(tree);</p>
            <p> DefaultMutableTreeNode root = <br>
              new DefaultMutableTreeNode(&quot;prices&quot;);</p>
            <p> root.add(new DefaultMutableTreeNode(new Double(10.99)));<br>
              root.add(new DefaultMutableTreeNode(new Double(8.99))); <br>
              root.add(new DefaultMutableTreeNode(new Double(6.95))); <br>
              root.add(new DefaultMutableTreeNode(new Double(8.00))); <br>
              root.add(new DefaultMutableTreeNode(new Double(7.59))); <br>
              root.add(new DefaultMutableTreeNode(new Double(2.49))); </p>
            <p> DefaultTreeModel model = <br>
              (DefaultTreeModel)tree.getModel();</p>
            <p> model.setRoot(root);</p>
            <p> tree.setCellRenderer(new FormattingRenderer());<br>
              tree.setEditable(true);<br>
              getContentPane().add(scrollPane);<br>
              }<br>
              }<br>
              class FormattingRenderer extends DefaultTreeCellRenderer {<br>
              public Component getTreeCellRendererComponent(<br>
              JTree tree, Object value, <br>
              boolean selected, boolean expanded,<br>
              boolean leaf, int row, <br>
              boolean hasFocus) {<br>
              // initialize renderer component (this) ...</p>
            <p> super.getTreeCellRendererComponent(<br>
              tree, value, selected, expanded, <br>
              leaf, row, hasFocus);</p>
            <p> // now format label text ...</p>
            <p> DefaultMutableTreeNode n = (DefaultMutableTreeNode)value;<br>
              Object userObject = n.getUserObject();</p>
            <p> if(userObject instanceof Double) { <br>
              Double d = (Double)userObject;<br>
              Format format = NumberFormat.getCurrencyInstance();</p>
            <p> setText(value == null ? &quot;&quot; : format.format(d));<br>
              }<br>
              return this;<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 20.6.2 Metal界面样式</p>
            <p>&nbsp;</p>
            <p> 20.6.3 根结点和根句柄</p>
            <p>&nbsp;</p>
            <p align="center"><b>例20-12 显示根节点和根节点句柄</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;
            <p>public class Test extends JApplet {<br>
              JTree tree = new JTree();<br>
              public void init() {<br>
              Container contentPane = getContentPane();<br>
              JScrollPane scrollPane = new JScrollPane(tree);<br>
              contentPane.add(new ControlPanel(), BorderLayout.NORTH);<br>
              contentPane.add(scrollPane, BorderLayout.CENTER);<br>
              }<br>
              class ControlPanel extends JPanel{<br>
              JCheckBox showRoot = new JCheckBox(&quot;show root node&quot;);<br>
              JCheckBox showRootHandles = new JCheckBox(<br>
              &quot;show root handle&quot;);<br>
              public ControlPanel(){<br>
              initializeCheckBoxes();<br>
              setLayout(new FlowLayout());<br>
              add(showRoot);<br>
              add(showRootHandles);<br>
              showRoot.addActionListener(new ActionListener(){<br>
              public void actionPerformed(ActionEvent e){<br>
              tree.setRootVisible(showRoot.isSelected());<br>
              }<br>
              });<br>
              showRootHandles.addActionListener(<br>
              new ActionListener(){<br>
              public void actionPerformed(ActionEvent e){<br>
              tree.setShowsRootHandles(<br>
              showRootHandles.isSelected());<br>
              }<br>
              });<br>
              }<br>
              private void initializeCheckBoxes(){<br>
              showRoot.setSelected(tree.isRootVisible());<br>
              showRootHandles.setSelected(<br>
              tree.getShowsRootHandles());<br>
              }<br>
              }<br>
              }</p>
            <p></p>
            <hr size="1" noshade>
            <p> 20.7 树单元编辑</p>
            <p>&nbsp;</p>
            <p align="center">&nbsp; </p>
            <p> 20.7.1 扩展DefaultCellEditor</p>
            <p>&nbsp;</p>
            <p align="center"><b>例20-13 一个扩展DefaultCellEditor的编辑器</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import javax.swing.tree.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;
            <p>public class Test extends JApplet {<br>
              public void init() {<br>
              JTree tree = new JTree();<br>
              JScrollPane scrollPane = new JScrollPane(tree);<br>
              JComboBox combo = new JComboBox();</p>
            <p> combo.addItem(&quot;red&quot;);<br>
              combo.addItem(&quot;blue&quot;);<br>
              combo.addItem(&quot;green&quot;);<br>
              combo.addItem(&quot;orange&quot;);<br>
              combo.addItem(&quot;yellow&quot;);<br>
              combo.addItem(&quot;magenta&quot;);</p>
            <p> tree.setCellEditor(new ColorEditor(tree, combo));<br>
              tree.setEditable(true);</p>
            <p> getContentPane().add(scrollPane);<br>
              }<br>
              }<br>
              class ColorEditor extends DefaultCellEditor {<br>
              private JTree tree;</p>
            <p> public ColorEditor(JTree tree, JComboBox comboBox) {<br>
              super(comboBox);<br>
              this.tree = tree;<br>
              }<br>
              public boolean isCellEditable(EventObject e) {<br>
              boolean rv = false; // return value</p>
            <p> if(e instanceof MouseEvent) {<br>
              MouseEvent me = (MouseEvent)e;</p>
            <p> if(me.getClickCount() == 3) {<br>
              TreePath path =<br>
              tree.getPathForLocation(me.getX(), me.getY()); </p>
            <p> if(path.getPathCount() == 1) // root node<br>
              return false;</p>
            <p> DefaultMutableTreeNode node = <br>
              (DefaultMutableTreeNode)<br>
              path.getLastPathComponent(); <br>
              <br>
              rv = node.getParent().toString().equals(&quot;colors&quot;);<br>
              }<br>
              }<br>
              return rv;<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 20.7.2 DefaultTreeCellEditor</p>
            <p>&nbsp;</p>
            <p align="center"><b>例20-14 使用DefaultTreeCellEditor</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import javax.swing.tree.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>