s17.htm

Java2Swingt界面设计

              <br>
              &quot;item[3]&quot;, &quot;item[4]&quot;, &quot;item[5]&quot;,<br>
              &quot;item[6]&quot;, &quot;item[7]&quot;, <br>
              &quot;item[8]&quot;, &quot;item[9]&quot; };</p>
            <p> JList list = new JList(items);</p>
            <p> list.setPrototypeCellValue(&quot;MMMMMMM&quot;);</p>
            <p> controlPanel = new ControlPanel(list);<br>
              controlPanel.update();</p>
            <p> listPanel.setBorder(BorderFactory.createEtchedBorder());<br>
              listPanel.add(new JScrollPane(list));</p>
            <p> contentPane.add(controlPanel, BorderLayout.NORTH);<br>
              contentPane.add(listPanel, BorderLayout.CENTER);</p>
            <p> list.addListSelectionListener(<br>
              new ListSelectionListener() {<br>
              public void valueChanged(ListSelectionEvent e) {<br>
              controlPanel.update();<br>
              }<br>
              });<br>
              }<br>
              }<br>
              class ControlPanel extends JPanel {<br>
              private JComboBox mode = new JComboBox();<br>
              private JButton clear = new JButton(&quot;clear selection&quot;);</p>
            <p> private String single = &quot;SINGLE_SELECTION&quot;,<br>
              singleInterval = &quot;SINGLE_INTERVAL_SELECTION&quot;,<br>
              multipleInterval = &quot;MULTIPLE_INTERVAL_SELECTION&quot;;</p>
            <p> private JLabel leadLabel = new JLabel(),<br>
              anchorLabel = new JLabel(),<br>
              minLabel = new JLabel(),<br>
              maxLabel = new JLabel(),<br>
              selIndicesLabel = new JLabel();</p>
            <p> private JList list;</p>
            <p> public ControlPanel(JList l) {<br>
              JPanel top = new JPanel(), <br>
              mid = new JPanel(),<br>
              bottom = new JPanel();</p>
            <p> this.list = l;</p>
            <p> setLayout(new BoxLayout(this, BoxLayout.Y_AXIS)); <br>
              setBorder(BorderFactory.createEtchedBorder());</p>
            <p> top.add(mode);<br>
              top.add(clear);</p>
            <p> mid.add(new JLabel(&quot;Lead:&quot;)); mid.add(leadLabel);<br>
              mid.add(new JLabel(&quot;Anchor:&quot;)); mid.add(anchorLabel);<br>
              mid.add(new JLabel(&quot;Minimum:&quot;)); mid.add(minLabel);<br>
              mid.add(new JLabel(&quot;Maximum:&quot;)); mid.add(maxLabel);</p>
            <p> add(top);<br>
              add(mid);<br>
              add(bottom);</p>
            <p> mode.addItem(single);<br>
              mode.addItem(singleInterval);<br>
              mode.addItem(multipleInterval);<br>
              initializeSelectionMode();</p>
            <p> bottom.add(new JLabel(&quot;Selected Indices:&quot;));<br>
              bottom.add(selIndicesLabel);</p>
            <p> mode.addItemListener(new ItemListener() {<br>
              public void itemStateChanged(ItemEvent e) {<br>
              if(e.getStateChange() == ItemEvent.SELECTED)<br>
              setSelectionMode((String)e.getItem());<br>
              }<br>
              });<br>
              clear.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              list.clearSelection();<br>
              }<br>
              });<br>
              }<br>
              public void update() {<br>
              int lead = list.getLeadSelectionIndex(),<br>
              min = list.getMinSelectionIndex(),<br>
              max = list.getMaxSelectionIndex(),<br>
              anchor = list.getAnchorSelectionIndex();</p>
            <p> leadLabel.setText(Integer.toString(lead) + &quot; / &quot;);<br>
              anchorLabel.setText(Integer.toString(anchor) + &quot; / &quot;);<br>
              minLabel.setText(Integer.toString(min) + &quot; / &quot;);<br>
              maxLabel.setText(Integer.toString(max) + &quot; / &quot;);</p>
            <p> int[] selected = list.getSelectedIndices();<br>
              String s = new String();</p>
            <p> for(int i = 0; i &lt; selected.length; ++i) {<br>
              s += Integer.toString(selected[i]);</p>
            <p> if(i &lt; selected.length-1)<br>
              s += &quot;,&quot;;<br>
              }<br>
              selIndicesLabel.setText(s);<br>
              validate();<br>
              }<br>
              private void initializeSelectionMode() {<br>
              int m = list.getSelectionMode();</p>
            <p> switch(m) {<br>
              case ListSelectionModel.SINGLE_SELECTION:<br>
              mode.setSelectedItem(single);<br>
              break;<br>
              case ListSelectionModel.SINGLE_INTERVAL_SELECTION:<br>
              mode.setSelectedItem(singleInterval);<br>
              break;<br>
              case ListSelectionModel.MULTIPLE_INTERVAL_SELECTION:<br>
              mode.setSelectedItem(multipleInterval);<br>
              break;<br>
              }<br>
              }<br>
              private void setSelectionMode(String s) {<br>
              if(s.equals(&quot;SINGLE_SELECTION&quot;)) {<br>
              list.setSelectionMode(<br>
              ListSelectionModel.SINGLE_SELECTION);<br>
              }<br>
              else if(s.equals(&quot;SINGLE_INTERVAL_SELECTION&quot;)) {<br>
              list.setSelectionMode(<br>
              ListSelectionModel.SINGLE_INTERVAL_SELECTION);<br>
              }<br>
              else if(s.equals(&quot;MULTIPLE_INTERVAL_SELECTION&quot;)) {<br>
              list.setSelectionMode(<br>
              ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);<br>
              }<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p align="center"><b>例17-6 处理列表数据事件</b></p>
            <hr noshade size="1">
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import javax.swing.*;<br>
            import javax.swing.event.*;
            <p>public class Test extends JApplet {<br>
              private JList list = new JList();</p>
            <p> private String[] items = { <br>
              &quot;item one&quot;, &quot;item two&quot;, &quot;item three&quot;, 
              <br>
              &quot;item four&quot;, &quot;item five&quot;, &quot;item six&quot;,<br>
              &quot;item seven&quot;, &quot;item eight&quot;, <br>
              &quot;item nine&quot;, &quot;item ten&quot; <br>
              };</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();</p>
            <p> JPanel controlPanel = new ControlPanel(this, list);</p>
            <p> contentPane.add(controlPanel, BorderLayout.NORTH);<br>
              contentPane.add(new JScrollPane(list), <br>
              BorderLayout.CENTER);<br>
              populateList();<br>
              }<br>
              public void populateList() {<br>
              final DefaultListModel model = new DefaultListModel();</p>
            <p> for(int i=0; i &lt; items.length; ++i)<br>
              model.addElement(items[i]);</p>
            <p> list.setModel(model);</p>
            <p> if(list.isShowing())<br>
              list.revalidate();</p>
            <p> model.addListDataListener(new ListDataListener() {<br>
              public void contentsChanged(ListDataEvent e) {<br>
              showStatus(&quot;contents changed&quot;);<br>
              }<br>
              public void intervalRemoved(ListDataEvent e) {<br>
              Object[] message = new Object[] {<br>
              &quot;Removed item at index &quot; + e.getIndex0(),<br>
              &quot; &quot;,<br>
              &quot;There are now &quot; + model.getSize() + &quot; items&quot;<br>
              };<br>
              JOptionPane.showMessageDialog(Test.this,<br>
              message,<br>
              &quot;Items Removed&quot;, // title<br>
              JOptionPane.INFORMATION_MESSAGE); // type<br>
              }<br>
              public void intervalAdded(ListDataEvent e) {<br>
              showStatus(&quot;interval added&quot;);<br>
              }<br>
              });<br>
              }<br>
              }<br>
              class ControlPanel extends JPanel {<br>
              JButton remove = new JButton(&quot;remove selected items&quot;);<br>
              JButton repopulate = new JButton(&quot;repopulate&quot;);</p>
            <p> public ControlPanel(final Test applet, final JList list) {<br>
              add(remove);<br>
              add(repopulate);</p>
            <p> remove.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              int[] selected = list.getSelectedIndices();<br>
              DefaultListModel model =<br>
              (DefaultListModel)list.getModel();</p>
            <p> for(int i=0; i &lt; selected.length; ++i) {<br>
              model.removeElementAt(selected[i] - i);<br>
              }<br>
              }<br>
              });<br>
              repopulate.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              applet.populateList();<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p>&nbsp;</p>
            <p>&nbsp;</p>
            <p align="center"><b>例17-7 处理鼠标双击和三击</b></p>
            <hr noshade size="1">
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import javax.swing.*;<br>
            import javax.swing.event.*;
            <p>public class Test extends JApplet {<br>
              public void init() {<br>
              Container contentPane = getContentPane();</p>
            <p> String[] items = { &quot;item one&quot;, &quot;item two&quot;, 
              &quot;item three&quot;, <br>
              &quot;item four&quot;, &quot;item five&quot;, &quot;item six&quot;,<br>
              &quot;item seven&quot;, &quot;item eight&quot;, <br>
              &quot;item nine&quot;, &quot;item ten&quot; };</p>
            <p> JList list = new JList(items);</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(new JScrollPane(list));</p>
            <p> list.addMouseListener(new MouseAdapter() {<br>
              public void mouseClicked(MouseEvent e) {<br>
              JList theList = (JList)e.getSource();<br>
              ListModel model = theList.getModel();</p>
            <p> int index = theList.locationToIndex(e.getPoint());<br>
              String itemString = <br>
              (String)model.getElementAt(index);</p>
            <p> String s = new String(&quot; for &quot; + <br>
              model.getElementAt(index));</p>
            <p> switch(e.getClickCount()) {<br>
              case 1:<br>
              showStatus(&quot;Single Click&quot; + s);<br>
              break;<br>
              case 2:<br>
              showStatus(&quot;Double Click&quot; + s);<br>
              break;<br>
              case 3:<br>
              showStatus(&quot;Triple Click&quot; + s);<br>
              break;<br>
              }<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 17.3.3 JList类总结</p>
            <p>&nbsp;</p>
            <p> 17.3.4 AWT兼容</p>
            <p>&nbsp;</p>
            <p> 17.4 本章回顾</p>
            <p>&nbsp;</p>
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