s06.htm

Java2Swingt界面设计

              putValue(Action.NAME,<br>
              undo.getUndoPresentationName());<br>
              }<br>
              }<br>
              }<br>
              class BackgroundColorEdit extends AbstractUndoableEdit {<br>
              public void undo() throws CannotUndoException {<br>
              super.undo();<br>
              toggleColor();<br>
              }<br>
              public void redo() throws CannotRedoException {<br>
              super.redo();<br>
              toggleColor();<br>
              }<br>
              public String getUndoPresentationName() {<br>
              return &quot;Undo&quot;;<br>
              }<br>
              public String getRedoPresentationName() {<br>
              return &quot;Redo&quot;;<br>
              }<br>
              private void toggleColor() {<br>
              Color color = colorPanel.getBackground();<br>
              colorPanel.setBackground(oldColor);<br>
              oldColor = color;<br>
              }<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 6.7.2 UndoableEditSupport</p>
            <p>&nbsp;</p>
            <p align="center"><b>例6-13 使用UndoableEditSupport</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import javax.swing.event.*;<br>
            import javax.swing.undo.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class Test extends JApplet {<br>
              private ColorPanel colorPanel = new ColorPanel();<br>
              private UndoAction undoAction = new UndoAction();</p>
            <p> public void init() {<br>
              colorPanel.setBorder(<br>
              BorderFactory.createTitledBorder(<br>
              &quot;Change color and subsequently undo &quot; +<br>
              &quot;from the Edit menu&quot;));</p>
            <p> makeMenuBar();<br>
              colorPanel.addUndoableEditListener(undoAction);<br>
              getContentPane().add(colorPanel, BorderLayout.CENTER);<br>
              }<br>
              private void makeMenuBar() {<br>
              JMenuBar menuBar = new JMenuBar();<br>
              JMenu editMenu = new JMenu(&quot;Edit&quot;);</p>
            <p> editMenu.add(new SetColorAction());<br>
              editMenu.add(undoAction);</p>
            <p> menuBar.add(editMenu);<br>
              setJMenuBar(menuBar);<br>
              }<br>
              class UndoAction extends AbstractAction <br>
              implements UndoableEditListener {<br>
              UndoableEdit lastEdit;</p>
            <p> public UndoAction() {<br>
              putValue(Action.NAME, &quot;Undo&quot;);<br>
              setEnabled(false);<br>
              }<br>
              public void actionPerformed(ActionEvent e) {<br>
              String name = (String)getValue(Action.NAME);<br>
              boolean isUndo = name.equals(<br>
              lastEdit.getUndoPresentationName());<br>
              if(isUndo) {<br>
              lastEdit.undo(); <br>
              putValue(Action.NAME,<br>
              lastEdit.getRedoPresentationName());<br>
              }<br>
              else {<br>
              lastEdit.redo(); <br>
              putValue(Action.NAME,<br>
              lastEdit.getUndoPresentationName());<br>
              }<br>
              }<br>
              public void undoableEditHappened(UndoableEditEvent e) {<br>
              lastEdit = e.getEdit();</p>
            <p> putValue(Action.NAME, <br>
              lastEdit.getUndoPresentationName());</p>
            <p> if(lastEdit.canUndo())<br>
              setEnabled(true);<br>
              }<br>
              }<br>
              class SetColorAction extends AbstractAction {<br>
              public SetColorAction() {<br>
              super(&quot;Set color ...&quot;);<br>
              }<br>
              public void actionPerformed(ActionEvent e) {<br>
              Color color = JColorChooser.showDialog(<br>
              Test.this, // parent component<br>
              &quot;Pick A Color&quot;, // dialog title<br>
              null); // initial color</p>
            <p> if(color != null) { <br>
              colorPanel.setBackground(color);<br>
              }<br>
              }<br>
              }<br>
              }<br>
              class ColorPanel extends JPanel {<br>
              UndoableEditSupport support;<br>
              BackgroundColorEdit edit = new BackgroundColorEdit();<br>
              Color oldColor;</p>
            <p> public void addUndoableEditListener(<br>
              UndoableEditListener l) {<br>
              support.addUndoableEditListener(l);<br>
              }<br>
              public void removeUndoableEditListener(<br>
              UndoableEditListener l) {<br>
              support.removeUndoableEditListener(l);<br>
              }<br>
              public void setBackground(Color color) {<br>
              oldColor = getBackground();<br>
              super.setBackground(color);</p>
            <p> if(support == null)<br>
              support = new UndoableEditSupport();</p>
            <p> support.postEdit(edit);<br>
              }<br>
              class BackgroundColorEdit extends AbstractUndoableEdit {<br>
              public void undo() throws CannotUndoException {<br>
              super.undo();<br>
              toggleColor();<br>
              }<br>
              public void redo() throws CannotRedoException {<br>
              super.redo();<br>
              toggleColor();<br>
              }<br>
              public String getUndoPresentationName() {<br>
              return &quot;Undo Background Color Change&quot;;<br>
              }<br>
              public String getRedoPresentationName() {<br>
              return &quot;Redo Background Color Change&quot;;<br>
              }<br>
              private void toggleColor() {<br>
              Color color = getBackground();<br>
              setBackground(oldColor);<br>
              oldColor = color;<br>
              }<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 6.7.3 组合编辑</p>
            <p>&nbsp;</p>
            <p align="center"><b>例6-14 使用组合编辑</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import javax.swing.event.*;<br>
            import javax.swing.undo.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class Test extends JApplet {<br>
              private UndoableList list = new UndoableList();<br>
              private JScrollPane scrollPane = new JScrollPane(list);</p>
            <p> private JButton addButton = new JButton(&quot;Add Item&quot;),<br>
              endButton = new JButton(&quot;End&quot;),<br>
              undoButton = new JButton(&quot;Undo&quot;);</p>
            <p> private UndoAction undoAction = new UndoAction();<br>
              private CompoundEdit compoundEdit = new CompoundEdit();<br>
              private int cnt=0;</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(addButton);<br>
              contentPane.add(endButton);<br>
              contentPane.add(undoButton);<br>
              contentPane.add(scrollPane);</p>
            <p> scrollPane.setPreferredSize(new Dimension(150,150));<br>
              list.addUndoableEditListener(undoAction);</p>
            <p> endButton.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              compoundEdit.end();<br>
              updateButtonsEnabledState();<br>
              }<br>
              });<br>
              addButton.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              list.undoableAdd(&quot;item #&quot; + cnt++);<br>
              updateButtonsEnabledState();<br>
              }<br>
              });<br>
              undoButton.addActionListener(undoAction);</p>
            <p> endButton.setEnabled(false);<br>
              undoButton.setEnabled(false);<br>
              }<br>
              private void updateButtonsEnabledState() {<br>
              boolean inProgress = compoundEdit.isInProgress();</p>
            <p> endButton.setEnabled(inProgress);<br>
              addButton.setEnabled(inProgress);</p>
            <p> if(undoButton.getText().equals(&quot;Undo&quot;))<br>
              undoButton.setEnabled(compoundEdit.canUndo());<br>
              else<br>
              undoButton.setEnabled(compoundEdit.canRedo());<br>
              }<br>
              class UndoAction extends AbstractAction <br>
              implements UndoableEditListener {</p>
            <p> public UndoAction() {<br>
              putValue(Action.NAME, &quot;Undo&quot;);<br>
              }<br>
              public void actionPerformed(ActionEvent e) {<br>
              String name = undoButton.getText();<br>
              boolean isUndo = name.equals(&quot;Undo&quot;);</p>
            <p> if(isUndo) compoundEdit.undo(); <br>
              else compoundEdit.redo(); </p>
            <p> undoButton.setText(isUndo ? &quot;Redo&quot; : &quot;Undo&quot;);<br>
              }<br>
              public void undoableEditHappened(UndoableEditEvent e) {<br>
              UndoableEdit edit = e.getEdit();<br>
              compoundEdit.addEdit(edit);<br>
              endButton.setEnabled(true);<br>
              }<br>
              }<br>
              }<br>
              class UndoableList extends JList {<br>
              UndoableEditSupport support = new UndoableEditSupport();<br>
              DefaultListModel model;</p>
            <p> public UndoableList() {<br>
              setModel(model = new DefaultListModel());<br>
              }<br>
              public void addUndoableEditListener(UndoableEditListener l) {<br>
              support.addUndoableEditListener(l);<br>
              }<br>
              public void removeUndoableEditListener(<br>
              UndoableEditListener l) {<br>
              support.removeUndoableEditListener(l);<br>
              }<br>
              public void undoableAdd(Object s) {<br>
              model.addElement(s);<br>
              support.postEdit(new AddItemEdit());<br>
              }<br>
              class AddItemEdit extends AbstractUndoableEdit {<br>
              Object lastItemAdded;</p>
            <p> public void undo() throws CannotUndoException {<br>
              super.undo();<br>
              lastItemAdded = model.getElementAt(model.getSize()-1);<br>
              model.removeElement(lastItemAdded);<br>
              }<br>
              public void redo() throws CannotRedoException {<br>
              super.redo();<br>
              model.addElement(lastItemAdded);<br>
              }<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 6.7.4 UndoManager</p>
            <p>&nbsp;</p>
            <p> 6.7.5 状态编辑</p>
            <p>&nbsp;</p>
            <p align="center"><b>例6-15 使用状态编辑</b></p>
            <hr noshade size="1">
            import javax.swing.*;<br>
            import javax.swing.event.*;<br>
            import javax.swing.undo.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;<br>
            import java.util.*;
            <p>public class Test extends JApplet {<br>
              private TextFieldPanel panel = new TextFieldPanel();<br>
              private StateEdit stateEdit;</p>
            <p> private JButton startButton = new JButton(&quot;Start Edit&quot;),<br>
              endButton = new JButton(&quot;End Edit&quot;),<br>
              undoButton = new JButton(&quot;Undo&quot;);</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(startButton);<br>
              contentPane.add(endButton);<br>
              contentPane.add(undoButton);<br>
              contentPane.add(panel);</p>
            <p> endButton.setEnabled(false);<br>
              undoButton.setEnabled(false);</p>
            <p> startButton.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              stateEdit = new StateEdit(panel);<br>
              endButton.setEnabled(true);<br>
              startButton.setEnabled(false);<br>
              }<br>
              });<br>
              endButton.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              stateEdit.end();<br>
              undoButton.setEnabled(true);<br>
              endButton.setEnabled(false);<br>
              }<br>
              });<br>
              undoButton.addActionListener(new ActionListener() {<br>
              public void actionPerformed(ActionEvent e) {<br>
              String name = undoButton.getText();<br>
              boolean isUndo = name.equals(&quot;Undo&quot;);</p>
            <p> if(isUndo) stateEdit.undo(); <br>
              else stateEdit.redo(); </p>
            <p> undoButton.setText(isUndo ? &quot;Redo&quot; : &quot;Undo&quot;);<br>
              }<br>
              });<br>
              }<br>
              }<br>
              class TextFieldPanel extends JPanel implements StateEditable {<br>
              JTextField[] fields = new JTextField[] {<br>
              new JTextField(&quot;text field 1&quot;), <br>
              new JTextField(&quot;text field 2&quot;),<br>
              new JTextField(&quot;text field 3&quot;), <br>
              new JTextField(&quot;text field 4&quot;),<br>
              };</p>
            <p> public TextFieldPanel() {<br>
              setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));</p>
            <p> for(int i=0; i &lt; fields.length; ++i)<br>
              add(fields[i]);<br>
              }<br>
              public void storeState(Hashtable hashtable) {<br>
              for(int i=0; i &lt; fields.length; ++i)<br>
              hashtable.put(fields[i], fields[i].getText());<br>
              }<br>
              public void restoreState(Hashtable hashtable) {<br>
              Enumeration keys = hashtable.keys();</p>
            <p> while(keys.hasMoreElements()) {<br>
              JTextField field = (JTextField)keys.nextElement();<br>
              field.setText((String)hashtable.get(field));<br>
              }<br>
              }<br>
              }</p>
            <hr noshade size="1">
            <p> 6.8 本章回顾</p>
            <p>&nbsp;</p>
            <p> [<a href="index.html" target="_self">目录</a>][<a href="s05.htm">上一页</a>][<a href="s07.htm">下一页</a>](飒龙收藏/2002.5.18) 
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