s04.htm

Java2Swingt界面设计

              logCheckBox.addItemListener(new ItemListener() {<br>
              public void itemStateChanged(ItemEvent e) {<br>
              AbstractButton b = (AbstractButton)e.getSource();</p>
            <p> if(b.isSelected()) logIsOn = true;<br>
              else logIsOn = false;<br>
              }<br>
              });</p>
            <p> return controls;<br>
              }<br>
              public static void main(String args[]) {<br>
              final JFrame f = new JFrame();<br>
              JApplet applet = new DebugGraphicsTest();</p>
            <p> applet.init();<br>
              f.setContentPane(applet.getContentPane());</p>
            <p> f.setBounds(100,100,300,175);<br>
              f.setTitle(&quot;DebugGraphicsTest&quot;);<br>
              f.setVisible(true);</p>
            <p> f.addWindowListener(new WindowAdapter() {<br>
              public void windowClosing(WindowEvent event) {<br>
              f.dispose();<br>
              System.exit(0);<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 4.6 自动滚动</p>
            <p>&nbsp;</p>
            <p align="center"><b>例4-15 包裹在滚动窗格中的一个列表</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;
            <p>public class TestApplet extends JApplet {<br>
              public void init() {<br>
              String[] items = { &quot;one&quot;, &quot;two&quot;, &quot;three&quot;, 
              <br>
              &quot;four&quot;, &quot;five&quot;, &quot;six&quot; };</p>
            <p> Container contentPane = getContentPane();<br>
              JList list = new JList(items);</p>
            <p> list.setVisibleRowCount(3);</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(new JScrollPane(list));<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p align="center"><b>例4-16 自动滚动测试小应用程序</b></p>
            <hr size="1" noshade>
            <hr size="1" noshade>
            <p>&nbsp;</p>
            <p align="center"><b>例4-17 AutoscrollViewport列表</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>class AutoscrollViewport extends JViewport {<br>
              Point scrollTo = new Point(), last = new Point();<br>
              boolean manualDragUnderway = false;<br>
              final int increment;</p>
            <p> public AutoscrollViewport(Component component, int inc) {<br>
              this.increment = inc;</p>
            <p> setView(component);</p>
            <p> setAutoscrolls(true);<br>
              setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));</p>
            <p> addMouseListener(new MouseAdapter() {<br>
              public void mousePressed(MouseEvent e) {<br>
              last.x = e.getPoint().x;<br>
              last.y = e.getPoint().y;<br>
              manualDragUnderway = true;<br>
              }<br>
              }); <br>
              addMouseMotionListener(new MouseMotionAdapter() {<br>
              public void mouseDragged(MouseEvent e) {<br>
              Point drag = e.getPoint();<br>
              Point viewPos = getViewPosition();<br>
              Point offset = new Point(drag.x - last.x,<br>
              drag.y - last.y);<br>
              last.x = drag.x;<br>
              last.y = drag.y;</p>
            <p> if(contains(drag)) {<br>
              if(manualDragUnderway) {<br>
              scrollTo.x = viewPos.x - offset.x;<br>
              scrollTo.y = viewPos.y - offset.y;<br>
              setViewPosition(scrollTo);<br>
              }<br>
              }<br>
              else { // autoscrolling ...<br>
              Rectangle bounds = getBounds();</p>
            <p> manualDragUnderway = false;</p>
            <p> if(drag.x &gt; bounds.x + bounds.width) {<br>
              // scroll right<br>
              viewPos.x -= increment;<br>
              setViewPosition(viewPos);<br>
              }<br>
              if(drag.x &lt; 0) {<br>
              // scroll left<br>
              viewPos.x += increment;<br>
              setViewPosition(viewPos);<br>
              }<br>
              if(drag.y &gt; bounds.y + bounds.height) {<br>
              // scroll down<br>
              viewPos.y -= increment;<br>
              setViewPosition(viewPos);<br>
              }<br>
              if(drag.y &lt; 0) {<br>
              // scroll up<br>
              viewPos.y += increment;<br>
              setViewPosition(viewPos);<br>
              }<br>
              }<br>
              }<br>
              });<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 4.7 工具提示</p>
            <p>&nbsp;</p>
            <p align="center"><b>例4-18 为一个按钮设置工具提示文本</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class ToolTipTest extends JApplet {<br>
              public void init() {<br>
              Container contentPane = getContentPane();<br>
              JButton button = new JButton(&quot;I've got a tooltip&quot;);</p>
            <p> button.setMnemonic(KeyEvent.VK_G);</p>
            <p> button.setToolTipText(<br>
              &quot;rather lengthy tooltip text for button&quot;);</p>
            <p> contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(button);<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 4.7.1 基于鼠标位置的工具提示</p>
            <p>&nbsp;</p>
            <p align="center"><b>例4-19 根据鼠标位置来显示不同的工具提示</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class ToolTipsBasedOnMousePosition extends JApplet {<br>
              public void init() {<br>
              Container contentPane = getContentPane();<br>
              <br>
              //ImageMap map = new ImageMap(&quot;tiger.gif&quot;);<br>
              Icon icon = new ImageIcon(this.getClass().getResource(&quot;tiger.gif&quot;));<br>
              ImageMap map = new ImageMap(icon);<br>
              <br>
              contentPane.setLayout(new FlowLayout());<br>
              contentPane.add(map);<br>
              }<br>
              }<br>
              class ImageMap extends JLabel {<br>
              private Rectangle teeth= new Rectangle(62,203,80,55),<br>
              nose = new Rectangle(37,164,130,30),<br>
              ear = new Rectangle(228,10,65,55),<br>
              rEye = new Rectangle(137,103,20,17),<br>
              lEye = new Rectangle(65,97,16,15);</p>
            <p> //public ImageMap(String imageName) {<br>
              public ImageMap(Icon imageName) {<br>
              //super(new ImageIcon(imageName));<br>
              super(imageName);<br>
              setToolTipText(&quot;tiger!&quot;);<br>
              }<br>
              public String getToolTipText(MouseEvent e) {<br>
              Point p = e.getPoint();<br>
              String s = null;</p>
            <p> if(teeth.contains(p)) s = &quot;ooooh, big teeth!&quot;;<br>
              else if(nose.contains(p)) s = &quot;keen sense of smell&quot;;<br>
              else if(ear.contains(p)) s = &quot;acute hearing&quot;;<br>
              else if(rEye.contains(p) || lEye.contains(p)) <br>
              s = &quot;excellent vision&quot;;</p>
            <p> return s == null ? getToolTipText() : s;<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 4.7.2 工具提示的首选位置</p>
            <p>&nbsp;</p>
            <p> 4.7.3 定制工具提示的行为</p>
            <p>&nbsp;</p>
            <p> 4.7.4 定制工具提示的界面样式</p>
            <p>&nbsp;</p>
            <p> 4.8 键击处理</p>
            <p>&nbsp;</p>
            <p align="center"><b>例4-20 处理嵌套键击</b></p>
            <hr size="1" noshade>
            import javax.swing.*;<br>
            import java.awt.*;<br>
            import java.awt.event.*;
            <p>public class KeystrokeTest extends JApplet {<br>
              private JButton button = new JButton(&quot;button&quot;);</p>
            <p> public void init() {<br>
              Container contentPane = getContentPane();<br>
              JPanel panel = new JPanel();<br>
              JCheckBox checkbox = new JCheckBox(&quot;checkbox&quot;);<br>
              JButton southButton = new JButton(&quot;south button&quot;);<br>
              Listener listener = new Listener();</p>
            <p> panel.setBorder(<br>
              BorderFactory.createTitledBorder(<br>
              (&quot;Ancestor of button and checkbox&quot;)));</p>
            <p> checkbox.registerKeyboardAction(<br>
              listener,<br>
              KeyStroke.getKeyStroke(KeyEvent.VK_F,0,false),<br>
              JComponent.WHEN_FOCUSED);</p>
            <p> panel.registerKeyboardAction(<br>
              listener,<br>
              KeyStroke.getKeyStroke(KeyEvent.VK_A, <br>
              InputEvent.ALT_MASK, false),<br>
              JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);</p>
            <p> southButton.registerKeyboardAction(<br>
              listener,<br>
              KeyStroke.getKeyStroke(KeyEvent.VK_W, 0, true),<br>
              JComponent.WHEN_IN_FOCUSED_WINDOW);</p>
            <p> panel.add(button);<br>
              panel.add(checkbox);</p>
            <p> contentPane.add(panel, &quot;Center&quot;);<br>
              contentPane.add(southButton, &quot;South&quot;);<br>
              }<br>
              }<br>
              class Listener implements ActionListener {<br>
              public void actionPerformed(ActionEvent e) {<br>
              Object src = e.getSource();<br>
              String cname = src.getClass().getName();</p>
            <p> if(src instanceof JCheckBox) {<br>
              System.out.print(&quot;'f' key PRESSED when checkbox&quot;);<br>
              System.out.println(&quot; had focus&quot;);<br>
              }<br>
              else if(src instanceof JPanel) {<br>
              System.out.print(&quot;'ALT-a' key PRESSED when ancestor&quot;);<br>
              System.out.println(&quot; of titled panel had focus&quot;);<br>
              }<br>
              else if(src instanceof JButton) {<br>
              System.out.print(&quot;'w' key RELEASED when any&quot;);<br>
              System.out.println(&quot; component in window had focus&quot;);<br>
              }<br>
              System.out.println(&quot;Source: &quot; + cname);<br>
              System.out.println();<br>
              }<br>
              }</p>
            <hr size="1" noshade>
            <p> 4.9 客户属性</p>