Java终端开发

Question

忍受我吧。我正在制作一个java控制台，类似于在这里找到的DragonConsole https://code.google.com/p/dragonconsole/。一切都按计划进行，但我想实现一个在DragonConsole中找到的特性。我想增加到我的能力，有垂直滚动条延伸到底部的框架，就像它在DC。

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这是我的。

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正如你所看到的，垂直滚动条没有延伸到底部，而国际海事组织，它看起来不专业。但我仍然是个业余爱好者

下面是我的程序的组织方式:输出是一个jScrollPane，输入是一个简单的jTextField。用户输入输入，并显示结果输出。

现在，我已经查看了DragonConsole的源代码，以及它对我来说是如何工作的复杂的方法。据我所知，有一个用户输入命令的jTextArea，但我不知道垂直滚动条是如何工作的。

有人能帮我模仿一下龙虎队的滚动条吗？

还可以看到，DC上的输入与垂直滚动条一起移动。我怎么也能做到这一点。

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输入区域没有地方可以看到..。

"cls“命令调用此函数：

public void clear() {
        console.setText("");
        print(""); // printing will automatically print the '> ' at the beginning
        startIndex = console.getText().length();
    }

打印功能：

public void print(String s) { // prints output to the console
        console.append(System.lineSeparator() + prompt + s);
    }

产生的错误：

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: bad position: 110
    at javax.swing.text.JTextComponent.setCaretPosition(JTextComponent.java:1678)   at javax.swing.text.JTextComponent.setCaretPosition(JTextComponent.java:1678)
    at Main.Terminal.caretUpdate(Terminal.java:198)
    at javax.swing.text.JTextComponent.fireCaretUpdate(JTextComponent.java:407)
    at javax.swing.text.JTextComponent$MutableCaretEvent.fire(JTextComponent.java:4417)
    at javax.swing.text.JTextComponent$MutableCaretEvent.stateChanged(JTextComponent.java:4439)
    at javax.swing.text.DefaultCaret.fireStateChanged(DefaultCaret.java:798)
    at javax.swing.text.DefaultCaret.changeCaretPosition(DefaultCaret.java:1273)
    at javax.swing.text.DefaultCaret.handleSetDot(DefaultCaret.java:1169)
    at javax.swing.text.DefaultCaret.setDot(DefaultCaret.java:1150)
    at javax.swing.text.DefaultCaret$Handler.removeUpdate(DefaultCaret.java:1796)
    at javax.swing.text.AbstractDocument.fireRemoveUpdate(AbstractDocument.java:260)
    at javax.swing.text.AbstractDocument.handleRemove(AbstractDocument.java:623)
    at javax.swing.text.AbstractDocument.remove(AbstractDocument.java:591)
    at javax.swing.text.AbstractDocument.replace(AbstractDocument.java:667)
    at javax.swing.text.JTextComponent.setText(JTextComponent.java:1718)
    at Main.Terminal.doCommand(Terminal.java:218)
    at Main.Terminal.keyPressed(Terminal.java:168)
    at java.awt.Component.processKeyEvent(Component.java:6463)
    at javax.swing.JComponent.processKeyEvent(JComponent.java:2829)
    at java.awt.Component.processEvent(Component.java:6282)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1895)
    at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:762)
    at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:1027)
    at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:899)
    at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:727)
    at java.awt.Component.dispatchEventImpl(Component.java:4731)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

它似乎指向了一个问题：

@Override
    public void caretUpdate(CaretEvent e) {
        // Ensure that the caret position can only be a valid location
        if (e.getDot() < startIndex) {
            console.setCaretPosition(startIndex);
            Toolkit.getDefaultToolkit().beep();
        }
    }

修正错误的代码

public void clear() {
        startIndex = 0; // set it to zero to prevent error from happening
        console.setText(""); // this will erase anything on screen, but start the input seqence on the next line
    }

​

​

再次感谢您的帮助@amurka :)

Answer 1

查看DragonConsole源代码，它支持两种模式:内联模式和不内联模式。首先，滚动条延伸到底部的图片是内联模式下的DragonConsole。

在这种模式下，它只是一个JTextPane，然后添加到一个JScrollPane中。这就是为什么滚动条延伸到底部的原因。然后将KeyListener (keyPressed方法)和CaretListener (caretUpdate函数)添加到JTextPane中。最后，它使用在DocumentFilter类中实现的自定义InputController来获取您看到的控制台行为。

因此，总结如下：

• 创建JTextPane。看看initializeConsole() in DragonConsole.java
• 将CaretListener和KeyListener添加到该文本窗格。看看caretUpdate()和keyPressed()中的DragonConsole.java
• 设置自定义DocumentFilter。查看InputController.java (实际上，在inializeConsole方法中设置文档样式是完成的)。

您这样做的方式实际上与DragonConsole在不采用内联模式时所做的方式相同。在本例中，它使用一个JTextPane作为输出区域，一个JTextArea用于输入区域，并且在滚动条方面应该是相同的。

编辑：下面是一个内联控制台的超级简单示例。

public class Console extends JPanel implements KeyListener, CaretListener {

    private static final String PROMPT = ">>";

    private JScrollPane scrollPane;
    private JTextArea consoleTextPane;

    private int startIndex;

    public Console() {
        super();

        // Create a text area
        consoleTextPane = new JTextArea();
        consoleTextPane.setText(PROMPT);
        consoleTextPane.setBorder(null);
        // Wraps the text if it goes longer than a line, but NOT on word boundary
        // like a normal console
        consoleTextPane.setLineWrap(true);
        consoleTextPane.setWrapStyleWord(false);

        // Set the initial caret position
        startIndex = consoleTextPane.getText().length();
        consoleTextPane.setCaretPosition(startIndex);

        // Add the caret and key listeners
        consoleTextPane.addCaretListener(this);
        consoleTextPane.addKeyListener(this);

        // Scrollbar, always show the vertical one
        scrollPane = new JScrollPane(consoleTextPane);
        scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        scrollPane.setBorder(null);

        JPanel panelCenter = new JPanel(new BorderLayout());
        panelCenter.setPreferredSize(new Dimension(400, 200));
        panelCenter.add(scrollPane, BorderLayout.CENTER);

        add(panelCenter, BorderLayout.CENTER);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Console");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.add(new Console());
        frame.pack();
        frame.setVisible(true);
    }

    @Override
    public void keyTyped(KeyEvent e) {
        // All processing in keyPressed
    }

    @Override
    public void keyReleased(KeyEvent e) {
        // All processing in keyPressed
    }

    @Override
    public void keyPressed(KeyEvent e) {
        switch(e.getKeyCode()) {
            case KeyEvent.VK_ENTER:
                // ENTER key was pressed
                // Get the "Command"
                String command = consoleTextPane.getText().substring(startIndex);

                if (!command.isEmpty()) {
                    // TODO: do something with the command
                    consoleTextPane.append(System.lineSeparator() 
                            + "Command Entered: " + command);
                }

                // Update the start index and append a new prompt
                consoleTextPane.append(System.lineSeparator() + PROMPT);
                startIndex = consoleTextPane.getText().length();

                // Consume the ENTER key event so further processing is not
                // performed
                e.consume();
                break;
            case KeyEvent.VK_BACK_SPACE:
                // Make sure this is a valid delete
                if (consoleTextPane.getCaretPosition() <= startIndex) {
                    e.consume();
                    Toolkit.getDefaultToolkit().beep();
                }

                break;
            // TODO: add key presses here as desired
            default:
                //System.out.println("Unhandled: " + e.getKeyCode());
                break;
        }
    }

    @Override
    public void caretUpdate(CaretEvent e) {
        // Ensure that the caret position can only be a valid location
        if (e.getDot() < startIndex) {
            consoleTextPane.setCaretPosition(startIndex);
            Toolkit.getDefaultToolkit().beep();
        }
    }
}