忍受我。我正在制作一个Java控制台，类似于在https://code.google.com/p/dragonconsole/处找到的DragonConsole。一切都按计划进行，但是我想实现DragonConsole中的一项功能。我想增加一下使垂直滚动条延伸到框架底部的能力，就像在DC中一样。
这是我的。
如您所见，垂直滚动条并没有延伸到底部，而IMO则看起来不专业。但是我还是一个业余爱好者：D
这是我的程序的组织方式：输出是jScrollPane，输入是简单的jTextField。用户输入输入，并显示结果输出。
现在，我浏览了DragonConsole的源代码，并通过复杂的方式告诉我这些东西是如何工作的。据我所知，有一个jTextArea用户可以在其中输入命令，但是我不知道垂直滚动条的功能如何。
请问有人可以帮我模仿DragonConsole的滚动条吗？
您还可以看到，DC上的输入与垂直滚动条一起移动。我也该怎么做。
输入区域无处可看...
“ 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)
它似乎在这里指向一个问题：
@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
}
再次感谢您对@amurka的帮助：）
最佳答案
查看DragonConsole源代码，它支持两种模式：内联和非内联。在滚动模式下，滚动条延伸到底部的第一张图片是DragonConsole。
在此模式下，只有一个JTextPane，然后将其添加到JScrollPane。这就是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。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，总而言之：
创建JTextPane。在DragonConsole.java中查看initializeConsole()
将CaretListener和KeyListener添加到该文本窗格。在DragonConsole.java中查看caretUpdate()和keyPressed()
设置自定义DocumentFilter。查看InputController.java（实际上，设置文档样式是通过inializeConsole方法完成的。）
实际上，它的执行方式与DragonConsole在非串联模式下的执行方式相同。在这种情况下，它将JTextPane用于输出区域，将JTextArea用于输入区域，并且在滚动条上应看起来相同。
编辑：这是一个内联控制台的超简单示例。
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();
}
}
}