java swing 键绑定(bind) - 缺少释放键的操作

Question

注册了“SPACE”和“released SPACE”的键绑定(bind)，当空格是唯一按下/释放的键时，它的工作方式与广告一样，我注意到按下空格，然后按下 ctrl(或任何其他修改键)，然后释放空间最后释放 ctrl 将导致执行与“SPACE”关联的操作，但不会执行与“released SPACE”关联的操作。

一旦不再按下空格(或同时按下修改键)，导致执行操作的首选方法是什么？我只在 64 位 Windows 7 上试过这个。

import javax.swing.SwingUtilities;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.AbstractAction;
import javax.swing.KeyStroke;
import java.awt.event.ActionEvent;
import java.awt.Cursor;

class Bind extends JPanel {
  {
    getInputMap().put(KeyStroke.getKeyStroke("SPACE"), "pressed");
    getInputMap().put(KeyStroke.getKeyStroke("released SPACE"), "released");
    getActionMap().put("pressed", new AbstractAction() {
      @Override public void actionPerformed(ActionEvent e) {
        System.out.println("pressed");
        setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR)); 
      }
    });
    getActionMap().put("released", new AbstractAction() {
      @Override public void actionPerformed(ActionEvent e) {
        System.out.println("released");
        setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR)); 
      }
    });
  }
  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
      @Override public void run() {
        JFrame f = new JFrame("Key Bindings");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        f.add(new Bind());
        f.setSize(640, 480);
        f.setVisible(true);
      }
    });
  }
}

更新:这是避免在释放空间之前意外按下 ctrl、alt 或 shift 时粘滞空间的方法:

import javax.swing.SwingUtilities;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.AbstractAction;
import javax.swing.KeyStroke;
import java.awt.event.ActionEvent;
import java.awt.Cursor;

class Bind extends JPanel {
  {
    getInputMap().put(KeyStroke.getKeyStroke("SPACE"), "pressed");
    getInputMap().put(KeyStroke.getKeyStroke("released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("ctrl released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("shift released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("shift ctrl released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("alt released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("alt ctrl released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("alt shift released SPACE"), "released");
    getInputMap().put(KeyStroke.getKeyStroke("alt shift ctrl released SPACE"), "released");
    getActionMap().put("pressed", new AbstractAction() {
      @Override public void actionPerformed(ActionEvent e) {
        System.out.println("pressed");
        setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR)); 
      }
    });
    getActionMap().put("released", new AbstractAction() {
      @Override public void actionPerformed(ActionEvent e) {
        System.out.println("released");
        setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR)); 
      }
    });
  }
  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
      @Override public void run() {
        JFrame f = new JFrame("Key Bindings");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        f.add(new Bind());
        f.setSize(640, 480);
        f.setVisible(true);
      }
    });
  }
}

Answer 1

released SPACE 事件在按住 Control 键时不会被触发是有道理的。我希望触发 control released SPACE 事件。

将以下内容添加到您的代码中:

getInputMap().put(KeyStroke.getKeyStroke("control released SPACE"), "released");

出于同样的原因，如果您首先按住 Control 键，则 SPACE 事件不会触发。因此，您还需要为 control SPACE 添加绑定(bind)。

您需要对所有修改键执行此操作，这可能是也可能不是比跟踪键事件更简单的解决方案。