Finding a Key Binding in a Component - Java Swing

Java examples for Swing:Key Event

  1. HOME
  2. Java
  3. Swing
  4. Key Event

Description

Finding a Key Binding in a Component

Demo Code



import java.awt.event.KeyEvent;

import javax.swing.Action;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.JTextComponent;
import javax.swing.text.Keymap;

public class Main {
  public void m() throws Exception {
    JTextField component = null;/* w  w w. ja  va  2 s.  c  o m*/
    FindResult r = find(KeyStroke.getKeyStroke("ctrl pressed C"), component);
    r = find(KeyStroke.getKeyStroke("ctrl released C"), component);
    r = find(KeyStroke.getKeyStroke("C"), component);
    r = find(KeyStroke.getKeyStroke("typed C"), component);
    r = find(KeyStroke.getKeyStroke(new Character('\u0002'), 0), component);
  }

  // Returns null if not found
  static FindResult find(KeyStroke k, JComponent c) {
    FindResult result;

    result = find(k, c.getInputMap(JComponent.WHEN_FOCUSED));
    if (result != null) {
      return result;
    }
    result = find(k,
        c.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT));
    if (result != null) {
      return result;
    }
    result = find(k, c.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW));
    if (result != null) {
      return result;
    }

    // Check keymaps
    if (c instanceof JTextComponent) {
      JTextComponent tc = (JTextComponent) c;
      result = new FindResult();

      // Check local keymap
      Keymap kmap = tc.getKeymap();
      if (kmap.isLocallyDefined(k)) {
        result.keymap = kmap;
        result.isLocal = true;
        return result;
      }

      // Check parent keymaps
      kmap = kmap.getResolveParent();
      while (kmap != null) {
        if (kmap.isLocallyDefined(k)) {
          result.keymap = kmap;
          return result;
        }
        kmap = kmap.getResolveParent();
      }

      // Look for default action
      if (k.getKeyEventType() == KeyEvent.KEY_TYPED) {
        // Check local keymap
        kmap = tc.getKeymap();
        if (kmap.getDefaultAction() != null) {
          result.keymap = kmap;
          result.defaultAction = kmap.getDefaultAction();
          result.isLocal = true;
          return result;
        }

        // Check parent keymaps
        kmap = kmap.getResolveParent();
        while (kmap != null) {
          if (kmap.getDefaultAction() != null) {
            result.keymap = kmap;
            result.defaultAction = kmap.getDefaultAction();
            return result;
          }
          kmap = kmap.getResolveParent();
        }
      }
    }
    return null;
  }

  static FindResult find(KeyStroke k, InputMap map) {
    // Check local inputmap
    KeyStroke[] keys = map.keys();
    for (int i = 0; keys != null && i < keys.length; i++) {
      if (k.equals(keys[i])) {
        FindResult result = new FindResult();
        result.inputMap = map;
        result.isLocal = true;
        return result;
      }
    }

    // Check parent inputmap
    map = map.getParent();
    while (map != null) {
      keys = map.keys();
      for (int i = 0; keys != null && i < keys.length; i++) {
        if (k.equals(keys[i])) {
          FindResult result = new FindResult();
          result.inputMap = map;
          return result;
        }
      }
      map = map.getParent();
    }
    return null;
  }
}

class FindResult {
  InputMap inputMap;
  Keymap keymap;
  Action defaultAction;
  boolean isLocal;

  public String toString() {
    StringBuffer b = new StringBuffer();

    b.append("inputmap=" + inputMap + ",keymap=" + keymap + ",defaultAction="
        + defaultAction + ",isLocal=" + isLocal);
    return b.toString();
  }
}

Related Tutorials