/*

 * Copyright 1998-2004 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package javax.swing;

import java.util.*;

import java.awt.*;

import java.awt.event.*;

import java.applet.*;

import java.beans.*;

import javax.swing.event.*;

import sun.awt.EmbeddedFrame;

/**

  * The KeyboardManager class is used to help dispatch keyboard actions for the

  * WHEN_IN_FOCUSED_WINDOW style actions.  Actions with other conditions are handled

  * directly in JComponent.

  *

  * Here's a description of the symantics of how keyboard dispatching should work

  * atleast as I understand it.

  *

  * KeyEvents are dispatched to the focused component.  The focus manager gets first

  * crack at processing this event.  If the focus manager doesn't want it, then

  * the JComponent calls super.processKeyEvent() this allows listeners a chance

  * to process the event.

  *

  * If none of the listeners "consumes" the event then the keybindings get a shot.

  * This is where things start to get interesting.  First, KeyStokes defined with the

  * WHEN_FOCUSED condition get a chance.  If none of these want the event, then the component

  * walks though it's parents looked for actions of type WHEN_ANCESTOR_OF_FOCUSED_COMPONENT.

  *

  * If no one has taken it yet, then it winds up here.  We then look for components registered

  * for WHEN_IN_FOCUSED_WINDOW events and fire to them.  Note that if none of those are found

  * then we pass the event to the menubars and let them have a crack at it.  They're handled differently.

  *

  * Lastly, we check if we're looking at an internal frame.  If we are and no one wanted the event

  * then we move up to the InternalFrame's creator and see if anyone wants the event (and so on and so on).

  *

  *

  * @see InputMap

  */

class KeyboardManager {

    static KeyboardManager currentManager = new KeyboardManager();

    /**

      * maps top-level containers to a sub-hashtable full of keystrokes

      */

    Hashtable containerMap = new Hashtable();

    /**

      * Maps component/keystroke pairs to a topLevel container

      * This is mainly used for fast unregister operations

      */

    Hashtable componentKeyStrokeMap = new Hashtable();

    public static KeyboardManager getCurrentManager() {

        return currentManager;

    }

    public static void setCurrentManager(KeyboardManager km) {

        currentManager = km;

    }

    /**

      * register keystrokes here which are for the WHEN_IN_FOCUSED_WINDOW

      * case.

      * Other types of keystrokes will be handled by walking the hierarchy

      * That simplifies some potentially hairy stuff.

      */

     public void registerKeyStroke(KeyStroke k, JComponent c) {

         Container topContainer = getTopAncestor(c);

         if (topContainer == null) {

             return;

         }

         Hashtable keyMap = (Hashtable)containerMap.get(topContainer);

         if (keyMap ==  null) {  // lazy evaluate one

             keyMap = registerNewTopContainer(topContainer);

         }

         Object tmp = keyMap.get(k);

         if (tmp == null) {

             keyMap.put(k,c);

         } else if (tmp instanceof Vector) {  // if there's a Vector there then add to it.

             Vector v = (Vector)tmp;

             if (!v.contains(c)) {  // only add if this keystroke isn't registered for this component

                 v.addElement(c);

             }

         } else if (tmp instanceof JComponent) {

           // if a JComponent is there then remove it and replace it with a vector

           // Then add the old compoennt and the new compoent to the vector

           // then insert the vector in the table

           if (tmp != c) {  // this means this is already registered for this component, no need to dup

               Vector v = new Vector();

               v.addElement(tmp);

               v.addElement(c);

               keyMap.put(k, v);

           }

         } else {

             System.out.println("Unexpected condition in registerKeyStroke");

             Thread.dumpStack();

         }

         componentKeyStrokeMap.put(new ComponentKeyStrokePair(c,k), topContainer);

         // Check for EmbeddedFrame case, they know how to process accelerators even

         // when focus is not in Java

         if (topContainer instanceof EmbeddedFrame) {

             ((EmbeddedFrame)topContainer).registerAccelerator(k);

         }

     }

     /**

       * Find the top focusable Window, Applet, or InternalFrame

       */

     private static Container getTopAncestor(JComponent c) {

        for(Container p = c.getParent(); p != null; p = p.getParent()) {

            if (p instanceof Window && ((Window)p).isFocusableWindow() ||

                p instanceof Applet || p instanceof JInternalFrame) {

                return p;

            }

        }

        return null;

     }

     public void unregisterKeyStroke(KeyStroke ks, JComponent c) {

       // component may have already been removed from the hierarchy, we

       // need to look up the container using the componentKeyStrokeMap.

         ComponentKeyStrokePair ckp = new ComponentKeyStrokePair(c,ks);

         Object topContainer = componentKeyStrokeMap.get(ckp);

         if (topContainer == null) {  // never heard of this pairing, so bail

             return;

         }

         Hashtable keyMap = (Hashtable)containerMap.get(topContainer);

         if  (keyMap == null) { // this should never happen, but I'm being safe

             Thread.dumpStack();

             return;

         }

         Object tmp = keyMap.get(ks);

         if (tmp == null) {  // this should never happen, but I'm being safe

             Thread.dumpStack();

             return;

         }

         if (tmp instanceof JComponent && tmp == c) {

             keyMap.remove(ks);  // remove the KeyStroke from the Map

             //System.out.println("removed a stroke" + ks);

         } else if (tmp instanceof Vector ) {  // this means there is more than one component reg for this key

             Vector v = (Vector)tmp;

             v.removeElement(c);

             if ( v.isEmpty() ) {

                 keyMap.remove(ks);  // remove the KeyStroke from the Map

                 //System.out.println("removed a ks vector");

             }

         }

         if ( keyMap.isEmpty() ) {  // if no more bindings in this table

             containerMap.remove(topContainer);  // remove table to enable GC

             //System.out.println("removed a container");

         }

         componentKeyStrokeMap.remove(ckp);

         // Check for EmbeddedFrame case, they know how to process accelerators even

         // when focus is not in Java

         if (topContainer instanceof EmbeddedFrame) {

             ((EmbeddedFrame)topContainer).unregisterAccelerator(ks);

         }

     }

    /**

      * This method is called when the focused component (and none of

      * its ancestors) want the key event.  This will look up the keystroke

      * to see if any chidren (or subchildren) of the specified container

      * want a crack at the event.

      * If one of them wants it, then it will "DO-THE-RIGHT-THING"

      */

    public boolean fireKeyboardAction(KeyEvent e, boolean pressed, Container topAncestor) {

         if (e.isConsumed()) {

              System.out.println("Aquired pre-used event!");

              Thread.dumpStack();

         }

         KeyStroke ks;

         if(e.getID() == KeyEvent.KEY_TYPED) {

               ks=KeyStroke.getKeyStroke(e.getKeyChar());

         } else {

               ks=KeyStroke.getKeyStroke(e.getKeyCode(), e.getModifiers(), !pressed);

         }

         Hashtable keyMap = (Hashtable)containerMap.get(topAncestor);

         if (keyMap != null) { // this container isn't registered, so bail

             Object tmp = keyMap.get(ks);

             if (tmp == null) {

               // don't do anything

             } else if ( tmp instanceof JComponent) {

                 JComponent c = (JComponent)tmp;

                 if ( c.isShowing() && c.isEnabled() ) { // only give it out if enabled and visible

                     fireBinding(c, ks, e, pressed);

                 }

             } else if ( tmp instanceof Vector) { //more than one comp registered for this

                 Vector v = (Vector)tmp;

                 // There is no well defined order for WHEN_IN_FOCUSED_WINDOW

                 // bindings, but we give precedence to those bindings just

                 // added. This is done so that JMenus WHEN_IN_FOCUSED_WINDOW

                 // bindings are accessed before those of the JRootPane (they

                 // both have a WHEN_IN_FOCUSED_WINDOW binding for enter).

                 for (int counter = v.size() - 1; counter >= 0; counter--) {

                     JComponent c = (JComponent)v.elementAt(counter);

                     //System.out.println("Trying collision: " + c + " vector = "+ v.size());

                     if ( c.isShowing() && c.isEnabled() ) { // don't want to give these out

                         fireBinding(c, ks, e, pressed);

                         if (e.isConsumed())

                             return true;

                     }

                 }

             } else  {

                 System.out.println( "Unexpected condition in fireKeyboardAction " + tmp);

                 // This means that tmp wasn't null, a JComponent, or a Vector.  What is it?

                 Thread.dumpStack();

             }

         }

         if (e.isConsumed()) {

             return true;

         }

         // if no one else handled it, then give the menus a crack

         // The're handled differently.  The key is to let any JMenuBars

         // process the event

         if ( keyMap != null) {

             Vector v = (Vector)keyMap.get(JMenuBar.class);

             if (v != null) {

                 Enumeration iter = v.elements();

                 while (iter.hasMoreElements()) {

                     JMenuBar mb = (JMenuBar)iter.nextElement();

                     if ( mb.isShowing() && mb.isEnabled() ) { // don't want to give these out

                         fireBinding(mb, ks, e, pressed);

                         if (e.isConsumed()) {

                             return true;

                         }

                     }

                 }

             }

         }

         return e.isConsumed();

    }

    void fireBinding(JComponent c, KeyStroke ks, KeyEvent e, boolean pressed) {

        if (c.processKeyBinding(ks, e, JComponent.WHEN_IN_FOCUSED_WINDOW,

                                pressed)) {

            e.consume();

        }

    }

    public void registerMenuBar(JMenuBar mb) {

        Container top = getTopAncestor(mb);

        if (top == null) {

            return;

        }

        Hashtable keyMap = (Hashtable)containerMap.get(top);

        if (keyMap ==  null) {  // lazy evaluate one

             keyMap = registerNewTopContainer(top);

        }

        // use the menubar class as the key

        Vector menuBars = (Vector)keyMap.get(JMenuBar.class);

        if (menuBars == null) {  // if we don't have a list of menubars,

                                 // then make one.

            menuBars = new Vector();

            keyMap.put(JMenuBar.class, menuBars);

        }

        if (!menuBars.contains(mb)) {

            menuBars.addElement(mb);

        }

    }

    public void unregisterMenuBar(JMenuBar mb) {

        Object topContainer = getTopAncestor(mb);

        if (topContainer == null) {

            return;

        }

        Hashtable keyMap = (Hashtable)containerMap.get(topContainer);

        if (keyMap!=null) {

            Vector v = (Vector)keyMap.get(JMenuBar.class);

            if (v != null) {

                v.removeElement(mb);

                if (v.isEmpty()) {

                    keyMap.remove(JMenuBar.class);

                    if (keyMap.isEmpty()) {

                        // remove table to enable GC

                        containerMap.remove(topContainer);

                    }

                }

            }

        }

    }

    protected Hashtable registerNewTopContainer(Container topContainer) {

             Hashtable keyMap = new Hashtable();

             containerMap.put(topContainer, keyMap);

             return keyMap;

    }

    /**

      * This class is used to create keys for a hashtable

      * which looks up topContainers based on component, keystroke pairs

      * This is used to make unregistering KeyStrokes fast

      */

    class ComponentKeyStrokePair {

        Object component;

        Object keyStroke;

        public ComponentKeyStrokePair(Object comp, Object key) {

            component = comp;

            keyStroke = key;

        }

        public boolean equals(Object o) {

            if ( !(o instanceof ComponentKeyStrokePair)) {

                return false;

            }

            ComponentKeyStrokePair ckp = (ComponentKeyStrokePair)o;

            return ((component.equals(ckp.component)) && (keyStroke.equals(ckp.keyStroke)));

        }

        public int hashCode() {

            return component.hashCode() * keyStroke.hashCode();

        }

    }

} // end KeyboardManager