Package javax.swing

Source Code of javax.swing.MenuSelectionManager

/*
* @(#)MenuSelectionManager.java  1.43 09/08/07
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.swing;

import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.event.*;

import sun.awt.AppContext;

/**
* A MenuSelectionManager owns the selection in menu hierarchy.
*
* @version 1.43 08/07/09
* @author Arnaud Weber
*/
public class MenuSelectionManager {
    private Vector selection = new Vector();

    /* diagnostic aids -- should be false for production builds. */
    private static final boolean TRACE =   false; // trace creates and disposes
    private static final boolean VERBOSE = false; // show reuse hits/misses
    private static final boolean DEBUG =   false// show bad params, misc.

    private static final Object MENU_SELECTION_MANAGER_KEY = new Object(); // javax.swing.MenuSelectionManager

    /**
     * Returns the default menu selection manager.
     *
     * @return a MenuSelectionManager object
     */
    public static MenuSelectionManager defaultManager() {
        synchronized (MENU_SELECTION_MANAGER_KEY) {
            AppContext context = AppContext.getAppContext();
            MenuSelectionManager msm = (MenuSelectionManager)context.get(
                                                 MENU_SELECTION_MANAGER_KEY);
            if (msm == null) {   
                msm = new MenuSelectionManager();  
                context.put(MENU_SELECTION_MANAGER_KEY, msm);  
            }

            return msm;
        }
    }
   
    /**
     * Only one ChangeEvent is needed per button model instance since the
     * event's only state is the source property.  The source of events
     * generated is always "this".
     */
    protected transient ChangeEvent changeEvent = null;
    protected EventListenerList listenerList = new EventListenerList();

    /**
     * Changes the selection in the menu hierarchy.  The elements
     * in the array are sorted in order from the root menu
     * element to the currently selected menu element.
     * <p>
     * Note that this method is public but is used by the look and
     * feel engine and should not be called by client applications.
     *
     * @param path  an array of <code>MenuElement</code> objects specifying
     *        the selected path
     */
    public void setSelectedPath(MenuElement[] path) {
        int i,c;
        int currentSelectionCount = selection.size();
        int firstDifference = 0;

        if(path == null) {
            path = new MenuElement[0];
        }

  if (DEBUG) {
      System.out.print("Previous:  "); printMenuElementArray(getSelectedPath());
      System.out.print("New:  "); printMenuElementArray(path);
  }

        for(i=0,c=path.length;i<c;i++) {
            if(i < currentSelectionCount && (MenuElement)selection.elementAt(i) == path[i])
                firstDifference++;
            else
                break;
        }

        for(i=currentSelectionCount - 1 ; i >= firstDifference ; i--) {
            MenuElement me = (MenuElement)selection.elementAt(i);
            selection.removeElementAt(i);
            me.menuSelectionChanged(false);
        }

        for(i = firstDifference, c = path.length ; i < c ; i++) {
      if (path[i] != null) {
    selection.addElement(path[i]);
    path[i].menuSelectionChanged(true);
      }       
  }

  fireStateChanged();
    }

    /**
     * Returns the path to the currently selected menu item
     *
     * @return an array of MenuElement objects representing the selected path
     */
    public MenuElement[] getSelectedPath() {
        MenuElement res[] = new MenuElement[selection.size()];
        int i,c;
        for(i=0,c=selection.size();i<c;i++)
            res[i] = (MenuElement) selection.elementAt(i);
        return res;
    }

    /**
     * Tell the menu selection to close and unselect all the menu components. Call this method
     * when a choice has been made
     */
    public void clearSelectedPath() {
        if (selection.size() > 0) {
            setSelectedPath(null);
        }
    }

    /**
     * Adds a ChangeListener to the button.
     *
     * @param l the listener to add
     */
    public void addChangeListener(ChangeListener l) {
        listenerList.add(ChangeListener.class, l);
    }
   
    /**
     * Removes a ChangeListener from the button.
     *
     * @param l the listener to remove
     */
    public void removeChangeListener(ChangeListener l) {
        listenerList.remove(ChangeListener.class, l);
    }

    /**
     * Returns an array of all the <code>ChangeListener</code>s added
     * to this MenuSelectionManager with addChangeListener().
     *
     * @return all of the <code>ChangeListener</code>s added or an empty
     *         array if no listeners have been added
     * @since 1.4
     */
    public ChangeListener[] getChangeListeners() {
        return (ChangeListener[])listenerList.getListeners(
                ChangeListener.class);
    }

    /**
     * Notifies all listeners that have registered interest for
     * notification on this event type.  The event instance
     * is created lazily.
     *
     * @see EventListenerList
     */
    protected void fireStateChanged() {
        // Guaranteed to return a non-null array
        Object[] listeners = listenerList.getListenerList();
        // Process the listeners last to first, notifying
        // those that are interested in this event
        for (int i = listeners.length-2; i>=0; i-=2) {
            if (listeners[i]==ChangeListener.class) {
                // Lazily create the event:
                if (changeEvent == null)
                    changeEvent = new ChangeEvent(this);
                ((ChangeListener)listeners[i+1]).stateChanged(changeEvent);
            }         
        }
    }  

    /**
     * When a MenuElement receives an event from a MouseListener, it should never process the event
     * directly. Instead all MenuElements should call this method with the event.
     *
     * @param event  a MouseEvent object
     */
    public void processMouseEvent(MouseEvent event) {
        int screenX,screenY;
        Point p;
        int i,c,j,d;
        Component mc;
        Rectangle r2;
        int cWidth,cHeight;
        MenuElement menuElement;
        MenuElement subElements[];
        MenuElement path[];
        Vector tmp;
        int selectionSize;
        p = event.getPoint();
 
        Component source = event.getComponent();

  if ((source != null) && !source.isShowing()) {
      // This can happen if a mouseReleased removes the
      // containing component -- bug 4146684
      return;
  }

  int type = event.getID();
  int modifiers = event.getModifiers();
  // 4188027: drag enter/exit added in JDK 1.1.7A, JDK1.2
  if ((type==MouseEvent.MOUSE_ENTERED||
       type==MouseEvent.MOUSE_EXITED)
      && ((modifiers & (InputEvent.BUTTON1_MASK |
            InputEvent.BUTTON2_MASK | InputEvent.BUTTON3_MASK)) !=0 )) {
      return;
  }

        if (source != null) {
            SwingUtilities.convertPointToScreen(p, source);
        }

        screenX = p.x;
        screenY = p.y;

        tmp = (Vector)selection.clone();
        selectionSize = tmp.size();
  boolean success = false;
  for (i=selectionSize - 1;i >= 0 && success == false; i--) {
            menuElement = (MenuElement) tmp.elementAt(i);
            subElements = menuElement.getSubElements();
           
            path = null;
      for (j = 0, d = subElements.length;j < d && success == false; j++) {
    if (subElements[j] == null)
        continue;
                mc = subElements[j].getComponent();
                if(!mc.isShowing())
                    continue;
                if(mc instanceof JComponent) {
                    cWidth  = ((JComponent)mc).getWidth();
                    cHeight = ((JComponent)mc).getHeight();
                } else {
                    r2 = mc.getBounds();
                    cWidth  = r2.width;
                    cHeight = r2.height;
                }
                p.x = screenX;
                p.y = screenY;
                SwingUtilities.convertPointFromScreen(p,mc);

                /** Send the event to visible menu element if menu element currently in
                 *  the selected path or contains the event location
                 */
                if(
                   (p.x >= 0 && p.x < cWidth && p.y >= 0 && p.y < cHeight)) {
                    int k;
                    if(path == null) {
                        path = new MenuElement[i+2];
                        for(k=0;k<=i;k++)
                            path[k] = (MenuElement)tmp.elementAt(k);
                    }
                    path[i+1] = subElements[j];
        MenuElement currentSelection[] = getSelectedPath();

        // Enter/exit detection -- needs tuning...
        if (currentSelection[currentSelection.length-1] !=
      path[i+1] &&
      (currentSelection.length < 2 ||
       currentSelection[currentSelection.length-2] !=
       path[i+1])) {
      Component oldMC = currentSelection[currentSelection.length-1].getComponent();

      MouseEvent exitEvent = new MouseEvent(oldMC, MouseEvent.MOUSE_EXITED,
                    event.getWhen(),
                    event.getModifiers(), p.x, p.y,
                                                              event.getXOnScreen(),
                                                              event.getYOnScreen(),
                    event.getClickCount(),
                    event.isPopupTrigger(),
                                                              MouseEvent.NOBUTTON);
      currentSelection[currentSelection.length-1].
          processMouseEvent(exitEvent, path, this);

      MouseEvent enterEvent = new MouseEvent(mc,
                     MouseEvent.MOUSE_ENTERED,
                     event.getWhen(),
                     event.getModifiers(), p.x, p.y,
                                                               event.getXOnScreen(),
                                                               event.getYOnScreen(),
                     event.getClickCount(),
                     event.isPopupTrigger(),
                                                               MouseEvent.NOBUTTON);
      subElements[j].processMouseEvent(enterEvent, path, this);
        }
        MouseEvent mouseEvent = new MouseEvent(mc, event.getID(),event. getWhen(),
                 event.getModifiers(), p.x, p.y,
                                                           event.getXOnScreen(),
                                                           event.getYOnScreen(),
                 event.getClickCount(),
                 event.isPopupTrigger(),
                                                           MouseEvent.NOBUTTON);
        subElements[j].processMouseEvent(mouseEvent, path, this);
        success = true;
        event.consume();
    }
            }
        }
    }

    private void printMenuElementArray(MenuElement path[]) {
  printMenuElementArray(path, false);
    }

    private void printMenuElementArray(MenuElement path[], boolean dumpStack) {
  System.out.println("Path is(");
  int i, j;
  for(i=0,j=path.length; i<j ;i++){
      for (int k=0; k<=i; k++)
    System.out.print("  ");
      MenuElement me = (MenuElement) path[i];
      if(me instanceof JMenuItem) {
    System.out.println(((JMenuItem)me).getText() + ", ");
      } else if (me instanceof JMenuBar) {
    System.out.println("JMenuBar, ");
      } else if(me instanceof JPopupMenu) {
    System.out.println("JPopupMenu, ");
      } else if (me == null) {
    System.out.println("NULL , ");
      } else {
    System.out.println("" + me + ", ");
      }
  }
  System.out.println(")");

  if (dumpStack == true)
      Thread.dumpStack();
    }

    /**
     * Returns the component in the currently selected path
     * which contains sourcePoint.
     *
     * @param source The component in whose coordinate space sourcePoint
     *        is given
     * @param sourcePoint The point which is being tested
     * @return The component in the currently selected path which
     *         contains sourcePoint (relative to the source component's
     *         coordinate space.  If sourcePoint is not inside a component
     *         on the currently selected path, null is returned.
     */
    public Component componentForPoint(Component source, Point sourcePoint) {
        int screenX,screenY;
        Point p = sourcePoint;
        int i,c,j,d;
        Component mc;
        Rectangle r2;
        int cWidth,cHeight;
        MenuElement menuElement;
        MenuElement subElements[];
        Vector tmp;
        int selectionSize;

        SwingUtilities.convertPointToScreen(p,source);

        screenX = p.x;
        screenY = p.y;

        tmp = (Vector)selection.clone();
        selectionSize = tmp.size();
        for(i=selectionSize - 1 ; i >= 0 ; i--) {
            menuElement = (MenuElement) tmp.elementAt(i);
            subElements = menuElement.getSubElements();
           
            for(j = 0, d = subElements.length ; j < d ; j++) {
    if (subElements[j] == null)
        continue;
                mc = subElements[j].getComponent();
                if(!mc.isShowing())
                    continue;
                if(mc instanceof JComponent) {
                    cWidth  = ((JComponent)mc).getWidth();
                    cHeight = ((JComponent)mc).getHeight();
                } else {
                    r2 = mc.getBounds();
                    cWidth  = r2.width;
                    cHeight = r2.height;
                }
                p.x = screenX;
                p.y = screenY;
                SwingUtilities.convertPointFromScreen(p,mc);
   
                /** Return the deepest component on the selection
     *  path in whose bounds the event's point occurs
                 */
                if (p.x >= 0 && p.x < cWidth && p.y >= 0 && p.y < cHeight) {
                    return mc;
                }
            }
        }
  return null;
    }

    /**
     * When a MenuElement receives an event from a KeyListener, it should never process the event
     * directly. Instead all MenuElements should call this method with the event.
     *
     * @param e  a KeyEvent object
     */
    public void processKeyEvent(KeyEvent e) {
        MenuElement[] sel2 = new MenuElement[0];
        sel2 = (MenuElement[])selection.toArray(sel2);
        int selSize = sel2.length;
        MenuElement[] path;

        if (selSize < 1) {
            return;
  }

        for (int i=selSize-1; i>=0; i--) {
            MenuElement elem = sel2[i];
            MenuElement[] subs = elem.getSubElements();
            path = null;

            for (int j=0; j<subs.length; j++) {
    if (subs[j] == null || !subs[j].getComponent().isShowing()
                    || !subs[j].getComponent().isEnabled()) {
        continue;
                }

                if(path == null) {
                    path = new MenuElement[i+2];
                    System.arraycopy(sel2, 0, path, 0, i+1);
                    }
                path[i+1] = subs[j];
                subs[j].processKeyEvent(e, path, this);
                if (e.isConsumed()) {
                    return;
            }
        }
    }

        // finally dispatch event to the first component in path
        path = new MenuElement[1];
        path[0] = sel2[0];
        path[0].processKeyEvent(e, path, this);
        if (e.isConsumed()) {
            return;
        }
    }
   
    /**
     * Return true if c is part of the currently used menu
     */
    public boolean isComponentPartOfCurrentMenu(Component c) {
        if(selection.size() > 0) {
            MenuElement me = (MenuElement)selection.elementAt(0);
            return isComponentPartOfCurrentMenu(me,c);
        } else
            return false;
    }

    private boolean isComponentPartOfCurrentMenu(MenuElement root,Component c) {
        MenuElement children[];
        int i,d;
 
  if (root == null)
      return false;

        if(root.getComponent() == c)
            return true;
        else {
            children = root.getSubElements();
            for(i=0,d=children.length;i<d;i++) {
                if(isComponentPartOfCurrentMenu(children[i],c))
                    return true;
            }
        }
        return false;
    }
}

TOP

Related Classes of javax.swing.MenuSelectionManager

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.