java/8 : javax/swing/MenuSelectionManager.java

MenuSelectionManager
https://openjdk.java.net/
GPLv2 + Classpath Exception
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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
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 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package javax.swing;

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

import sun.awt.AppContext;
import sun.awt.AWTAccessor;
import sun.awt.AWTAccessor.MouseEventAccessor;
import sun.swing.SwingUtilities2;

A MenuSelectionManager owns the selection in menu hierarchy.
Author: Arnaud Weber/**
 * A MenuSelectionManager owns the selection in menu hierarchy.
 *
 * @author Arnaud Weber
 */
public class MenuSelectionManager {
    private Vector<MenuElement> selection = new Vector<MenuElement>();

    /* 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 StringBuilder MENU_SELECTION_MANAGER_KEY =
                       new StringBuilder("javax.swing.MenuSelectionManager");

    Returns the default menu selection manager.
Returns: a MenuSelectionManager object/**
     * 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);

                // installing additional listener if found in the AppContext
                Object o = context.get(SwingUtilities2.MENU_SELECTION_MANAGER_LISTENER_KEY);
                if (o != null && o instanceof ChangeListener) {
                    msm.addChangeListener((ChangeListener) o);
                }
            }

            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".
/**
     * 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.

Note that this method is public but is used by the look and
feel engine and should not be called by client applications.
Params: path –  an array of MenuElement objects specifying
       the selected path/**
     * 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 && selection.elementAt(i) == path[i])
                firstDifference++;
            else
                break;
        }

        for(i=currentSelectionCount - 1 ; i >= firstDifference ; i--) {
            MenuElement me = 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
Returns: an array of MenuElement objects representing the selected path/**
     * 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] = 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
/**
     * 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.
Params: l – the listener to add/**
     * 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.
Params: l – the listener to remove/**
     * 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 ChangeListeners added
to this MenuSelectionManager with addChangeListener().
Returns: all of the ChangeListeners added or an empty
        array if no listeners have been added
Since: 1.4/**
     * 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 listenerList.getListeners(ChangeListener.class);
    }

    Notifies all listeners that have registered interest for
notification on this event type.  The event instance
is created lazily.
See Also: EventListenerList/**
     * 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.
Params: event –  a MouseEvent object/**
     * 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<MenuElement> 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<MenuElement>)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  = mc.getWidth();
                    cHeight = 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);
                        MouseEventAccessor meAccessor = AWTAccessor.getMouseEventAccessor();
                        meAccessor.setCausedByTouchEvent(exitEvent,
                            meAccessor.isCausedByTouchEvent(event));
                        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);
                        meAccessor.setCausedByTouchEvent(enterEvent,
                            meAccessor.isCausedByTouchEvent(event));
                        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);
                    MouseEventAccessor meAccessor = AWTAccessor.getMouseEventAccessor();
                    meAccessor.setCausedByTouchEvent(mouseEvent,
                        meAccessor.isCausedByTouchEvent(event));
                    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 = 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.
Params: source – The component in whose coordinate space sourcePoint
       is given
sourcePoint – The point which is being tested
Returns: 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./**
     * 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<MenuElement> tmp;
        int selectionSize;

        SwingUtilities.convertPointToScreen(p,source);

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

        tmp = (Vector<MenuElement>)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  = mc.getWidth();
                    cHeight = 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.
Params: e –  a KeyEvent object/**
     * 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 = 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
/**
     * Return true if c is part of the currently used menu
     */
    public boolean isComponentPartOfCurrentMenu(Component c) {
        if(selection.size() > 0) {
            MenuElement me = 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;
    }
}
Returns:	all of the `ChangeListener`s added or an empty array if no listeners have been added
Since:	1.4
Params:	source – The component in whose coordinate space sourcePoint is given sourcePoint – The point which is being tested
Returns:	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.
/

java/ 8/ javax/swing/MenuSelectionManager.java
