JDK8/Java8源码在线阅读
/*
* Copyright (c) 1997, 2014, Oracle and/or its affiliates. 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. Oracle designates this
* 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
* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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.swing.SwingUtilities2;
/**
* 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.
*
* @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".
*/
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 && 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
*
* @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
*/
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 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<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);
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 = 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<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.
*
* @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;
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