basicpopupmenuui.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

        Actions(String key) {
            super(key);
        }

	public void actionPerformed(ActionEvent e) {
            String key = getName();
            if (key == CANCEL) {
                cancel();
            }
            else if (key == SELECT_NEXT) {
                selectItem(FORWARD);
            }
            else if (key == SELECT_PREVIOUS) {
                selectItem(BACKWARD);
            }
            else if (key == SELECT_PARENT) {
                selectParentChild(PARENT);
            }
            else if (key == SELECT_CHILD) {
                selectParentChild(CHILD);
            }
            else if (key == RETURN) {
                doReturn();
            }
        }

	private void doReturn() {
            KeyboardFocusManager fmgr =
                KeyboardFocusManager.getCurrentKeyboardFocusManager();
            Component focusOwner = fmgr.getFocusOwner();
            if(focusOwner != null && !(focusOwner instanceof JRootPane)) {
                return;
            }

            MenuSelectionManager msm = MenuSelectionManager.defaultManager();
	    MenuElement path[] = msm.getSelectedPath();
	    MenuElement lastElement;
	    if(path.length > 0) {
		lastElement = path[path.length-1];
		if(lastElement instanceof JMenu) {
		    MenuElement newPath[] = new MenuElement[path.length+1];
		    System.arraycopy(path,0,newPath,0,path.length);
		    newPath[path.length] = ((JMenu)lastElement).getPopupMenu();
		    msm.setSelectedPath(newPath);
		} else if(lastElement instanceof JMenuItem) {
                    JMenuItem mi = (JMenuItem)lastElement;

                    if (mi.getUI() instanceof BasicMenuItemUI) {
                        ((BasicMenuItemUI)mi.getUI()).doClick(msm);
                    }
                    else {
                        msm.clearSelectedPath();
                        mi.doClick(0);
                    }
		}
	    }
	}
	private void selectParentChild(boolean direction) {
            MenuSelectionManager msm = MenuSelectionManager.defaultManager();
            MenuElement path[] = msm.getSelectedPath();
            int len = path.length;

            if (direction == PARENT) {
                // selecting parent
                int popupIndex = len-1;

                if (len > 2 &&
                    // check if we have an open submenu. A submenu item may or
                    // may not be selected, so submenu popup can be either the
                    // last or next to the last item.
                    (path[popupIndex] instanceof JPopupMenu ||
                     path[--popupIndex] instanceof JPopupMenu) &&
                    !((JMenu)path[popupIndex-1]).isTopLevelMenu()) {

                    // we have a submenu, just close it
                    MenuElement newPath[] = new MenuElement[popupIndex];
                    System.arraycopy(path, 0, newPath, 0, popupIndex);
                    msm.setSelectedPath(newPath);
                    return;
                }
            } else {
                // selecting child
                if (len > 0 && path[len-1] instanceof JMenu &&
                    !((JMenu)path[len-1]).isTopLevelMenu()) {

                    // we have a submenu, open it
                    JMenu menu = (JMenu)path[len-1];
                    JPopupMenu popup = menu.getPopupMenu();
                    MenuElement[] subs = popup.getSubElements();
                    MenuElement item = findEnabledChild(subs, -1, true);
                    MenuElement[] newPath;

                    if (item == null) {
                        newPath = new MenuElement[len+1];
                    } else {
                        newPath = new MenuElement[len+2];
                        newPath[len+1] = item;
                    }
                    System.arraycopy(path, 0, newPath, 0, len);
                    newPath[len] = popup;
                    msm.setSelectedPath(newPath);
                    return;
                }
            }

            // check if we have a toplevel menu selected.
            // If this is the case, we select another toplevel menu
	    if (len > 1 && path[0] instanceof JMenuBar) {
                MenuElement currentMenu = path[1];
		MenuElement nextMenu = findEnabledChild(
                    path[0].getSubElements(), currentMenu, direction);

		if (nextMenu != null && nextMenu != currentMenu) {
		    MenuElement newSelection[];
		    if (len == 2) {
                        // menu is selected but its popup not shown
			newSelection = new MenuElement[2];
			newSelection[0] = path[0];
			newSelection[1] = nextMenu;
		    } else {
                        // menu is selected and its popup is shown
			newSelection = new MenuElement[3];
			newSelection[0] = path[0];
			newSelection[1] = nextMenu;
			newSelection[2] = ((JMenu)nextMenu).getPopupMenu();
                    }
		    msm.setSelectedPath(newSelection);
		}
	    }
	}

        private void selectItem(boolean direction) {
            MenuSelectionManager msm = MenuSelectionManager.defaultManager();
            MenuElement path[] = msm.getSelectedPath();
            if (path.length == 0) {
                return;
            }
            int len = path.length;
            if (len == 1 && path[0] instanceof JPopupMenu) {
             
                JPopupMenu popup = (JPopupMenu) path[0];
                MenuElement[] newPath = new MenuElement[2];
                newPath[0] = popup;
                newPath[1] = findEnabledChild(popup.getSubElements(), -1, direction);
                msm.setSelectedPath(newPath);
            } else if (len == 2 &&
                    path[0] instanceof JMenuBar && path[1] instanceof JMenu) {

                // a toplevel menu is selected, but its popup not shown.
                // Show the popup and select the first item
                JPopupMenu popup = ((JMenu)path[1]).getPopupMenu();
                MenuElement next =
                    findEnabledChild(popup.getSubElements(), -1, FORWARD);
                MenuElement[] newPath;

                if (next != null) {
                    // an enabled item found -- include it in newPath
                    newPath = new MenuElement[4];
                    newPath[3] = next;
                } else {
                    // menu has no enabled items -- still must show the popup
                    newPath = new MenuElement[3];
                }
                System.arraycopy(path, 0, newPath, 0, 2);
                newPath[2] = popup;
                msm.setSelectedPath(newPath);

            } else if (path[len-1] instanceof JPopupMenu &&
                       path[len-2] instanceof JMenu) {

                // a menu (not necessarily toplevel) is open and its popup
                // shown. Select the appropriate menu item
                JMenu menu = (JMenu)path[len-2];
                JPopupMenu popup = menu.getPopupMenu();
                MenuElement next =
                    findEnabledChild(popup.getSubElements(), -1, direction);

                if (next != null) {
                    MenuElement[] newPath = new MenuElement[len+1];
                    System.arraycopy(path, 0, newPath, 0, len);
                    newPath[len] = next;
                    msm.setSelectedPath(newPath);
                } else {
                    // all items in the popup are disabled.
                    // We're going to find the parent popup menu and select
                    // its next item. If there's no parent popup menu (i.e.
                    // current menu is toplevel), do nothing
                    if (len > 2 && path[len-3] instanceof JPopupMenu) {
                        popup = ((JPopupMenu)path[len-3]);
                        next = findEnabledChild(popup.getSubElements(),
                                                menu, direction);

                        if (next != null && next != menu) {
                            MenuElement[] newPath = new MenuElement[len-1];
                            System.arraycopy(path, 0, newPath, 0, len-2);
                            newPath[len-2] = next;
                            msm.setSelectedPath(newPath);
                        }
                    }
                }

            } else {
                // just select the next item, no path expansion needed
                MenuElement subs[] = path[len-2].getSubElements();
                MenuElement nextChild =
                    findEnabledChild(subs, path[len-1], direction);
                if (nextChild == null) {
                    nextChild = findEnabledChild(subs, -1, direction);
                }
                if (nextChild != null) {
                    path[len-1] = nextChild;
                    msm.setSelectedPath(path);
		}
	    }
	}

        private void cancel() {
	    // 4234793: This action should call JPopupMenu.firePopupMenuCanceled but it's
	    // a protected method. The real solution could be to make 
	    // firePopupMenuCanceled public and call it directly.
	    JPopupMenu lastPopup = (JPopupMenu)getLastPopup();
	    if (lastPopup != null) {
		lastPopup.putClientProperty("JPopupMenu.firePopupMenuCanceled", Boolean.TRUE);
	    }

	    MenuElement path[] = MenuSelectionManager.defaultManager().getSelectedPath();
	    if(path.length > 4) { /* PENDING(arnaud) Change this to 2 when a mouse grabber is available for MenuBar */
		MenuElement newPath[] = new MenuElement[path.length - 2];
		System.arraycopy(path,0,newPath,0,path.length-2);
		MenuSelectionManager.defaultManager().setSelectedPath(newPath);
	    } else
		MenuSelectionManager.defaultManager().clearSelectedPath();
	}
    }

    private static MenuElement nextEnabledChild(MenuElement e[],
                                                int fromIndex, int toIndex) {
	for (int i=fromIndex; i<=toIndex; i++) {
            if (e[i] != null) {
                Component comp = e[i].getComponent();
                if ( comp != null 
                        && (comp.isEnabled() || UIManager.getBoolean("MenuItem.disabledAreNavigable"))
                        && comp.isVisible()) {
                    return e[i];
                }
            }
	}
	return null;
    }

    private static MenuElement previousEnabledChild(MenuElement e[],
                                                int fromIndex, int toIndex) {
	for (int i=fromIndex; i>=toIndex; i--) {
	    if (e[i] != null) {
		Component comp = e[i].getComponent();
                if ( comp != null 
                        && (comp.isEnabled() || UIManager.getBoolean("MenuItem.disabledAreNavigable"))
                        && comp.isVisible()) {
                    return e[i];
                }
	    }
	}
	return null;
    }

    static MenuElement findEnabledChild(MenuElement e[], int fromIndex,
                                                boolean forward) {
        MenuElement result = null;
        if (forward) {
            result = nextEnabledChild(e, fromIndex+1, e.length-1);
            if (result == null) result = nextEnabledChild(e, 0, fromIndex-1);
        } else {
            result = previousEnabledChild(e, fromIndex-1, 0);
            if (result == null) result = previousEnabledChild(e, e.length-1,
                                                              fromIndex+1);
        }
	return result;
    }

    static MenuElement findEnabledChild(MenuElement e[],
                                   MenuElement elem, boolean forward) {
        for (int i=0; i<e.length; i++) {
            if (e[i] == elem) {
                return findEnabledChild(e, i, forward);
            }
        }
        return null;
    }

    static class MouseGrabber implements ChangeListener,
        AWTEventListener, ComponentListener, WindowListener {

        Window grabbedWindow;
	MenuElement[] lastPathSelected;

        public MouseGrabber() {
	    MenuSelectionManager msm = MenuSelectionManager.defaultManager();
	    msm.addChangeListener(this);
            this.lastPathSelected = msm.getSelectedPath();
            if(this.lastPathSelected.length != 0) {
                grabWindow(this.lastPathSelected);
            }
        }

        void uninstall() {
            synchronized (BasicPopupMenuUI.MOUSE_GRABBER_KEY) {
                MenuSelectionManager.defaultManager().removeChangeListener(this);
                ungrabWindow();
                AppContext.getAppContext().remove(MOUSE_GRABBER_KEY);
            }
        }

        void grabWindow(MenuElement[] newPath) {
            // A grab needs to be added
            final Toolkit tk = Toolkit.getDefaultToolkit();
            java.security.AccessController.doPrivileged(
                new java.security.PrivilegedAction() {
                    public Object run() {
                        tk.addAWTEventListener(MouseGrabber.this,
                                AWTEvent.MOUSE_EVENT_MASK |
                                AWTEvent.MOUSE_MOTION_EVENT_MASK |
                                AWTEvent.MOUSE_WHEEL_EVENT_MASK |
                                AWTEvent.WINDOW_EVENT_MASK | sun.awt.SunToolkit.GRAB_EVENT_MASK);
                        return null;
                    }
                }
            );

            Component invoker = newPath[0].getComponent();
            if (invoker instanceof JPopupMenu) {
                invoker = ((JPopupMenu)invoker).getInvoker();
            }
            grabbedWindow = invoker instanceof Window?
                    (Window)invoker :
                    SwingUtilities.getWindowAncestor(invoker);
            if(grabbedWindow != null) {
                if(tk instanceof sun.awt.SunToolkit) {
                    ((sun.awt.SunToolkit)tk).grab(grabbedWindow);
                } else {
                    grabbedWindow.addComponentListener(this);
                    grabbedWindow.addWindowListener(this);
                }
            }
        }

        void ungrabWindow() {
            final Toolkit tk = Toolkit.getDefaultToolkit();
            // The grab should be removed
             java.security.AccessController.doPrivileged(
                new java.security.PrivilegedAction() {
                    public Object run() {
                        tk.removeAWTEventListener(MouseGrabber.this);
                        return null;
                    }
                }
            );
            if(grabbedWindow != null) {
                if(tk instanceof sun.awt.SunToolkit) {
                    ((sun.awt.SunToolkit)tk).ungrab(grabbedWindow);
                } else {
                    grabbedWindow.removeComponentListener(this);
                    grabbedWindow.removeWindowListener(this);
                }
                grabbedWindow = null;
            }
        }

	public void stateChanged(ChangeEvent e) {
	    MenuSelectionManager msm = MenuSelectionManager.defaultManager();
	    MenuElement[] p = msm.getSelectedPath();

	    if (lastPathSelected.length == 0 && p.length != 0) {
                grabWindow(p);
            }

	    if (lastPathSelected.length != 0 && p.length == 0) {
                ungrabWindow();
            }

            lastPathSelected = p;
        }

        public void eventDispatched(AWTEvent ev) {
            if(ev instanceof sun.awt.UngrabEvent) {
                // Popup should be canceled in case of ungrab event
                cancelPopupMenu( );
                return;
            }