org.eclipse.jface.action.MenuManager.java Source code

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/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Remy Chi Jian Suen <remy.suen@gmail.com> - Bug 12116 [Contributions] widgets: MenuManager.setImageDescriptor() method needed
 *     Lars Vogel <Lars.Vogel@gmail.com> - Bug 440252
 *     Andrey Loskutov <loskutov@gmx.de> - Bug 436225
 *     Dirk Fauth <dirk.fauth@googlemail.com> - Bug 488500, Bug 488978
 *******************************************************************************/
package org.eclipse.jface.action;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.internal.MenuManagerEventHelper;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.resource.LocalResourceManager;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MenuAdapter;
import org.eclipse.swt.events.MenuEvent;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.CoolBar;
import org.eclipse.swt.widgets.Decorations;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolBar;

/**
 * A menu manager is a contribution manager which realizes itself and its items
 * in a menu control; either as a menu bar, a sub-menu, or a context menu.
 * <p>
 * This class may be instantiated; it may also be subclassed.
 * </p>
 */
public class MenuManager extends ContributionManager implements IMenuManager {
    /**
     * The key under which the {@link MenuManager} is added to the data properties
     * of the {@link Menu} created by the manager.
     *
     * @since 3.12
     */
    public static final String MANAGER_KEY = "org.eclipse.jface.action.MenuManager.managerKey"; //$NON-NLS-1$

    /**
     * The menu id.
     */
    private String id;

    /**
     * List of registered menu listeners (element type: <code>IMenuListener</code>).
     */
    private ListenerList<IMenuListener> listeners = new ListenerList<>();

    /**
     * The menu control; <code>null</code> before creation and after disposal.
     */
    private Menu menu = null;

    /**
     * The menu item widget; <code>null</code> before creation and after disposal.
     * This field is used when this menu manager is a sub-menu.
     */
    private MenuItem menuItem;

    /**
     * The text for a sub-menu.
     */
    private String menuText;

    /**
     * The image for a sub-menu.
     */
    private ImageDescriptor image;

    /**
     * A resource manager to remember all of the images that have been used by this
     * menu.
     */
    private LocalResourceManager imageManager;

    /**
     * The overrides for items of this manager
     */
    private IContributionManagerOverrides overrides;

    /**
     * The parent contribution manager.
     */
    private IContributionManager parent;

    /**
     * Indicates whether <code>removeAll</code> should be called just before the
     * menu is displayed.
     */
    private boolean removeAllWhenShown = false;

    /**
     * Indicates this item is visible in its manager; <code>true</code> by default.
     *
     * @since 3.3
     */
    protected boolean visible = true;

    /**
     * allows a submenu to display a shortcut key. This is often used with the
     * QuickMenu command or action which can pop up a menu using the shortcut.
     */
    private String definitionId = null;

    /**
     * Creates a menu manager. The text and id are <code>null</code>. Typically used
     * for creating a context menu, where it doesn't need to be referred to by id.
     */
    public MenuManager() {
        this(null, null, null);
    }

    /**
     * Creates a menu manager with the given text. The id of the menu is
     * <code>null</code>. Typically used for creating a sub-menu, where it doesn't
     * need to be referred to by id.
     *
     * @param text the text for the menu, or <code>null</code> if none
     */
    public MenuManager(String text) {
        this(text, null, null);
    }

    /**
     * Creates a menu manager with the given text and id. Typically used for
     * creating a sub-menu, where it needs to be referred to by id.
     *
     * @param text the text for the menu, or <code>null</code> if none
     * @param id   the menu id, or <code>null</code> if it is to have no id
     */
    public MenuManager(String text, String id) {
        this(text, null, id);
    }

    /**
     * Creates a menu manager with the given text, image, and id. Typically used for
     * creating a sub-menu, where it needs to be referred to by id.
     *
     * @param text  the text for the menu, or <code>null</code> if none
     * @param image the image for the menu, or <code>null</code> if none
     * @param id    the menu id, or <code>null</code> if it is to have no id
     * @since 3.4
     */
    public MenuManager(String text, ImageDescriptor image, String id) {
        this.menuText = text;
        this.image = image;
        this.id = id;
    }

    @Override
    public void addMenuListener(IMenuListener listener) {
        listeners.add(listener);
    }

    /**
     * Creates and returns an SWT context menu control for this menu, and installs
     * all registered contributions. Does not create a new control if one already
     * exists.
     * <p>
     * Note that the menu is not expected to be dynamic.
     * </p>
     *
     * @param parent the parent control
     * @return the menu control
     */
    public Menu createContextMenu(Control parent) {
        if (!menuExist()) {
            menu = new Menu(parent);
            menu.setData(MANAGER_KEY, this);
            initializeMenu();
        }
        return menu;
    }

    /**
     * Creates and returns an SWT menu bar control for this menu, for use in the
     * given <code>Decorations</code>, and installs all registered contributions.
     * Does not create a new control if one already exists.
     *
     * @param parent the parent decorations
     * @return the menu control
     * @since 2.1
     */
    public Menu createMenuBar(Decorations parent) {
        if (!menuExist()) {
            menu = new Menu(parent, SWT.BAR);
            menu.setData(MANAGER_KEY, this);
            update(false);
        }
        return menu;
    }

    /**
     * Creates and returns an SWT menu bar control for this menu, for use in the
     * given <code>Shell</code>, and installs all registered contributions. Does not
     * create a new control if one already exists. This implementation simply calls
     * the <code>createMenuBar(Decorations)</code> method
     *
     * @param parent the parent decorations
     * @return the menu control
     * @deprecated use <code>createMenuBar(Decorations)</code> instead.
     */
    @Deprecated
    public Menu createMenuBar(Shell parent) {
        return createMenuBar((Decorations) parent);
    }

    /**
     * Disposes of this menu manager and frees all allocated SWT resources. Notifies
     * all contribution items of the dispose.
     */
    @Override
    public void dispose() {
        if (menuExist()) {
            menu.dispose();
        }
        menu = null;

        if (menuItem != null) {
            menuItem.dispose();
            menuItem = null;
        }

        disposeOldImages();
        // remember items for disposal before removing them all
        IContributionItem[] items = getItems();
        removeAll();
        for (IContributionItem item : items) {
            item.dispose();
        }
        markDirty();
        parent = null;
    }

    @Override
    public void fill(Composite parent) {
    }

    @Override
    public void fill(CoolBar parent, int index) {
    }

    @Override
    public void fill(Menu parent, int index) {
        if (menuItem == null || menuItem.isDisposed()) {
            if (index >= 0) {
                menuItem = new MenuItem(parent, SWT.CASCADE, index);
            } else {
                menuItem = new MenuItem(parent, SWT.CASCADE);
            }

            String text = getMenuText();
            if (text != null) {
                menuItem.setText(text);
            }

            if (image != null) {
                LocalResourceManager localManager = new LocalResourceManager(JFaceResources.getResources());
                menuItem.setImage(localManager.createImage(image));
                disposeOldImages();
                imageManager = localManager;
            }

            if (!menuExist()) {
                menu = new Menu(parent);
                menu.setData(MANAGER_KEY, this);
            }

            menuItem.setMenu(menu);

            initializeMenu();

            setDirty(true);
        }
    }

    @Override
    public void fill(ToolBar parent, int index) {
    }

    @Override
    public IMenuManager findMenuUsingPath(String path) {
        IContributionItem item = findUsingPath(path);
        if (item instanceof IMenuManager) {
            return (IMenuManager) item;
        }
        return null;
    }

    @Override
    public IContributionItem findUsingPath(String path) {
        String id = path;
        String rest = null;
        int separator = path.indexOf('/');
        if (separator != -1) {
            id = path.substring(0, separator);
            rest = path.substring(separator + 1);
        } else {
            return super.find(path);
        }

        IContributionItem item = super.find(id);
        if (item instanceof IMenuManager) {
            IMenuManager manager = (IMenuManager) item;
            return manager.findUsingPath(rest);
        }
        return null;
    }

    /**
     * Notifies any menu listeners that a menu is about to show. Only listeners
     * registered at the time this method is called are notified.
     *
     * @param manager the menu manager
     *
     * @see IMenuListener#menuAboutToShow
     */
    private void fireAboutToShow(IMenuManager manager) {
        for (IMenuListener listener : this.listeners) {
            listener.menuAboutToShow(manager);
        }
    }

    /**
     * Notifies any menu listeners that a menu is about to hide. Only listeners
     * registered at the time this method is called are notified.
     *
     * @param manager the menu manager
     *
     */
    private void fireAboutToHide(IMenuManager manager) {
        for (IMenuListener listener : this.listeners) {
            if (listener instanceof IMenuListener2) {
                ((IMenuListener2) listener).menuAboutToHide(manager);
            }
        }
    }

    /**
     * Returns the menu id. The menu id is used when creating a contribution item
     * for adding this menu as a sub menu of another.
     *
     * @return the menu id
     */
    @Override
    public String getId() {
        return id;
    }

    /**
     * Returns the SWT menu control for this menu manager.
     *
     * @return the menu control
     */
    public Menu getMenu() {
        return menu;
    }

    /**
     * Returns the text shown in the menu, potentially with a shortcut appended.
     *
     * @return the menu text
     */
    public String getMenuText() {
        if (definitionId == null) {
            return menuText;
        }
        ExternalActionManager.ICallback callback = ExternalActionManager.getInstance().getCallback();
        if (callback != null) {
            String shortCut = callback.getAcceleratorText(definitionId);
            if (shortCut == null) {
                return menuText;
            }
            return menuText + "\t" + shortCut; //$NON-NLS-1$
        }
        return menuText;
    }

    /**
     * Returns the image for this menu as an image descriptor.
     *
     * @return the image, or <code>null</code> if this menu has no image
     * @since 3.4
     */
    public ImageDescriptor getImageDescriptor() {
        return image;
    }

    @Override
    public IContributionManagerOverrides getOverrides() {
        if (overrides == null) {
            if (parent == null) {
                overrides = new IContributionManagerOverrides() {
                    @Override
                    public Integer getAccelerator(IContributionItem item) {
                        return null;
                    }

                    @Override
                    public String getAcceleratorText(IContributionItem item) {
                        return null;
                    }

                    @Override
                    public Boolean getEnabled(IContributionItem item) {
                        return null;
                    }

                    @Override
                    public String getText(IContributionItem item) {
                        return null;
                    }

                    @Override
                    public Boolean getVisible(IContributionItem item) {
                        return null;
                    }
                };
            } else {
                overrides = parent.getOverrides();
            }
            super.setOverrides(overrides);
        }
        return overrides;
    }

    /**
     * Returns the parent contribution manager of this manger.
     *
     * @return the parent contribution manager
     * @since 2.0
     */
    public IContributionManager getParent() {
        return parent;
    }

    @Override
    public boolean getRemoveAllWhenShown() {
        return removeAllWhenShown;
    }

    /**
     * Notifies all listeners that this menu is about to appear.
     */
    private void handleAboutToShow() {
        if (removeAllWhenShown) {
            removeAll();
        }
        MenuManagerEventHelper.getInstance().showEventPreHelper(this);
        fireAboutToShow(this);
        MenuManagerEventHelper.getInstance().showEventPostHelper(this);
        update(false, false);
    }

    /**
     * Notifies all listeners that this menu is about to disappear.
     */
    private void handleAboutToHide() {
        MenuManagerEventHelper.getInstance().hideEventPreHelper(this);
        fireAboutToHide(this);
        MenuManagerEventHelper.getInstance().hideEventPostHelper(this);
    }

    /**
     * Initializes the menu control.
     */
    private void initializeMenu() {
        menu.addMenuListener(new MenuAdapter() {
            @Override
            public void menuHidden(MenuEvent e) {
                // ApplicationWindow.resetDescription(e.widget);
                handleAboutToHide();
            }

            @Override
            public void menuShown(MenuEvent e) {
                handleAboutToShow();
            }
        });
        // Don't do an update(true) here, in case menu is never opened.
        // Always do it lazily in handleAboutToShow().
    }

    @Override
    public boolean isDynamic() {
        return false;
    }

    /**
     * Returns whether this menu should be enabled or not. Used to enable the menu
     * item containing this menu when it is realized as a sub-menu.
     * <p>
     * The default implementation of this framework method returns
     * <code>true</code>. Subclasses may reimplement.
     * </p>
     *
     * @return <code>true</code> if enabled, and <code>false</code> if disabled
     */
    @Override
    public boolean isEnabled() {
        return true;
    }

    @Override
    public boolean isGroupMarker() {
        return false;
    }

    @Override
    public boolean isSeparator() {
        return false;
    }

    /**
     * Check if the contribution is item is a subsitute for ourselves
     *
     * @param item the contribution item
     * @return <code>true</code> if give item is a substitution for ourselves
     * @deprecated this method is no longer a part of the
     *             {@link org.eclipse.jface.action.IContributionItem} API.
     */
    @Deprecated
    public boolean isSubstituteFor(IContributionItem item) {
        return this.equals(item);
    }

    @Override
    public boolean isVisible() {
        if (!visible) {
            return false; // short circuit calculations in this case
        }

        if (removeAllWhenShown) {
            // we have no way of knowing if the menu has children
            return true;
        }

        // menus aren't visible if all of its children are invisible (or only contains
        // visible separators).
        IContributionItem[] childItems = getItems();
        boolean visibleChildren = false;
        for (IContributionItem childItem : childItems) {
            if (isChildVisible(childItem) && !childItem.isSeparator()) {
                visibleChildren = true;
                break;
            }
        }

        return visibleChildren;
    }

    /**
     * The <code>MenuManager</code> implementation of this
     * <code>ContributionManager</code> method also propagates the dirty flag up the
     * parent chain.
     *
     * @since 3.1
     */
    @Override
    public void markDirty() {
        super.markDirty();
        // Can't optimize by short-circuiting when the first dirty manager is
        // encountered,
        // since non-visible children are not even processed.
        // That is, it's possible to have a dirty sub-menu under a non-dirty parent menu
        // even after the parent menu has been updated.
        // If items are added/removed in the sub-menu, we still need to propagate the
        // dirty flag up,
        // even if the sub-menu is already dirty, since the result of isVisible() may
        // change
        // due to the added/removed items.
        IContributionManager parent = getParent();
        if (parent != null) {
            parent.markDirty();
        }
    }

    /**
     * Returns whether the menu control is created and not disposed.
     *
     * @return <code>true</code> if the control is created and not disposed,
     *         <code>false</code> otherwise
     * @since 3.4 protected, was added in 3.1 as private method
     */
    protected boolean menuExist() {
        return menu != null && !menu.isDisposed();
    }

    @Override
    public void removeMenuListener(IMenuListener listener) {
        listeners.remove(listener);
    }

    @Override
    public void saveWidgetState() {
    }

    /**
     * Sets the overrides for this contribution manager
     *
     * @param newOverrides the overrides for the items of this manager
     * @since 2.0
     */
    @Override
    public void setOverrides(IContributionManagerOverrides newOverrides) {
        overrides = newOverrides;
        super.setOverrides(overrides);
    }

    @Override
    public void setParent(IContributionManager manager) {
        parent = manager;
    }

    @Override
    public void setRemoveAllWhenShown(boolean removeAll) {
        this.removeAllWhenShown = removeAll;
    }

    @Override
    public void setVisible(boolean visible) {
        this.visible = visible;
    }

    /**
     * Sets the action definition id of this action. This simply allows the menu
     * item text to include a short cut if available. It can be used to notify a
     * user of a key combination that will open a quick menu.
     *
     * @param definitionId the command definition id
     * @since 3.4
     */
    public void setActionDefinitionId(String definitionId) {
        this.definitionId = definitionId;
    }

    @Override
    public void update() {
        //      This used to disable the menu item if this menu manager was part of a
        //      parent menu and the sub menu is empty. This is not necessary anymore,
        //      because in that case the menu is completely invisible.
        //      See bugs #34969, #47098, #552413, #552659.
        //      See isVisible().
    }

    /**
     * The <code>MenuManager</code> implementation of this
     * <code>IContributionManager</code> updates this menu, but not any of its
     * submenus.
     *
     * @see #updateAll
     */
    @Override
    public void update(boolean force) {
        update(force, false);
    }

    /**
     * Get all the items from the implementation's widget.
     *
     * @return the menu items
     * @since 3.4
     */
    protected Item[] getMenuItems() {
        if (menu != null) {
            return menu.getItems();
        }
        return null;
    }

    /**
     * Get an item from the implementation's widget.
     *
     * @param index of the item
     * @return the menu item
     * @since 3.4
     */
    protected Item getMenuItem(int index) {
        if (menu != null) {
            return menu.getItem(index);
        }
        return null;
    }

    /**
     * Get the menu item count for the implementation's widget.
     *
     * @return the number of items
     * @since 3.4
     */
    protected int getMenuItemCount() {
        if (menu != null) {
            return menu.getItemCount();
        }
        return 0;
    }

    /**
     * Call an <code>IContributionItem</code>'s fill method with the
     * implementation's widget. The default is to use the <code>Menu</code>
     * widget.<br>
     * <code>fill(Menu menu, int index)</code>
     *
     * @param ci    An <code>IContributionItem</code> whose <code>fill()</code>
     *              method should be called.
     * @param index The position the <code>fill()</code> method should start
     *              inserting at.
     * @since 3.4
     */
    protected void doItemFill(IContributionItem ci, int index) {
        ci.fill(menu, index);
    }

    /**
     * Incrementally builds the menu from the contribution items. This method leaves
     * out double separators and separators in the first or last position.
     *
     * @param force     <code>true</code> means update even if not dirty, and
     *                  <code>false</code> for normal incremental updating
     * @param recursive <code>true</code> means recursively update all submenus, and
     *                  <code>false</code> means just this menu
     */
    protected void update(boolean force, boolean recursive) {
        if (isDirty() || force) {
            if (menuExist()) {
                // clean contains all active items without double separators
                IContributionItem[] items = getItems();
                List<IContributionItem> clean = new ArrayList<>(items.length);
                IContributionItem separator = null;
                for (IContributionItem item : items) {
                    IContributionItem ci = item;
                    if (!isChildVisible(ci)) {
                        continue;
                    }
                    if (ci.isSeparator()) {
                        // delay creation until necessary
                        // (handles both adjacent separators, and separator at end)
                        separator = ci;
                    } else {
                        if (separator != null) {
                            if (clean.size() > 0) {
                                clean.add(separator);
                            }
                            separator = null;
                        }
                        clean.add(ci);
                    }
                }

                // remove obsolete (removed or non active)
                Item[] mi = getMenuItems();

                for (Item element : mi) {
                    Object data = element.getData();

                    if (data == null || !clean.contains(data)) {
                        element.dispose();
                    } else if (data instanceof IContributionItem && ((IContributionItem) data).isDynamic()
                            && ((IContributionItem) data).isDirty()) {
                        element.dispose();
                    }
                }

                // add new
                mi = getMenuItems();
                int srcIx = 0;
                int destIx = 0;

                for (IContributionItem src : clean) {
                    IContributionItem dest;

                    // get corresponding item in SWT widget
                    if (srcIx < mi.length) {
                        dest = (IContributionItem) mi[srcIx].getData();
                    } else {
                        dest = null;
                    }

                    if (dest != null && src.equals(dest)) {
                        srcIx++;
                        destIx++;
                    } else if (dest != null && dest.isSeparator() && src.isSeparator()) {
                        mi[srcIx].setData(src);
                        srcIx++;
                        destIx++;
                    } else {
                        int start = getMenuItemCount();
                        doItemFill(src, destIx);
                        int newItems = getMenuItemCount() - start;
                        for (int i = 0; i < newItems; i++) {
                            Item item = getMenuItem(destIx++);
                            item.setData(src);
                        }
                    }

                    // May be we can optimize this call. If the menu has just
                    // been created via the call src.fill(fMenuBar, destIx) then
                    // the menu has already been updated with update(true)
                    // (see MenuManager). So if force is true we do it again. But
                    // we can't set force to false since then information for the
                    // sub sub menus is lost.
                    if (recursive) {
                        IContributionItem item = src;
                        if (item instanceof SubContributionItem) {
                            item = ((SubContributionItem) item).getInnerItem();
                        }
                        if (item instanceof IMenuManager) {
                            ((IMenuManager) item).updateAll(force);
                        }
                    }

                }

                // remove any old menu items not accounted for
                for (; srcIx < mi.length; srcIx++) {
                    mi[srcIx].dispose();
                }

                setDirty(false);
            }
        } else {
            // I am not dirty. Check if I must recursivly walk down the hierarchy.
            if (recursive) {
                IContributionItem[] items = getItems();
                for (IContributionItem ci : items) {
                    if (ci instanceof IMenuManager) {
                        IMenuManager mm = (IMenuManager) ci;
                        if (isChildVisible(mm)) {
                            mm.updateAll(force);
                        }
                    }
                }
            }
        }
    }

    @Override
    public void update(String property) {
        IContributionItem items[] = getItems();

        for (IContributionItem item : items) {
            item.update(property);
        }

        if (menu != null && !menu.isDisposed() && menu.getParentItem() != null) {
            if (IAction.TEXT.equals(property)) {
                String text = getOverrides().getText(this);

                if (text == null) {
                    text = getMenuText();
                }

                if (text != null) {
                    ExternalActionManager.ICallback callback = ExternalActionManager.getInstance().getCallback();

                    if (callback != null) {
                        int index = text.indexOf('&');

                        if (index >= 0 && index < text.length() - 1) {
                            char character = Character.toUpperCase(text.charAt(index + 1));

                            if (callback.isAcceleratorInUse(SWT.ALT | character) && isTopLevelMenu()) {
                                if (index == 0) {
                                    text = text.substring(1);
                                } else {
                                    text = text.substring(0, index) + text.substring(index + 1);
                                }
                            }
                        }
                    }

                    menu.getParentItem().setText(text);
                }
            } else if (IAction.IMAGE.equals(property) && image != null) {
                LocalResourceManager localManager = new LocalResourceManager(JFaceResources.getResources());
                menu.getParentItem().setImage(localManager.createImage(image));
                disposeOldImages();
                imageManager = localManager;
            }
        }
    }

    private boolean isTopLevelMenu() {
        if (menu != null && !menu.isDisposed() && menuItem != null && !menuItem.isDisposed()) {
            Menu parentMenu = menuItem.getParent();
            return parentMenu != null && ((parentMenu.getStyle() & SWT.BAR) == SWT.BAR);
        }
        return false;
    }

    /**
     * Dispose any images allocated for this menu
     */
    private void disposeOldImages() {
        if (imageManager != null) {
            imageManager.dispose();
            imageManager = null;
        }
    }

    @Override
    public void updateAll(boolean force) {
        update(force, true);
    }

    private boolean isChildVisible(IContributionItem item) {
        Boolean v = getOverrides().getVisible(item);
        if (v != null) {
            return v.booleanValue();
        }
        return item.isVisible();
    }

    /**
     * @param menuText The text (label) of the menu.
     * @since 3.10
     */
    public void setMenuText(String menuText) {
        this.menuText = menuText;
    }

    /**
     * @param imageDescriptor The image descriptor to set.
     * @since 3.10
     */
    public void setImageDescriptor(ImageDescriptor imageDescriptor) {
        this.image = imageDescriptor;
    }

    @Override
    public String toString() {
        return "MenuManager [" + (menuText != null ? "text=" + menuText + ", " : "") //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
                + (id != null ? "id=" + id + ", " : "") + "visible=" + visible + "]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$
    }

}