Java tutorial
/******************************************************************************* * 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 + "]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ } }