Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2015 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 * Lars Vogel <Lars.Vogel@gmail.com> - Bug 431093, 440080, 440270, 475873 *******************************************************************************/ package org.eclipse.jface.resource; import java.net.URL; import java.text.MessageFormat; import java.util.HashMap; import java.util.Map; import java.util.MissingResourceException; import java.util.ResourceBundle; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.FileLocator; import org.eclipse.core.runtime.Path; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.PopupDialog; import org.eclipse.jface.dialogs.TitleAreaDialog; import org.eclipse.jface.preference.PreferenceDialog; import org.eclipse.jface.wizard.Wizard; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Display; import org.osgi.framework.Bundle; import org.osgi.framework.FrameworkUtil; /** * Utility methods to access JFace-specific resources. * <p> * All methods declared on this class are static. This class cannot be * instantiated. * </p> * <p> * The following global state is also maintained by this class: * </p> * <ul> * <li>a font registry</li> * <li>a color registry</li> * <li>an image registry</li> * <li>a resource bundle</li> * </ul> * * @noinstantiate This class is not intended to be instantiated by clients. * @noextend This class is not intended to be subclassed by clients. */ public class JFaceResources { /** * The path to the icons in the resources. */ private static final String ICONS_PATH = "$nl$/icons/full/";//$NON-NLS-1$ /** * Map of Display onto DeviceResourceManager. Holds all the resources for * the associated display. */ private static final Map<Display, DeviceResourceManager> registries = new HashMap<>(); /** * The symbolic font name for the banner font (value * <code>"org.eclipse.jface.bannerfont"</code>). */ public static final String BANNER_FONT = "org.eclipse.jface.bannerfont"; //$NON-NLS-1$ /** * The JFace resource bundle; eagerly initialized. */ private static final ResourceBundle bundle = ResourceBundle.getBundle("org.eclipse.jface.messages"); //$NON-NLS-1$ /** * The JFace color registry; <code>null</code> until lazily initialized or * explicitly set. */ private static ColorRegistry colorRegistry; /** * The symbolic font name for the standard font (value * <code>"org.eclipse.jface.defaultfont"</code>). */ public static final String DEFAULT_FONT = "org.eclipse.jface.defaultfont"; //$NON-NLS-1$ /** * The symbolic font name for the dialog font (value * <code>"org.eclipse.jface.dialogfont"</code>). */ public static final String DIALOG_FONT = "org.eclipse.jface.dialogfont"; //$NON-NLS-1$ /** * The JFace font registry; <code>null</code> until lazily initialized or * explicitly set. */ private static FontRegistry fontRegistry = null; /** * The symbolic font name for the header font (value * <code>"org.eclipse.jface.headerfont"</code>). */ public static final String HEADER_FONT = "org.eclipse.jface.headerfont"; //$NON-NLS-1$ /** * The JFace image registry; <code>null</code> until lazily initialized. */ private static ImageRegistry imageRegistry = null; /** * The symbolic font name for the text font (value * <code>"org.eclipse.jface.textfont"</code>). */ public static final String TEXT_FONT = "org.eclipse.jface.textfont"; //$NON-NLS-1$ /** * The symbolic font name for the viewer font (value * <code>"org.eclipse.jface.viewerfont"</code>). * * @deprecated This font is not in use */ @Deprecated public static final String VIEWER_FONT = "org.eclipse.jface.viewerfont"; //$NON-NLS-1$ /** * The symbolic font name for the window font (value * <code>"org.eclipse.jface.windowfont"</code>). * * @deprecated This font is not in use */ @Deprecated public static final String WINDOW_FONT = "org.eclipse.jface.windowfont"; //$NON-NLS-1$ /** * Returns the formatted message for the given key in JFace's resource * bundle. * * @param key * the resource name * @param args * the message arguments * @return the string */ public static String format(String key, Object... args) { return MessageFormat.format(getString(key), args); } /** * Returns the JFace's banner font. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.BANNER_FONT) * </pre> * * @return the font */ public static Font getBannerFont() { return getFontRegistry().get(BANNER_FONT); } /** * Returns the resource bundle for JFace itself. The resource bundle is * obtained from * <code>ResourceBundle.getBundle("org.eclipse.jface.jface_nls")</code>. * <p> * Note that several static convenience methods are also provided on this * class for directly accessing resources in this bundle. * </p> * * @return the resource bundle */ public static ResourceBundle getBundle() { return bundle; } /** * Returns the color registry for JFace itself. * <p> * * @return the <code>ColorRegistry</code>. * @since 3.0 */ public static ColorRegistry getColorRegistry() { if (colorRegistry == null) { colorRegistry = new ColorRegistry(); } return colorRegistry; } /** * Returns the global resource manager for the given display * * @since 3.1 * * @param toQuery * display to query * @return the global resource manager for the given display */ public static ResourceManager getResources(final Display toQuery) { ResourceManager reg = registries.get(toQuery); if (reg == null) { final DeviceResourceManager mgr = new DeviceResourceManager(toQuery); reg = mgr; registries.put(toQuery, mgr); toQuery.disposeExec(() -> { mgr.dispose(); registries.remove(toQuery); }); } return reg; } /** * Returns the ResourceManager for the current display. May only be called * from a UI thread. * * @since 3.1 * * @return the global ResourceManager for the current display */ public static ResourceManager getResources() { return getResources(Display.getCurrent()); } /** * Returns JFace's standard font. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.DEFAULT_FONT) * </pre> * * @return the font */ public static Font getDefaultFont() { return getFontRegistry().defaultFont(); } /** * Returns the descriptor for JFace's standard font. Convenience method * equivalent to * * <pre> * JFaceResources.getFontRegistry().getDescriptor(JFaceResources.DEFAULT_FONT) * </pre> * * @return the font * @since 3.3 */ public static FontDescriptor getDefaultFontDescriptor() { return getFontRegistry().defaultFontDescriptor(); } /** * Returns the JFace's dialog font. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.DIALOG_FONT) * </pre> * * @return the font */ public static Font getDialogFont() { return getFontRegistry().get(DIALOG_FONT); } /** * Returns the descriptor for JFace's dialog font. Convenience method * equivalent to * * <pre> * JFaceResources.getFontRegistry().getDescriptor(JFaceResources.DIALOG_FONT) * </pre> * * @return the font * @since 3.3 */ public static FontDescriptor getDialogFontDescriptor() { return getFontRegistry().getDescriptor(DIALOG_FONT); } /** * Returns the font in JFace's font registry with the given symbolic font * name. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(symbolicName) * </pre> * * If an error occurs, return the default font. * * @param symbolicName * the symbolic font name * @return the font */ public static Font getFont(String symbolicName) { return getFontRegistry().get(symbolicName); } /** * Returns the font descriptor for in JFace's font registry with the given * symbolic name. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().getDescriptor(symbolicName) * </pre> * * If an error occurs, return the default font. * * @param symbolicName * the symbolic font name * @return the font descriptor (never null) * @since 3.3 */ public static FontDescriptor getFontDescriptor(String symbolicName) { return getFontRegistry().getDescriptor(symbolicName); } /** * Returns the font registry for JFace itself. If the value has not been * established by an earlier call to <code>setFontRegistry</code>, is it * initialized to * <code>new FontRegistry("org.eclipse.jface.resource.jfacefonts")</code>. * <p> * Note that several static convenience methods are also provided on this * class for directly accessing JFace's standard fonts. * </p> * * @return the JFace font registry */ public static FontRegistry getFontRegistry() { if (fontRegistry == null) { fontRegistry = new FontRegistry("org.eclipse.jface.resource.jfacefonts"); //$NON-NLS-1$ } return fontRegistry; } /** * Returns the JFace's header font. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.HEADER_FONT) * </pre> * * @return the font */ public static Font getHeaderFont() { return getFontRegistry().get(HEADER_FONT); } /** * Returns the descriptor for JFace's header font. Convenience method * equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.HEADER_FONT) * </pre> * * @return the font descriptor (never null) * @since 3.3 */ public static FontDescriptor getHeaderFontDescriptor() { return getFontRegistry().getDescriptor(HEADER_FONT); } /** * Returns the image in JFace's image registry with the given key, or * <code>null</code> if none. Convenience method equivalent to * * <pre> * JFaceResources.getImageRegistry().get(key) * </pre> * * @param key * the key * @return the image, or <code>null</code> if none */ public static Image getImage(String key) { return getImageRegistry().get(key); } /** * Returns the image registry for JFace itself. * <p> * Note that the static convenience method <code>getImage</code> is also * provided on this class. * </p> * * @return the JFace image registry */ public static ImageRegistry getImageRegistry() { if (imageRegistry == null) { imageRegistry = new ImageRegistry(getResources(Display.getCurrent())); initializeDefaultImages(); } return imageRegistry; } /** * Initialize default images in JFace's image registry. * */ private static void initializeDefaultImages() { Object bundle = null; try { bundle = FrameworkUtil.getBundle(JFaceResources.class); } catch (Throwable exception) { // Test to see if OSGI is present } declareImage(bundle, Wizard.DEFAULT_IMAGE, ICONS_PATH + "page.png", //$NON-NLS-1$ Wizard.class, "images/page.png"); //$NON-NLS-1$ // register default images for dialogs declareImage(bundle, Dialog.DLG_IMG_MESSAGE_INFO, ICONS_PATH + "message_info.png", Dialog.class, //$NON-NLS-1$ "images/message_info.png"); //$NON-NLS-1$ declareImage(bundle, Dialog.DLG_IMG_MESSAGE_WARNING, ICONS_PATH + "message_warning.png", Dialog.class, //$NON-NLS-1$ "images/message_warning.png"); //$NON-NLS-1$ declareImage(bundle, Dialog.DLG_IMG_MESSAGE_ERROR, ICONS_PATH + "message_error.png", Dialog.class, //$NON-NLS-1$ "images/message_error.png");//$NON-NLS-1$ declareImage(bundle, Dialog.DLG_IMG_HELP, ICONS_PATH + "help.png", Dialog.class, "images/help.png");//$NON-NLS-1$ //$NON-NLS-2$ declareImage(bundle, TitleAreaDialog.DLG_IMG_TITLE_BANNER, ICONS_PATH + "title_banner.png", //$NON-NLS-1$ TitleAreaDialog.class, "images/title_banner.png");//$NON-NLS-1$ declareImage(bundle, PreferenceDialog.PREF_DLG_TITLE_IMG, ICONS_PATH + "pref_dialog_title.png", //$NON-NLS-1$ PreferenceDialog.class, "images/pref_dialog_title.png");//$NON-NLS-1$ declareImage(bundle, PopupDialog.POPUP_IMG_MENU, ICONS_PATH + "popup_menu.png", PopupDialog.class, //$NON-NLS-1$ "images/popup_menu.png");//$NON-NLS-1$ declareImage(bundle, PopupDialog.POPUP_IMG_MENU_DISABLED, ICONS_PATH + "popup_menu_disabled.png", //$NON-NLS-1$ PopupDialog.class, "images/popup_menu_disabled.png");//$NON-NLS-1$ } /** * Declares a JFace image given the path of the image file (relative to the * JFace plug-in). This is a helper method that creates the image descriptor * and passes it to the main <code>declareImage</code> method. * * @param bundle * the {@link Bundle} or <code>null</code> of the Bundle cannot * be found * @param key * the symbolic name of the image * @param path * the path of the image file relative to the base of the * workbench plug-ins install directory * @param fallback * the {@link Class} where the fallback implementation of the * image is relative to * @param fallbackPath * the path relative to the fallback {@link Class} * */ private static final void declareImage(Object bundle, String key, String path, Class<?> fallback, String fallbackPath) { ImageDescriptor descriptor = null; if (bundle != null) { URL url = FileLocator.find((Bundle) bundle, new Path(path), null); if (url != null) descriptor = ImageDescriptor.createFromURL(url); } // If we failed then load from the backup file if (descriptor == null) descriptor = ImageDescriptor.createFromFile(fallback, fallbackPath); imageRegistry.put(key, descriptor); } /** * Returns the resource object with the given key in JFace's resource * bundle. If there isn't any value under the given key, the key is * returned. * * @param key * the resource name * @return the string */ public static String getString(String key) { try { return bundle.getString(key); } catch (MissingResourceException e) { return key; } } /** * Returns a list of string values corresponding to the given list of keys. * The lookup is done with <code>getString</code>. The values are in the * same order as the keys. * * @param keys * a list of keys * @return a list of corresponding string values */ public static String[] getStrings(String[] keys) { Assert.isNotNull(keys); int length = keys.length; String[] result = new String[length]; for (int i = 0; i < length; i++) { result[i] = getString(keys[i]); } return result; } /** * Returns JFace's text font. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.TEXT_FONT) * </pre> * * @return the font */ public static Font getTextFont() { return getFontRegistry().get(TEXT_FONT); } /** * Returns the descriptor for JFace's text font. Convenience method * equivalent to * * <pre> * JFaceResources.getFontRegistry().getDescriptor(JFaceResources.TEXT_FONT) * </pre> * * @return the font descriptor (never null) * @since 3.3 */ public static FontDescriptor getTextFontDescriptor() { return getFontRegistry().getDescriptor(TEXT_FONT); } /** * Returns JFace's viewer font. Convenience method equivalent to * * <pre> * JFaceResources.getFontRegistry().get(JFaceResources.VIEWER_FONT) * </pre> * * @return the font * @deprecated This font is not in use */ @Deprecated public static Font getViewerFont() { return getFontRegistry().get(VIEWER_FONT); } /** * Sets JFace's font registry to the given value. This method may only be * called once; the call must occur before * <code>JFaceResources.getFontRegistry</code> is invoked (either directly * or indirectly). * * @param registry * a font registry */ public static void setFontRegistry(FontRegistry registry) { Assert.isTrue(fontRegistry == null, "Font registry can only be set once."); //$NON-NLS-1$ fontRegistry = registry; } /** * Declare a private constructor to block instantiation. */ private JFaceResources() { // no-op } }