| /******************************************************************************* |
| * Copyright (c) 2004, 2005 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jface.resource; |
| |
| import org.eclipse.swt.graphics.Device; |
| import org.eclipse.swt.graphics.Font; |
| import org.eclipse.swt.graphics.FontData; |
| |
| /** |
| * Lightweight descriptor for a font. Creates the described font on demand. |
| * Subclasses can implement different ways of describing a font. These objects |
| * will be compared, so hashCode(...) and equals(...) must return something |
| * meaningful. |
| * |
| * @since 3.1 |
| */ |
| public abstract class FontDescriptor extends DeviceResourceDescriptor { |
| |
| /** |
| * Creates a FontDescriptor that describes an existing font. The resulting |
| * descriptor depends on the Font. Disposing the Font while the descriptor |
| * is still in use may throw a graphic disposed exception. |
| * |
| * @since 3.1 |
| * |
| * @param font a font to describe |
| * @param originalDevice must be the same Device that was passed into |
| * the font's constructor when it was first created. |
| * @return a newly created FontDescriptor. |
| */ |
| public static FontDescriptor createFrom(Font font, Device originalDevice) { |
| return new ArrayFontDescriptor(font, originalDevice); |
| } |
| |
| /** |
| * Creates a FontDescriptor that describes an existing font. The resulting |
| * descriptor depends on the original Font, and disposing the original Font |
| * while the descriptor is still in use may cause SWT to throw a graphic |
| * disposed exception. This is less efficient than <code>createFrom(Font, Device) |
| * </code>, so the other version should be used whenever possible. |
| * |
| * @since 3.1 |
| * |
| * @param font font to create |
| * @return a newly created FontDescriptor that describes the given font |
| */ |
| public static FontDescriptor createFrom(Font font) { |
| return new ArrayFontDescriptor(font); |
| } |
| |
| /** |
| * Creates a new FontDescriptor given the an array of FontData that describes |
| * the font. |
| * |
| * @since 3.1 |
| * |
| * @param data an array of FontData that describes the font (will be passed into |
| * the Font's constructor) |
| * @return a FontDescriptor that describes the given font |
| */ |
| public static FontDescriptor createFrom(FontData[] data) { |
| return new ArrayFontDescriptor(data); |
| } |
| |
| /** |
| * Creates a new FontDescriptor given the associated FontData |
| * |
| * @param data FontData describing the font to create |
| * @return a newly created FontDescriptor |
| */ |
| public static FontDescriptor createFrom(FontData data) { |
| return new NamedFontDescriptor(data); |
| } |
| |
| /** |
| * Creates a new FontDescriptor given an OS-specific font name, height, and style. |
| * |
| * @see Font#Font(org.eclipse.swt.graphics.Device, java.lang.String, int, int) |
| * |
| * @param name os-specific font name |
| * @param height height (pixels) |
| * @param style a bitwise combination of NORMAL, BOLD, ITALIC |
| * @return a new FontDescriptor |
| */ |
| public static FontDescriptor createFrom(String name, int height, int style) { |
| return createFrom(new FontData(name, height, style)); |
| } |
| |
| /** |
| * Creates the Font described by this descriptor. |
| * |
| * @since 3.1 |
| * |
| * @param device device on which to allocate the font |
| * @return a newly allocated Font (never null) |
| * @throws DeviceResourceException if unable to allocate the Font |
| */ |
| public abstract Font createFont(Device device) throws DeviceResourceException; |
| |
| /** |
| * Deallocates anything that was allocated by createFont, given a font |
| * that was allocated by an equal FontDescriptor. |
| * |
| * @since 3.1 |
| * |
| * @param previouslyCreatedFont previously allocated font |
| */ |
| public abstract void destroyFont(Font previouslyCreatedFont); |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jface.resource.DeviceResourceDescriptor#create(org.eclipse.swt.graphics.Device) |
| */ |
| public final Object createResource(Device device) throws DeviceResourceException { |
| return createFont(device); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jface.resource.DeviceResourceDescriptor#destroy(java.lang.Object) |
| */ |
| public final void destroyResource(Object previouslyCreatedObject) { |
| destroyFont((Font)previouslyCreatedObject); |
| } |
| } |