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/******************************************************************************* * Copyright (c) 2004, 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 *******************************************************************************/ package org.eclipse.jface.resource; import org.eclipse.swt.graphics.Device; import org.eclipse.swt.graphics.Font; import org.eclipse.swt.graphics.FontData; import org.eclipse.swt.widgets.Display; /** * 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 * * @deprecated use {@link FontDescriptor#createFrom(Font)} * * @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. */ @Deprecated public static FontDescriptor createFrom(Font font, Device originalDevice) { return new ArrayFontDescriptor(font); } /** * 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. * * @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 ArrayFontDescriptor(new FontData[] { 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)); } /** * Returns the set of FontData associated with this font. Modifying the elements * in the returned array has no effect on the original FontDescriptor. * * @return the set of FontData associated with this font * @since 3.3 */ public FontData[] getFontData() { Font tempFont = createFont(Display.getCurrent()); FontData[] result = tempFont.getFontData(); destroyFont(tempFont); return result; } /** * Returns an array of FontData containing copies of the FontData * from the original. * * @param original array to copy * @return a deep copy of the original array * @since 3.3 */ public static FontData[] copy(FontData[] original) { FontData[] result = new FontData[original.length]; for (int i = 0; i < original.length; i++) { FontData next = original[i]; result[i] = copy(next); } return result; } /** * Returns a copy of the original FontData * * @param next FontData to copy * @return a copy of the given FontData * @since 3.3 */ public static FontData copy(FontData next) { FontData result = new FontData(next.getName(), next.getHeight(), next.getStyle()); result.setLocale(next.getLocale()); return result; } /** * Returns a FontDescriptor that is equivalent to the receiver, but uses * the given style bits. * * <p>Does not modify the receiver.</p> * * @param style a bitwise combination of SWT.NORMAL, SWT.ITALIC and SWT.BOLD * @return a new FontDescriptor with the given style * * @since 3.3 */ public final FontDescriptor setStyle(int style) { FontData[] data = getFontData(); for (FontData next : data) { next.setStyle(style); } // Optimization: avoid holding onto extra instances by returning the receiver if // if it is exactly the same as the result FontDescriptor result = new ArrayFontDescriptor(data); if (result.equals(this)) { return this; } return result; } /** * <p>Returns a FontDescriptor that is equivalent to the receiver, but * has the given style bits, in addition to any styles the receiver already has.</p> * * <p>Does not modify the receiver.</p> * * @param style a bitwise combination of SWT.NORMAL, SWT.ITALIC and SWT.BOLD * @return a new FontDescriptor with the given additional style bits * @since 3.3 */ public final FontDescriptor withStyle(int style) { FontData[] data = getFontData(); for (FontData next : data) { next.setStyle(next.getStyle() | style); } // Optimization: avoid allocating extra instances by returning the receiver if // if it is exactly the same as the result FontDescriptor result = new ArrayFontDescriptor(data); if (result.equals(this)) { return this; } return result; } /** * <p>Returns a new FontDescriptor that is equivalent to the receiver, but * has the given height.</p> * * <p>Does not modify the receiver.</p> * * @param height a height, in points * @return a new FontDescriptor with the height, in points * @since 3.3 */ public final FontDescriptor setHeight(int height) { FontData[] data = getFontData(); for (FontData next : data) { next.setHeight(height); } // Optimization: avoid holding onto extra instances by returning the receiver if // if it is exactly the same as the result FontDescriptor result = new ArrayFontDescriptor(data); if (result.equals(this)) { return this; } return result; } /** * <p>Returns a FontDescriptor that is equivalent to the receiver, but whose height * is larger by the given number of points.</p> * * <p>Does not modify the receiver.</p> * * @param heightDelta a change in height, in points. Negative values will return smaller * fonts. * @return a FontDescriptor whose height differs from the receiver by the given number * of points. * @since 3.3 */ public final FontDescriptor increaseHeight(int heightDelta) { if (heightDelta == 0) { return this; } FontData[] data = getFontData(); for (FontData next : data) { next.setHeight(next.getHeight() + heightDelta); } return new ArrayFontDescriptor(data); } /** * 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); @Override public final Object createResource(Device device) throws DeviceResourceException { return createFont(device); } @Override public final void destroyResource(Object previouslyCreatedObject) { destroyFont((Font) previouslyCreatedObject); } }