| /* | |
| * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved. | |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| * | |
| * This code is free software; you can redistribute it and/or modify it | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. Oracle designates this | |
| * particular file as subject to the "Classpath" exception as provided | |
| * by Oracle in the LICENSE file that accompanied this code. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
| * 2 along with this work; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| package sun.font; | |
| /* | |
| * This class is used so that a java.awt.Font does not directly | |
| * reference a Font2D object. This introduces occasional minor | |
| * de-referencing overhead but increases robustness of the | |
| * implementation when "bad fonts" are encountered. | |
| * A handle is created by a Font2D constructor and references | |
| * the Font2D itself. In the event that the Font2D implementation | |
| * determines it the font resource has errors (a bad font file) | |
| * it makes its handle point at another "stable" Font2D. | |
| * Once all referrers no longer have a reference to the Font2D it | |
| * may be GC'd and its resources freed. | |
| * This does not immediately help in the case that objects are | |
| * already using a bad Font2D (ie have already dereferenced the | |
| * handle) so there is a window for more problems. However this | |
| * is already the case as this is the code which must detect the | |
| * problem. | |
| * However there is also the possibility of intercepting problems | |
| * even when a font2D reference is already directly held. Certain | |
| * validation points may check that font2Dhandle.font2D == font2D | |
| * If this is not true, then this font2D is not valid. Arguably | |
| * this check also just needs to be a de-referencing assignment : | |
| * font2D = font2DHandle.font2D. | |
| * The net effect of these steps is that very soon after a font | |
| * is identified as bad, that references and uses of it will be | |
| * eliminated. | |
| * In the initial implementation a Font2DHandle is what is held by | |
| * - java.awt.Font | |
| * - FontManager.initialisedFonts map | |
| * Font2D is held by | |
| * - FontFamily objects | |
| * - FontManager.registeredFonts map | |
| * - FontInfo object on a SunGraphics2D | |
| * | |
| * On discovering a bad font, all but the latter remove references to | |
| * the font. See FontManager.deRegisterBadFont(Font2D) | |
| */ | |
| public final class Font2DHandle { | |
| public Font2D font2D; | |
| public Font2DHandle(Font2D font) { | |
| font2D = font; | |
| } | |
| } |