/* * 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 referers 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; }}
/*
* 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 referers 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;
}
}