Java tutorial
/* * Copyright (c) 1998, 2013, 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. */ /* ******************************************************************** ********************************************************************** ********************************************************************** *** COPYRIGHT (c) Eastman Kodak Company, 1997 *** *** As an unpublished work pursuant to Title 17 of the United *** *** States Code. All rights reserved. *** ********************************************************************** ********************************************************************** **********************************************************************/ package java.awt.image.renderable; import java.util.Vector; import java.awt.RenderingHints; import java.awt.image.*; /** * A RenderableImage is a common interface for rendering-independent * images (a notion which subsumes resolution independence). That is, * images which are described and have operations applied to them * independent of any specific rendering of the image. For example, a * RenderableImage can be rotated and cropped in * resolution-independent terms. Then, it can be rendered for various * specific contexts, such as a draft preview, a high-quality screen * display, or a printer, each in an optimal fashion. * * <p> A RenderedImage is returned from a RenderableImage via the * createRendering() method, which takes a RenderContext. The * RenderContext specifies how the RenderedImage should be * constructed. Note that it is not possible to extract pixels * directly from a RenderableImage. * * <p> The createDefaultRendering() and createScaledRendering() methods are * convenience methods that construct an appropriate RenderContext * internally. All of the rendering methods may return a reference to a * previously produced rendering. */ public interface RenderableImage { /** * String constant that can be used to identify a property on * a RenderedImage obtained via the createRendering or * createScaledRendering methods. If such a property exists, * the value of the property will be a RenderingHints object * specifying which hints were observed in creating the rendering. */ static final String HINTS_OBSERVED = "HINTS_OBSERVED"; /** * Returns a vector of RenderableImages that are the sources of * image data for this RenderableImage. Note that this method may * return an empty vector, to indicate that the image has no sources, * or null, to indicate that no information is available. * * @return a (possibly empty) Vector of RenderableImages, or null. */ Vector<RenderableImage> getSources(); /** * Gets a property from the property set of this image. * If the property name is not recognized, java.awt.Image.UndefinedProperty * will be returned. * * @param name the name of the property to get, as a String. * @return a reference to the property Object, or the value * java.awt.Image.UndefinedProperty. */ Object getProperty(String name); /** * Returns a list of names recognized by getProperty. * @return a list of property names. */ String[] getPropertyNames(); /** * Returns true if successive renderings (that is, calls to * createRendering() or createScaledRendering()) with the same arguments * may produce different results. This method may be used to * determine whether an existing rendering may be cached and * reused. It is always safe to return true. * @return {@code true} if successive renderings with the * same arguments might produce different results; * {@code false} otherwise. */ boolean isDynamic(); /** * Gets the width in user coordinate space. By convention, the * usual width of a RenderableImage is equal to the image's aspect * ratio (width divided by height). * * @return the width of the image in user coordinates. */ float getWidth(); /** * Gets the height in user coordinate space. By convention, the * usual height of a RenderedImage is equal to 1.0F. * * @return the height of the image in user coordinates. */ float getHeight(); /** * Gets the minimum X coordinate of the rendering-independent image data. * @return the minimum X coordinate of the rendering-independent image * data. */ float getMinX(); /** * Gets the minimum Y coordinate of the rendering-independent image data. * @return the minimum Y coordinate of the rendering-independent image * data. */ float getMinY(); /** * Creates a RenderedImage instance of this image with width w, and * height h in pixels. The RenderContext is built automatically * with an appropriate usr2dev transform and an area of interest * of the full image. All the rendering hints come from hints * passed in. * * <p> If w == 0, it will be taken to equal * Math.round(h*(getWidth()/getHeight())). * Similarly, if h == 0, it will be taken to equal * Math.round(w*(getHeight()/getWidth())). One of * w or h must be non-zero or else an IllegalArgumentException * will be thrown. * * <p> The created RenderedImage may have a property identified * by the String HINTS_OBSERVED to indicate which RenderingHints * were used to create the image. In addition any RenderedImages * that are obtained via the getSources() method on the created * RenderedImage may have such a property. * * @param w the width of rendered image in pixels, or 0. * @param h the height of rendered image in pixels, or 0. * @param hints a RenderingHints object containing hints. * @return a RenderedImage containing the rendered data. */ RenderedImage createScaledRendering(int w, int h, RenderingHints hints); /** * Returns a RenderedImage instance of this image with a default * width and height in pixels. The RenderContext is built * automatically with an appropriate usr2dev transform and an area * of interest of the full image. The rendering hints are * empty. createDefaultRendering may make use of a stored * rendering for speed. * * @return a RenderedImage containing the rendered data. */ RenderedImage createDefaultRendering(); /** * Creates a RenderedImage that represented a rendering of this image * using a given RenderContext. This is the most general way to obtain a * rendering of a RenderableImage. * * <p> The created RenderedImage may have a property identified * by the String HINTS_OBSERVED to indicate which RenderingHints * (from the RenderContext) were used to create the image. * In addition any RenderedImages * that are obtained via the getSources() method on the created * RenderedImage may have such a property. * * @param renderContext the RenderContext to use to produce the rendering. * @return a RenderedImage containing the rendered data. */ RenderedImage createRendering(RenderContext renderContext); }