| /* |
| * Copyright (c) 2000, 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 |
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| */ |
| |
| package javax.imageio.metadata; |
| |
| /** |
| * An interface to be implemented by objects that can determine the |
| * settings of an {@code IIOMetadata} object, either by putting |
| * up a GUI to obtain values from a user, or by other means. This |
| * interface merely specifies a generic {@code activate} method |
| * that invokes the controller, without regard for how the controller |
| * obtains values (<i>i.e.</i>, whether the controller puts up a GUI |
| * or merely computes a set of values is irrelevant to this |
| * interface). |
| * |
| * <p> Within the {@code activate} method, a controller obtains |
| * initial values by querying the {@code IIOMetadata} object's |
| * settings, either using the XML DOM tree or a plug-in specific |
| * interface, modifies values by whatever means, then modifies the |
| * {@code IIOMetadata} object's settings, using either the |
| * {@code setFromTree} or {@code mergeTree} methods, or a |
| * plug-in specific interface. In general, applications may expect |
| * that when the {@code activate} method returns |
| * {@code true}, the {@code IIOMetadata} object is ready for |
| * use in a write operation. |
| * |
| * <p> Vendors may choose to provide GUIs for the |
| * {@code IIOMetadata} subclasses they define for a particular |
| * plug-in. These can be set up as default controllers in the |
| * corresponding {@code IIOMetadata} subclasses. |
| * |
| * <p> Alternatively, an algorithmic process such as a database lookup |
| * or the parsing of a command line could be used as a controller, in |
| * which case the {@code activate} method would simply look up or |
| * compute the settings, call methods on {@code IIOMetadata} to |
| * set its state, and return {@code true}. |
| * |
| * @see IIOMetadata#setController |
| * @see IIOMetadata#getController |
| * @see IIOMetadata#getDefaultController |
| * @see IIOMetadata#hasController |
| * @see IIOMetadata#activateController |
| * |
| */ |
| public interface IIOMetadataController { |
| |
| /** |
| * Activates the controller. If {@code true} is returned, |
| * all settings in the {@code IIOMetadata} object should be |
| * ready for use in a write operation. If {@code false} is |
| * returned, no settings in the {@code IIOMetadata} object |
| * will be disturbed (<i>i.e.</i>, the user canceled the |
| * operation). |
| * |
| * @param metadata the {@code IIOMetadata} object to be modified. |
| * |
| * @return {@code true} if the {@code IIOMetadata} has been |
| * modified, {@code false} otherwise. |
| * |
| * @exception IllegalArgumentException if {@code metadata} is |
| * {@code null} or is not an instance of the correct class. |
| */ |
| boolean activate(IIOMetadata metadata); |
| } |