tools/layoutlib/api/src/com/android/layoutlib/api/ILayoutBridge.java

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.layoutlib.api;

import java.util.Map;

/**
 * Entry point of the Layout Lib. Implementations of this interface provide a method to compute
 * and render a layout.
 */
public interface ILayoutBridge {

    /**
     * Initializes the Bridge object.
     * @param fontOsLocation the location of the fonts.
     * @param enumValueMap map attrName => { map enumFlagName => Integer value }.
     * @return true if success.
     */
    boolean init(String fontOsLocation, Map<String, Map<String, Integer>> enumValueMap);


    /**
     * Computes and renders a layout
     * @param layoutDescription the {@link IXmlPullParser} letting the LayoutLib Bridge visit the
     * layout file.
     * @param projectKey An Object identifying the project. This is used for the cache mechanism.
     * @param screenWidth
     * @param screenHeight
     * @param themeName The name of the theme to use. In order to differentiate project and platform
     * themes sharing the same name, all project themes must be prepended with a '*' character.
     * @param projectResources the resources of the project. The map contains (String, map) pairs
     * where the string is the type of the resource reference used in the layout file, and the
     * map contains (String, {@link IResourceValue}) pairs where the key is the resource name,
     * and the value is the resource value.
     * @param frameworkResources the framework resources. The map contains (String, map) pairs
     * where the string is the type of the resource reference used in the layout file, and the map
     * contains (String, {@link IResourceValue}) pairs where the key is the resource name, and the
     * value is the resource value.
     * @param projectCallback The {@link IProjectCallback} object to get information from
     * the project.
     * @param logger the object responsible for displaying warning/errors to the user.
     * @return an {@link ILayoutResult} object that contains the result of the layout.
     */
    ILayoutResult computeLayout(IXmlPullParser layoutDescription,
            Object projectKey,
            int screenWidth, int screenHeight, String themeName,
            Map<String, Map<String, IResourceValue>> projectResources,
            Map<String, Map<String, IResourceValue>> frameworkResources,
            IProjectCallback projectCallback, ILayoutLog logger);
    
    /**
     * Clears the resource cache for a specific project.
     * <p/>This cache contains bitmaps and nine patches that are loaded from the disk and reused
     * until this method is called.
     * <p/>The cache is not configuration dependent and should only be cleared when a
     * resource changes (at this time only bitmaps and 9 patches go into the cache).
     * @param objectKey the key for the project.
     */
    void clearCaches(Object projectKey);
}