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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.webkit;
     18 
     19 import android.annotation.SystemApi;
     20 import android.app.ActivityThread;
     21 import android.app.Application;
     22 import android.content.Context;
     23 import android.content.res.Resources;
     24 import android.graphics.Canvas;
     25 import android.net.http.ErrorStrings;
     26 import android.os.SystemProperties;
     27 import android.os.Trace;
     28 import android.util.SparseArray;
     29 import android.view.HardwareCanvas;
     30 import android.view.View;
     31 import android.view.ViewRootImpl;
     32 
     33 /**
     34  * Delegate used by the WebView provider implementation to access
     35  * the required framework functionality needed to implement a {@link WebView}.
     36  *
     37  * @hide
     38  */
     39 @SystemApi
     40 public final class WebViewDelegate {
     41 
     42     /* package */ WebViewDelegate() { }
     43 
     44     /**
     45      * Listener that gets notified whenever tracing has been enabled/disabled.
     46      */
     47     public interface OnTraceEnabledChangeListener {
     48         void onTraceEnabledChange(boolean enabled);
     49     }
     50 
     51     /**
     52      * Register a callback to be invoked when tracing for the WebView component has been
     53      * enabled/disabled.
     54      */
     55     public void setOnTraceEnabledChangeListener(final OnTraceEnabledChangeListener listener) {
     56         SystemProperties.addChangeCallback(new Runnable() {
     57             @Override
     58             public void run() {
     59                 listener.onTraceEnabledChange(isTraceTagEnabled());
     60             }
     61         });
     62     }
     63 
     64     /**
     65      * Returns true if the WebView trace tag is enabled and false otherwise.
     66      */
     67     public boolean isTraceTagEnabled() {
     68         return Trace.isTagEnabled(Trace.TRACE_TAG_WEBVIEW);
     69     }
     70 
     71     /**
     72      * Returns true if the draw GL functor can be invoked (see {@link #invokeDrawGlFunctor})
     73      * and false otherwise.
     74      */
     75     public boolean canInvokeDrawGlFunctor(View containerView) {
     76         ViewRootImpl viewRootImpl = containerView.getViewRootImpl();
     77          // viewRootImpl can be null during teardown when window is leaked.
     78         return viewRootImpl != null;
     79     }
     80 
     81     /**
     82      * Invokes the draw GL functor. If waitForCompletion is false the functor
     83      * may be invoked asynchronously.
     84      *
     85      * @param nativeDrawGLFunctor the pointer to the native functor that implements
     86      *        system/core/include/utils/Functor.h
     87      */
     88     public void invokeDrawGlFunctor(View containerView, long nativeDrawGLFunctor,
     89             boolean waitForCompletion) {
     90         ViewRootImpl viewRootImpl = containerView.getViewRootImpl();
     91         viewRootImpl.invokeFunctor(nativeDrawGLFunctor, waitForCompletion);
     92     }
     93 
     94     /**
     95      * Calls the function specified with the nativeDrawGLFunctor functor pointer. This
     96      * functionality is used by the WebView for calling into their renderer from the
     97      * framework display lists.
     98      *
     99      * @param canvas a hardware accelerated canvas (see {@link Canvas#isHardwareAccelerated()})
    100      * @param nativeDrawGLFunctor the pointer to the native functor that implements
    101      *        system/core/include/utils/Functor.h
    102      * @throws IllegalArgumentException if the canvas is not hardware accelerated
    103      */
    104     public void callDrawGlFunction(Canvas canvas, long nativeDrawGLFunctor) {
    105         if (!(canvas instanceof HardwareCanvas)) {
    106             // Canvas#isHardwareAccelerated() is only true for subclasses of HardwareCanvas.
    107             throw new IllegalArgumentException(canvas.getClass().getName()
    108                     + " is not hardware accelerated");
    109         }
    110         ((HardwareCanvas) canvas).callDrawGLFunction2(nativeDrawGLFunctor);
    111     }
    112 
    113     /**
    114      * Detaches the draw GL functor.
    115      *
    116      * @param nativeDrawGLFunctor the pointer to the native functor that implements
    117      *        system/core/include/utils/Functor.h
    118      */
    119     public void detachDrawGlFunctor(View containerView, long nativeDrawGLFunctor) {
    120         ViewRootImpl viewRootImpl = containerView.getViewRootImpl();
    121         if (nativeDrawGLFunctor != 0 && viewRootImpl != null) {
    122             viewRootImpl.detachFunctor(nativeDrawGLFunctor);
    123         }
    124     }
    125 
    126     /**
    127      * Returns the package id of the given {@code packageName}.
    128      */
    129     public int getPackageId(Resources resources, String packageName) {
    130         SparseArray<String> packageIdentifiers =
    131                 resources.getAssets().getAssignedPackageIdentifiers();
    132         for (int i = 0; i < packageIdentifiers.size(); i++) {
    133             final String name = packageIdentifiers.valueAt(i);
    134 
    135             if (packageName.equals(name)) {
    136                 return packageIdentifiers.keyAt(i);
    137             }
    138         }
    139         throw new RuntimeException("Package not found: " + packageName);
    140     }
    141 
    142     /**
    143      * Returns the application which is embedding the WebView.
    144      */
    145     public Application getApplication() {
    146         return ActivityThread.currentApplication();
    147     }
    148 
    149     /**
    150      * Returns the error string for the given {@code errorCode}.
    151      */
    152     public String getErrorString(Context context, int errorCode) {
    153         return ErrorStrings.getString(errorCode, context);
    154     }
    155 
    156     /**
    157      * Adds the WebView asset path to {@link AssetManager}.
    158      */
    159     public void addWebViewAssetPath(Context context) {
    160         context.getAssets().addAssetPath(
    161                 WebViewFactory.getLoadedPackageInfo().applicationInfo.sourceDir);
    162     }
    163 }
    164