Home | History | Annotate | Download | only in widget 
      1 /*
      2  * Copyright (C) 2015 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 androidx.appcompat.widget;
     18 
     19 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
     20 
     21 import android.content.Context;
     22 import android.content.res.Resources;
     23 import android.graphics.drawable.Drawable;
     24 import android.os.Build;
     25 
     26 import androidx.annotation.NonNull;
     27 import androidx.annotation.RestrictTo;
     28 
     29 import java.lang.ref.WeakReference;
     30 
     31 /**
     32  * This class allows us to intercept calls so that we can tint resources (if applicable), and
     33  * inflate vector resources from within drawable containers pre-L.
     34  *
     35  * @hide
     36  */
     37 @RestrictTo(LIBRARY_GROUP)
     38 public class VectorEnabledTintResources extends Resources {
     39     private static boolean sCompatVectorFromResourcesEnabled = false;
     40 
     41     public static boolean shouldBeUsed() {
     42         return isCompatVectorFromResourcesEnabled()
     43                 && Build.VERSION.SDK_INT <= MAX_SDK_WHERE_REQUIRED;
     44     }
     45 
     46     /**
     47      * The maximum API level where this class is needed.
     48      */
     49     public static final int MAX_SDK_WHERE_REQUIRED = 20;
     50 
     51     private final WeakReference<Context> mContextRef;
     52 
     53     public VectorEnabledTintResources(@NonNull final Context context,
     54             @NonNull final Resources res) {
     55         super(res.getAssets(), res.getDisplayMetrics(), res.getConfiguration());
     56         mContextRef = new WeakReference<>(context);
     57     }
     58 
     59     /**
     60      * We intercept this call so that we tint the result (if applicable). This is needed for
     61      * things like {@link android.graphics.drawable.DrawableContainer}s which can retrieve
     62      * their children via this method.
     63      */
     64     @Override
     65     public Drawable getDrawable(int id) throws NotFoundException {
     66         final Context context = mContextRef.get();
     67         if (context != null) {
     68             return AppCompatDrawableManager.get().onDrawableLoadedFromResources(context, this, id);
     69         } else {
     70             return super.getDrawable(id);
     71         }
     72     }
     73 
     74     final Drawable superGetDrawable(int id) {
     75         return super.getDrawable(id);
     76     }
     77 
     78     /**
     79      * Sets whether vector drawables on older platforms (< API 21) can be used within
     80      * {@link android.graphics.drawable.DrawableContainer} resources.
     81      */
     82     public static void setCompatVectorFromResourcesEnabled(boolean enabled) {
     83         sCompatVectorFromResourcesEnabled = enabled;
     84     }
     85 
     86     /**
     87      * Returns whether vector drawables on older platforms (< API 21) can be accessed from within
     88      * resources.
     89      *
     90      * @see #setCompatVectorFromResourcesEnabled(boolean)
     91      */
     92     public static boolean isCompatVectorFromResourcesEnabled() {
     93         return sCompatVectorFromResourcesEnabled;
     94     }
     95 }