Home | History | Annotate | Download | only in view 
      1 /*
      2  * Copyright (C) 2006 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.view;
     18 
     19 import android.content.Context;
     20 import android.content.ContextWrapper;
     21 import android.content.res.Resources;
     22 import android.os.Build;
     23 
     24 /**
     25  * A ContextWrapper that allows you to modify the theme from what is in the
     26  * wrapped context.
     27  */
     28 public class ContextThemeWrapper extends ContextWrapper {
     29     private Context mBase;
     30     private int mThemeResource;
     31     private Resources.Theme mTheme;
     32     private LayoutInflater mInflater;
     33 
     34     public ContextThemeWrapper() {
     35         super(null);
     36     }
     37 
     38     public ContextThemeWrapper(Context base, int themeres) {
     39         super(base);
     40         mBase = base;
     41         mThemeResource = themeres;
     42     }
     43 
     44     @Override protected void attachBaseContext(Context newBase) {
     45         super.attachBaseContext(newBase);
     46         mBase = newBase;
     47     }
     48 
     49     @Override public void setTheme(int resid) {
     50         mThemeResource = resid;
     51         initializeTheme();
     52     }
     53 
     54     /** @hide */
     55     @Override
     56     public int getThemeResId() {
     57         return mThemeResource;
     58     }
     59 
     60     @Override public Resources.Theme getTheme() {
     61         if (mTheme != null) {
     62             return mTheme;
     63         }
     64 
     65         mThemeResource = Resources.selectDefaultTheme(mThemeResource,
     66                 getApplicationInfo().targetSdkVersion);
     67         initializeTheme();
     68 
     69         return mTheme;
     70     }
     71 
     72     @Override public Object getSystemService(String name) {
     73         if (LAYOUT_INFLATER_SERVICE.equals(name)) {
     74             if (mInflater == null) {
     75                 mInflater = LayoutInflater.from(mBase).cloneInContext(this);
     76             }
     77             return mInflater;
     78         }
     79         return mBase.getSystemService(name);
     80     }
     81 
     82     /**
     83      * Called by {@link #setTheme} and {@link #getTheme} to apply a theme
     84      * resource to the current Theme object.  Can override to change the
     85      * default (simple) behavior.  This method will not be called in multiple
     86      * threads simultaneously.
     87      *
     88      * @param theme The Theme object being modified.
     89      * @param resid The theme style resource being applied to <var>theme</var>.
     90      * @param first Set to true if this is the first time a style is being
     91      *              applied to <var>theme</var>.
     92      */
     93     protected void onApplyThemeResource(Resources.Theme theme, int resid, boolean first) {
     94         theme.applyStyle(resid, true);
     95     }
     96 
     97     private void initializeTheme() {
     98         final boolean first = mTheme == null;
     99         if (first) {
    100             mTheme = getResources().newTheme();
    101             Resources.Theme theme = mBase.getTheme();
    102             if (theme != null) {
    103                 mTheme.setTo(theme);
    104             }
    105         }
    106         onApplyThemeResource(mTheme, mThemeResource, first);
    107     }
    108 }
    109 
    110