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 17package android.support.v7.view; 18 19import android.content.Context; 20import android.content.ContextWrapper; 21import android.content.res.Resources; 22import android.support.annotation.RestrictTo; 23import android.support.annotation.StyleRes; 24import android.support.v7.appcompat.R; 25import android.view.LayoutInflater; 26 27import static android.support.annotation.RestrictTo.Scope.GROUP_ID; 28 29/** 30 * A ContextWrapper that allows you to modify the theme from what is in the 31 * wrapped context. 32 * 33 * @hide 34 */ 35@RestrictTo(GROUP_ID) 36public class ContextThemeWrapper extends ContextWrapper { 37 private int mThemeResource; 38 private Resources.Theme mTheme; 39 private LayoutInflater mInflater; 40 41 public ContextThemeWrapper(Context base, @StyleRes int themeResId) { 42 super(base); 43 mThemeResource = themeResId; 44 } 45 46 public ContextThemeWrapper(Context base, Resources.Theme theme) { 47 super(base); 48 mTheme = theme; 49 } 50 51 @Override 52 public void setTheme(int resid) { 53 if (mThemeResource != resid) { 54 mThemeResource = resid; 55 initializeTheme(); 56 } 57 } 58 59 public int getThemeResId() { 60 return mThemeResource; 61 } 62 63 @Override 64 public Resources.Theme getTheme() { 65 if (mTheme != null) { 66 return mTheme; 67 } 68 69 if (mThemeResource == 0) { 70 mThemeResource = R.style.Theme_AppCompat_Light; 71 } 72 initializeTheme(); 73 74 return mTheme; 75 } 76 77 @Override 78 public Object getSystemService(String name) { 79 if (LAYOUT_INFLATER_SERVICE.equals(name)) { 80 if (mInflater == null) { 81 mInflater = LayoutInflater.from(getBaseContext()).cloneInContext(this); 82 } 83 return mInflater; 84 } 85 return getBaseContext().getSystemService(name); 86 } 87 88 /** 89 * Called by {@link #setTheme} and {@link #getTheme} to apply a theme 90 * resource to the current Theme object. Can override to change the 91 * default (simple) behavior. This method will not be called in multiple 92 * threads simultaneously. 93 * 94 * @param theme The Theme object being modified. 95 * @param resid The theme style resource being applied to <var>theme</var>. 96 * @param first Set to true if this is the first time a style is being 97 * applied to <var>theme</var>. 98 */ 99 protected void onApplyThemeResource(Resources.Theme theme, int resid, boolean first) { 100 theme.applyStyle(resid, true); 101 } 102 103 private void initializeTheme() { 104 final boolean first = mTheme == null; 105 if (first) { 106 mTheme = getResources().newTheme(); 107 Resources.Theme theme = getBaseContext().getTheme(); 108 if (theme != null) { 109 mTheme.setTo(theme); 110 } 111 } 112 onApplyThemeResource(mTheme, mThemeResource, first); 113 } 114} 115 116