1/*
2 * Copyright (C) 2013 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
18package android.support.v4.app;
19
20import android.R;
21import android.app.ActionBar;
22import android.app.Activity;
23import android.content.Context;
24import android.content.res.TypedArray;
25import android.graphics.drawable.Drawable;
26import android.os.Build;
27import android.util.Log;
28import android.view.View;
29import android.view.ViewGroup;
30import android.widget.ImageView;
31
32import java.lang.reflect.Method;
33
34/**
35 * This class encapsulates some awful hacks.
36 *
37 * Before JB-MR2 (API 18) it was not possible to change the home-as-up indicator glyph
38 * in an action bar without some really gross hacks. Since the MR2 SDK is not published as of
39 * this writing, the new API is accessed via reflection here if available.
40 */
41class ActionBarDrawerToggleHoneycomb {
42    private static final String TAG = "ActionBarDrawerToggleHoneycomb";
43
44    private static final int[] THEME_ATTRS = new int[] {
45            R.attr.homeAsUpIndicator
46    };
47
48    public static Object setActionBarUpIndicator(Object info, Activity activity,
49            Drawable drawable, int contentDescRes) {
50        if (info == null) {
51            info = new SetIndicatorInfo(activity);
52        }
53        final SetIndicatorInfo sii = (SetIndicatorInfo) info;
54        if (sii.setHomeAsUpIndicator != null) {
55            try {
56                final ActionBar actionBar = activity.getActionBar();
57                sii.setHomeAsUpIndicator.invoke(actionBar, drawable);
58                sii.setHomeActionContentDescription.invoke(actionBar, contentDescRes);
59            } catch (Exception e) {
60                Log.w(TAG, "Couldn't set home-as-up indicator via JB-MR2 API", e);
61            }
62        } else if (sii.upIndicatorView != null) {
63            sii.upIndicatorView.setImageDrawable(drawable);
64        } else {
65            Log.w(TAG, "Couldn't set home-as-up indicator");
66        }
67        return info;
68    }
69
70    public static Object setActionBarDescription(Object info, Activity activity,
71            int contentDescRes) {
72        if (info == null) {
73            info = new SetIndicatorInfo(activity);
74        }
75        final SetIndicatorInfo sii = (SetIndicatorInfo) info;
76        if (sii.setHomeAsUpIndicator != null) {
77            try {
78                final ActionBar actionBar = activity.getActionBar();
79                sii.setHomeActionContentDescription.invoke(actionBar, contentDescRes);
80                if (Build.VERSION.SDK_INT <= 19) {
81                    // For API 19 and earlier, we need to manually force the
82                    // action bar to generate a new content description.
83                    actionBar.setSubtitle(actionBar.getSubtitle());
84                }
85            } catch (Exception e) {
86                Log.w(TAG, "Couldn't set content description via JB-MR2 API", e);
87            }
88        }
89        return info;
90    }
91
92    public static Drawable getThemeUpIndicator(Activity activity) {
93        final TypedArray a = activity.obtainStyledAttributes(THEME_ATTRS);
94        final Drawable result = a.getDrawable(0);
95        a.recycle();
96        return result;
97    }
98
99    private static class SetIndicatorInfo {
100        public Method setHomeAsUpIndicator;
101        public Method setHomeActionContentDescription;
102        public ImageView upIndicatorView;
103
104        SetIndicatorInfo(Activity activity) {
105            try {
106                setHomeAsUpIndicator = ActionBar.class.getDeclaredMethod("setHomeAsUpIndicator",
107                        Drawable.class);
108                setHomeActionContentDescription = ActionBar.class.getDeclaredMethod(
109                        "setHomeActionContentDescription", Integer.TYPE);
110
111                // If we got the method we won't need the stuff below.
112                return;
113            } catch (NoSuchMethodException e) {
114                // Oh well. We'll use the other mechanism below instead.
115            }
116
117            final View home = activity.findViewById(android.R.id.home);
118            if (home == null) {
119                // Action bar doesn't have a known configuration, an OEM messed with things.
120                return;
121            }
122
123            final ViewGroup parent = (ViewGroup) home.getParent();
124            final int childCount = parent.getChildCount();
125            if (childCount != 2) {
126                // No idea which one will be the right one, an OEM messed with things.
127                return;
128            }
129
130            final View first = parent.getChildAt(0);
131            final View second = parent.getChildAt(1);
132            final View up = first.getId() == android.R.id.home ? second : first;
133
134            if (up instanceof ImageView) {
135                // Jackpot! (Probably...)
136                upIndicatorView = (ImageView) up;
137            }
138        }
139    }
140}
141