1/*
2 * Copyright 2018 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 com.android.support.mediarouter.app;
18
19import android.content.Context;
20import android.content.res.TypedArray;
21import android.graphics.Color;
22import android.support.annotation.IntDef;
23import android.support.v4.graphics.ColorUtils;
24import android.util.TypedValue;
25import android.view.ContextThemeWrapper;
26import android.view.View;
27
28import com.android.media.update.R;
29
30import java.lang.annotation.Retention;
31import java.lang.annotation.RetentionPolicy;
32
33final class MediaRouterThemeHelper {
34    private static final float MIN_CONTRAST = 3.0f;
35
36    @IntDef({COLOR_DARK_ON_LIGHT_BACKGROUND, COLOR_WHITE_ON_DARK_BACKGROUND})
37    @Retention(RetentionPolicy.SOURCE)
38    private @interface ControllerColorType {}
39
40    static final int COLOR_DARK_ON_LIGHT_BACKGROUND = 0xDE000000; /* Opacity of 87% */
41    static final int COLOR_WHITE_ON_DARK_BACKGROUND = Color.WHITE;
42
43    private MediaRouterThemeHelper() {
44    }
45
46    static Context createThemedButtonContext(Context context) {
47        // Apply base Media Router theme.
48        context = new ContextThemeWrapper(context, getRouterThemeId(context));
49
50        // Apply custom Media Router theme.
51        int style = getThemeResource(context, R.attr.mediaRouteTheme);
52        if (style != 0) {
53            context = new ContextThemeWrapper(context, style);
54        }
55
56        return context;
57    }
58
59    /*
60     * The following two methods are to be used in conjunction. They should be used to prepare
61     * the context and theme for a super class constructor (the latter method relies on the
62     * former method to properly prepare the context):
63     *   super(context = createThemedDialogContext(context, theme),
64     *           createThemedDialogStyle(context));
65     *
66     * It will apply theme in the following order (style lookups will be done in reverse):
67     *   1) Current theme
68     *   2) Supplied theme
69     *   3) Base Media Router theme
70     *   4) Custom Media Router theme, if provided
71     */
72    static Context createThemedDialogContext(Context context, int theme, boolean alertDialog) {
73        // 1) Current theme is already applied to the context
74
75        // 2) If no theme is supplied, look it up from the context (dialogTheme/alertDialogTheme)
76        if (theme == 0) {
77            theme = getThemeResource(context,
78                    !alertDialog ? android.R.attr.dialogTheme : android.R.attr.alertDialogTheme);
79        }
80        //    Apply it
81        context = new ContextThemeWrapper(context, theme);
82
83        // 3) If a custom Media Router theme is provided then apply the base theme
84        if (getThemeResource(context, R.attr.mediaRouteTheme) != 0) {
85            context = new ContextThemeWrapper(context, getRouterThemeId(context));
86        }
87
88        return context;
89    }
90    // This method should be used in conjunction with the previous method.
91    static int createThemedDialogStyle(Context context) {
92        // 4) Apply the custom Media Router theme
93        int theme = getThemeResource(context, R.attr.mediaRouteTheme);
94        if (theme == 0) {
95            // 3) No custom MediaRouter theme was provided so apply the base theme instead
96            theme = getRouterThemeId(context);
97        }
98
99        return theme;
100    }
101    // END. Previous two methods should be used in conjunction.
102
103    static int getThemeResource(Context context, int attr) {
104        TypedValue value = new TypedValue();
105        return context.getTheme().resolveAttribute(attr, value, true) ? value.resourceId : 0;
106    }
107
108    static float getDisabledAlpha(Context context) {
109        TypedValue value = new TypedValue();
110        return context.getTheme().resolveAttribute(android.R.attr.disabledAlpha, value, true)
111                ? value.getFloat() : 0.5f;
112    }
113
114    static @ControllerColorType int getControllerColor(Context context, int style) {
115        int primaryColor = getThemeColor(context, style, android.R.attr.colorPrimary);
116        if (primaryColor == 0) {
117            primaryColor = getThemeColor(context, style, android.R.attr.colorPrimary);
118            if (primaryColor == 0) {
119                primaryColor = 0xFF000000;
120            }
121        }
122        if (ColorUtils.calculateContrast(COLOR_WHITE_ON_DARK_BACKGROUND, primaryColor)
123                >= MIN_CONTRAST) {
124            return COLOR_WHITE_ON_DARK_BACKGROUND;
125        }
126        return COLOR_DARK_ON_LIGHT_BACKGROUND;
127    }
128
129    static int getButtonTextColor(Context context) {
130        int primaryColor = getThemeColor(context, 0, android.R.attr.colorPrimary);
131        int backgroundColor = getThemeColor(context, 0, android.R.attr.colorBackground);
132
133        if (ColorUtils.calculateContrast(primaryColor, backgroundColor) < MIN_CONTRAST) {
134            // Default to colorAccent if the contrast ratio is low.
135            return getThemeColor(context, 0, android.R.attr.colorAccent);
136        }
137        return primaryColor;
138    }
139
140    static void setMediaControlsBackgroundColor(
141            Context context, View mainControls, View groupControls, boolean hasGroup) {
142        int primaryColor = getThemeColor(context, 0, android.R.attr.colorPrimary);
143        int primaryDarkColor = getThemeColor(context, 0, android.R.attr.colorPrimaryDark);
144        if (hasGroup && getControllerColor(context, 0) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
145            // Instead of showing dark controls in a possibly dark (i.e. the primary dark), model
146            // the white dialog and use the primary color for the group controls.
147            primaryDarkColor = primaryColor;
148            primaryColor = Color.WHITE;
149        }
150        mainControls.setBackgroundColor(primaryColor);
151        groupControls.setBackgroundColor(primaryDarkColor);
152        // Also store the background colors to the view tags. They are used in
153        // setVolumeSliderColor() below.
154        mainControls.setTag(primaryColor);
155        groupControls.setTag(primaryDarkColor);
156    }
157
158    static void setVolumeSliderColor(
159            Context context, MediaRouteVolumeSlider volumeSlider, View backgroundView) {
160        int controllerColor = getControllerColor(context, 0);
161        if (Color.alpha(controllerColor) != 0xFF) {
162            // Composite with the background in order not to show the underlying progress bar
163            // through the thumb.
164            int backgroundColor = (int) backgroundView.getTag();
165            controllerColor = ColorUtils.compositeColors(controllerColor, backgroundColor);
166        }
167        volumeSlider.setColor(controllerColor);
168    }
169
170    private static boolean isLightTheme(Context context) {
171        TypedValue value = new TypedValue();
172        // TODO(sungsoo): Switch to com.android.internal.R.attr.isLightTheme
173        return context.getTheme().resolveAttribute(android.support.v7.appcompat.R.attr.isLightTheme,
174                value, true) && value.data != 0;
175    }
176
177    private static int getThemeColor(Context context, int style, int attr) {
178        if (style != 0) {
179            int[] attrs = { attr };
180            TypedArray ta = context.obtainStyledAttributes(style, attrs);
181            int color = ta.getColor(0, 0);
182            ta.recycle();
183            if (color != 0) {
184                return color;
185            }
186        }
187        TypedValue value = new TypedValue();
188        context.getTheme().resolveAttribute(attr, value, true);
189        if (value.resourceId != 0) {
190            return context.getResources().getColor(value.resourceId);
191        }
192        return value.data;
193    }
194
195    static int getRouterThemeId(Context context) {
196        int themeId;
197        if (isLightTheme(context)) {
198            if (getControllerColor(context, 0) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
199                themeId = R.style.Theme_MediaRouter_Light;
200            } else {
201                themeId = R.style.Theme_MediaRouter_Light_DarkControlPanel;
202            }
203        } else {
204            if (getControllerColor(context, 0) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
205                themeId = R.style.Theme_MediaRouter_LightControlPanel;
206            } else {
207                themeId = R.style.Theme_MediaRouter;
208            }
209        }
210        return themeId;
211    }
212}
213