Added ColorExtractionService and ExtractedColors.

- Launcher has an instance of ExtractedColors, which is loaded from
  LauncherProvider in onCreate() and whenever the wallpaper changes.
  - When the wallpaper changes, the ColorExtractionService is started
    in the :wallpaper-chooser process.
  - ColorExtractionService builds an ExtractedColors instance and saves
    it as a String in LauncherProvider.
  - When the results are saved, Launcher gets a callback through
    LauncherProviderChangeListener and reloads the ExtractedColors.
- Whenever Launcher loads Extractecolors, it also re-colors items
  (currently a no-op).

Change-Id: I319e2cfe0a86abcbc6bb39ef6b9fbbcad54ad743

3 files changed, 269 insertions, 0 deletions

diff --git a/src/com/android/launcher3/dynamicui/ColorExtractionService.java b/src/com/android/launcher3/dynamicui/ColorExtractionService.java
new file mode 100644
index 000000000..95a62b957
--- /dev/null
+++ b/src/com/android/launcher3/dynamicui/ColorExtractionService.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.dynamicui;
+
+import android.app.IntentService;
+import android.app.WallpaperManager;
+import android.content.Intent;
+import android.graphics.Bitmap;
+import android.graphics.drawable.BitmapDrawable;
+import android.os.Bundle;
+import android.support.v7.graphics.Palette;
+
+import com.android.launcher3.LauncherProvider;
+import com.android.launcher3.LauncherSettings;
+
+/**
+ * Extracts colors from the wallpaper, and saves results to {@link LauncherProvider}.
+ */
+public class ColorExtractionService extends IntentService {
+
+    public ColorExtractionService() {
+        super("ColorExtractionService");
+    }
+
+    @Override
+    protected void onHandleIntent(Intent intent) {
+        WallpaperManager wallpaperManager = WallpaperManager.getInstance(this);
+        int wallpaperId = ExtractionUtils.getWallpaperId(wallpaperManager);
+        ExtractedColors extractedColors = new ExtractedColors();
+        if (wallpaperManager.getWallpaperInfo() != null) {
+            // We can't extract colors from live wallpapers, so just use the default color always.
+            extractedColors.updatePalette(null);
+        } else {
+            Bitmap wallpaper = ((BitmapDrawable) wallpaperManager.getDrawable()).getBitmap();
+            Palette palette = Palette.from(wallpaper).generate();
+            extractedColors.updatePalette(palette);
+        }
+
+        // Save the extracted colors and wallpaper id to LauncherProvider.
+        String colorsString = extractedColors.encodeAsString();
+        Bundle extras = new Bundle();
+        extras.putInt(LauncherSettings.Settings.EXTRA_WALLPAPER_ID, wallpaperId);
+        extras.putString(LauncherSettings.Settings.EXTRA_EXTRACTED_COLORS, colorsString);
+        getContentResolver().call(
+                LauncherSettings.Settings.CONTENT_URI,
+                LauncherSettings.Settings.METHOD_SET_EXTRACTED_COLORS_AND_WALLPAPER_ID,
+                null, extras);
+    }
+}
diff --git a/src/com/android/launcher3/dynamicui/ExtractedColors.java b/src/com/android/launcher3/dynamicui/ExtractedColors.java
new file mode 100644
index 000000000..4d17ff764
--- /dev/null
+++ b/src/com/android/launcher3/dynamicui/ExtractedColors.java
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.dynamicui;
+
+import android.content.Context;
+import android.graphics.Color;
+import android.support.v7.graphics.Palette;
+import android.util.Log;
+
+import com.android.launcher3.Utilities;
+
+/**
+ * Saves and loads colors extracted from the wallpaper, as well as the associated wallpaper id.
+ */
+public class ExtractedColors {
+    private static final String TAG = "ExtractedColors";
+
+    public static final int DEFAULT_LIGHT = Color.WHITE;
+    public static final int DEFAULT_DARK = Color.BLACK;
+    public static final int DEFAULT_COLOR = DEFAULT_LIGHT;
+
+    // These color profile indices should NOT be changed, since they are used when saving and
+    // loading extracted colors. New colors should always be added at the end.
+    public static final int DEFAULT_INDEX = 0;
+    public static final int VIBRANT_INDEX = 1;
+    public static final int VIBRANT_DARK_INDEX = 2;
+    public static final int VIBRANT_LIGHT_INDEX = 3;
+    public static final int MUTED_INDEX = 4;
+    public static final int MUTED_DARK_INDEX = 5;
+    public static final int MUTED_LIGHT_INDEX = 6;
+
+    public static final int NUM_COLOR_PROFILES = 7;
+
+    private static final String COLOR_SEPARATOR = ",";
+
+    private int[] mColors;
+
+    public ExtractedColors() {
+        mColors = new int[NUM_COLOR_PROFILES];
+    }
+
+    public void setColorAtIndex(int index, int color) {
+        if (index >= 0 && index < mColors.length) {
+            mColors[index] = color;
+        } else {
+            Log.e(TAG, "Attempted to set a color at an invalid index " + index);
+        }
+    }
+
+    /**
+     * Encodes {@link #mColors} as a comma-separated String.
+     */
+    String encodeAsString() {
+        StringBuilder colorsStringBuilder = new StringBuilder();
+        for (int color : mColors) {
+            colorsStringBuilder.append(color).append(COLOR_SEPARATOR);
+        }
+        return colorsStringBuilder.toString();
+    }
+
+    /**
+     * Decodes a comma-separated String into {@link #mColors}.
+     */
+    void decodeFromString(String colorsString) {
+        String[] splitColorsString = colorsString.split(COLOR_SEPARATOR);
+        mColors = new int[splitColorsString.length];
+        for (int i = 0; i < mColors.length; i++) {
+            mColors[i] = Integer.parseInt(splitColorsString[i]);
+        }
+    }
+
+    /**
+     * Loads colors and wallpaper id from {@link Utilities#getPrefs(Context)}.
+     * These were saved there in {@link ColorExtractionService}.
+     */
+    public void load(Context context) {
+        String encodedString = Utilities.getPrefs(context).getString(
+                ExtractionUtils.EXTRACTED_COLORS_PREFERENCE_KEY, DEFAULT_COLOR + "");
+
+        decodeFromString(encodedString);
+    }
+
+    /** @param index must be one of the index values defined at the top of this class. */
+    public int getColor(int index) {
+        if (index >= 0 && index < mColors.length) {
+            return mColors[index];
+        }
+        return DEFAULT_COLOR;
+    }
+
+    /**
+     * Updates colors based on the palette.
+     * If the palette is null, the default color is used in all cases.
+     */
+    public void updatePalette(Palette palette) {
+        if (palette == null) {
+            for (int i = 0; i < NUM_COLOR_PROFILES; i++) {
+                setColorAtIndex(i, ExtractedColors.DEFAULT_COLOR);
+            }
+        } else {
+            setColorAtIndex(ExtractedColors.DEFAULT_INDEX,
+                    ExtractedColors.DEFAULT_COLOR);
+            setColorAtIndex(ExtractedColors.VIBRANT_INDEX,
+                    palette.getVibrantColor(ExtractedColors.DEFAULT_COLOR));
+            setColorAtIndex(ExtractedColors.VIBRANT_DARK_INDEX,
+                    palette.getDarkVibrantColor(ExtractedColors.DEFAULT_DARK));
+            setColorAtIndex(ExtractedColors.VIBRANT_LIGHT_INDEX,
+                    palette.getLightVibrantColor(ExtractedColors.DEFAULT_LIGHT));
+            setColorAtIndex(ExtractedColors.MUTED_INDEX,
+                    palette.getMutedColor(ExtractedColors.DEFAULT_COLOR));
+            setColorAtIndex(ExtractedColors.MUTED_DARK_INDEX,
+                    palette.getDarkMutedColor(ExtractedColors.DEFAULT_DARK));
+            setColorAtIndex(ExtractedColors.MUTED_LIGHT_INDEX,
+                    palette.getLightVibrantColor(ExtractedColors.DEFAULT_LIGHT));
+        }
+    }
+}
diff --git a/src/com/android/launcher3/dynamicui/ExtractionUtils.java b/src/com/android/launcher3/dynamicui/ExtractionUtils.java
new file mode 100644
index 000000000..a2ff60713
--- /dev/null
+++ b/src/com/android/launcher3/dynamicui/ExtractionUtils.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.dynamicui;
+
+import android.app.WallpaperManager;
+import android.content.Context;
+import android.content.Intent;
+import android.content.SharedPreferences;
+
+import com.android.launcher3.Utilities;
+import com.android.wallpaperpicker.common.WallpaperManagerCompat;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+/**
+ * Contains helper fields and methods related to extracting colors from the wallpaper.
+ */
+public class ExtractionUtils {
+    public static final String EXTRACTED_COLORS_PREFERENCE_KEY = "pref_extractedColors";
+    public static final String WALLPAPER_ID_PREFERENCE_KEY = "pref_wallpaperId";
+
+    /**
+     * Extract colors in the :wallpaper-chooser process, if the wallpaper id has changed.
+     * When the new colors are saved in the LauncherProvider,
+     * Launcher will be notified in Launcher#onSettingsChanged(String, String).
+     */
+    public static void startColorExtractionServiceIfNecessary(final Context context) {
+        // Run on a background thread, since the service is asynchronous anyway.
+        Utilities.THREAD_POOL_EXECUTOR.execute(new Runnable() {
+            @Override
+            public void run() {
+                if (hasWallpaperIdChanged(context)) {
+                    context.startService(new Intent(context, ColorExtractionService.class));
+                }
+            }
+        });
+    }
+
+    private static boolean hasWallpaperIdChanged(Context context) {
+        if (!Utilities.isNycOrAbove()) {
+            // TODO: update an id in sharedprefs in onWallpaperChanged broadcast, and read it here.
+            return false;
+        }
+        final SharedPreferences sharedPrefs = Utilities.getPrefs(context);
+        int wallpaperId = getWallpaperId(WallpaperManager.getInstance(context));
+        int savedWallpaperId = sharedPrefs.getInt(ExtractionUtils.WALLPAPER_ID_PREFERENCE_KEY, -1);
+        return wallpaperId != savedWallpaperId;
+    }
+
+    public static int getWallpaperId(WallpaperManager wallpaperManager) {
+        // TODO: use WallpaperManager#getWallpaperId(WallpaperManager.FLAG_SET_SYSTEM) directly.
+        try {
+            Method getWallpaperId = WallpaperManager.class.getMethod("getWallpaperId", int.class);
+            return (int) getWallpaperId.invoke(wallpaperManager,
+                    WallpaperManagerCompat.FLAG_SET_SYSTEM);
+        } catch (InvocationTargetException | NoSuchMethodException | IllegalAccessException e) {
+            return -1;
+        }
+    }
+}