Merge changes Id2732a94,Id8c01bf0

* changes:
  Adds a new activity for Gesture Navigation settings
  Adds BackGestureIndicatorView to animate left and right insets

AndroidManifest.xml

@@ -3244,6 +3244,24 @@
                 android:value="com.android.settings.gestures.GlobalActionsPanelSettings" />
         </activity>
 
+        <activity
+            android:name="Settings$GestureNavigationSettingsActivity"
+            android:label="@string/gesture_settings_activity_title"
+            android:enabled="true">
+            <intent-filter android:priority="32">
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="com.android.settings.SHORTCUT" />
+            </intent-filter>
+            <intent-filter android:priority="1">
+                <action android:name="com.android.settings.GESTURE_NAVIGATION_SETTINGS" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+            <meta-data android:name="com.android.settings.FRAGMENT_CLASS"
+                       android:value="com.android.settings.gestures.GestureNavigationSettingsFragment" />
+            <meta-data android:name="com.android.settings.PRIMARY_PROFILE_CONTROLLED"
+                       android:value="true" />
+        </activity>
+
         <!-- This is the longest AndroidManifest.xml ever. -->
     </application>
 </manifest>

res/layout/back_gesture_indicator_container.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2019 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
+  -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+              android:orientation="horizontal"
+              android:layout_width="match_parent"
+              android:layout_height="match_parent">
+
+    <ImageView
+        android:layout_width="@dimen/back_gesture_indicator_width"
+        android:layout_height="match_parent"
+        android:id="@+id/indicator_left">
+    </ImageView>
+
+    <Space
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        android:layout_weight="1" />
+
+    <ImageView
+        android:layout_width="@dimen/back_gesture_indicator_width"
+        android:layout_height="match_parent"
+        android:id="@+id/indicator_right">
+    </ImageView>
+
+</LinearLayout>
+

res/values/colors.xml

@@ -146,4 +146,6 @@
     <color name="dialog_background">@*android:color/background_device_default_light</color>
 
     <color name="face_intro_outline">#ffdadce0</color>
+
+    <color name="back_gesture_indicator">#4182ef</color>
 </resources>

res/values/dimens.xml

@@ -403,6 +403,8 @@
     <!-- System navigation settings illustration height -->
     <dimen name="system_navigation_illustration_height">320dp</dimen>
 
+    <dimen name="back_gesture_indicator_width">60dp</dimen>
+
     <!-- Header title size of advanced bluetooth device -->
     <dimen name="advanced_bluetooth_header_title_text_size">16sp</dimen>
 

res/values/strings.xml

@@ -10252,6 +10252,9 @@
     <!-- Title for the screen to show all the gesture navigation settings [CHAR LIMIT=80] -->
     <string name="gesture_settings_activity_title">Gesture Settings</string>
 
+    <!-- Keywords for the gesture navigation settings. [CHAR LIMIT=NONE] -->
+    <string name="keywords_gesture_navigation_settings">gesture navigation, back sensitivity, back gesture</string>
+
     <!-- Preference and settings suggestion title text for ambient display double tap (phone) [CHAR LIMIT=60]-->
     <string name="ambient_display_title" product="default">Double-tap to check phone</string>
     <!-- Preference and settings suggestion title text for ambient display double tap (tablet) [CHAR LIMIT=60]-->

res/xml/gesture_navigation_settings.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (C) 2019 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
+  -->
+
+<PreferenceScreen
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:settings="http://schemas.android.com/apk/res-auto"
+    android:key="gesture_navigation_settings_page"
+    android:title="@string/gesture_settings_activity_title"
+    settings:keywords="@string/keywords_gesture_navigation_settings">
+
+    <PreferenceCategory
+        android:key="back_sensitivity_category"
+        android:persistent="false"
+        android:title="@string/back_sensitivity_dialog_title">
+
+        <com.android.settings.gestures.GestureNavigationSeekBarPreference
+            android:key="gesture_left_back_sensitivity"
+            android:title="@string/left_edge"
+            android:max="3"
+            android:selectable="true"/>
+
+        <com.android.settings.gestures.GestureNavigationSeekBarPreference
+            android:key="gesture_right_back_sensitivity"
+            android:title="@string/right_edge"
+            android:max="3"
+            android:selectable="true"/>
+    </PreferenceCategory>
+
+    <com.android.settingslib.widget.FooterPreference
+        android:key="gesture_navigation_settings_footer"
+        android:title="@string/back_sensitivity_dialog_message"
+        android:selectable="false"
+        settings:searchable="false"
+        settings:allowDividerAbove="true"/>
+</PreferenceScreen>
+

src/com/android/settings/Settings.java

@@ -131,6 +131,7 @@ public class Settings extends SettingsActivity {
     public static class PhotosStorageActivity extends SettingsActivity {
         /* empty */
     }
+    public static class GestureNavigationSettingsActivity extends SettingsActivity { /* empty */ }
 
     public static class ApnSettingsActivity extends SettingsActivity { /* empty */ }
     public static class WifiCallingSettingsActivity extends SettingsActivity { /* empty */ }

src/com/android/settings/core/gateway/SettingsGateway.java

@@ -87,6 +87,7 @@ import com.android.settings.gestures.AssistGestureSettings;
 import com.android.settings.gestures.DoubleTapPowerSettings;
 import com.android.settings.gestures.DoubleTapScreenSettings;
 import com.android.settings.gestures.DoubleTwistGestureSettings;
+import com.android.settings.gestures.GestureNavigationSettingsFragment;
 import com.android.settings.gestures.GlobalActionsPanelSettings;
 import com.android.settings.gestures.PickupGestureSettings;
 import com.android.settings.gestures.SwipeToNotificationSettings;
@@ -289,7 +290,8 @@ public class SettingsGateway {
             MobileNetworkListFragment.class.getName(),
             GlobalActionsPanelSettings.class.getName(),
             DarkModeSettingsFragment.class.getName(),
-            BugReportHandlerPicker.class.getName()
+            BugReportHandlerPicker.class.getName(),
+            GestureNavigationSettingsFragment.class.getName()
     };
 
     public static final String[] SETTINGS_FOR_RESTRICTED = {

src/com/android/settings/gestures/BackGestureIndicatorDrawable.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2019 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.settings.gestures;
+
+import android.animation.TimeAnimator;
+import android.annotation.IntRange;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Message;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.settings.R;
+
+/** A drawable to animate the inset back gesture in both edges of the screen */
+public class BackGestureIndicatorDrawable extends Drawable {
+
+    private static final String TAG = "BackGestureIndicatorDrawable";
+
+    private static final int MSG_SET_INDICATOR_WIDTH = 1;
+    private static final int MSG_HIDE_INDICATOR = 3;
+
+    private static final long ANIMATION_DURATION_MS = 200L;
+    private static final long HIDE_DELAY_MS = 700L;
+
+    private static final int ALPHA_MAX = 64;
+
+    private Context mContext;
+
+    private Paint mPaint = new Paint();
+    private boolean mReversed;
+
+    private float mFinalWidth;
+    private float mCurrentWidth;
+    private float mWidthChangePerMs;
+
+    private TimeAnimator mTimeAnimator = new TimeAnimator();
+
+    private final Handler mHandler = new Handler(Looper.getMainLooper()) {
+        @Override
+        public void handleMessage(Message msg) {
+            switch(msg.what) {
+                case MSG_SET_INDICATOR_WIDTH:
+                    mTimeAnimator.end();
+                    mFinalWidth = msg.arg1;
+                    mWidthChangePerMs = Math.abs(mCurrentWidth - mFinalWidth)
+                            / ANIMATION_DURATION_MS;
+                    mTimeAnimator.start();
+                    break;
+                case MSG_HIDE_INDICATOR:
+                    mCurrentWidth = mFinalWidth;
+                    removeMessages(MSG_SET_INDICATOR_WIDTH);
+                    sendMessageDelayed(obtainMessage(MSG_SET_INDICATOR_WIDTH, 0, 0), HIDE_DELAY_MS);
+                    invalidateSelf();
+                    break;
+                default:
+                    break;
+            }
+        }
+    };
+
+    /**
+     * Creates an indicator drawable that responds to back gesture inset size change
+     * @param reversed If false, indicator will expand right. If true, indicator will expand left
+     */
+    public BackGestureIndicatorDrawable(Context context, boolean reversed) {
+        mContext = context;
+        mReversed = reversed;
+
+        // Restart the timer whenever a change is detected, so we can shrink/fade the indicators
+        mTimeAnimator.setTimeListener((TimeAnimator animation, long totalTime, long deltaTime) -> {
+            updateCurrentWidth(totalTime, deltaTime);
+            invalidateSelf();
+        });
+    }
+
+    private void updateCurrentWidth(long totalTime, long deltaTime) {
+        synchronized (mTimeAnimator) {
+            float step = deltaTime * mWidthChangePerMs;
+            if (totalTime >= ANIMATION_DURATION_MS
+                    || step >= Math.abs(mFinalWidth - mCurrentWidth)) {
+                mCurrentWidth = mFinalWidth;
+                mTimeAnimator.end();
+            } else {
+                float direction = mCurrentWidth < mFinalWidth ? 1 : -1;
+                mCurrentWidth += direction * step;
+            }
+        }
+    }
+
+    @Override
+    public void draw(@NonNull Canvas canvas) {
+
+        mPaint.setAntiAlias(true);
+        mPaint.setColor(mContext.getResources().getColor(R.color.back_gesture_indicator));
+        mPaint.setAlpha(ALPHA_MAX);
+
+        final int top = 0;
+        final int bottom = canvas.getHeight();
+        final int width = (int) mCurrentWidth;
+
+        Rect rect = new Rect(0, top, width, bottom);
+        if (mReversed) {
+            rect.offset(canvas.getWidth() - width, 0);
+        }
+
+        canvas.drawRect(rect, mPaint);
+    }
+
+    @Override
+    public void setAlpha(@IntRange(from = 0, to = 255) int alpha) {
+
+    }
+
+    @Override
+    public void setColorFilter(@Nullable ColorFilter colorFilter) {
+
+    }
+
+    @Override
+    public int getOpacity() {
+        return 0;
+    }
+
+    /**
+     * Sets the visible width of the indicator in pixels.
+     */
+    public void setWidth(int width) {
+        if (width == 0) {
+            mHandler.sendEmptyMessage(MSG_HIDE_INDICATOR);
+        } else {
+            mHandler.sendMessage(mHandler.obtainMessage(MSG_SET_INDICATOR_WIDTH, width, 0));
+        }
+    }
+
+    @VisibleForTesting
+    public int getWidth() {
+        return (int) mFinalWidth;
+    }
+}

src/com/android/settings/gestures/BackGestureIndicatorView.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2019 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.settings.gestures;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.PixelFormat;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.WindowManager;
+import android.widget.ImageView;
+import android.widget.LinearLayout;
+
+import com.android.settings.R;
+
+/**
+ * A linear layout containing the left and right location indicators.
+ */
+public class BackGestureIndicatorView extends LinearLayout {
+    private ViewGroup mLayout;
+    private ImageView mLeftIndicator;
+    private ImageView mRightIndicator;
+    private BackGestureIndicatorDrawable mLeftDrawable;
+    private BackGestureIndicatorDrawable mRightDrawable;
+
+    public BackGestureIndicatorView(Context context) {
+        super(context);
+
+        LayoutInflater factory = LayoutInflater.from(context);
+        mLayout = (ViewGroup) factory.inflate(R.layout.back_gesture_indicator_container,
+                this, false);
+
+        if (mLayout == null) {
+            return;
+        }
+
+        addView(mLayout);
+
+        mLeftDrawable = new BackGestureIndicatorDrawable(context, false);
+        mRightDrawable = new BackGestureIndicatorDrawable(context, true);
+
+        mLeftIndicator = mLayout.findViewById(R.id.indicator_left);
+        mRightIndicator = mLayout.findViewById(R.id.indicator_right);
+
+        mLeftIndicator.setImageDrawable(mLeftDrawable);
+        mRightIndicator.setImageDrawable(mRightDrawable);
+
+        TypedArray a = context.obtainStyledAttributes(new int[] {
+                android.R.attr.windowLightNavigationBar,
+                android.R.attr.windowLightStatusBar});
+        if (a.getBoolean(0, false)) {
+            setSystemUiVisibility(
+                    getSystemUiVisibility() | View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR);
+        }
+        if (a.getBoolean(1, false)) {
+            setSystemUiVisibility(
+                    getSystemUiVisibility() | View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
+        }
+        a.recycle();
+    }
+
+    public void setIndicatorWidth(int width, boolean leftIndicator) {
+        BackGestureIndicatorDrawable indicator = leftIndicator ? mLeftDrawable : mRightDrawable;
+        indicator.setWidth(width);
+    }
+
+    public WindowManager.LayoutParams getLayoutParams(
+            WindowManager.LayoutParams parentWindowAttributes) {
+        int copiedFlags = (parentWindowAttributes.flags
+                & WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
+        final WindowManager.LayoutParams lp = new WindowManager.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                WindowManager.LayoutParams.TYPE_APPLICATION,
+                WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED
+                        | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE
+                        | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
+                        | copiedFlags,
+                PixelFormat.TRANSLUCENT);
+
+        lp.setTitle("BackGestureIndicatorView");
+        lp.token = getContext().getActivityToken();
+        return lp;
+    }
+}

src/com/android/settings/gestures/GestureNavigationSettingsFragment.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2019 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.settings.gestures;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.os.Bundle;
+import android.provider.Settings;
+import android.view.WindowManager;
+
+import com.android.settings.R;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.search.BaseSearchIndexProvider;
+import com.android.settingslib.search.SearchIndexable;
+
+/**
+ * A fragment to include all the settings related to Gesture Navigation mode.
+ */
+@SearchIndexable(forTarget = SearchIndexable.ALL & ~SearchIndexable.ARC)
+public class GestureNavigationSettingsFragment extends DashboardFragment {
+
+    public static final String TAG = "GestureNavigationSettingsFragment";
+
+    public static final String GESTURE_NAVIGATION_SETTINGS =
+            "com.android.settings.GESTURE_NAVIGATION_SETTINGS";
+
+    private static final String LEFT_EDGE_SEEKBAR_KEY = "gesture_left_back_sensitivity";
+    private static final String RIGHT_EDGE_SEEKBAR_KEY = "gesture_right_back_sensitivity";
+
+    private WindowManager mWindowManager;
+    private BackGestureIndicatorView mIndicatorView;
+
+    private static final float[] BACK_GESTURE_INSET_SCALES = {0.75f, 1.0f, 1.33f, 1.66f};
+
+    private float mDefaultBackGestureInset;
+
+    public GestureNavigationSettingsFragment() {
+        super();
+    }
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mIndicatorView = new BackGestureIndicatorView(getActivity());
+        mWindowManager = (WindowManager) getActivity().getSystemService(Context.WINDOW_SERVICE);
+
+        mDefaultBackGestureInset = getActivity().getResources().getDimensionPixelSize(
+                com.android.internal.R.dimen.config_backGestureInset);
+    }
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        super.onCreatePreferences(savedInstanceState, rootKey);
+
+        initSeekBarPreference(LEFT_EDGE_SEEKBAR_KEY);
+        initSeekBarPreference(RIGHT_EDGE_SEEKBAR_KEY);
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+
+        mWindowManager.addView(mIndicatorView, mIndicatorView.getLayoutParams(
+                getActivity().getWindow().getAttributes()));
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+
+        mWindowManager.removeView(mIndicatorView);
+    }
+
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.gesture_navigation_settings;
+    }
+
+    @Override
+    public int getHelpResource() {
+        // TODO(b/146001201): Replace with gesture navigation help page when ready.
+        return R.string.help_uri_default;
+    }
+
+    @Override
+    protected String getLogTag() {
+        return TAG;
+    }
+
+    @Override
+    public int getMetricsCategory() {
+        return SettingsEnums.SETTINGS_GESTURE_NAV_BACK_SENSITIVITY_DLG;
+    }
+
+    private void initSeekBarPreference(final String key) {
+        final GestureNavigationSeekBarPreference pref = getPreferenceScreen().findPreference(key);
+        pref.setContinuousUpdates(true);
+
+        final String settingsKey = key == LEFT_EDGE_SEEKBAR_KEY
+                ? Settings.Secure.BACK_GESTURE_INSET_SCALE_LEFT
+                : Settings.Secure.BACK_GESTURE_INSET_SCALE_RIGHT;
+        final float initScale = Settings.Secure.getFloat(
+                getContext().getContentResolver(), settingsKey, 1.0f);
+
+        // Find the closest value to initScale
+        float minDistance = Float.MAX_VALUE;
+        int minDistanceIndex = -1;
+        for (int i = 0; i < BACK_GESTURE_INSET_SCALES.length; i++) {
+            float d = Math.abs(BACK_GESTURE_INSET_SCALES[i] - initScale);
+            if (d < minDistance) {
+                minDistance = d;
+                minDistanceIndex = i;
+            }
+        }
+        pref.setProgress(minDistanceIndex);
+
+        pref.setOnPreferenceChangeListener((p, v) -> {
+            final int width = (int) (mDefaultBackGestureInset * BACK_GESTURE_INSET_SCALES[(int) v]);
+            mIndicatorView.setIndicatorWidth(width, key == LEFT_EDGE_SEEKBAR_KEY);
+            return true;
+        });
+
+        pref.setOnPreferenceChangeStopListener((p, v) -> {
+            mIndicatorView.setIndicatorWidth(0, key == LEFT_EDGE_SEEKBAR_KEY);
+            final float scale = BACK_GESTURE_INSET_SCALES[(int) v];
+            Settings.Secure.putFloat(getContext().getContentResolver(), settingsKey, scale);
+            return true;
+        });
+    }
+
+    public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
+            new BaseSearchIndexProvider(R.xml.gesture_navigation_settings);
+}

tests/robotests/src/com/android/settings/gestures/BackGestureIndicatorViewTest.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2019 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.settings.gestures;
+
+import static org.junit.Assert.assertEquals;
+
+import android.content.Context;
+import android.widget.ImageView;
+
+import com.android.settings.R;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public class BackGestureIndicatorViewTest {
+
+    private Context mContext;
+
+    private BackGestureIndicatorDrawable mLeftDrawable;
+    private BackGestureIndicatorDrawable mRightDrawable;
+
+    private BackGestureIndicatorView mView;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        mView = new BackGestureIndicatorView(mContext);
+
+        mLeftDrawable = (BackGestureIndicatorDrawable) ((ImageView) mView.findViewById(
+                R.id.indicator_left)).getDrawable();
+        mRightDrawable = (BackGestureIndicatorDrawable) ((ImageView) mView.findViewById(
+                R.id.indicator_right)).getDrawable();
+    }
+
+    @Test
+    public void testSetIndicatoreWidth() {
+        mView.setIndicatorWidth(25, true);
+        mView.setIndicatorWidth(52, false);
+
+        assertEquals(25, mLeftDrawable.getWidth());
+        assertEquals(52, mRightDrawable.getWidth());
+    }
+}