Draw preference divider based on preference group.

Bug: 32179750
Test: RunSettingsRoboTests
Change-Id: I3ea1cd662c5baec825fae615883b94b26e648409
diff --git a/res/xml/ia_display_settings.xml b/res/xml/ia_display_settings.xml
index 7f1af9a..31b524a 100644
--- a/res/xml/ia_display_settings.xml
+++ b/res/xml/ia_display_settings.xml
@@ -19,12 +19,12 @@
         android:title="@string/display_settings"
         settings:keywords="@string/keywords_display">
 
-        <PreferenceScreen
+        <Preference
                 android:key="brightness"
                 android:title="@string/brightness"
                 settings:keywords="@string/keywords_display_brightness_level">
             <intent android:action="android.intent.action.SHOW_BRIGHTNESS_DIALOG" />
-        </PreferenceScreen>
+        </Preference>
 
         <com.android.settingslib.RestrictedPreference
             android:key="wallpaper"
diff --git a/res/xml/storage_dashboard_fragment.xml b/res/xml/storage_dashboard_fragment.xml
index 81191e8..92e3ddb 100644
--- a/res/xml/storage_dashboard_fragment.xml
+++ b/res/xml/storage_dashboard_fragment.xml
@@ -17,9 +17,9 @@
 <PreferenceScreen
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:title="@string/storage_settings">
-    <com.android.settings.dashboard.DashboardTilePreference
+    <Preference
         android:key="pref_manage_storage"
         android:title="@string/storage_menu_manage"
         android:fragment="com.android.settings.deletionhelper.AutomaticStorageManagerSettings">
-    </com.android.settings.dashboard.DashboardTilePreference>
+    </Preference>
 </PreferenceScreen>
\ No newline at end of file
diff --git a/res/xml/system_dashboard_fragment.xml b/res/xml/system_dashboard_fragment.xml
index 3e83387..519ae8e 100644
--- a/res/xml/system_dashboard_fragment.xml
+++ b/res/xml/system_dashboard_fragment.xml
@@ -19,21 +19,21 @@
     android:title="@string/header_category_system">
 
     <!-- System updates -->
-    <com.android.settings.dashboard.DashboardTilePreference
+    <Preference
         android:key="system_update_settings"
         android:title="@string/system_update_settings_list_item_title"
         android:summary="@string/system_update_settings_list_item_summary"
         android:order="-30">
         <intent android:action="android.settings.SYSTEM_UPDATE_SETTINGS"/>
-    </com.android.settings.dashboard.DashboardTilePreference>
+    </Preference>
 
-    <com.android.settings.dashboard.DashboardTilePreference
+    <Preference
         android:key="additional_system_update_settings"
         android:title="@string/additional_system_update_settings_list_item_title"
         android:order="-31">
         <intent android:action="android.intent.action.MAIN"
                 android:targetPackage="@string/additional_system_update"
                 android:targetClass="@string/additional_system_update_menu"/>
-    </com.android.settings.dashboard.DashboardTilePreference>
+    </Preference>
 
 </PreferenceScreen>
\ No newline at end of file
diff --git a/src/com/android/settings/dashboard/DashboardDividerDecoration.java b/src/com/android/settings/dashboard/DashboardDividerDecoration.java
new file mode 100644
index 0000000..706bbc8
--- /dev/null
+++ b/src/com/android/settings/dashboard/DashboardDividerDecoration.java
@@ -0,0 +1,89 @@
+/*
+ * 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.settings.dashboard;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.drawable.Drawable;
+import android.support.v4.view.ViewCompat;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceGroupAdapter;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+
+import com.android.settings.overlay.FeatureFactory;
+
+public class DashboardDividerDecoration extends RecyclerView.ItemDecoration {
+
+    private final DashboardFeatureProvider mDashboardFeatureProvider;
+
+    private Drawable mDivider;
+    private int mDividerHeight;
+
+    public DashboardDividerDecoration(Context context) {
+        mDashboardFeatureProvider = FeatureFactory.getFactory(context)
+                .getDashboardFeatureProvider(context);
+    }
+
+    public void setDivider(Drawable divider) {
+        if (divider != null) {
+            mDividerHeight = divider.getIntrinsicHeight();
+        } else {
+            mDividerHeight = 0;
+        }
+        mDivider = divider;
+    }
+
+    public void setDividerHeight(int dividerHeight) {
+        mDividerHeight = dividerHeight;
+    }
+
+    @Override
+    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
+        if (mDivider == null) {
+            return;
+        }
+        final int childCount = parent.getChildCount();
+        final int width = parent.getWidth();
+        for (int childViewIndex = 0; childViewIndex < childCount - 1; childViewIndex++) {
+            final View view = parent.getChildAt(childViewIndex);
+            if (shouldDrawDividerBelow(view, parent)) {
+                int top = (int) ViewCompat.getY(view) + view.getHeight();
+                mDivider.setBounds(0, top, width, top + mDividerHeight);
+                mDivider.draw(c);
+            }
+        }
+    }
+
+    private boolean shouldDrawDividerBelow(View view, RecyclerView parent) {
+        final RecyclerView.Adapter adapter = parent.getAdapter();
+        if (adapter == null || !(adapter instanceof PreferenceGroupAdapter)) {
+            return false;
+        }
+        final PreferenceGroupAdapter prefAdapter = (PreferenceGroupAdapter) adapter;
+        final int adapterPosition = parent.getChildAdapterPosition(view);
+        final Preference pref = prefAdapter.getItem(adapterPosition);
+        final Preference nextPref = prefAdapter.getItem(adapterPosition + 1);
+        if (nextPref == null) {
+            return false;
+        }
+
+        return mDashboardFeatureProvider.getPriorityGroup(pref)
+                != mDashboardFeatureProvider.getPriorityGroup(nextPref);
+    }
+
+}
diff --git a/src/com/android/settings/dashboard/DashboardFeatureProvider.java b/src/com/android/settings/dashboard/DashboardFeatureProvider.java
index 51efdc9..92154be 100644
--- a/src/com/android/settings/dashboard/DashboardFeatureProvider.java
+++ b/src/com/android/settings/dashboard/DashboardFeatureProvider.java
@@ -15,6 +15,8 @@
  */
 package com.android.settings.dashboard;
 
+import android.support.v7.preference.Preference;
+
 import com.android.settingslib.drawer.DashboardCategory;
 import com.android.settingslib.drawer.Tile;
 
@@ -45,7 +47,7 @@
      * priority 100 - 199 belongs to priority level 100, tiles with priority 200 - 299 is in
      * group 200, and so on.
      */
-    int getPriorityGroup(Tile tile);
+    int getPriorityGroup(Preference preference);
 
     /**
      * Returns an unique string key for the tile.
diff --git a/src/com/android/settings/dashboard/DashboardFeatureProviderImpl.java b/src/com/android/settings/dashboard/DashboardFeatureProviderImpl.java
index ca0236e..df3f6ef 100644
--- a/src/com/android/settings/dashboard/DashboardFeatureProviderImpl.java
+++ b/src/com/android/settings/dashboard/DashboardFeatureProviderImpl.java
@@ -18,8 +18,8 @@
 
 import android.content.ComponentName;
 import android.content.Context;
+import android.support.v7.preference.Preference;
 
-import com.android.settingslib.drawer.CategoryKey;
 import com.android.settingslib.drawer.CategoryManager;
 import com.android.settingslib.drawer.DashboardCategory;
 import com.android.settingslib.drawer.Tile;
@@ -58,8 +58,8 @@
     }
 
     @Override
-    public int getPriorityGroup(Tile tile) {
-        return tile.priority / 100;
+    public int getPriorityGroup(Preference preference) {
+        return preference.getOrder() / 100;
     }
 
     @Override
diff --git a/src/com/android/settings/dashboard/DashboardFragment.java b/src/com/android/settings/dashboard/DashboardFragment.java
index a72717d..f2f4f77 100644
--- a/src/com/android/settings/dashboard/DashboardFragment.java
+++ b/src/com/android/settings/dashboard/DashboardFragment.java
@@ -18,6 +18,9 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.graphics.Color;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceScreen;
@@ -25,6 +28,9 @@
 import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
 
 import com.android.settings.SettingsActivity;
 import com.android.settings.SettingsPreferenceFragment;
@@ -50,6 +56,7 @@
     private final Map<Class, PreferenceController> mPreferenceControllers =
             new ArrayMap<>();
     private final Set<String> mDashboardTilePrefKeys = new ArraySet<>();
+    private DashboardDividerDecoration mDividerDecoration;
 
     protected DashboardFeatureProvider mDashboardFeatureProvider;
     private boolean mListeningToCategoryChange;
@@ -83,6 +90,7 @@
     @Override
     public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         super.onCreatePreferences(savedInstanceState, rootKey);
+        mDividerDecoration = new DashboardDividerDecoration(getContext());
         refreshAllPreferences(getLogTag());
     }
 
@@ -250,6 +258,14 @@
         }
     }
 
+    @Override
+    public View onCreateView(LayoutInflater inflater, ViewGroup container,
+            Bundle savedInstanceState) {
+        final View view = super.onCreateView(inflater, container, savedInstanceState);
+        getListView().addItemDecoration(mDividerDecoration);
+        return view;
+    }
+
     /**
      * Update state of each preference managed by PreferenceController.
      */
@@ -261,6 +277,14 @@
         }
     }
 
+    @Override
+    public void setDivider(Drawable divider) {
+        // Intercept divider and set it transparent so system divider decoration is disabled.
+        // We will use our decoration to draw divider more intelligently.
+        mDividerDecoration.setDivider(divider);
+        super.setDivider(new ColorDrawable(Color.TRANSPARENT));
+    }
+
     /**
      * Refresh all preference items, including both static prefs from xml, and dynamic items from
      * DashboardCategory.
@@ -272,7 +296,6 @@
             screen.removeAll();
         }
 
-
         // Add resource based tiles.
         displayResourceTiles();
 
@@ -293,5 +316,4 @@
         mDashboardTilePrefKeys.clear();
         displayDashboardTiles(TAG, getPreferenceScreen());
     }
-
 }
diff --git a/tests/robotests/src/com/android/settings/dashboard/DashboardDividerDecorationTest.java b/tests/robotests/src/com/android/settings/dashboard/DashboardDividerDecorationTest.java
new file mode 100644
index 0000000..adfa608
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/dashboard/DashboardDividerDecorationTest.java
@@ -0,0 +1,109 @@
+/*
+ * 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.settings.dashboard;
+
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.drawable.Drawable;
+import android.support.v7.preference.Preference;
+import android.support.v7.preference.PreferenceGroupAdapter;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+
+import com.android.settings.TestConfig;
+import com.android.settings.overlay.FeatureFactory;
+import com.android.settings.testutils.FakeFeatureFactory;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Answers;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class DashboardDividerDecorationTest {
+
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private Context mContext;
+    @Mock
+    private Drawable mDrawable;
+    @Mock
+    private Canvas mCanvas;
+    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
+    private RecyclerView mRecyclerView;
+    @Mock
+    private PreferenceGroupAdapter mAdapter;
+    @Mock
+    private Preference pref1;
+    @Mock
+    private Preference pref2;
+    private DashboardDividerDecoration mDecoration;
+    private FakeFeatureFactory mFactory;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        FakeFeatureFactory.setupForTest(mContext);
+        mFactory = (FakeFeatureFactory) FeatureFactory.getFactory(mContext);
+        mDecoration = new DashboardDividerDecoration(mContext);
+        mDecoration.setDivider(mDrawable);
+        mDecoration.setDividerHeight(3);
+    }
+
+    @Test
+    public void drawOver_differentPriorityGroup_shouldDrawDivider() {
+        when(mRecyclerView.getAdapter()).thenReturn(mAdapter);
+        when(mRecyclerView.getChildCount()).thenReturn(2);
+        when(mRecyclerView.getChildAdapterPosition(any(View.class)))
+                .thenReturn(0)
+                .thenReturn(1);
+        when(mAdapter.getItem(0)).thenReturn(pref1);
+        when(mAdapter.getItem(1)).thenReturn(pref2);
+        when(mFactory.dashboardFeatureProvider.getPriorityGroup(pref1)).thenReturn(1);
+        when(mFactory.dashboardFeatureProvider.getPriorityGroup(pref2)).thenReturn(2);
+
+        mDecoration.onDrawOver(mCanvas, mRecyclerView, null /* state */);
+
+        verify(mDrawable).draw(mCanvas);
+    }
+
+
+    @Test
+    public void drawOver_samePriorityGroup_doNotDrawDivider() {
+        when(mRecyclerView.getAdapter()).thenReturn(mAdapter);
+        when(mRecyclerView.getChildCount()).thenReturn(2);
+        when(mRecyclerView.getChildAdapterPosition(any(View.class)))
+                .thenReturn(0)
+                .thenReturn(1);
+        when(mAdapter.getItem(0)).thenReturn(pref1);
+        when(mAdapter.getItem(1)).thenReturn(pref2);
+
+        mDecoration.onDrawOver(mCanvas, mRecyclerView, null /* state */);
+
+        verify(mDrawable, never()).draw(mCanvas);
+    }
+}