Polish UX of expandable switch

- Padding from the expandable arrow is now 4dp
- Arrow is pushed down 2.5dp (by modifying the drawable) to align
  with the text
- Switch and the switch divider is now fixed 36dp from top rather
  than vertically aligned

Bug: 37576453
Test: ./gradlew connectedAndroidTest test
Change-Id: Ibb3028d3bb17ca9d054911e4ff27098a200af0da

library/gingerbread/res/drawable/suw_ic_expand_less.xml

@@ -16,11 +16,13 @@
 -->
 
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="18dp"
-    android:height="18dp"
-    android:viewportHeight="24.0"
-    android:viewportWidth="24.0">
+    android:width="20dp"
+    android:height="24dp"
+    android:viewportWidth="20.0"
+    android:viewportHeight="24.0">
+
     <path
         android:fillColor="#ff000000"
-        android:pathData="M12,8l-6,6 1.41,1.41L12,10.83l4.59,4.58L18,14z" />
+        android:pathData="M10,9.17l-5,5 1.18,1.18L10,11.53l3.83,3.82L15,14.17z" />
+
 </vector>

library/gingerbread/res/drawable/suw_ic_expand_more.xml

@@ -16,11 +16,13 @@
 -->
 
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="18dp"
-    android:height="18dp"
-    android:viewportWidth="24.0"
+    android:width="20dp"
+    android:height="24dp"
+    android:viewportWidth="20.0"
     android:viewportHeight="24.0">
+
     <path
         android:fillColor="#ff000000"
-        android:pathData="M16.59,8.59L12,13.17 7.41,8.59 6,10l6,6 6,-6z"/>
+        android:pathData="M13.83,9.66L10,13.48 6.18,9.66 5,10.83l5,5 5,-5z"/>
+
 </vector>

library/gingerbread/res/layout/suw_items_expandable_switch.xml

@@ -94,7 +94,8 @@
         android:id="@+id/suw_items_switch_divider"
         android:layout_width="1dp"
         android:layout_height="@dimen/suw_switch_divider_height"
-        android:layout_gravity="center_vertical"
+        android:layout_gravity="top"
+        android:layout_marginTop="@dimen/suw_switch_divider_padding_top"
         android:background="?android:attr/listDivider" />
 
     <android.support.v7.widget.SwitchCompat
@@ -102,6 +103,8 @@
         style="@style/SuwSwitchStyle.Divided"
         android:layout_width="wrap_content"
         android:layout_height="match_parent"
-        android:layout_gravity="center_vertical" />
+        android:layout_gravity="top"
+        android:gravity="top"
+        android:paddingTop="@dimen/suw_switch_padding_top" />
 
 </LinearLayout>

library/gingerbread/res/values/dimens.xml

@@ -20,10 +20,12 @@
     <!-- SwitchItem -->
     <dimen name="suw_switch_padding_start">16dp</dimen>
     <dimen name="suw_switch_padding_end">0dp</dimen>
+    <dimen name="suw_switch_padding_top">39dp</dimen>
     <dimen name="suw_switch_divider_height">32dp</dimen>
+    <dimen name="suw_switch_divider_padding_top">36dp</dimen>
     <dimen name="suw_switch_content_padding_end">16dp</dimen>
 
     <!-- ExpandableSwithItem -->
-    <dimen name="suw_expand_arrow_drawable_padding">6dp</dimen>
+    <dimen name="suw_expand_arrow_drawable_padding">4dp</dimen>
 
 </resources>

library/gingerbread/test/robotest/src/com/android/setupwizardlib/util/DimensionConsistencyTest.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2017 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.setupwizardlib.util;
+
+import static org.junit.Assert.assertEquals;
+import static org.robolectric.RuntimeEnvironment.application;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.util.DisplayMetrics;
+import android.util.TypedValue;
+import android.view.ContextThemeWrapper;
+
+import com.android.setupwizardlib.BuildConfig;
+import com.android.setupwizardlib.R;
+import com.android.setupwizardlib.robolectric.SuwLibRobolectricTestRunner;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.annotation.Config;
+
+@RunWith(SuwLibRobolectricTestRunner.class)
+@Config(constants = BuildConfig.class, sdk = Config.ALL_SDKS)
+public class DimensionConsistencyTest {
+
+    // Visual height of the framework switch widget
+    private static final int SWTICH_HEIGHT_DP = 26;
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = new ContextThemeWrapper(application, R.style.SuwThemeGlif_Light);
+    }
+
+    @Test
+    public void testSwitchPaddingTop() {
+        final Resources res = mContext.getResources();
+
+        assertEquals(
+                "Switch and divider should be aligned at center vertically: "
+                        + "suw_switch_padding_top + SWITCH_HEIGHT / 2 = "
+                        + "suw_switch_divider_padding_top + suw_switch_divider_height / 2",
+                res.getDimensionPixelSize(R.dimen.suw_switch_divider_padding_top)
+                        + (res.getDimensionPixelSize(R.dimen.suw_switch_divider_height) / 2),
+                res.getDimensionPixelSize(R.dimen.suw_switch_padding_top)
+                        + (dp2Px(SWTICH_HEIGHT_DP) / 2));
+    }
+
+    private int dp2Px(float dp) {
+        DisplayMetrics displayMetrics = mContext.getResources().getDisplayMetrics();
+        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, displayMetrics);
+    }
+}