Add new expandable preference component

Bug: 177406865
Bug: 185187729
Test: make SettingsRoboTests
Test: make SettingsGoogleRoboTests
Change-Id: Id2b2a1f4fa557467efcaa013aa9e978b2c66d974
diff --git a/res/drawable/ic_settings_expand_less.xml b/res/drawable/ic_settings_expand_less.xml
new file mode 100644
index 0000000..a6a2241
--- /dev/null
+++ b/res/drawable/ic_settings_expand_less.xml
@@ -0,0 +1,25 @@
+<!--
+    Copyright (C) 2021 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M18.59,16.41L20,15l-8,-8 -8,8 1.41,1.41L12,9.83"/>
+</vector>
diff --git a/res/drawable/ic_settings_expand_more.xml b/res/drawable/ic_settings_expand_more.xml
new file mode 100644
index 0000000..7a4042d
--- /dev/null
+++ b/res/drawable/ic_settings_expand_more.xml
@@ -0,0 +1,25 @@
+<!--
+    Copyright (C) 2021 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.
+-->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M5.41,7.59L4,9l8,8 8,-8 -1.41,-1.41L12,14.17"/>
+</vector>
diff --git a/res/layout/preference_expand_divider.xml b/res/layout/preference_expand_divider.xml
new file mode 100644
index 0000000..685ec0e
--- /dev/null
+++ b/res/layout/preference_expand_divider.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Copyright (C) 2021 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:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:minHeight="?android:attr/listPreferredItemHeightSmall"
+    android:gravity="center_vertical"
+    android:paddingLeft="?android:attr/listPreferredItemPaddingLeft"
+    android:paddingStart="?android:attr/listPreferredItemPaddingStart"
+    android:paddingRight="?android:attr/listPreferredItemPaddingRight"
+    android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
+    android:background="?android:attr/selectableItemBackground"
+    android:orientation="horizontal"
+    android:clipToPadding="false"
+    android:baselineAligned="false">
+
+    <TextView
+        android:id="@+id/expand_title"
+        android:layout_width="0px"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:paddingEnd="4dp"
+        android:singleLine="true"
+        android:textAlignment="viewStart"
+        android:text="@string/battery_system_usage_for_past_24"
+        style="@style/PreferenceCategoryTitleTextStyle"/>
+
+    <ImageView
+        android:id="@+id/expand_icon"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:src="@drawable/ic_settings_expand_more"/>
+
+</LinearLayout>
diff --git a/src/com/android/settings/fuelgauge/ExpandDividerPreference.java b/src/com/android/settings/fuelgauge/ExpandDividerPreference.java
new file mode 100644
index 0000000..06476df
--- /dev/null
+++ b/src/com/android/settings/fuelgauge/ExpandDividerPreference.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2021 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.fuelgauge;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceViewHolder;
+
+import com.android.settings.R;
+
+/** A preference for expandable section divider. */
+public class ExpandDividerPreference extends Preference {
+    private static final String TAG = "ExpandDividerPreference";
+    @VisibleForTesting
+    static final String PREFERENCE_KEY = "expandable_divider";
+
+    @VisibleForTesting TextView mTextView;
+    @VisibleForTesting ImageView mImageView;
+    private OnExpandListener mOnExpandListener;
+
+    private boolean mIsExpanded = false;
+
+    /** A callback listener for expand state is changed by users. */
+    public interface OnExpandListener {
+        void onExpand(boolean isExpanded);
+    }
+
+    public ExpandDividerPreference(Context context) {
+        this(context, /*attrs=*/ null);
+    }
+
+    public ExpandDividerPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        setLayoutResource(R.layout.preference_expand_divider);
+        setKey(PREFERENCE_KEY);
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder view) {
+        super.onBindViewHolder(view);
+        mTextView = (TextView) view.findViewById(R.id.expand_title);
+        mImageView = (ImageView) view.findViewById(R.id.expand_icon);
+        refreshState();
+    }
+
+    @Override
+    public void onClick() {
+        mIsExpanded = !mIsExpanded;
+        refreshState();
+        if (mOnExpandListener != null) {
+            mOnExpandListener.onExpand(mIsExpanded);
+        }
+    }
+
+    void setTitle(String titleContent) {
+        if (mTextView != null) {
+            mTextView.setText(titleContent);
+        }
+    }
+
+    void setIsExpanded(boolean isExpanded) {
+        mIsExpanded = isExpanded;
+        refreshState();
+    }
+
+    void setOnExpandListener(OnExpandListener listener) {
+        mOnExpandListener = listener;
+    }
+
+    private void refreshState() {
+        final int iconId =
+            mIsExpanded
+                ? R.drawable.ic_settings_expand_less
+                : R.drawable.ic_settings_expand_more;
+        if (mImageView != null) {
+            mImageView.setImageResource(iconId);
+        }
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/fuelgauge/ExpandDividerPreferenceTest.java b/tests/robotests/src/com/android/settings/fuelgauge/ExpandDividerPreferenceTest.java
new file mode 100644
index 0000000..f9009a1
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/fuelgauge/ExpandDividerPreferenceTest.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2021 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.fuelgauge;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import com.android.settings.R;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(RobolectricTestRunner.class)
+public final class ExpandDividerPreferenceTest {
+
+    private Context mContext;
+    private ExpandDividerPreference mExpandDividerPreference;
+
+    @Mock private ImageView mImageView;
+    @Mock private TextView mTextView;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application);
+        mExpandDividerPreference = new ExpandDividerPreference(mContext);
+        doReturn(R.id.expand_title).when(mTextView).getId();
+        doReturn(R.id.expand_icon).when(mImageView).getId();
+    }
+
+    @Test
+    public void testConstructor_returnExpectedResult() {
+        assertThat(mExpandDividerPreference.getKey())
+            .isEqualTo(ExpandDividerPreference.PREFERENCE_KEY);
+        assertThat(mExpandDividerPreference.getLayoutResource())
+            .isEqualTo(R.layout.preference_expand_divider);
+    }
+
+    @Test
+    public void testSetTitle_setTitleContentIntoTextView() {
+        final String titleContent = "title content";
+        mExpandDividerPreference.mTextView = mTextView;
+
+        mExpandDividerPreference.setTitle(titleContent);
+        verify(mTextView).setText(titleContent);
+    }
+
+    @Test
+    public void testOnClick_switchExpandStateAndInvokeCallback() {
+        final boolean[] isExpandedArray = new boolean[] {false};
+        mExpandDividerPreference.mImageView = mImageView;
+        mExpandDividerPreference.setOnExpandListener(
+            isExpanded -> isExpandedArray[0] = isExpanded);
+
+        // Click the item first time from false -> true.
+        mExpandDividerPreference.onClick();
+        // Verifies the first time click result.
+        verify(mImageView).setImageResource(R.drawable.ic_settings_expand_less);
+        assertThat(isExpandedArray[0]).isTrue();
+
+        // Clicks the item second time from true -> false.
+        mExpandDividerPreference.onClick();
+        // Verifies the second time click result.
+        verify(mImageView).setImageResource(R.drawable.ic_settings_expand_more);
+        assertThat(isExpandedArray[0]).isFalse();
+    }
+
+    @Test
+    public void testSetIsExpanded_updateStateButNotInvokeCallback() {
+        final boolean[] isExpandedArray = new boolean[] {false};
+        mExpandDividerPreference.mImageView = mImageView;
+        mExpandDividerPreference.setOnExpandListener(
+            isExpanded -> isExpandedArray[0] = isExpanded);
+
+        mExpandDividerPreference.setIsExpanded(true);
+
+        verify(mImageView).setImageResource(R.drawable.ic_settings_expand_less);
+        assertThat(isExpandedArray[0]).isFalse();
+    }
+}