diff --git a/res/drawable/ic_settings_expand_less.xml b/res/drawable/ic_settings_expand_less.xml
new file mode 100644
index 00000000000..a6a22413e73
--- /dev/null
+++ b/res/drawable/ic_settings_expand_less.xml
@@ -0,0 +1,25 @@
+
+
+
+
diff --git a/res/drawable/ic_settings_expand_more.xml b/res/drawable/ic_settings_expand_more.xml
new file mode 100644
index 00000000000..7a4042d06aa
--- /dev/null
+++ b/res/drawable/ic_settings_expand_more.xml
@@ -0,0 +1,25 @@
+
+
+
+
diff --git a/res/layout/preference_expand_divider.xml b/res/layout/preference_expand_divider.xml
new file mode 100644
index 00000000000..685ec0ea2e6
--- /dev/null
+++ b/res/layout/preference_expand_divider.xml
@@ -0,0 +1,50 @@
+
+
+
+
+
+
+
+
+
+
diff --git a/src/com/android/settings/fuelgauge/ExpandDividerPreference.java b/src/com/android/settings/fuelgauge/ExpandDividerPreference.java
new file mode 100644
index 00000000000..06476df4564
--- /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 00000000000..f9009a145b8
--- /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();
+ }
+}