diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/Android.bp b/packages/SettingsLib/CollapsingToolbarBaseActivity/Android.bp
new file mode 100644
index 0000000..c23ff05
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/Android.bp
@@ -0,0 +1,14 @@
+android_library {
+    name: "SettingsLibCollapsingToolbarBaseActivity",
+
+    srcs: ["src/**/*.java"],
+    resource_dirs: ["res"],
+
+    static_libs: [
+        "androidx.annotation_annotation",
+        "androidx.core_core",
+        "com.google.android.material_material",
+    ],
+    sdk_version: "system_current",
+    min_sdk_version: "21",
+}
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/AndroidManifest.xml b/packages/SettingsLib/CollapsingToolbarBaseActivity/AndroidManifest.xml
new file mode 100644
index 0000000..dabba68
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/AndroidManifest.xml
@@ -0,0 +1,23 @@
+<?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.
+-->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="com.android.settingslib.collapsingtoolbar">
+
+    <uses-sdk android:minSdkVersion="21" />
+
+</manifest>
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/res/layout/collapsing_toolbar_base_layout.xml b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/layout/collapsing_toolbar_base_layout.xml
new file mode 100644
index 0000000..e376930
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/layout/collapsing_toolbar_base_layout.xml
@@ -0,0 +1,60 @@
+<?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.
+-->
+<androidx.coordinatorlayout.widget.CoordinatorLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/content_parent"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:transitionGroup="true">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/app_bar"
+        android:layout_width="match_parent"
+        android:layout_height="180dp"
+        android:theme="@style/Theme.CollapsingToolbar.Settings">
+
+        <com.android.settingslib.collapsingtoolbar.AdjustableToolbarLayout
+            android:id="@+id/collapsing_toolbar"
+            android:background="?android:attr/colorPrimary"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:maxLines="3"
+            app:contentScrim="?android:attr/colorPrimary"
+            app:collapsedTitleTextAppearance="@style/CollapsingToolbarTitle.Collapsed"
+            app:statusBarScrim="?android:attr/colorPrimary"
+            app:layout_scrollFlags="scroll|exitUntilCollapsed"
+            app:expandedTitleMarginStart="18dp"
+            app:expandedTitleMarginEnd="18dp"
+            app:toolbarId="@id/action_bar">
+
+            <Toolbar
+                android:id="@+id/action_bar"
+                android:layout_width="match_parent"
+                android:layout_height="?attr/actionBarSize"
+                android:theme="?android:attr/actionBarTheme"
+                app:layout_collapseMode="pin"/>
+
+        </com.android.settingslib.collapsingtoolbar.AdjustableToolbarLayout>
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <FrameLayout
+        android:id="@+id/content_frame"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
\ No newline at end of file
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values-night/themes.xml b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values-night/themes.xml
new file mode 100644
index 0000000..e20775e
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values-night/themes.xml
@@ -0,0 +1,23 @@
+<?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.
+-->
+<resources>
+    <style name="Theme.CollapsingToolbar.Settings"
+           parent="@style/Theme.MaterialComponents.DayNight">
+        <item name="colorPrimary">@*android:color/primary_dark_device_default_settings</item>
+        <item name="colorAccent">@*android:color/accent_device_default_dark</item>
+    </style>
+</resources>
\ No newline at end of file
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values/styles.xml b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values/styles.xml
new file mode 100644
index 0000000..e1a64d4
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values/styles.xml
@@ -0,0 +1,30 @@
+<?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.
+-->
+<resources>
+    <style name="CollapsingToolbarTitle.Collapsed"
+           parent="@android:style/TextAppearance.DeviceDefault.Widget.ActionBar.Title">
+    </style>
+
+    <style name="CollapsingToolbarTitle"
+           parent="@android:style/TextAppearance.DeviceDefault.Widget.ActionBar.Title">
+        <item name="android:textSize">36sp</item>
+    </style>
+
+    <style name="CollapsingToolbarTitle.MoreThanTwoLines">
+        <item name="android:textSize">24sp</item>
+    </style>
+</resources>
\ No newline at end of file
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values/themes.xml b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values/themes.xml
new file mode 100644
index 0000000..de545b0
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/res/values/themes.xml
@@ -0,0 +1,23 @@
+<?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.
+-->
+<resources>
+    <style name="Theme.CollapsingToolbar.Settings"
+           parent="@style/Theme.MaterialComponents.DayNight">
+        <item name="colorPrimary">@*android:color/primary_device_default_settings_light</item>
+        <item name="colorAccent">@*android:color/accent_device_default_light</item>
+    </style>
+</resources>
\ No newline at end of file
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/src/com/android/settingslib/collapsingtoolbar/AdjustableToolbarLayout.java b/packages/SettingsLib/CollapsingToolbarBaseActivity/src/com/android/settingslib/collapsingtoolbar/AdjustableToolbarLayout.java
new file mode 100644
index 0000000..e75a978
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/src/com/android/settingslib/collapsingtoolbar/AdjustableToolbarLayout.java
@@ -0,0 +1,92 @@
+/*
+ * 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.settingslib.collapsingtoolbar;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.google.android.material.appbar.CollapsingToolbarLayout;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+/**
+ * A customized version of CollapsingToolbarLayout that can apply different font size based on
+ * the line count of its title.
+ */
+public class AdjustableToolbarLayout extends CollapsingToolbarLayout {
+
+    private static final int TOOLBAR_MAX_LINE_NUMBER = 2;
+
+    public AdjustableToolbarLayout(@NonNull Context context) {
+        this(context, null);
+
+    }
+
+    public AdjustableToolbarLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public AdjustableToolbarLayout(@NonNull Context context, @Nullable AttributeSet attrs,
+            int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        initCollapsingToolbar();
+    }
+
+    private void initCollapsingToolbar() {
+        this.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
+            @Override
+            public void onLayoutChange(View v, int left, int top, int right, int bottom,
+                    int oldLeft, int oldTop, int oldRight, int oldBottom) {
+                v.removeOnLayoutChangeListener(this);
+                final int count = getLineCount();
+                if (count > TOOLBAR_MAX_LINE_NUMBER) {
+                    setExpandedTitleTextAppearance(R.style.CollapsingToolbarTitle_MoreThanTwoLines);
+                } else {
+                    setExpandedTitleTextAppearance(R.style.CollapsingToolbarTitle);
+                }
+            }
+        });
+    }
+
+    /**
+     * Returns a number of title line count for CollapsingToolbarLayout so that facilitates the
+     * determination to apply what kind of font size. Since the title of CollapsingToolbarLayout is
+     * drawn in a canvas and the text process is wrapped in a CollapsingTextHelper, the way we used
+     * here is to get the line count from the CollapsingTextHelper via Java Reflection.
+     */
+    private int getLineCount() {
+        try {
+            final Field textHelperField = this.getClass().getDeclaredField("collapsingTextHelper");
+            textHelperField.setAccessible(true);
+            final Object textHelperObj = textHelperField.get(this);
+
+            final Field layoutField = textHelperObj.getClass().getDeclaredField("textLayout");
+            layoutField.setAccessible(true);
+            final Object layoutObj = layoutField.get(textHelperObj);
+
+            final Method method = layoutObj.getClass().getDeclaredMethod("getLineCount");
+            return (int) method.invoke(layoutObj);
+        } catch (Exception e) {
+            return 0;
+        }
+    }
+}
diff --git a/packages/SettingsLib/CollapsingToolbarBaseActivity/src/com/android/settingslib/collapsingtoolbar/CollapsingToolbarBaseActivity.java b/packages/SettingsLib/CollapsingToolbarBaseActivity/src/com/android/settingslib/collapsingtoolbar/CollapsingToolbarBaseActivity.java
new file mode 100644
index 0000000..637805f
--- /dev/null
+++ b/packages/SettingsLib/CollapsingToolbarBaseActivity/src/com/android/settingslib/collapsingtoolbar/CollapsingToolbarBaseActivity.java
@@ -0,0 +1,99 @@
+/*
+ * 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.settingslib.collapsingtoolbar;
+
+import android.app.ActionBar;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Toolbar;
+
+import androidx.annotation.Nullable;
+import androidx.fragment.app.FragmentActivity;
+
+import com.google.android.material.appbar.CollapsingToolbarLayout;
+
+/**
+ * A base Activity that has a collapsing toolbar layout is used for the activities intending to
+ * enable the collapsing toolbar function.
+ */
+public class CollapsingToolbarBaseActivity extends FragmentActivity {
+
+    private CollapsingToolbarLayout mCollapsingToolbarLayout;
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        super.setContentView(R.layout.collapsing_toolbar_base_layout);
+        mCollapsingToolbarLayout = findViewById(R.id.collapsing_toolbar);
+
+        final Toolbar toolbar = findViewById(R.id.action_bar);
+        setActionBar(toolbar);
+
+        // Enable title and home button by default
+        final ActionBar actionBar = getActionBar();
+        if (actionBar != null) {
+            actionBar.setDisplayHomeAsUpEnabled(true);
+            actionBar.setHomeButtonEnabled(true);
+            actionBar.setDisplayShowTitleEnabled(true);
+        }
+    }
+
+    @Override
+    public void setContentView(int layoutResID) {
+        final ViewGroup parent = findViewById(R.id.content_frame);
+        if (parent != null) {
+            parent.removeAllViews();
+        }
+        LayoutInflater.from(this).inflate(layoutResID, parent);
+    }
+
+    @Override
+    public void setContentView(View view) {
+        ((ViewGroup) findViewById(R.id.content_frame)).addView(view);
+    }
+
+    @Override
+    public void setContentView(View view, ViewGroup.LayoutParams params) {
+        ((ViewGroup) findViewById(R.id.content_frame)).addView(view, params);
+    }
+
+    @Override
+    public void setTitle(CharSequence title) {
+        if (mCollapsingToolbarLayout != null) {
+            mCollapsingToolbarLayout.setTitle(title);
+        }
+        super.setTitle(title);
+    }
+
+    @Override
+    public void setTitle(int titleId) {
+        if (mCollapsingToolbarLayout != null) {
+            mCollapsingToolbarLayout.setTitle(getText(titleId));
+        }
+        super.setTitle(titleId);
+    }
+
+    /**
+     * Returns an instance of collapsing toolbar.
+     */
+    public CollapsingToolbarLayout getCollapsingToolbarLayout() {
+        return mCollapsingToolbarLayout;
+    }
+}