Merge "Make preview scrollable under a feature flag." into main

14 files changed, 947 insertions, 78 deletions

diff --git a/java/res/layout/chooser_grid_scrollable_preview.xml b/java/res/layout/chooser_grid_scrollable_preview.xml
new file mode 100644
index 00000000..a5ac75a2
--- /dev/null
+++ b/java/res/layout/chooser_grid_scrollable_preview.xml
@@ -0,0 +1,128 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/*
+* Copyright 2015, 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.
+*/
+-->
+<com.android.intentresolver.widget.ResolverDrawerLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:layout_gravity="center"
+    app:maxCollapsedHeight="0dp"
+    app:maxCollapsedHeightSmall="56dp"
+    app:useScrollablePreviewNestedFlingLogic="true"
+    android:maxWidth="@dimen/chooser_width"
+    android:id="@androidprv:id/contentPanel">
+
+    <RelativeLayout
+        android:id="@androidprv:id/chooser_header"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_alwaysShow="true"
+        android:elevation="0dp"
+        android:background="@drawable/bottomsheet_background">
+
+        <View
+            android:id="@androidprv:id/drag"
+            android:layout_width="64dp"
+            android:layout_height="4dp"
+            android:background="@drawable/ic_drag_handle"
+            android:layout_marginTop="@dimen/chooser_edge_margin_thin"
+            android:layout_marginBottom="@dimen/chooser_edge_margin_thin"
+            android:layout_centerHorizontal="true"
+            android:layout_alignParentTop="true" />
+
+        <TextView android:id="@android:id/title"
+                  android:layout_height="wrap_content"
+                  android:layout_width="wrap_content"
+                  android:textAppearance="@android:style/TextAppearance.DeviceDefault.WindowTitle"
+                  android:gravity="center"
+                  android:paddingBottom="@dimen/chooser_view_spacing"
+                  android:paddingLeft="24dp"
+                  android:paddingRight="24dp"
+                  android:visibility="gone"
+                  android:layout_below="@androidprv:id/drag"
+                  android:layout_centerHorizontal="true"/>
+    </RelativeLayout>
+
+    <FrameLayout
+        android:id="@+id/chooser_headline_row_container"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_alwaysShow="true"
+        android:background="?androidprv:attr/materialColorSurfaceContainer">
+
+        <ViewStub
+            android:id="@+id/chooser_headline_row_stub"
+            android:inflatedId="@+id/chooser_headline_row"
+            android:layout="@layout/chooser_headline_row"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingHorizontal="@dimen/chooser_edge_margin_normal"
+            android:layout_marginBottom="@dimen/chooser_view_spacing" />
+    </FrameLayout>
+
+    <com.android.intentresolver.widget.ChooserNestedScrollView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical"
+            android:background="#f00">
+
+            <FrameLayout
+                android:id="@androidprv:id/content_preview_container"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:visibility="gone" />
+
+            <TabHost
+                android:id="@androidprv:id/profile_tabhost"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_alignParentTop="true"
+                android:layout_centerHorizontal="true"
+                android:background="?androidprv:attr/materialColorSurfaceContainer">
+                <LinearLayout
+                    android:orientation="vertical"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content">
+                    <TabWidget
+                        android:id="@android:id/tabs"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content"
+                        android:visibility="gone">
+                    </TabWidget>
+                    <FrameLayout
+                        android:id="@android:id/tabcontent"
+                        android:layout_width="match_parent"
+                        android:layout_height="wrap_content">
+                        <com.android.intentresolver.ResolverViewPager
+                            android:id="@androidprv:id/profile_pager"
+                            android:layout_width="match_parent"
+                            android:layout_height="wrap_content"/>
+                    </FrameLayout>
+                </LinearLayout>
+            </TabHost>
+    </LinearLayout>
+
+    </com.android.intentresolver.widget.ChooserNestedScrollView>
+
+</com.android.intentresolver.widget.ResolverDrawerLayout>
diff --git a/java/res/layout/chooser_list_per_profile_wrap.xml b/java/res/layout/chooser_list_per_profile_wrap.xml
new file mode 100644
index 00000000..157fa75d
--- /dev/null
+++ b/java/res/layout/chooser_list_per_profile_wrap.xml
@@ -0,0 +1,42 @@
+<!--
+  ~ Copyright (C) 2019 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.
+  -->
+<RelativeLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:androidprv="http://schemas.android.com/apk/prv/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:descendantFocusability="blocksDescendants">
+    <!--    ^^^ Block descendants from receiving focus to prevent NestedScrollView
+    (ChooserNestedScrollView) scrolling to the focused view when switching tabs. Without it, TabHost
+    view will request focus on the newly activated tab. The RecyclerView from this layout gets
+    focused and  notifies its parents (including NestedScrollView) about it through
+    #requestChildFocus method call. NestedScrollView's view implementation of the method  will
+    scroll to the focused view. -->
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layoutManager="com.android.intentresolver.ChooserGridLayoutManager"
+        android:id="@androidprv:id/resolver_list"
+        android:clipToPadding="false"
+        android:background="?androidprv:attr/materialColorSurfaceContainer"
+        android:scrollbars="none"
+        android:elevation="1dp"
+        android:nestedScrollingEnabled="true" />
+
+    <include layout="@layout/resolver_empty_states" />
+</RelativeLayout>
diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index 67acb3ae..c9f2c300 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -32,6 +32,11 @@
              will push all ignoreOffset siblings below it when the drawer is moved i.e. setting the
              top limit the ignoreOffset elements. -->
         <attr name="ignoreOffsetTopLimit" format="reference" />
+        <!-- Specifies whether ResolverDrawerLayout should use an alternative nested fling logic
+        adjusted for the scrollable preview feature.
+        Controlled by the flag com.android.intentresolver.Flags#FLAG_SCROLLABLE_PREVIEW.
+        -->
+        <attr name="useScrollablePreviewNestedFlingLogic" format="boolean" />
     </declare-styleable>
 
     <declare-styleable name="ResolverDrawerLayout_LayoutParams">
diff --git a/java/src/com/android/intentresolver/ChooserActivity.java b/java/src/com/android/intentresolver/ChooserActivity.java
index 26dbd224..f455be4c 100644
--- a/java/src/com/android/intentresolver/ChooserActivity.java
+++ b/java/src/com/android/intentresolver/ChooserActivity.java
@@ -491,7 +491,8 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
                 /* workProfileQuietModeChecker= */ () -> false,
                 /* workProfileUserHandle= */ null,
                 getAnnotatedUserHandles().cloneProfileUserHandle,
-                mMaxTargetsPerRow);
+                mMaxTargetsPerRow,
+                mFeatureFlags);
     }
 
     private ChooserMultiProfilePagerAdapter createChooserMultiProfilePagerAdapterForTwoProfiles(
@@ -525,7 +526,8 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
                 selectedProfile,
                 getAnnotatedUserHandles().workProfileUserHandle,
                 getAnnotatedUserHandles().cloneProfileUserHandle,
-                mMaxTargetsPerRow);
+                mMaxTargetsPerRow,
+                mFeatureFlags);
     }
 
     private int findSelectedProfile() {
@@ -667,7 +669,9 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
                 getResources(),
                 getLayoutInflater(),
                 parent,
-                /*headlineViewParent=*/null);
+                mFeatureFlags.scrollablePreview()
+                        ? findViewById(R.id.chooser_headline_row_container)
+                        : null);
 
         if (layout != null) {
             adjustPreviewWidth(getResources().getConfiguration().orientation, layout);
@@ -788,7 +792,9 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
 
     @Override
     public int getLayoutResource() {
-        return R.layout.chooser_grid;
+        return mFeatureFlags.scrollablePreview()
+                ? R.layout.chooser_grid_scrollable_preview
+                : R.layout.chooser_grid;
     }
 
     @Override // ResolverListCommunicator
@@ -1208,7 +1214,8 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
                 },
                 chooserListAdapter,
                 shouldShowContentPreview(),
-                mMaxTargetsPerRow);
+                mMaxTargetsPerRow,
+                mFeatureFlags);
     }
 
     @VisibleForTesting
@@ -1639,11 +1646,13 @@ public class ChooserActivity extends Hilt_ChooserActivity implements
     }
 
     private boolean shouldShowStickyContentPreviewNoOrientationCheck() {
-        return shouldShowTabs()
-                && (mMultiProfilePagerAdapter.getListAdapterForUserHandle(
-                UserHandle.of(UserHandle.myUserId())).getCount() > 0
-                || shouldShowContentPreviewWhenEmpty())
-                && shouldShowContentPreview();
+        if (!shouldShowContentPreview()) {
+            return false;
+        }
+        boolean isEmpty = mMultiProfilePagerAdapter.getListAdapterForUserHandle(
+                UserHandle.of(UserHandle.myUserId())).getCount() == 0;
+        return (mFeatureFlags.scrollablePreview() || shouldShowTabs())
+                && (!isEmpty || shouldShowContentPreviewWhenEmpty());
     }
 
     /**
diff --git a/java/src/com/android/intentresolver/ChooserMultiProfilePagerAdapter.java b/java/src/com/android/intentresolver/ChooserMultiProfilePagerAdapter.java
index c159243e..ba35ae5d 100644
--- a/java/src/com/android/intentresolver/ChooserMultiProfilePagerAdapter.java
+++ b/java/src/com/android/intentresolver/ChooserMultiProfilePagerAdapter.java
@@ -52,7 +52,8 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
             Supplier<Boolean> workProfileQuietModeChecker,
             UserHandle workProfileUserHandle,
             UserHandle cloneProfileUserHandle,
-            int maxTargetsPerRow) {
+            int maxTargetsPerRow,
+            FeatureFlags featureFlags) {
         this(
                 context,
                 new ChooserProfileAdapterBinder(maxTargetsPerRow),
@@ -62,7 +63,8 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
                 /* defaultProfile= */ 0,
                 workProfileUserHandle,
                 cloneProfileUserHandle,
-                new BottomPaddingOverrideSupplier(context));
+                new BottomPaddingOverrideSupplier(context),
+                featureFlags);
     }
 
     ChooserMultiProfilePagerAdapter(
@@ -74,7 +76,8 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
             @Profile int defaultProfile,
             UserHandle workProfileUserHandle,
             UserHandle cloneProfileUserHandle,
-            int maxTargetsPerRow) {
+            int maxTargetsPerRow,
+            FeatureFlags featureFlags) {
         this(
                 context,
                 new ChooserProfileAdapterBinder(maxTargetsPerRow),
@@ -84,7 +87,8 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
                 defaultProfile,
                 workProfileUserHandle,
                 cloneProfileUserHandle,
-                new BottomPaddingOverrideSupplier(context));
+                new BottomPaddingOverrideSupplier(context),
+                featureFlags);
     }
 
     private ChooserMultiProfilePagerAdapter(
@@ -96,7 +100,8 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
             @Profile int defaultProfile,
             UserHandle workProfileUserHandle,
             UserHandle cloneProfileUserHandle,
-            BottomPaddingOverrideSupplier bottomPaddingOverrideSupplier) {
+            BottomPaddingOverrideSupplier bottomPaddingOverrideSupplier,
+            FeatureFlags featureFlags) {
         super(
                 context,
                         gridAdapter -> gridAdapter.getListAdapter(),
@@ -107,7 +112,7 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
                 defaultProfile,
                 workProfileUserHandle,
                 cloneProfileUserHandle,
-                        () -> makeProfileView(context),
+                        () -> makeProfileView(context, featureFlags),
                 bottomPaddingOverrideSupplier);
         mAdapterBinder = adapterBinder;
         mBottomPaddingOverrideSupplier = bottomPaddingOverrideSupplier;
@@ -131,10 +136,12 @@ public class ChooserMultiProfilePagerAdapter extends GenericMultiProfilePagerAda
         }
     }
 
-    private static ViewGroup makeProfileView(Context context) {
+    private static ViewGroup makeProfileView(
+            Context context, FeatureFlags featureFlags) {
         LayoutInflater inflater = LayoutInflater.from(context);
-        ViewGroup rootView = (ViewGroup) inflater.inflate(
-                R.layout.chooser_list_per_profile, null, false);
+        ViewGroup rootView = featureFlags.scrollablePreview()
+                ? (ViewGroup) inflater.inflate(R.layout.chooser_list_per_profile_wrap, null, false)
+                : (ViewGroup) inflater.inflate(R.layout.chooser_list_per_profile, null, false);
         RecyclerView recyclerView = rootView.findViewById(com.android.internal.R.id.resolver_list);
         recyclerView.setAccessibilityDelegateCompat(
                 new ChooserRecyclerViewAccessibilityDelegate(recyclerView));
diff --git a/java/src/com/android/intentresolver/grid/ChooserGridAdapter.java b/java/src/com/android/intentresolver/grid/ChooserGridAdapter.java
index fadea934..2ab38f30 100644
--- a/java/src/com/android/intentresolver/grid/ChooserGridAdapter.java
+++ b/java/src/com/android/intentresolver/grid/ChooserGridAdapter.java
@@ -32,9 +32,12 @@ import android.view.animation.DecelerateInterpolator;
 import android.widget.Space;
 import android.widget.TextView;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.intentresolver.ChooserListAdapter;
+import com.android.intentresolver.FeatureFlags;
 import com.android.intentresolver.R;
 import com.android.intentresolver.ResolverListAdapter.ViewHolder;
 import com.android.internal.annotations.VisibleForTesting;
@@ -107,6 +110,9 @@ public final class ChooserGridAdapter extends RecyclerView.Adapter<RecyclerView.
     private final boolean mShouldShowContentPreview;
     private final int mChooserWidthPixels;
     private final int mChooserRowTextOptionTranslatePixelSize;
+    private final FeatureFlags mFeatureFlags;
+    @Nullable
+    private RecyclerView mRecyclerView;
 
     private int mChooserTargetWidth = 0;
 
@@ -119,7 +125,8 @@ public final class ChooserGridAdapter extends RecyclerView.Adapter<RecyclerView.
             ChooserActivityDelegate chooserActivityDelegate,
             ChooserListAdapter wrappedAdapter,
             boolean shouldShowContentPreview,
-            int maxTargetsPerRow) {
+            int maxTargetsPerRow,
+            FeatureFlags featureFlags) {
         super();
 
         mChooserActivityDelegate = chooserActivityDelegate;
@@ -133,6 +140,7 @@ public final class ChooserGridAdapter extends RecyclerView.Adapter<RecyclerView.
         mChooserWidthPixels = context.getResources().getDimensionPixelSize(R.dimen.chooser_width);
         mChooserRowTextOptionTranslatePixelSize = context.getResources().getDimensionPixelSize(
                 R.dimen.chooser_row_text_option_translate);
+        mFeatureFlags = featureFlags;
 
         wrappedAdapter.registerDataSetObserver(new DataSetObserver() {
             @Override
@@ -149,6 +157,18 @@ public final class ChooserGridAdapter extends RecyclerView.Adapter<RecyclerView.
         });
     }
 
+    @Override
+    public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {
+        if (mFeatureFlags.scrollablePreview()) {
+            mRecyclerView = recyclerView;
+        }
+    }
+
+    @Override
+    public void onDetachedFromRecyclerView(@NonNull RecyclerView recyclerView) {
+        mRecyclerView = null;
+    }
+
     public void setFooterHeight(int height) {
         mFooterHeight = height;
     }
@@ -198,7 +218,8 @@ public final class ChooserGridAdapter extends RecyclerView.Adapter<RecyclerView.
     public int getSystemRowCount() {
         // For the tabbed case we show the sticky content preview above the tabs,
         // please refer to shouldShowStickyContentPreview
-        if (mChooserActivityDelegate.shouldShowTabs()) {
+        if (mChooserActivityDelegate.shouldShowTabs()
+                || mFeatureFlags.scrollablePreview()) {
             return 0;
         }
 
@@ -318,6 +339,15 @@ public final class ChooserGridAdapter extends RecyclerView.Adapter<RecyclerView.
         mAzLabelVisibility = isVisible;
         int azRowPos = getAzLabelRowPosition();
         if (azRowPos >= 0) {
+            if (mRecyclerView != null) {
+                for (int i = 0, size = mRecyclerView.getChildCount(); i < size; i++) {
+                    View child = mRecyclerView.getChildAt(i);
+                    if (mRecyclerView.getChildAdapterPosition(child) == azRowPos) {
+                        child.setVisibility(isVisible ? View.VISIBLE : View.GONE);
+                    }
+                }
+                return;
+            }
             notifyItemChanged(azRowPos);
         }
     }
diff --git a/java/src/com/android/intentresolver/widget/ChooserNestedScrollView.kt b/java/src/com/android/intentresolver/widget/ChooserNestedScrollView.kt
new file mode 100644
index 00000000..26464ca1
--- /dev/null
+++ b/java/src/com/android/intentresolver/widget/ChooserNestedScrollView.kt
@@ -0,0 +1,90 @@
+package com.android.intentresolver.widget
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.View
+import android.widget.LinearLayout
+import androidx.core.view.ScrollingView
+import androidx.core.view.marginBottom
+import androidx.core.view.marginLeft
+import androidx.core.view.marginRight
+import androidx.core.view.marginTop
+import androidx.core.widget.NestedScrollView
+
+/**
+ * A narrowly tailored [NestedScrollView] to be used inside [ResolverDrawerLayout] and help to
+ * orchestrate content preview scrolling. It expects one [LinearLayout] child with
+ * [LinearLayout.VERTICAL] orientation. If the child has more than one child, the first its child
+ * will be made scrollable (it is expected to be a content preview view).
+ */
+class ChooserNestedScrollView : NestedScrollView {
+    constructor(context: Context) : super(context)
+    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
+    constructor(
+        context: Context,
+        attrs: AttributeSet?,
+        defStyleAttr: Int
+    ) : super(context, attrs, defStyleAttr)
+
+    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        val content =
+            getChildAt(0) as? LinearLayout ?: error("Exactly one child, LinerLayout, is expected")
+        require(content.orientation == LinearLayout.VERTICAL) { "VERTICAL orientation is expected" }
+        require(MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY) {
+            "Expected to have an exact width"
+        }
+
+        val lp = content.layoutParams ?: error("LayoutParams is missing")
+        val contentWidthSpec =
+            getChildMeasureSpec(
+                widthMeasureSpec,
+                paddingLeft + content.marginLeft + content.marginRight + paddingRight,
+                lp.width
+            )
+        val contentHeightSpec =
+            getChildMeasureSpec(
+                heightMeasureSpec,
+                paddingTop + content.marginTop + content.marginBottom + paddingBottom,
+                lp.height
+            )
+        content.measure(contentWidthSpec, contentHeightSpec)
+
+        if (content.childCount > 1) {
+            // We expect that the first child should be scrollable up
+            val child = content.getChildAt(0)
+            val height =
+                MeasureSpec.getSize(heightMeasureSpec) +
+                    child.measuredHeight +
+                    child.marginTop +
+                    child.marginBottom
+
+            content.measure(
+                contentWidthSpec,
+                MeasureSpec.makeMeasureSpec(height, MeasureSpec.getMode(heightMeasureSpec))
+            )
+        }
+        setMeasuredDimension(
+            MeasureSpec.getSize(widthMeasureSpec),
+            minOf(
+                MeasureSpec.getSize(heightMeasureSpec),
+                paddingTop +
+                    content.marginTop +
+                    content.measuredHeight +
+                    content.marginBottom +
+                    paddingBottom
+            )
+        )
+    }
+
+    override fun onNestedPreScroll(target: View, dx: Int, dy: Int, consumed: IntArray, type: Int) {
+        // let the parent scroll
+        super.onNestedPreScroll(target, dx, dy, consumed, type)
+        // scroll ourselves, if recycler has not scrolled
+        val delta = dy - consumed[1]
+        if (delta > 0 && target is ScrollingView && !target.canScrollVertically(-1)) {
+            val preScrollY = scrollY
+            scrollBy(0, delta)
+            consumed[1] += scrollY - preScrollY
+        }
+    }
+}
diff --git a/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java b/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java
index de76a1d2..b8fbedbf 100644
--- a/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java
+++ b/java/src/com/android/intentresolver/widget/ResolverDrawerLayout.java
@@ -45,6 +45,8 @@ import android.view.animation.AnimationUtils;
 import android.widget.AbsListView;
 import android.widget.OverScroller;
 
+import androidx.annotation.Nullable;
+import androidx.core.view.ScrollingView;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.intentresolver.R;
@@ -131,6 +133,9 @@ public class ResolverDrawerLayout extends ViewGroup {
     private AbsListView mNestedListChild;
     private RecyclerView mNestedRecyclerChild;
 
+    @Nullable
+    private final ScrollablePreviewFlingLogicDelegate mFlingLogicDelegate;
+
     private final ViewTreeObserver.OnTouchModeChangeListener mTouchModeChangeListener =
             new ViewTreeObserver.OnTouchModeChangeListener() {
                 @Override
@@ -167,6 +172,12 @@ public class ResolverDrawerLayout extends ViewGroup {
             mIgnoreOffsetTopLimitViewId = a.getResourceId(
                     R.styleable.ResolverDrawerLayout_ignoreOffsetTopLimit, ID_NULL);
         }
+        mFlingLogicDelegate =
+                a.getBoolean(
+                        R.styleable.ResolverDrawerLayout_useScrollablePreviewNestedFlingLogic,
+                        false)
+                    ? new ScrollablePreviewFlingLogicDelegate() {}
+                    : null;
         a.recycle();
 
         mScrollIndicatorDrawable = mContext.getDrawable(
@@ -832,6 +843,9 @@ public class ResolverDrawerLayout extends ViewGroup {
 
     @Override
     public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
+        if (mFlingLogicDelegate != null) {
+            return mFlingLogicDelegate.onNestedPreFling(this, target, velocityX, velocityY);
+        }
         if (!getShowAtTop() && velocityY > mMinFlingVelocity && mCollapseOffset != 0) {
             smoothScrollTo(0, velocityY);
             return true;
@@ -841,9 +855,12 @@ public class ResolverDrawerLayout extends ViewGroup {
 
     @Override
     public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
+        if (mFlingLogicDelegate != null) {
+            return mFlingLogicDelegate.onNestedFling(this, target, velocityX, velocityY, consumed);
+        }
         // TODO: find a more suitable way to fix it.
         //  RecyclerView started reporting `consumed` as true whenever a scrolling is enabled,
-        //  previously the value was based whether the fling can be performed in given direction
+        //  previously the value was based on whether the fling can be performed in given direction
         //  i.e. whether it is at the top or at the bottom. isRecyclerViewAtTheTop method is a
         //  workaround that restores the legacy functionality.
         boolean shouldConsume = (Math.abs(velocityY) > mMinFlingVelocity)
@@ -885,6 +902,13 @@ public class ResolverDrawerLayout extends ViewGroup {
                 && firstChild.getTop() >= recyclerView.getPaddingTop();
     }
 
+    private static boolean isFlingTargetAtTop(View target) {
+        if (target instanceof ScrollingView) {
+            return !target.canScrollVertically(-1);
+        }
+        return false;
+    }
+
     private boolean performAccessibilityActionCommon(int action) {
         switch (action) {
             case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD:
@@ -1299,4 +1323,74 @@ public class ResolverDrawerLayout extends ViewGroup {
         }
         return mMetricsLogger;
     }
+
+    /**
+     * Controlled by
+     * {@link com.android.intentresolver.Flags#FLAG_SCROLLABLE_PREVIEW}
+     */
+    private interface ScrollablePreviewFlingLogicDelegate {
+        default boolean onNestedPreFling(
+                ResolverDrawerLayout drawer, View target, float velocityX, float velocityY) {
+            boolean shouldScroll = !drawer.getShowAtTop() && velocityY > drawer.mMinFlingVelocity
+                    && drawer.mCollapseOffset != 0;
+            if (shouldScroll) {
+                drawer.smoothScrollTo(0, velocityY);
+                return true;
+            }
+            boolean shouldDismiss = (Math.abs(velocityY) > drawer.mMinFlingVelocity)
+                    && velocityY < 0
+                    && isFlingTargetAtTop(target);
+            if (shouldDismiss) {
+                if (drawer.getShowAtTop()) {
+                    drawer.smoothScrollTo(drawer.mCollapsibleHeight, velocityY);
+                } else {
+                    if (drawer.isDismissable()
+                            && drawer.mCollapseOffset > drawer.mCollapsibleHeight) {
+                        drawer.smoothScrollTo(drawer.mHeightUsed, velocityY);
+                        drawer.mDismissOnScrollerFinished = true;
+                    } else {
+                        drawer.smoothScrollTo(drawer.mCollapsibleHeight, velocityY);
+                    }
+                }
+                return true;
+            }
+            return false;
+        }
+
+        default boolean onNestedFling(
+                ResolverDrawerLayout drawer,
+                View target,
+                float velocityX,
+                float velocityY,
+                boolean consumed) {
+            // TODO: find a more suitable way to fix it.
+            //  RecyclerView started reporting `consumed` as true whenever a scrolling is enabled,
+            //  previously the value was based on whether the fling can be performed in given
+            //  direction i.e. whether it is at the top or at the bottom. isRecyclerViewAtTheTop
+            //  method is a workaround that restores the legacy functionality.
+            boolean shouldConsume = (Math.abs(velocityY) > drawer.mMinFlingVelocity) && !consumed;
+            if (shouldConsume) {
+                if (drawer.getShowAtTop()) {
+                    if (drawer.isDismissable() && velocityY > 0) {
+                        drawer.abortAnimation();
+                        drawer.dismiss();
+                    } else {
+                        drawer.smoothScrollTo(
+                                velocityY < 0 ? drawer.mCollapsibleHeight : 0, velocityY);
+                    }
+                } else {
+                    if (drawer.isDismissable()
+                            && velocityY < 0
+                            && drawer.mCollapseOffset > drawer.mCollapsibleHeight) {
+                        drawer.smoothScrollTo(drawer.mHeightUsed, velocityY);
+                        drawer.mDismissOnScrollerFinished = true;
+                    } else {
+                        drawer.smoothScrollTo(
+                                velocityY > 0 ? 0 : drawer.mCollapsibleHeight, velocityY);
+                    }
+                }
+            }
+            return shouldConsume;
+        }
+    }
 }
diff --git a/java/tests/Android.bp b/java/tests/Android.bp
index 974b8a47..5244bf7b 100644
--- a/java/tests/Android.bp
+++ b/java/tests/Android.bp
@@ -51,6 +51,8 @@ android_test {
         "mockito-target-minus-junit4",
         "testables",
         "truth-prebuilt",
+        "flag-junit",
+        "platform-test-annotations",
     ],
     plugins: ["dagger2-compiler"],
     test_suites: ["general-tests"],
diff --git a/java/tests/src/com/android/intentresolver/UnbundledChooserActivityTest.java b/java/tests/src/com/android/intentresolver/UnbundledChooserActivityTest.java
index c0b15b6d..bc9e521c 100644
--- a/java/tests/src/com/android/intentresolver/UnbundledChooserActivityTest.java
+++ b/java/tests/src/com/android/intentresolver/UnbundledChooserActivityTest.java
@@ -17,6 +17,7 @@
 package com.android.intentresolver;
 
 import static android.app.Activity.RESULT_OK;
+
 import static androidx.test.espresso.Espresso.onView;
 import static androidx.test.espresso.action.ViewActions.click;
 import static androidx.test.espresso.action.ViewActions.longClick;
@@ -24,10 +25,12 @@ import static androidx.test.espresso.action.ViewActions.swipeUp;
 import static androidx.test.espresso.assertion.ViewAssertions.doesNotExist;
 import static androidx.test.espresso.assertion.ViewAssertions.matches;
 import static androidx.test.espresso.matcher.ViewMatchers.hasSibling;
+import static androidx.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed;
 import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
 import static androidx.test.espresso.matcher.ViewMatchers.withEffectiveVisibility;
 import static androidx.test.espresso.matcher.ViewMatchers.withId;
 import static androidx.test.espresso.matcher.ViewMatchers.withText;
+
 import static com.android.intentresolver.ChooserActivity.TARGET_TYPE_CHOOSER_TARGET;
 import static com.android.intentresolver.ChooserActivity.TARGET_TYPE_DEFAULT;
 import static com.android.intentresolver.ChooserActivity.TARGET_TYPE_SHORTCUTS_FROM_PREDICTION_SERVICE;
@@ -35,9 +38,12 @@ import static com.android.intentresolver.ChooserActivity.TARGET_TYPE_SHORTCUTS_F
 import static com.android.intentresolver.ChooserListAdapter.CALLER_TARGET_SCORE_BOOST;
 import static com.android.intentresolver.ChooserListAdapter.SHORTCUT_TARGET_SCORE_BOOST;
 import static com.android.intentresolver.MatcherUtils.first;
+
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
+
 import static junit.framework.Assert.assertNull;
+
 import static org.hamcrest.CoreMatchers.allOf;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.not;
@@ -82,6 +88,9 @@ import android.graphics.drawable.Icon;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.UserHandle;
+import android.platform.test.annotations.RequiresFlagsEnabled;
+import android.platform.test.flag.junit.CheckFlagsRule;
+import android.platform.test.flag.junit.DeviceFlagsValueProvider;
 import android.provider.DeviceConfig;
 import android.service.chooser.ChooserAction;
 import android.service.chooser.ChooserTarget;
@@ -190,11 +199,13 @@ public class UnbundledChooserActivityTest {
     private static final int CONTENT_PREVIEW_FILE = 2;
     private static final int CONTENT_PREVIEW_TEXT = 3;
 
-
     @Rule(order = 0)
-    public HiltAndroidRule mHiltAndroidRule = new HiltAndroidRule(this);
+    public CheckFlagsRule mCheckFlagsRule = DeviceFlagsValueProvider.createCheckFlagsRule();
 
     @Rule(order = 1)
+    public HiltAndroidRule mHiltAndroidRule = new HiltAndroidRule(this);
+
+    @Rule(order = 2)
     public ActivityTestRule<ChooserWrapperActivity> mActivityRule =
             new ActivityTestRule<>(ChooserWrapperActivity.class, false, false);
 
@@ -2160,6 +2171,42 @@ public class UnbundledChooserActivityTest {
                 .check(matches(isDisplayed()));
     }
 
+    @Test
+    @RequiresFlagsEnabled(Flags.FLAG_SCROLLABLE_PREVIEW)
+    public void testWorkTab_previewIsScrollable() {
+        markOtherProfileAvailability(/* workAvailable= */ true, /* cloneAvailable= */ false);
+        List<ResolvedComponentInfo> personalResolvedComponentInfos =
+                createResolvedComponentsForTest(300);
+        List<ResolvedComponentInfo> workResolvedComponentInfos =
+                createResolvedComponentsForTest(3);
+        setupResolverControllers(personalResolvedComponentInfos, workResolvedComponentInfos);
+
+        Uri uri = createTestContentProviderUri("image/png", null);
+
+        ArrayList<Uri> uris = new ArrayList<>();
+        uris.add(uri);
+
+        Intent sendIntent = createSendUriIntentWithPreview(uris);
+        ChooserActivityOverrideData.getInstance().imageLoader =
+                createImageLoader(uri, createWideBitmap());
+
+        mActivityRule.launchActivity(Intent.createChooser(sendIntent, "Scrollable preview test"));
+        waitForIdle();
+
+        onView(withId(com.android.intentresolver.R.id.scrollable_image_preview))
+                .check(matches(isDisplayed()));
+
+        onView(withId(com.android.internal.R.id.contentPanel)).perform(swipeUp());
+        waitForIdle();
+
+        onView(withId(com.android.intentresolver.R.id.chooser_headline_row_container))
+                .check(matches(isCompletelyDisplayed()));
+        onView(withId(com.android.intentresolver.R.id.headline))
+                .check(matches(isDisplayed()));
+        onView(withId(com.android.intentresolver.R.id.scrollable_image_preview))
+                .check(matches(not(isDisplayed())));
+    }
+
     @Ignore // b/220067877
     @Test
     public void testWorkTab_xProfileOff_noAppsAvailable_workOff_xProfileOffEmptyStateShown() {
diff --git a/java/tests/src/com/android/intentresolver/contentpreview/FileContentPreviewUiTest.kt b/java/tests/src/com/android/intentresolver/contentpreview/FileContentPreviewUiTest.kt
index 6409da8a..d2d952ae 100644
--- a/java/tests/src/com/android/intentresolver/contentpreview/FileContentPreviewUiTest.kt
+++ b/java/tests/src/com/android/intentresolver/contentpreview/FileContentPreviewUiTest.kt
@@ -17,6 +17,7 @@
 package com.android.intentresolver.contentpreview
 
 import android.view.LayoutInflater
+import android.view.View
 import android.view.ViewGroup
 import android.widget.TextView
 import androidx.test.ext.junit.runners.AndroidJUnit4
@@ -25,7 +26,7 @@ import com.android.intentresolver.R
 import com.android.intentresolver.mock
 import com.android.intentresolver.whenever
 import com.android.intentresolver.widget.ActionRow
-import com.google.common.truth.Truth
+import com.google.common.truth.Truth.assertThat
 import java.util.function.Consumer
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -48,15 +49,15 @@ class FileContentPreviewUiTest {
     private val context
         get() = InstrumentationRegistry.getInstrumentation().context
 
+    private val testSubject =
+        FileContentPreviewUi(
+            fileCount,
+            actionFactory,
+            headlineGenerator,
+        )
+
     @Test
     fun test_display_titleIsDisplayed() {
-        val testSubject =
-            FileContentPreviewUi(
-                fileCount,
-                actionFactory,
-                headlineGenerator,
-            )
-
         val layoutInflater = LayoutInflater.from(context)
         val gridLayout = layoutInflater.inflate(R.layout.chooser_grid, null, false) as ViewGroup
 
@@ -68,9 +69,31 @@ class FileContentPreviewUiTest {
                 /*headlineViewParent=*/ null
             )
 
-        Truth.assertThat(previewView).isNotNull()
+        assertThat(previewView).isNotNull()
         val headlineView = previewView?.findViewById<TextView>(R.id.headline)
-        Truth.assertThat(headlineView).isNotNull()
-        Truth.assertThat(headlineView?.text).isEqualTo(text)
+        assertThat(headlineView).isNotNull()
+        assertThat(headlineView?.text).isEqualTo(text)
+    }
+
+    @Test
+    fun test_displayWithExternalHeaderView() {
+        val layoutInflater = LayoutInflater.from(context)
+        val gridLayout =
+            layoutInflater.inflate(R.layout.chooser_grid_scrollable_preview, null, false)
+                as ViewGroup
+        val externalHeaderView =
+            gridLayout.requireViewById<View>(R.id.chooser_headline_row_container)
+
+        assertThat(externalHeaderView.findViewById<View>(R.id.headline)).isNull()
+
+        val previewView =
+            testSubject.display(context.resources, layoutInflater, gridLayout, externalHeaderView)
+
+        assertThat(previewView).isNotNull()
+        assertThat(previewView.findViewById<View>(R.id.headline)).isNull()
+
+        val headlineView = externalHeaderView.findViewById<TextView>(R.id.headline)
+        assertThat(headlineView).isNotNull()
+        assertThat(headlineView?.text).isEqualTo(text)
     }
 }
diff --git a/java/tests/src/com/android/intentresolver/contentpreview/FilesPlusTextContentPreviewUiTest.kt b/java/tests/src/com/android/intentresolver/contentpreview/FilesPlusTextContentPreviewUiTest.kt
index 1144e3c9..0976dbf1 100644
--- a/java/tests/src/com/android/intentresolver/contentpreview/FilesPlusTextContentPreviewUiTest.kt
+++ b/java/tests/src/com/android/intentresolver/contentpreview/FilesPlusTextContentPreviewUiTest.kt
@@ -18,6 +18,7 @@ package com.android.intentresolver.contentpreview
 
 import android.net.Uri
 import android.view.LayoutInflater
+import android.view.View
 import android.view.ViewGroup
 import android.widget.TextView
 import androidx.lifecycle.testing.TestLifecycleOwner
@@ -28,6 +29,7 @@ import com.android.intentresolver.mock
 import com.android.intentresolver.whenever
 import com.android.intentresolver.widget.ActionRow
 import com.google.common.truth.Truth.assertThat
+import com.google.common.truth.Truth.assertWithMessage
 import java.util.function.Consumer
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -74,6 +76,17 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayImagesPlusTextWithoutUriMetadataExternalHeader_showImagesHeadline() {
+        val sharedFileCount = 2
+        val (previewView, headerParent) = testLoadingExternalHeadline("image/*", sharedFileCount)
+
+        verify(headlineGenerator, times(1)).getImagesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_IMAGES)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayVideosPlusTextWithoutUriMetadata_showVideosHeadline() {
         val sharedFileCount = 2
         val previewView = testLoadingHeadline("video/*", sharedFileCount)
@@ -84,6 +97,17 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayVideosPlusTextWithoutUriMetadataExternalHeader_showVideosHeadline() {
+        val sharedFileCount = 2
+        val (previewView, headerParent) = testLoadingExternalHeadline("video/*", sharedFileCount)
+
+        verify(headlineGenerator, times(1)).getVideosHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_VIDEOS)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayDocsPlusTextWithoutUriMetadata_showFilesHeadline() {
         val sharedFileCount = 2
         val previewView = testLoadingHeadline("application/pdf", sharedFileCount)
@@ -94,6 +118,18 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayDocsPlusTextWithoutUriMetadataExternalHeader_showFilesHeadline() {
+        val sharedFileCount = 2
+        val (previewView, headerParent) =
+            testLoadingExternalHeadline("application/pdf", sharedFileCount)
+
+        verify(headlineGenerator, times(1)).getFilesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_FILES)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayMixedContentPlusTextWithoutUriMetadata_showFilesHeadline() {
         val sharedFileCount = 2
         val previewView = testLoadingHeadline("*/*", sharedFileCount)
@@ -104,6 +140,17 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayMixedContentPlusTextWithoutUriMetadataExternalHeader_showFilesHeadline() {
+        val sharedFileCount = 2
+        val (previewView, headerParent) = testLoadingExternalHeadline("*/*", sharedFileCount)
+
+        verify(headlineGenerator, times(1)).getFilesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_FILES)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayImagesPlusTextWithUriMetadataSet_showImagesHeadline() {
         val loadedFileMetadata = createFileInfosWithMimeTypes("image/png", "image/jpeg")
         val sharedFileCount = loadedFileMetadata.size
@@ -115,6 +162,19 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayImagesPlusTextWithUriMetadataSetExternalHeader_showImagesHeadline() {
+        val loadedFileMetadata = createFileInfosWithMimeTypes("image/png", "image/jpeg")
+        val sharedFileCount = loadedFileMetadata.size
+        val (previewView, headerParent) =
+            testLoadingExternalHeadline("image/*", sharedFileCount, loadedFileMetadata)
+
+        verify(headlineGenerator, times(1)).getImagesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_IMAGES)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayVideosPlusTextWithUriMetadataSet_showVideosHeadline() {
         val loadedFileMetadata = createFileInfosWithMimeTypes("video/mp4", "video/mp4")
         val sharedFileCount = loadedFileMetadata.size
@@ -126,6 +186,19 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayVideosPlusTextWithUriMetadataSetExternalHeader_showVideosHeadline() {
+        val loadedFileMetadata = createFileInfosWithMimeTypes("video/mp4", "video/mp4")
+        val sharedFileCount = loadedFileMetadata.size
+        val (previewView, headerParent) =
+            testLoadingExternalHeadline("video/*", sharedFileCount, loadedFileMetadata)
+
+        verify(headlineGenerator, times(1)).getVideosHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_VIDEOS)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayImagesAndVideosPlusTextWithUriMetadataSet_showFilesHeadline() {
         val loadedFileMetadata = createFileInfosWithMimeTypes("image/png", "video/mp4")
         val sharedFileCount = loadedFileMetadata.size
@@ -137,6 +210,19 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayImagesAndVideosPlusTextWithUriMetadataSetExternalHeader_showFilesHeadline() {
+        val loadedFileMetadata = createFileInfosWithMimeTypes("image/png", "video/mp4")
+        val sharedFileCount = loadedFileMetadata.size
+        val (previewView, headerParent) =
+            testLoadingExternalHeadline("*/*", sharedFileCount, loadedFileMetadata)
+
+        verify(headlineGenerator, times(1)).getFilesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_FILES)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_displayDocsPlusTextWithUriMetadataSet_showFilesHeadline() {
         val loadedFileMetadata = createFileInfosWithMimeTypes("application/pdf", "application/pdf")
         val sharedFileCount = loadedFileMetadata.size
@@ -149,6 +235,19 @@ class FilesPlusTextContentPreviewUiTest {
     }
 
     @Test
+    fun test_displayDocsPlusTextWithUriMetadataSetExternalHeader_showFilesHeadline() {
+        val loadedFileMetadata = createFileInfosWithMimeTypes("application/pdf", "application/pdf")
+        val sharedFileCount = loadedFileMetadata.size
+        val (previewView, headerParent) =
+            testLoadingExternalHeadline("application/pdf", sharedFileCount, loadedFileMetadata)
+
+        verify(headlineGenerator, times(1)).getFilesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(headerParent, HEADLINE_FILES)
+        verifySharedText(previewView)
+    }
+
+    @Test
     fun test_uriMetadataIsMoreSpecificThanIntentMimeType_headlineGetsUpdated() {
         val sharedFileCount = 2
         val testSubject =
@@ -180,10 +279,56 @@ class FilesPlusTextContentPreviewUiTest {
         verifyPreviewHeadline(previewView, HEADLINE_IMAGES)
     }
 
+    @Test
+    fun test_uriMetadataIsMoreSpecificThanIntentMimeTypeExternalHeader_headlineGetsUpdated() {
+        val sharedFileCount = 2
+        val testSubject =
+            FilesPlusTextContentPreviewUi(
+                lifecycleOwner.lifecycle,
+                /*isSingleImage=*/ false,
+                sharedFileCount,
+                SHARED_TEXT,
+                /*intentMimeType=*/ "*/*",
+                actionFactory,
+                imageLoader,
+                DefaultMimeTypeClassifier,
+                headlineGenerator
+            )
+        val layoutInflater = LayoutInflater.from(context)
+        val gridLayout =
+            layoutInflater.inflate(R.layout.chooser_grid_scrollable_preview, null, false)
+                as ViewGroup
+        val externalHeaderView =
+            gridLayout.requireViewById<View>(R.id.chooser_headline_row_container)
+
+        assertWithMessage("External headline should not be inflated by default")
+            .that(externalHeaderView.findViewById<View>(R.id.headline))
+            .isNull()
+
+        val previewView =
+            testSubject.display(
+                context.resources,
+                LayoutInflater.from(context),
+                gridLayout,
+                externalHeaderView
+            )
+
+        verify(headlineGenerator, times(1)).getFilesHeadline(sharedFileCount)
+        verify(headlineGenerator, never()).getImagesHeadline(sharedFileCount)
+        verifyInternalHeadlineAbsence(previewView)
+        verifyPreviewHeadline(externalHeaderView, HEADLINE_FILES)
+
+        testSubject.updatePreviewMetadata(createFileInfosWithMimeTypes("image/png", "image/jpg"))
+
+        verify(headlineGenerator, times(1)).getFilesHeadline(sharedFileCount)
+        verify(headlineGenerator, times(1)).getImagesHeadline(sharedFileCount)
+        verifyPreviewHeadline(externalHeaderView, HEADLINE_IMAGES)
+    }
+
     private fun testLoadingHeadline(
         intentMimeType: String,
         sharedFileCount: Int,
-        loadedFileMetadata: List<FileInfo>? = null
+        loadedFileMetadata: List<FileInfo>? = null,
     ): ViewGroup? {
         val testSubject =
             FilesPlusTextContentPreviewUi(
@@ -209,14 +354,51 @@ class FilesPlusTextContentPreviewUiTest {
         )
     }
 
+    private fun testLoadingExternalHeadline(
+        intentMimeType: String,
+        sharedFileCount: Int,
+        loadedFileMetadata: List<FileInfo>? = null,
+    ): Pair<ViewGroup?, View> {
+        val testSubject =
+            FilesPlusTextContentPreviewUi(
+                lifecycleOwner.lifecycle,
+                /*isSingleImage=*/ false,
+                sharedFileCount,
+                SHARED_TEXT,
+                intentMimeType,
+                actionFactory,
+                imageLoader,
+                DefaultMimeTypeClassifier,
+                headlineGenerator
+            )
+        val layoutInflater = LayoutInflater.from(context)
+        val gridLayout =
+            layoutInflater.inflate(R.layout.chooser_grid_scrollable_preview, null, false)
+                as ViewGroup
+        val externalHeaderView =
+            gridLayout.requireViewById<View>(R.id.chooser_headline_row_container)
+
+        assertWithMessage("External headline should not be inflated by default")
+            .that(externalHeaderView.findViewById<View>(R.id.headline))
+            .isNull()
+
+        loadedFileMetadata?.let(testSubject::updatePreviewMetadata)
+        return testSubject.display(
+            context.resources,
+            LayoutInflater.from(context),
+            gridLayout,
+            externalHeaderView
+        ) to externalHeaderView
+    }
+
     private fun createFileInfosWithMimeTypes(vararg mimeTypes: String): List<FileInfo> {
         val uri = Uri.parse("content://pkg.app/file")
         return mimeTypes.map { mimeType -> FileInfo.Builder(uri).withMimeType(mimeType).build() }
     }
 
-    private fun verifyPreviewHeadline(previewView: ViewGroup?, expectedText: String) {
-        assertThat(previewView).isNotNull()
-        val headlineView = previewView?.findViewById<TextView>(R.id.headline)
+    private fun verifyPreviewHeadline(headerViewParent: View?, expectedText: String) {
+        assertThat(headerViewParent).isNotNull()
+        val headlineView = headerViewParent?.findViewById<TextView>(R.id.headline)
         assertThat(headlineView).isNotNull()
         assertThat(headlineView?.text).isEqualTo(expectedText)
     }
@@ -227,4 +409,13 @@ class FilesPlusTextContentPreviewUiTest {
         assertThat(textContentView).isNotNull()
         assertThat(textContentView?.text).isEqualTo(SHARED_TEXT)
     }
+
+    private fun verifyInternalHeadlineAbsence(previewView: ViewGroup?) {
+        assertWithMessage("Preview parent should not be null").that(previewView).isNotNull()
+        assertWithMessage(
+                "Preview headline should not be inflated when an external headline is used"
+            )
+            .that(previewView?.findViewById<View>(R.id.headline))
+            .isNull()
+    }
 }
diff --git a/java/tests/src/com/android/intentresolver/contentpreview/TextContentPreviewUiTest.kt b/java/tests/src/com/android/intentresolver/contentpreview/TextContentPreviewUiTest.kt
index 69053f73..b91ed436 100644
--- a/java/tests/src/com/android/intentresolver/contentpreview/TextContentPreviewUiTest.kt
+++ b/java/tests/src/com/android/intentresolver/contentpreview/TextContentPreviewUiTest.kt
@@ -17,6 +17,7 @@
 package com.android.intentresolver.contentpreview
 
 import android.view.LayoutInflater
+import android.view.View
 import android.view.ViewGroup
 import android.widget.TextView
 import androidx.lifecycle.testing.TestLifecycleOwner
@@ -51,18 +52,19 @@ class TextContentPreviewUiTest {
     private val context
         get() = InstrumentationRegistry.getInstrumentation().context
 
+    private val testSubject =
+        TextContentPreviewUi(
+            lifecycleOwner.lifecycle,
+            text,
+            title,
+            /*previewThumbnail=*/ null,
+            actionFactory,
+            imageLoader,
+            headlineGenerator,
+        )
+
     @Test
     fun test_display_headlineIsDisplayed() {
-        val testSubject =
-            TextContentPreviewUi(
-                lifecycleOwner.lifecycle,
-                text,
-                title,
-                /*previewThumbnail=*/ null,
-                actionFactory,
-                imageLoader,
-                headlineGenerator,
-            )
         val layoutInflater = LayoutInflater.from(context)
         val gridLayout = layoutInflater.inflate(R.layout.chooser_grid, null, false) as ViewGroup
 
@@ -79,4 +81,26 @@ class TextContentPreviewUiTest {
         assertThat(headlineView).isNotNull()
         assertThat(headlineView?.text).isEqualTo(text)
     }
+
+    @Test
+    fun test_displayWithExternalHeaderView_externalHeaderIsDisplayed() {
+        val layoutInflater = LayoutInflater.from(context)
+        val gridLayout =
+            layoutInflater.inflate(R.layout.chooser_grid_scrollable_preview, null, false)
+                as ViewGroup
+        val externalHeaderView =
+            gridLayout.requireViewById<View>(R.id.chooser_headline_row_container)
+
+        assertThat(externalHeaderView.findViewById<View>(R.id.headline)).isNull()
+
+        val previewView =
+            testSubject.display(context.resources, layoutInflater, gridLayout, externalHeaderView)
+
+        assertThat(previewView).isNotNull()
+        assertThat(previewView.findViewById<View>(R.id.headline)).isNull()
+
+        val headlineView = externalHeaderView.findViewById<TextView>(R.id.headline)
+        assertThat(headlineView).isNotNull()
+        assertThat(headlineView?.text).isEqualTo(text)
+    }
 }
diff --git a/java/tests/src/com/android/intentresolver/contentpreview/UnifiedContentPreviewUiTest.kt b/java/tests/src/com/android/intentresolver/contentpreview/UnifiedContentPreviewUiTest.kt
index 6b22b850..7e07e0ca 100644
--- a/java/tests/src/com/android/intentresolver/contentpreview/UnifiedContentPreviewUiTest.kt
+++ b/java/tests/src/com/android/intentresolver/contentpreview/UnifiedContentPreviewUiTest.kt
@@ -18,13 +18,17 @@ package com.android.intentresolver.contentpreview
 
 import android.net.Uri
 import android.view.LayoutInflater
+import android.view.View
 import android.view.ViewGroup
+import android.widget.TextView
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
-import com.android.intentresolver.R.layout.chooser_grid
+import com.android.intentresolver.R
 import com.android.intentresolver.mock
 import com.android.intentresolver.whenever
 import com.android.intentresolver.widget.ImagePreviewView.TransitionElementStatusCallback
+import com.google.common.truth.Truth
+import com.google.common.truth.Truth.assertWithMessage
 import kotlin.coroutines.EmptyCoroutineContext
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.asFlow
@@ -38,6 +42,10 @@ import org.mockito.Mockito.anyInt
 import org.mockito.Mockito.times
 import org.mockito.Mockito.verify
 
+private const val IMAGE_HEADLINE = "Image Headline"
+private const val VIDEO_HEADLINE = "Video Headline"
+private const val FILES_HEADLINE = "Files Headline"
+
 @RunWith(AndroidJUnit4::class)
 class UnifiedContentPreviewUiTest {
     private val testScope = TestScope(EmptyCoroutineContext + UnconfinedTestDispatcher())
@@ -48,40 +56,76 @@ class UnifiedContentPreviewUiTest {
     private val imageLoader = mock<ImageLoader>()
     private val headlineGenerator =
         mock<HeadlineGenerator> {
-            whenever(getImagesHeadline(anyInt())).thenReturn("Image Headline")
-            whenever(getVideosHeadline(anyInt())).thenReturn("Video Headline")
-            whenever(getFilesHeadline(anyInt())).thenReturn("Files Headline")
+            whenever(getImagesHeadline(anyInt())).thenReturn(IMAGE_HEADLINE)
+            whenever(getVideosHeadline(anyInt())).thenReturn(VIDEO_HEADLINE)
+            whenever(getFilesHeadline(anyInt())).thenReturn(FILES_HEADLINE)
         }
 
     private val context
-        get() = getInstrumentation().getContext()
+        get() = getInstrumentation().context
 
     @Test
     fun test_displayImagesWithoutUriMetadata_showImagesHeadline() {
-        testLoadingHeadline("image/*", files = null)
+        testLoadingHeadline("image/*", files = null) { previewView ->
+            verify(headlineGenerator, times(1)).getImagesHeadline(2)
+            verifyPreviewHeadline(previewView, IMAGE_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getImagesHeadline(2)
+    @Test
+    fun test_displayImagesWithoutUriMetadataExternalHeader_showImagesHeadline() {
+        testLoadingExternalHeadline("image/*", files = null) { externalHeaderView ->
+            verify(headlineGenerator, times(1)).getImagesHeadline(2)
+            verifyPreviewHeadline(externalHeaderView, IMAGE_HEADLINE)
+        }
     }
 
     @Test
     fun test_displayVideosWithoutUriMetadata_showImagesHeadline() {
-        testLoadingHeadline("video/*", files = null)
+        testLoadingHeadline("video/*", files = null) { previewView ->
+            verify(headlineGenerator, times(1)).getVideosHeadline(2)
+            verifyPreviewHeadline(previewView, VIDEO_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getVideosHeadline(2)
+    @Test
+    fun test_displayVideosWithoutUriMetadataExternalHeader_showImagesHeadline() {
+        testLoadingExternalHeadline("video/*", files = null) { externalHeaderView ->
+            verify(headlineGenerator, times(1)).getVideosHeadline(2)
+            verifyPreviewHeadline(externalHeaderView, VIDEO_HEADLINE)
+        }
     }
 
     @Test
     fun test_displayDocumentsWithoutUriMetadata_showImagesHeadline() {
-        testLoadingHeadline("application/pdf", files = null)
+        testLoadingHeadline("application/pdf", files = null) { previewView ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(previewView, FILES_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getFilesHeadline(2)
+    @Test
+    fun test_displayDocumentsWithoutUriMetadataExternalHeader_showImagesHeadline() {
+        testLoadingExternalHeadline("application/pdf", files = null) { externalHeaderView ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(externalHeaderView, FILES_HEADLINE)
+        }
     }
 
     @Test
     fun test_displayMixedContentWithoutUriMetadata_showImagesHeadline() {
-        testLoadingHeadline("*/*", files = null)
+        testLoadingHeadline("*/*", files = null) { previewView ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(previewView, FILES_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getFilesHeadline(2)
+    @Test
+    fun test_displayMixedContentWithoutUriMetadataExternalHeader_showImagesHeadline() {
+        testLoadingExternalHeadline("*/*", files = null) { externalHeader ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(externalHeader, FILES_HEADLINE)
+        }
     }
 
     @Test
@@ -92,9 +136,24 @@ class UnifiedContentPreviewUiTest {
                 FileInfo.Builder(uri).withMimeType("image/png").build(),
                 FileInfo.Builder(uri).withMimeType("image/jpeg").build(),
             )
-        testLoadingHeadline("image/*", files)
+        testLoadingHeadline("image/*", files) { preivewView ->
+            verify(headlineGenerator, times(1)).getImagesHeadline(2)
+            verifyPreviewHeadline(preivewView, IMAGE_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getImagesHeadline(2)
+    @Test
+    fun test_displayImagesWithUriMetadataSetExternalHeader_showImagesHeadline() {
+        val uri = Uri.parse("content://pkg.app/image.png")
+        val files =
+            listOf(
+                FileInfo.Builder(uri).withMimeType("image/png").build(),
+                FileInfo.Builder(uri).withMimeType("image/jpeg").build(),
+            )
+        testLoadingExternalHeadline("image/*", files) { externalHeader ->
+            verify(headlineGenerator, times(1)).getImagesHeadline(2)
+            verifyPreviewHeadline(externalHeader, IMAGE_HEADLINE)
+        }
     }
 
     @Test
@@ -105,9 +164,24 @@ class UnifiedContentPreviewUiTest {
                 FileInfo.Builder(uri).withMimeType("video/mp4").build(),
                 FileInfo.Builder(uri).withMimeType("video/mp4").build(),
             )
-        testLoadingHeadline("video/*", files)
+        testLoadingHeadline("video/*", files) { previewView ->
+            verify(headlineGenerator, times(1)).getVideosHeadline(2)
+            verifyPreviewHeadline(previewView, VIDEO_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getVideosHeadline(2)
+    @Test
+    fun test_displayVideosWithUriMetadataSetExternalHeader_showImagesHeadline() {
+        val uri = Uri.parse("content://pkg.app/image.png")
+        val files =
+            listOf(
+                FileInfo.Builder(uri).withMimeType("video/mp4").build(),
+                FileInfo.Builder(uri).withMimeType("video/mp4").build(),
+            )
+        testLoadingExternalHeadline("video/*", files) { externalHeader ->
+            verify(headlineGenerator, times(1)).getVideosHeadline(2)
+            verifyPreviewHeadline(externalHeader, VIDEO_HEADLINE)
+        }
     }
 
     @Test
@@ -118,9 +192,24 @@ class UnifiedContentPreviewUiTest {
                 FileInfo.Builder(uri).withMimeType("image/png").build(),
                 FileInfo.Builder(uri).withMimeType("video/mp4").build(),
             )
-        testLoadingHeadline("*/*", files)
+        testLoadingHeadline("*/*", files) { previewView ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(previewView, FILES_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getFilesHeadline(2)
+    @Test
+    fun test_displayImagesAndVideosWithUriMetadataSetExternalHeader_showImagesHeadline() {
+        val uri = Uri.parse("content://pkg.app/image.png")
+        val files =
+            listOf(
+                FileInfo.Builder(uri).withMimeType("image/png").build(),
+                FileInfo.Builder(uri).withMimeType("video/mp4").build(),
+            )
+        testLoadingExternalHeadline("*/*", files) { externalHeader ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(externalHeader, FILES_HEADLINE)
+        }
     }
 
     @Test
@@ -131,12 +220,31 @@ class UnifiedContentPreviewUiTest {
                 FileInfo.Builder(uri).withMimeType("application/pdf").build(),
                 FileInfo.Builder(uri).withMimeType("application/pdf").build(),
             )
-        testLoadingHeadline("application/pdf", files)
+        testLoadingHeadline("application/pdf", files) { previewView ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(previewView, FILES_HEADLINE)
+        }
+    }
 
-        verify(headlineGenerator, times(1)).getFilesHeadline(2)
+    @Test
+    fun test_displayDocumentsWithUriMetadataSetExternalHeader_showImagesHeadline() {
+        val uri = Uri.parse("content://pkg.app/image.png")
+        val files =
+            listOf(
+                FileInfo.Builder(uri).withMimeType("application/pdf").build(),
+                FileInfo.Builder(uri).withMimeType("application/pdf").build(),
+            )
+        testLoadingExternalHeadline("application/pdf", files) { externalHeader ->
+            verify(headlineGenerator, times(1)).getFilesHeadline(2)
+            verifyPreviewHeadline(externalHeader, FILES_HEADLINE)
+        }
     }
 
-    private fun testLoadingHeadline(intentMimeType: String, files: List<FileInfo>?) {
+    private fun testLoadingHeadline(
+        intentMimeType: String,
+        files: List<FileInfo>?,
+        verificationBlock: (ViewGroup?) -> Unit,
+    ) {
         testScope.runTest {
             val endMarker = FileInfo.Builder(Uri.EMPTY).build()
             val emptySourceFlow = MutableSharedFlow<FileInfo>(replay = 1)
@@ -157,15 +265,84 @@ class UnifiedContentPreviewUiTest {
                     headlineGenerator
                 )
             val layoutInflater = LayoutInflater.from(context)
-            val gridLayout = layoutInflater.inflate(chooser_grid, null, false) as ViewGroup
+            val gridLayout = layoutInflater.inflate(R.layout.chooser_grid, null, false) as ViewGroup
 
-            testSubject.display(
-                context.resources,
-                LayoutInflater.from(context),
-                gridLayout,
-                /*headlineViewParent=*/ null
-            )
+            val previewView =
+                testSubject.display(
+                    context.resources,
+                    LayoutInflater.from(context),
+                    gridLayout,
+                    /*headlineViewParent=*/ null
+                )
             emptySourceFlow.tryEmit(endMarker)
+
+            verificationBlock(previewView)
         }
     }
+
+    private fun testLoadingExternalHeadline(
+        intentMimeType: String,
+        files: List<FileInfo>?,
+        verificationBlock: (View?) -> Unit,
+    ) {
+        testScope.runTest {
+            val endMarker = FileInfo.Builder(Uri.EMPTY).build()
+            val emptySourceFlow = MutableSharedFlow<FileInfo>(replay = 1)
+            val testSubject =
+                UnifiedContentPreviewUi(
+                    testScope,
+                    /*isSingleImage=*/ false,
+                    intentMimeType,
+                    actionFactory,
+                    imageLoader,
+                    DefaultMimeTypeClassifier,
+                    object : TransitionElementStatusCallback {
+                        override fun onTransitionElementReady(name: String) = Unit
+                        override fun onAllTransitionElementsReady() = Unit
+                    },
+                    files?.let { it.asFlow() } ?: emptySourceFlow.takeWhile { it !== endMarker },
+                    /*itemCount=*/ 2,
+                    headlineGenerator
+                )
+            val layoutInflater = LayoutInflater.from(context)
+            val gridLayout =
+                layoutInflater.inflate(R.layout.chooser_grid_scrollable_preview, null, false)
+                    as ViewGroup
+            val externalHeaderView =
+                gridLayout.requireViewById<View>(R.id.chooser_headline_row_container)
+
+            assertWithMessage("External headline should not be inflated by default")
+                .that(externalHeaderView.findViewById<View>(R.id.headline))
+                .isNull()
+
+            val previewView =
+                testSubject.display(
+                    context.resources,
+                    LayoutInflater.from(context),
+                    gridLayout,
+                    externalHeaderView,
+                )
+
+            emptySourceFlow.tryEmit(endMarker)
+
+            verifyInternalHeadlineAbsence(previewView)
+            verificationBlock(externalHeaderView)
+        }
+    }
+
+    private fun verifyPreviewHeadline(headerViewParent: View?, expectedText: String) {
+        Truth.assertThat(headerViewParent).isNotNull()
+        val headlineView = headerViewParent?.findViewById<TextView>(R.id.headline)
+        Truth.assertThat(headlineView).isNotNull()
+        Truth.assertThat(headlineView?.text).isEqualTo(expectedText)
+    }
+
+    private fun verifyInternalHeadlineAbsence(previewView: ViewGroup?) {
+        assertWithMessage("Preview parent should not be null").that(previewView).isNotNull()
+        assertWithMessage(
+                "Preview headline should not be inflated when an external headline is used"
+            )
+            .that(previewView?.findViewById<View>(R.id.headline))
+            .isNull()
+    }
 }