src/com/android/launcher3/allapps/AllAppsRecyclerView.java - LeafOS-Project/android_packages_apps_Launcher3 - Gitiles

 /*
  * Copyright (C) 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.
  */
 package com.android.launcher3.allapps;

 import static com.android.launcher3.config.FeatureFlags.ALL_APPS_GONE_VISIBILITY;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_ALL_APPS_RV_PREINFLATION;
 import static com.android.launcher3.logger.LauncherAtom.ContainerInfo;
 import static com.android.launcher3.logger.LauncherAtom.SearchResultContainer;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_DOWN;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_UP;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SCROLLED_UNKNOWN_DIRECTION;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SEARCH_SCROLLED_DOWN;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SEARCH_SCROLLED_UP;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_VERTICAL_SWIPE_BEGIN;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_VERTICAL_SWIPE_END;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_WORK_FAB_BUTTON_COLLAPSE;
 import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_WORK_FAB_BUTTON_EXTEND;
 import static com.android.launcher3.recyclerview.AllAppsRecyclerViewPoolKt.EXTRA_ICONS_COUNT;
 import static com.android.launcher3.recyclerview.AllAppsRecyclerViewPoolKt.PREINFLATE_ICONS_ROW_COUNT;
 import static com.android.launcher3.util.LogConfig.SEARCH_LOGGING;

 import android.content.Context;
 import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.View;

 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.core.util.Consumer;
 import androidx.recyclerview.widget.RecyclerView;

 import com.android.launcher3.DeviceProfile;
 import com.android.launcher3.ExtendedEditText;
 import com.android.launcher3.FastScrollRecyclerView;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.logging.StatsLogManager;
 import com.android.launcher3.views.ActivityContext;

 import java.util.List;

 /**
  * A RecyclerView with custom fast scroll support for the all apps view.
  */
 public class AllAppsRecyclerView extends FastScrollRecyclerView {
     protected static final String TAG = "AllAppsRecyclerView";
     private static final boolean DEBUG = false;
     private static final boolean DEBUG_LATENCY = Utilities.isPropertyEnabled(SEARCH_LOGGING);
     private Consumer<View> mChildAttachedConsumer;

     protected final int mNumAppsPerRow;
     private final AllAppsFastScrollHelper mFastScrollHelper;
     private int mCumulativeVerticalScroll;

     protected AlphabeticalAppsList<?> mApps;

     public AllAppsRecyclerView(Context context) {
         this(context, null);
     }

     public AllAppsRecyclerView(Context context, AttributeSet attrs) {
         this(context, attrs, 0);
     }

     public AllAppsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
         this(context, attrs, defStyleAttr, 0);
     }

     public AllAppsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr,
             int defStyleRes) {
         super(context, attrs, defStyleAttr);
         mNumAppsPerRow = LauncherAppState.getIDP(context).numColumns;
         mFastScrollHelper = new AllAppsFastScrollHelper(this);
     }

     /**
      * Sets the list of apps in this view, used to determine the fastscroll position.
      */
     public void setApps(AlphabeticalAppsList<?> apps) {
         mApps = apps;
     }

     public AlphabeticalAppsList<?> getApps() {
         return mApps;
     }

     protected void updatePoolSize() {
         updatePoolSize(false);
     }

     void updatePoolSize(boolean hasWorkProfile) {
         DeviceProfile grid = ActivityContext.lookupContext(getContext()).getDeviceProfile();
         RecyclerView.RecycledViewPool pool = getRecycledViewPool();
         pool.setMaxRecycledViews(AllAppsGridAdapter.VIEW_TYPE_EMPTY_SEARCH, 1);
         pool.setMaxRecycledViews(AllAppsGridAdapter.VIEW_TYPE_ALL_APPS_DIVIDER, 1);

         // By default the max num of pool size for app icons is num of app icons in one page of
         // all apps.
         int maxPoolSizeForAppIcons = grid.getMaxAllAppsRowCount()
                 * grid.numShownAllAppsColumns;
         if (ALL_APPS_GONE_VISIBILITY.get() && ENABLE_ALL_APPS_RV_PREINFLATION.get()) {
             // If we set all apps' hidden visibility to GONE and enable pre-inflation, we want to
             // preinflate one page of all apps icons plus [PREINFLATE_ICONS_ROW_COUNT] rows +
             // [EXTRA_ICONS_COUNT]. Thus we need to bump the max pool size of app icons accordingly.
             maxPoolSizeForAppIcons +=
                     PREINFLATE_ICONS_ROW_COUNT * grid.numShownAllAppsColumns + EXTRA_ICONS_COUNT;
         }
         if (hasWorkProfile) {
             maxPoolSizeForAppIcons *= 2;
         }
         pool.setMaxRecycledViews(
                 AllAppsGridAdapter.VIEW_TYPE_ICON, maxPoolSizeForAppIcons);
     }

     @Override
     public void onDraw(Canvas c) {
         if (DEBUG) {
             Log.d(TAG, "onDraw at = " + System.currentTimeMillis());
         }
         if (DEBUG_LATENCY) {
             Log.d(SEARCH_LOGGING,  getClass().getSimpleName() + " onDraw; time stamp = "
                     + System.currentTimeMillis());
         }
         super.onDraw(c);
     }

     @Override
     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
         updatePoolSize();
     }

     public void onSearchResultsChanged() {
         // Always scroll the view to the top so the user can see the changed results
         scrollToTop();
     }

     @Override
     public void onScrollStateChanged(int state) {
         super.onScrollStateChanged(state);

         StatsLogManager mgr = ActivityContext.lookupContext(getContext()).getStatsLogManager();
         switch (state) {
             case SCROLL_STATE_DRAGGING:
                 mCumulativeVerticalScroll = 0;
                 requestFocus();
                 mgr.logger().sendToInteractionJankMonitor(
                         LAUNCHER_ALLAPPS_VERTICAL_SWIPE_BEGIN, this);
                 ActivityContext.lookupContext(getContext()).hideKeyboard();
                 break;
             case SCROLL_STATE_IDLE:
                 mgr.logger().sendToInteractionJankMonitor(
                         LAUNCHER_ALLAPPS_VERTICAL_SWIPE_END, this);
                 logCumulativeVerticalScroll();
                 break;
         }
     }

     @Override
     public void onScrolled(int dx, int dy) {
         super.onScrolled(dx, dy);
         mCumulativeVerticalScroll += dy;
     }

     /**
      * Maps the touch (from 0..1) to the adapter position that should be visible.
      */
     @Override
     public String scrollToPositionAtProgress(float touchFraction) {
         int rowCount = mApps.getNumAppRows();
         if (rowCount == 0) {
             return "";
         }

         // Find the fastscroll section that maps to this touch fraction
         List<AlphabeticalAppsList.FastScrollSectionInfo> fastScrollSections =
                 mApps.getFastScrollerSections();
         int count = fastScrollSections.size();
         if (count == 0) {
             return "";
         }
         int index = Utilities.boundToRange((int) (touchFraction * count), 0, count - 1);
         AlphabeticalAppsList.FastScrollSectionInfo section = fastScrollSections.get(index);
         mFastScrollHelper.smoothScrollToSection(section);
         return section.sectionName;
     }

     @Override
     public void onFastScrollCompleted() {
         super.onFastScrollCompleted();
         mFastScrollHelper.onFastScrollCompleted();
     }

     @Override
     protected boolean isPaddingOffsetRequired() {
         return true;
     }

     @Override
     protected int getTopPaddingOffset() {
         return -getPaddingTop();
     }

     /**
      * Updates the bounds for the scrollbar.
      */
     @Override
     public void onUpdateScrollbar(int dy) {
         if (mApps == null) {
             return;
         }
         List<AllAppsGridAdapter.AdapterItem> items = mApps.getAdapterItems();

         // Skip early if there are no items or we haven't been measured
         if (items.isEmpty() || mNumAppsPerRow == 0 || getChildCount() == 0) {
             mScrollbar.setThumbOffsetY(-1);
             return;
         }

         // Skip early if, there no child laid out in the container.
         int scrollY = computeVerticalScrollOffset();
         if (scrollY < 0) {
             mScrollbar.setThumbOffsetY(-1);
             return;
         }

         // Only show the scrollbar if there is height to be scrolled
         int availableScrollBarHeight = getAvailableScrollBarHeight();
         int availableScrollHeight = getAvailableScrollHeight();
         if (availableScrollHeight <= 0) {
             mScrollbar.setThumbOffsetY(-1);
             return;
         }

         if (mScrollbar.isThumbDetached()) {
             if (!mScrollbar.isDraggingThumb()) {
                 // Calculate the current scroll position, the scrollY of the recycler view accounts
                 // for the view padding, while the scrollBarY is drawn right up to the background
                 // padding (ignoring padding)
                 int scrollBarY = (int)
                         (((float) scrollY / availableScrollHeight) * availableScrollBarHeight);

                 int thumbScrollY = mScrollbar.getThumbOffsetY();
                 int diffScrollY = scrollBarY - thumbScrollY;
                 if (diffScrollY * dy > 0f) {
                     // User is scrolling in the same direction the thumb needs to catch up to the
                     // current scroll position.  We do this by mapping the difference in movement
                     // from the original scroll bar position to the difference in movement necessary
                     // in the detached thumb position to ensure that both speed towards the same
                     // position at either end of the list.
                     if (dy < 0) {
                         int offset = (int) ((dy * thumbScrollY) / (float) scrollBarY);
                         thumbScrollY += Math.max(offset, diffScrollY);
                     } else {
                         int offset = (int) ((dy * (availableScrollBarHeight - thumbScrollY)) /
                                 (float) (availableScrollBarHeight - scrollBarY));
                         thumbScrollY += Math.min(offset, diffScrollY);
                     }
                     thumbScrollY = Math.max(0, Math.min(availableScrollBarHeight, thumbScrollY));
                     mScrollbar.setThumbOffsetY(thumbScrollY);
                     if (scrollBarY == thumbScrollY) {
                         mScrollbar.reattachThumbToScroll();
                     }
                 } else {
                     // User is scrolling in an opposite direction to the direction that the thumb
                     // needs to catch up to the scroll position.  Do nothing except for updating
                     // the scroll bar x to match the thumb width.
                     mScrollbar.setThumbOffsetY(thumbScrollY);
                 }
             }
         } else {
             synchronizeScrollBarThumbOffsetToViewScroll(scrollY, availableScrollHeight);
         }
     }

     /**
      * This will be called just before a new child is attached to the window. Passing in null will
      * remove the consumer.
      */
     protected void setChildAttachedConsumer(@Nullable Consumer<View> childAttachedConsumer) {
         mChildAttachedConsumer = childAttachedConsumer;
     }

     @Override
     public void onChildAttachedToWindow(@NonNull View child) {
         if (mChildAttachedConsumer != null) {
             mChildAttachedConsumer.accept(child);
         }
         super.onChildAttachedToWindow(child);
     }

     @Override
     public int getScrollBarTop() {
         return ActivityContext.lookupContext(getContext()).getAppsView().isSearchSupported()
                 ? getResources().getDimensionPixelOffset(R.dimen.all_apps_header_top_padding)
                 : 0;
     }

     @Override
     public int getScrollBarMarginBottom() {
         return getRootWindowInsets() == null ? 0
                 : getRootWindowInsets().getSystemWindowInsetBottom();
     }

     @Override
     public boolean hasOverlappingRendering() {
         return false;
     }

     private void logCumulativeVerticalScroll() {
         ActivityContext context = ActivityContext.lookupContext(getContext());
         StatsLogManager mgr = context.getStatsLogManager();
         ActivityAllAppsContainerView<?> appsView = context.getAppsView();
         ExtendedEditText editText = appsView.getSearchUiManager().getEditText();
         ContainerInfo containerInfo = ContainerInfo.newBuilder().setSearchResultContainer(
                 SearchResultContainer
                         .newBuilder()
                         .setQueryLength((editText == null) ? -1 : editText.length())).build();
         if (mCumulativeVerticalScroll == 0) {
             // mCumulativeVerticalScroll == 0 when user comes back to original position, we
             // don't know the direction of scrolling.
             mgr.logger().withContainerInfo(containerInfo).log(
                     LAUNCHER_ALLAPPS_SCROLLED_UNKNOWN_DIRECTION);
             return;
         } else if (appsView.isSearching()) {
             // In search results page
             mgr.logger().withContainerInfo(containerInfo).log((mCumulativeVerticalScroll > 0)
                     ? LAUNCHER_ALLAPPS_SEARCH_SCROLLED_DOWN
                     : LAUNCHER_ALLAPPS_SEARCH_SCROLLED_UP);
             return;
         } else if (appsView.mViewPager != null) {
             int currentPage = appsView.mViewPager.getCurrentPage();
             if (currentPage == ActivityAllAppsContainerView.AdapterHolder.WORK) {
                 // In work A-Z list
                 mgr.logger().withContainerInfo(containerInfo).log((mCumulativeVerticalScroll > 0)
                         ? LAUNCHER_WORK_FAB_BUTTON_COLLAPSE
                         : LAUNCHER_WORK_FAB_BUTTON_EXTEND);
                 return;
             }
         }
         // In personal A-Z list
         mgr.logger().withContainerInfo(containerInfo).log((mCumulativeVerticalScroll > 0)
                 ? LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_DOWN
                 : LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_UP);
     }
 }
	/*
	* Copyright (C) 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.
	*/
	package com.android.launcher3.allapps;

	import static com.android.launcher3.config.FeatureFlags.ALL_APPS_GONE_VISIBILITY;
	import static com.android.launcher3.config.FeatureFlags.ENABLE_ALL_APPS_RV_PREINFLATION;
	import static com.android.launcher3.logger.LauncherAtom.ContainerInfo;
	import static com.android.launcher3.logger.LauncherAtom.SearchResultContainer;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_DOWN;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_UP;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SCROLLED_UNKNOWN_DIRECTION;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SEARCH_SCROLLED_DOWN;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_SEARCH_SCROLLED_UP;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_VERTICAL_SWIPE_BEGIN;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_ALLAPPS_VERTICAL_SWIPE_END;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_WORK_FAB_BUTTON_COLLAPSE;
	import static com.android.launcher3.logging.StatsLogManager.LauncherEvent.LAUNCHER_WORK_FAB_BUTTON_EXTEND;
	import static com.android.launcher3.recyclerview.AllAppsRecyclerViewPoolKt.EXTRA_ICONS_COUNT;
	import static com.android.launcher3.recyclerview.AllAppsRecyclerViewPoolKt.PREINFLATE_ICONS_ROW_COUNT;
	import static com.android.launcher3.util.LogConfig.SEARCH_LOGGING;

	import android.content.Context;
	import android.graphics.Canvas;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.View;

	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;
	import androidx.core.util.Consumer;
	import androidx.recyclerview.widget.RecyclerView;

	import com.android.launcher3.DeviceProfile;
	import com.android.launcher3.ExtendedEditText;
	import com.android.launcher3.FastScrollRecyclerView;
	import com.android.launcher3.LauncherAppState;
	import com.android.launcher3.R;
	import com.android.launcher3.Utilities;
	import com.android.launcher3.logging.StatsLogManager;
	import com.android.launcher3.views.ActivityContext;

	import java.util.List;

	/**
	* A RecyclerView with custom fast scroll support for the all apps view.
	*/
	public class AllAppsRecyclerView extends FastScrollRecyclerView {
	protected static final String TAG = "AllAppsRecyclerView";
	private static final boolean DEBUG = false;
	private static final boolean DEBUG_LATENCY = Utilities.isPropertyEnabled(SEARCH_LOGGING);
	private Consumer<View> mChildAttachedConsumer;

	protected final int mNumAppsPerRow;
	private final AllAppsFastScrollHelper mFastScrollHelper;
	private int mCumulativeVerticalScroll;

	protected AlphabeticalAppsList<?> mApps;

	public AllAppsRecyclerView(Context context) {
	this(context, null);
	}

	public AllAppsRecyclerView(Context context, AttributeSet attrs) {
	this(context, attrs, 0);
	}

	public AllAppsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr) {
	this(context, attrs, defStyleAttr, 0);
	}

	public AllAppsRecyclerView(Context context, AttributeSet attrs, int defStyleAttr,
	int defStyleRes) {
	super(context, attrs, defStyleAttr);
	mNumAppsPerRow = LauncherAppState.getIDP(context).numColumns;
	mFastScrollHelper = new AllAppsFastScrollHelper(this);
	}

	/**
	* Sets the list of apps in this view, used to determine the fastscroll position.
	*/
	public void setApps(AlphabeticalAppsList<?> apps) {
	mApps = apps;
	}

	public AlphabeticalAppsList<?> getApps() {
	return mApps;
	}

	protected void updatePoolSize() {
	updatePoolSize(false);
	}

	void updatePoolSize(boolean hasWorkProfile) {
	DeviceProfile grid = ActivityContext.lookupContext(getContext()).getDeviceProfile();
	RecyclerView.RecycledViewPool pool = getRecycledViewPool();
	pool.setMaxRecycledViews(AllAppsGridAdapter.VIEW_TYPE_EMPTY_SEARCH, 1);
	pool.setMaxRecycledViews(AllAppsGridAdapter.VIEW_TYPE_ALL_APPS_DIVIDER, 1);

	// By default the max num of pool size for app icons is num of app icons in one page of
	// all apps.
	int maxPoolSizeForAppIcons = grid.getMaxAllAppsRowCount()
	* grid.numShownAllAppsColumns;
	if (ALL_APPS_GONE_VISIBILITY.get() && ENABLE_ALL_APPS_RV_PREINFLATION.get()) {
	// If we set all apps' hidden visibility to GONE and enable pre-inflation, we want to
	// preinflate one page of all apps icons plus [PREINFLATE_ICONS_ROW_COUNT] rows +
	// [EXTRA_ICONS_COUNT]. Thus we need to bump the max pool size of app icons accordingly.
	maxPoolSizeForAppIcons +=
	PREINFLATE_ICONS_ROW_COUNT * grid.numShownAllAppsColumns + EXTRA_ICONS_COUNT;
	}
	if (hasWorkProfile) {
	maxPoolSizeForAppIcons *= 2;
	}
	pool.setMaxRecycledViews(
	AllAppsGridAdapter.VIEW_TYPE_ICON, maxPoolSizeForAppIcons);
	}

	@Override
	public void onDraw(Canvas c) {
	if (DEBUG) {
	Log.d(TAG, "onDraw at = " + System.currentTimeMillis());
	}
	if (DEBUG_LATENCY) {
	Log.d(SEARCH_LOGGING, getClass().getSimpleName() + " onDraw; time stamp = "
	+ System.currentTimeMillis());
	}
	super.onDraw(c);
	}

	@Override
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
	updatePoolSize();
	}

	public void onSearchResultsChanged() {
	// Always scroll the view to the top so the user can see the changed results
	scrollToTop();
	}

	@Override
	public void onScrollStateChanged(int state) {
	super.onScrollStateChanged(state);

	StatsLogManager mgr = ActivityContext.lookupContext(getContext()).getStatsLogManager();
	switch (state) {
	case SCROLL_STATE_DRAGGING:
	mCumulativeVerticalScroll = 0;
	requestFocus();
	mgr.logger().sendToInteractionJankMonitor(
	LAUNCHER_ALLAPPS_VERTICAL_SWIPE_BEGIN, this);
	ActivityContext.lookupContext(getContext()).hideKeyboard();
	break;
	case SCROLL_STATE_IDLE:
	mgr.logger().sendToInteractionJankMonitor(
	LAUNCHER_ALLAPPS_VERTICAL_SWIPE_END, this);
	logCumulativeVerticalScroll();
	break;
	}
	}

	@Override
	public void onScrolled(int dx, int dy) {
	super.onScrolled(dx, dy);
	mCumulativeVerticalScroll += dy;
	}

	/**
	* Maps the touch (from 0..1) to the adapter position that should be visible.
	*/
	@Override
	public String scrollToPositionAtProgress(float touchFraction) {
	int rowCount = mApps.getNumAppRows();
	if (rowCount == 0) {
	return "";
	}

	// Find the fastscroll section that maps to this touch fraction
	List<AlphabeticalAppsList.FastScrollSectionInfo> fastScrollSections =
	mApps.getFastScrollerSections();
	int count = fastScrollSections.size();
	if (count == 0) {
	return "";
	}
	int index = Utilities.boundToRange((int) (touchFraction * count), 0, count - 1);
	AlphabeticalAppsList.FastScrollSectionInfo section = fastScrollSections.get(index);
	mFastScrollHelper.smoothScrollToSection(section);
	return section.sectionName;
	}

	@Override
	public void onFastScrollCompleted() {
	super.onFastScrollCompleted();
	mFastScrollHelper.onFastScrollCompleted();
	}

	@Override
	protected boolean isPaddingOffsetRequired() {
	return true;
	}

	@Override
	protected int getTopPaddingOffset() {
	return -getPaddingTop();
	}

	/**
	* Updates the bounds for the scrollbar.
	*/
	@Override
	public void onUpdateScrollbar(int dy) {
	if (mApps == null) {
	return;
	}
	List<AllAppsGridAdapter.AdapterItem> items = mApps.getAdapterItems();

	// Skip early if there are no items or we haven't been measured
	if (items.isEmpty() \|\| mNumAppsPerRow == 0 \|\| getChildCount() == 0) {
	mScrollbar.setThumbOffsetY(-1);
	return;
	}

	// Skip early if, there no child laid out in the container.
	int scrollY = computeVerticalScrollOffset();
	if (scrollY < 0) {
	mScrollbar.setThumbOffsetY(-1);
	return;
	}

	// Only show the scrollbar if there is height to be scrolled
	int availableScrollBarHeight = getAvailableScrollBarHeight();
	int availableScrollHeight = getAvailableScrollHeight();
	if (availableScrollHeight <= 0) {
	mScrollbar.setThumbOffsetY(-1);
	return;
	}

	if (mScrollbar.isThumbDetached()) {
	if (!mScrollbar.isDraggingThumb()) {
	// Calculate the current scroll position, the scrollY of the recycler view accounts
	// for the view padding, while the scrollBarY is drawn right up to the background
	// padding (ignoring padding)
	int scrollBarY = (int)
	(((float) scrollY / availableScrollHeight) * availableScrollBarHeight);

	int thumbScrollY = mScrollbar.getThumbOffsetY();
	int diffScrollY = scrollBarY - thumbScrollY;
	if (diffScrollY * dy > 0f) {
	// User is scrolling in the same direction the thumb needs to catch up to the
	// current scroll position. We do this by mapping the difference in movement
	// from the original scroll bar position to the difference in movement necessary
	// in the detached thumb position to ensure that both speed towards the same
	// position at either end of the list.
	if (dy < 0) {
	int offset = (int) ((dy * thumbScrollY) / (float) scrollBarY);
	thumbScrollY += Math.max(offset, diffScrollY);
	} else {
	int offset = (int) ((dy * (availableScrollBarHeight - thumbScrollY)) /
	(float) (availableScrollBarHeight - scrollBarY));
	thumbScrollY += Math.min(offset, diffScrollY);
	}
	thumbScrollY = Math.max(0, Math.min(availableScrollBarHeight, thumbScrollY));
	mScrollbar.setThumbOffsetY(thumbScrollY);
	if (scrollBarY == thumbScrollY) {
	mScrollbar.reattachThumbToScroll();
	}
	} else {
	// User is scrolling in an opposite direction to the direction that the thumb
	// needs to catch up to the scroll position. Do nothing except for updating
	// the scroll bar x to match the thumb width.
	mScrollbar.setThumbOffsetY(thumbScrollY);
	}
	}
	} else {
	synchronizeScrollBarThumbOffsetToViewScroll(scrollY, availableScrollHeight);
	}
	}

	/**
	* This will be called just before a new child is attached to the window. Passing in null will
	* remove the consumer.
	*/
	protected void setChildAttachedConsumer(@Nullable Consumer<View> childAttachedConsumer) {
	mChildAttachedConsumer = childAttachedConsumer;
	}

	@Override
	public void onChildAttachedToWindow(@NonNull View child) {
	if (mChildAttachedConsumer != null) {
	mChildAttachedConsumer.accept(child);
	}
	super.onChildAttachedToWindow(child);
	}

	@Override
	public int getScrollBarTop() {
	return ActivityContext.lookupContext(getContext()).getAppsView().isSearchSupported()
	? getResources().getDimensionPixelOffset(R.dimen.all_apps_header_top_padding)
	: 0;
	}

	@Override
	public int getScrollBarMarginBottom() {
	return getRootWindowInsets() == null ? 0
	: getRootWindowInsets().getSystemWindowInsetBottom();
	}

	@Override
	public boolean hasOverlappingRendering() {
	return false;
	}

	private void logCumulativeVerticalScroll() {
	ActivityContext context = ActivityContext.lookupContext(getContext());
	StatsLogManager mgr = context.getStatsLogManager();
	ActivityAllAppsContainerView<?> appsView = context.getAppsView();
	ExtendedEditText editText = appsView.getSearchUiManager().getEditText();
	ContainerInfo containerInfo = ContainerInfo.newBuilder().setSearchResultContainer(
	SearchResultContainer
	.newBuilder()
	.setQueryLength((editText == null) ? -1 : editText.length())).build();
	if (mCumulativeVerticalScroll == 0) {
	// mCumulativeVerticalScroll == 0 when user comes back to original position, we
	// don't know the direction of scrolling.
	mgr.logger().withContainerInfo(containerInfo).log(
	LAUNCHER_ALLAPPS_SCROLLED_UNKNOWN_DIRECTION);
	return;
	} else if (appsView.isSearching()) {
	// In search results page
	mgr.logger().withContainerInfo(containerInfo).log((mCumulativeVerticalScroll > 0)
	? LAUNCHER_ALLAPPS_SEARCH_SCROLLED_DOWN
	: LAUNCHER_ALLAPPS_SEARCH_SCROLLED_UP);
	return;
	} else if (appsView.mViewPager != null) {
	int currentPage = appsView.mViewPager.getCurrentPage();
	if (currentPage == ActivityAllAppsContainerView.AdapterHolder.WORK) {
	// In work A-Z list
	mgr.logger().withContainerInfo(containerInfo).log((mCumulativeVerticalScroll > 0)
	? LAUNCHER_WORK_FAB_BUTTON_COLLAPSE
	: LAUNCHER_WORK_FAB_BUTTON_EXTEND);
	return;
	}
	}
	// In personal A-Z list
	mgr.logger().withContainerInfo(containerInfo).log((mCumulativeVerticalScroll > 0)
	? LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_DOWN
	: LAUNCHER_ALLAPPS_PERSONAL_SCROLLED_UP);
	}
	}