src/com/android/launcher3/folder/FolderPagedView.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.folder;

 import static com.android.launcher3.AbstractFloatingView.TYPE_ALL;
 import static com.android.launcher3.AbstractFloatingView.TYPE_FOLDER;

 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.graphics.Path;
 import android.graphics.drawable.Drawable;
 import android.util.ArrayMap;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewDebug;

 import androidx.annotation.Nullable;

 import com.android.launcher3.AbstractFloatingView;
 import com.android.launcher3.BubbleTextView;
 import com.android.launcher3.CellLayout;
 import com.android.launcher3.DeviceProfile;
 import com.android.launcher3.PagedView;
 import com.android.launcher3.R;
 import com.android.launcher3.ShortcutAndWidgetContainer;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.celllayout.CellLayoutLayoutParams;
 import com.android.launcher3.keyboard.ViewGroupFocusHelper;
 import com.android.launcher3.model.data.ItemInfo;
 import com.android.launcher3.model.data.WorkspaceItemInfo;
 import com.android.launcher3.pageindicators.PageIndicatorDots;
 import com.android.launcher3.util.LauncherBindableItemsContainer.ItemOperator;
 import com.android.launcher3.util.Thunk;
 import com.android.launcher3.util.ViewCache;
 import com.android.launcher3.views.ActivityContext;
 import com.android.launcher3.views.ClipPathView;

 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.function.ToIntFunction;
 import java.util.stream.Collectors;

 public class FolderPagedView extends PagedView<PageIndicatorDots> implements ClipPathView {

     private static final String TAG = "FolderPagedView";

     private static final int REORDER_ANIMATION_DURATION = 230;
     private static final int START_VIEW_REORDER_DELAY = 30;
     private static final float VIEW_REORDER_DELAY_FACTOR = 0.9f;

     /**
      * Fraction of the width to scroll when showing the next page hint.
      */
     private static final float SCROLL_HINT_FRACTION = 0.07f;

     private static final int[] sTmpArray = new int[2];

     public final boolean mIsRtl;

     private final ViewGroupFocusHelper mFocusIndicatorHelper;

     @Thunk final ArrayMap<View, Runnable> mPendingAnimations = new ArrayMap<>();

     private final FolderGridOrganizer mOrganizer;
     private final ViewCache mViewCache;

     private int mAllocatedContentSize;
     @ViewDebug.ExportedProperty(category = "launcher")
     private int mGridCountX;
     @ViewDebug.ExportedProperty(category = "launcher")
     private int mGridCountY;

     private Folder mFolder;

     private Path mClipPath;

     // If the views are attached to the folder or not. A folder should be bound when its
     // animating or is open.
     private boolean mViewsBound = false;

     public FolderPagedView(Context context, AttributeSet attrs) {
         super(context, attrs);
         ActivityContext activityContext = ActivityContext.lookupContext(context);
         DeviceProfile profile = activityContext.getDeviceProfile();
         mOrganizer = new FolderGridOrganizer(profile);

         mIsRtl = Utilities.isRtl(getResources());
         setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);

         mFocusIndicatorHelper = new ViewGroupFocusHelper(this);
         mViewCache = activityContext.getViewCache();
     }

     public void setFolder(Folder folder) {
         mFolder = folder;
         mPageIndicator = folder.findViewById(R.id.folder_page_indicator);
         initParentViews(folder);
     }

     /**
      * Sets up the grid size such that {@param count} items can fit in the grid.
      */
     private void setupContentDimensions(int count) {
         mAllocatedContentSize = count;
         mOrganizer.setContentSize(count);
         mGridCountX = mOrganizer.getCountX();
         mGridCountY = mOrganizer.getCountY();

         // Update grid size
         for (int i = getPageCount() - 1; i >= 0; i--) {
             getPageAt(i).setGridSize(mGridCountX, mGridCountY);
         }
     }

     @Override
     protected void dispatchDraw(Canvas canvas) {
         if (mClipPath != null) {
             int count = canvas.save();
             canvas.clipPath(mClipPath);
             mFocusIndicatorHelper.draw(canvas);
             super.dispatchDraw(canvas);
             canvas.restoreToCount(count);
         } else {
             mFocusIndicatorHelper.draw(canvas);
             super.dispatchDraw(canvas);
         }
     }

     /**
      * Binds items to the layout.
      */
     public void bindItems(List<WorkspaceItemInfo> items) {
         if (mViewsBound) {
             unbindItems();
         }
         arrangeChildren(items.stream().map(this::createNewView).collect(Collectors.toList()));
         mViewsBound = true;
     }

     /**
      * Removes all the icons from the folder
      */
     public void unbindItems() {
         for (int i = getChildCount() - 1; i >= 0; i--) {
             CellLayout page = (CellLayout) getChildAt(i);
             ShortcutAndWidgetContainer container = page.getShortcutsAndWidgets();
             for (int j = container.getChildCount() - 1; j >= 0; j--) {
                 container.getChildAt(j).setVisibility(View.VISIBLE);
                 mViewCache.recycleView(R.layout.folder_application, container.getChildAt(j));
             }
             page.removeAllViews();
             mViewCache.recycleView(R.layout.folder_page, page);
         }
         removeAllViews();
         mViewsBound = false;
     }

     /**
      * Returns true if the icons are bound to the folder
      */
     public boolean areViewsBound() {
         return mViewsBound;
     }

     /**
      * Creates and adds an icon corresponding to the provided rank
      * @return the created icon
      */
     public View createAndAddViewForRank(WorkspaceItemInfo item, int rank) {
         View icon = createNewView(item);
         if (!mViewsBound) {
             return icon;
         }
         ArrayList<View> views = new ArrayList<>(mFolder.getIconsInReadingOrder());
         views.add(rank, icon);
         arrangeChildren(views);
         return icon;
     }

     /**
      * Adds the {@param view} to the layout based on {@param rank} and updated the position
      * related attributes. It assumes that {@param item} is already attached to the view.
      */
     public void addViewForRank(View view, WorkspaceItemInfo item, int rank) {
         int pageNo = rank / mOrganizer.getMaxItemsPerPage();

         CellLayoutLayoutParams lp = (CellLayoutLayoutParams) view.getLayoutParams();
         lp.setCellXY(mOrganizer.getPosForRank(rank));
         getPageAt(pageNo).addViewToCellLayout(view, -1, item.getViewId(), lp, true);
     }

     @SuppressLint("InflateParams")
     public View createNewView(WorkspaceItemInfo item) {
         if (item == null) {
             return null;
         }
         final BubbleTextView textView = mViewCache.getView(
                 R.layout.folder_application, getContext(), null);
         textView.applyFromWorkspaceItem(item);
         textView.setOnClickListener(mFolder.mActivityContext.getItemOnClickListener());
         textView.setOnLongClickListener(mFolder);
         textView.setOnFocusChangeListener(mFocusIndicatorHelper);
         CellLayoutLayoutParams lp = (CellLayoutLayoutParams) textView.getLayoutParams();
         if (lp == null) {
             textView.setLayoutParams(new CellLayoutLayoutParams(
                     item.cellX, item.cellY, item.spanX, item.spanY));
         } else {
             lp.setCellX(item.cellX);
             lp.setCellY(item.cellY);
             lp.cellHSpan = lp.cellVSpan = 1;
         }
         return textView;
     }

     @Nullable
     @Override
     public CellLayout getPageAt(int index) {
         return (CellLayout) getChildAt(index);
     }

     @Nullable
     public CellLayout getCurrentCellLayout() {
         return getPageAt(getNextPage());
     }

     private CellLayout createAndAddNewPage() {
         DeviceProfile grid = mFolder.mActivityContext.getDeviceProfile();
         CellLayout page = mViewCache.getView(R.layout.folder_page, getContext(), this);
         page.setCellDimensions(grid.folderCellWidthPx, grid.folderCellHeightPx);
         page.getShortcutsAndWidgets().setMotionEventSplittingEnabled(false);
         page.setInvertIfRtl(true);
         page.setGridSize(mGridCountX, mGridCountY);

         addView(page, -1, generateDefaultLayoutParams());
         return page;
     }

     @Override
     protected int getChildGap(int fromIndex, int toIndex) {
         return getPaddingLeft() + getPaddingRight();
     }

     public void setFixedSize(int width, int height) {
         width -= (getPaddingLeft() + getPaddingRight());
         height -= (getPaddingTop() + getPaddingBottom());
         for (int i = getChildCount() - 1; i >= 0; i --) {
             ((CellLayout) getChildAt(i)).setFixedSize(width, height);
         }
     }

     public void removeItem(View v) {
         for (int i = getChildCount() - 1; i >= 0; i --) {
             getPageAt(i).removeView(v);
         }
     }

     @Override
     protected void onScrollChanged(int l, int t, int oldl, int oldt) {
         super.onScrollChanged(l, t, oldl, oldt);
         if (mMaxScroll > 0) mPageIndicator.setScroll(l, mMaxScroll);
     }

     /**
      * Updates position and rank of all the children in the view.
      * It essentially removes all views from all the pages and then adds them again in appropriate
      * page.
      *
      * @param list the ordered list of children.
      */
     @SuppressLint("RtlHardcoded")
     public void arrangeChildren(List<View> list) {
         int itemCount = list.size();
         ArrayList<CellLayout> pages = new ArrayList<>();
         for (int i = 0; i < getChildCount(); i++) {
             CellLayout page = (CellLayout) getChildAt(i);
             page.removeAllViews();
             pages.add(page);
         }
         mOrganizer.setFolderInfo(mFolder.getInfo());
         setupContentDimensions(itemCount);

         Iterator<CellLayout> pageItr = pages.iterator();
         CellLayout currentPage = null;

         int position = 0;
         int rank = 0;

         for (int i = 0; i < itemCount; i++) {
             View v = list.size() > i ? list.get(i) : null;
             if (currentPage == null || position >= mOrganizer.getMaxItemsPerPage()) {
                 // Next page
                 if (pageItr.hasNext()) {
                     currentPage = pageItr.next();
                 } else {
                     currentPage = createAndAddNewPage();
                 }
                 position = 0;
             }

             if (v != null) {
                 CellLayoutLayoutParams lp = (CellLayoutLayoutParams) v.getLayoutParams();
                 ItemInfo info = (ItemInfo) v.getTag();
                 lp.setCellXY(mOrganizer.getPosForRank(rank));
                 currentPage.addViewToCellLayout(v, -1, info.getViewId(), lp, true);

                 if (mOrganizer.isItemInPreview(rank) && v instanceof BubbleTextView) {
                     ((BubbleTextView) v).verifyHighRes();
                 }
             }

             rank++;
             position++;
         }

         // Remove extra views.
         boolean removed = false;
         while (pageItr.hasNext()) {
             removeView(pageItr.next());
             removed = true;
         }
         if (removed) {
             setCurrentPage(0);
         }

         setEnableOverscroll(getPageCount() > 1);

         // Update footer
         mPageIndicator.setVisibility(getPageCount() > 1 ? View.VISIBLE : View.GONE);
         // Set the gravity as LEFT or RIGHT instead of START, as START depends on the actual text.
         mFolder.mFolderName.setGravity(getPageCount() > 1 ?
                 (mIsRtl ? Gravity.RIGHT : Gravity.LEFT) : Gravity.CENTER_HORIZONTAL);
     }

     public int getDesiredWidth() {
         return getPageCount() > 0 ?
                 (getPageAt(0).getDesiredWidth() + getPaddingLeft() + getPaddingRight()) : 0;
     }

     public int getDesiredHeight()  {
         return  getPageCount() > 0 ?
                 (getPageAt(0).getDesiredHeight() + getPaddingTop() + getPaddingBottom()) : 0;
     }

     /**
      * @return the rank of the cell nearest to the provided pixel position.
      */
     public int findNearestArea(int pixelX, int pixelY) {
         int pageIndex = getNextPage();
         CellLayout page = getPageAt(pageIndex);
         page.findNearestAreaIgnoreOccupied(pixelX, pixelY, 1, 1, sTmpArray);
         if (mFolder.isLayoutRtl()) {
             sTmpArray[0] = page.getCountX() - sTmpArray[0] - 1;
         }
         return Math.min(mAllocatedContentSize - 1,
                 pageIndex * mOrganizer.getMaxItemsPerPage()
                         + sTmpArray[1] * mGridCountX + sTmpArray[0]);
     }

     public View getFirstItem() {
         return getViewInCurrentPage(c -> 0);
     }

     public View getLastItem() {
         return getViewInCurrentPage(c -> c.getChildCount() - 1);
     }

     private View getViewInCurrentPage(ToIntFunction<ShortcutAndWidgetContainer> rankProvider) {
         if (getChildCount() < 1 || getCurrentCellLayout() == null) {
             return null;
         }
         ShortcutAndWidgetContainer container = getCurrentCellLayout().getShortcutsAndWidgets();
         int rank = rankProvider.applyAsInt(container);
         if (mGridCountX > 0) {
             return container.getChildAt(rank % mGridCountX, rank / mGridCountX);
         } else {
             return container.getChildAt(rank);
         }
     }

     /**
      * Iterates over all its items in a reading order.
      * @return the view for which the operator returned true.
      */
     public View iterateOverItems(ItemOperator op) {
         for (int k = 0 ; k < getChildCount(); k++) {
             CellLayout page = getPageAt(k);
             for (int j = 0; j < page.getCountY(); j++) {
                 for (int i = 0; i < page.getCountX(); i++) {
                     View v = page.getChildAt(i, j);
                     if ((v != null) && op.evaluate((ItemInfo) v.getTag(), v)) {
                         return v;
                     }
                 }
             }
         }
         return null;
     }

     public String getAccessibilityDescription() {
         return getContext().getString(R.string.folder_opened, mGridCountX, mGridCountY);
     }

     /**
      * Sets the focus on the first visible child.
      */
     public void setFocusOnFirstChild() {
         CellLayout currentCellLayout = getCurrentCellLayout();
         if (currentCellLayout == null) {
             return;
         }
         View firstChild = currentCellLayout.getChildAt(0, 0);
         if (firstChild == null) {
             return;
         }
         firstChild.requestFocus();
     }

     @Override
     protected void notifyPageSwitchListener(int prevPage) {
         super.notifyPageSwitchListener(prevPage);
         if (mFolder != null) {
             mFolder.updateTextViewFocus();
         }
     }

     /**
      * Scrolls the current view by a fraction
      */
     public void showScrollHint(int direction) {
         float fraction = (direction == Folder.SCROLL_LEFT) ^ mIsRtl
                 ? -SCROLL_HINT_FRACTION : SCROLL_HINT_FRACTION;
         int hint = (int) (fraction * getWidth());
         int scroll = getScrollForPage(getNextPage()) + hint;
         int delta = scroll - getScrollX();
         if (delta != 0) {
             mScroller.startScroll(getScrollX(), 0, delta, 0, Folder.SCROLL_HINT_DURATION);
             invalidate();
         }
     }

     public void clearScrollHint() {
         if (getScrollX() != getScrollForPage(getNextPage())) {
             snapToPage(getNextPage());
         }
     }

     /**
      * Finish animation all the views which are animating across pages
      */
     public void completePendingPageChanges() {
         if (!mPendingAnimations.isEmpty()) {
             ArrayMap<View, Runnable> pendingViews = new ArrayMap<>(mPendingAnimations);
             for (Map.Entry<View, Runnable> e : pendingViews.entrySet()) {
                 e.getKey().animate().cancel();
                 e.getValue().run();
             }
         }
     }

     public boolean rankOnCurrentPage(int rank) {
         int p = rank / mOrganizer.getMaxItemsPerPage();
         return p == getNextPage();
     }

     @Override
     protected void onPageBeginTransition() {
         super.onPageBeginTransition();
         // Ensure that adjacent pages have high resolution icons
         verifyVisibleHighResIcons(getCurrentPage() - 1);
         verifyVisibleHighResIcons(getCurrentPage() + 1);
     }

     /**
      * Ensures that all the icons on the given page are of high-res
      */
     public void verifyVisibleHighResIcons(int pageNo) {
         CellLayout page = getPageAt(pageNo);
         if (page != null) {
             ShortcutAndWidgetContainer parent = page.getShortcutsAndWidgets();
             for (int i = parent.getChildCount() - 1; i >= 0; i--) {
                 BubbleTextView icon = ((BubbleTextView) parent.getChildAt(i));
                 icon.verifyHighRes();
                 // Set the callback back to the actual icon, in case
                 // it was captured by the FolderIcon
                 Drawable d = icon.getIcon();
                 if (d != null) {
                     d.setCallback(icon);
                 }
             }
         }
     }

     public int getAllocatedContentSize() {
         return mAllocatedContentSize;
     }

     /**
      * Reorders the items such that the {@param empty} spot moves to {@param target}
      */
     public void realTimeReorder(int empty, int target) {
         if (!mViewsBound) {
             return;
         }
         completePendingPageChanges();
         int delay = 0;
         float delayAmount = START_VIEW_REORDER_DELAY;

         // Animation only happens on the current page.
         int pageToAnimate = getNextPage();
         int maxItemsPerPage = mOrganizer.getMaxItemsPerPage();

         int pageT = target / maxItemsPerPage;
         int pagePosT = target % maxItemsPerPage;

         if (pageT != pageToAnimate) {
             Log.e(TAG, "Cannot animate when the target cell is invisible");
         }
         int pagePosE = empty % maxItemsPerPage;
         int pageE = empty / maxItemsPerPage;

         int startPos, endPos;
         int moveStart, moveEnd;
         int direction;

         if (target == empty) {
             // No animation
             return;
         } else if (target > empty) {
             // Items will move backwards to make room for the empty cell.
             direction = 1;

             // If empty cell is in a different page, move them instantly.
             if (pageE < pageToAnimate) {
                 moveStart = empty;
                 // Instantly move the first item in the current page.
                 moveEnd = pageToAnimate * maxItemsPerPage;
                 // Animate the 2nd item in the current page, as the first item was already moved to
                 // the last page.
                 startPos = 0;
             } else {
                 moveStart = moveEnd = -1;
                 startPos = pagePosE;
             }

             endPos = pagePosT;
         } else {
             // The items will move forward.
             direction = -1;

             if (pageE > pageToAnimate) {
                 // Move the items immediately.
                 moveStart = empty;
                 // Instantly move the last item in the current page.
                 moveEnd = (pageToAnimate + 1) * maxItemsPerPage - 1;

                 // Animations start with the second last item in the page
                 startPos = maxItemsPerPage - 1;
             } else {
                 moveStart = moveEnd = -1;
                 startPos = pagePosE;
             }

             endPos = pagePosT;
         }

         // Instant moving views.
         while (moveStart != moveEnd) {
             int rankToMove = moveStart + direction;
             int p = rankToMove / maxItemsPerPage;
             int pagePos = rankToMove % maxItemsPerPage;
             int x = pagePos % mGridCountX;
             int y = pagePos / mGridCountX;

             final CellLayout page = getPageAt(p);
             final View v = page.getChildAt(x, y);
             if (v != null) {
                 if (pageToAnimate != p) {
                     page.removeView(v);
                     addViewForRank(v, (WorkspaceItemInfo) v.getTag(), moveStart);
                 } else {
                     // Do a fake animation before removing it.
                     final int newRank = moveStart;
                     final float oldTranslateX = v.getTranslationX();

                     Runnable endAction = new Runnable() {

                         @Override
                         public void run() {
                             mPendingAnimations.remove(v);
                             v.setTranslationX(oldTranslateX);
                             ((CellLayout) v.getParent().getParent()).removeView(v);
                             addViewForRank(v, (WorkspaceItemInfo) v.getTag(), newRank);
                         }
                     };
                     v.animate()
                         .translationXBy((direction > 0 ^ mIsRtl) ? -v.getWidth() : v.getWidth())
                         .setDuration(REORDER_ANIMATION_DURATION)
                         .setStartDelay(0)
                         .withEndAction(endAction);
                     mPendingAnimations.put(v, endAction);
                 }
             }
             moveStart = rankToMove;
         }

         if ((endPos - startPos) * direction <= 0) {
             // No animation
             return;
         }

         CellLayout page = getPageAt(pageToAnimate);
         for (int i = startPos; i != endPos; i += direction) {
             int nextPos = i + direction;
             View v = page.getChildAt(nextPos % mGridCountX, nextPos / mGridCountX);
             if (page.animateChildToPosition(v, i % mGridCountX, i / mGridCountX,
                     REORDER_ANIMATION_DURATION, delay, true, true)) {
                 delay += delayAmount;
                 delayAmount *= VIEW_REORDER_DELAY_FACTOR;
             }
         }
     }

     @Override
     protected boolean canScroll(float absVScroll, float absHScroll) {
         return AbstractFloatingView.getTopOpenViewWithType(mFolder.mActivityContext,
                 TYPE_ALL & ~TYPE_FOLDER) == null;
     }

     public int itemsPerPage() {
         return mOrganizer.getMaxItemsPerPage();
     }

     @Override
     public void setClipPath(Path clipPath) {
         mClipPath = clipPath;
         invalidate();
     }
 }
	/*
	* 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.folder;

	import static com.android.launcher3.AbstractFloatingView.TYPE_ALL;
	import static com.android.launcher3.AbstractFloatingView.TYPE_FOLDER;

	import android.annotation.SuppressLint;
	import android.content.Context;
	import android.graphics.Canvas;
	import android.graphics.Path;
	import android.graphics.drawable.Drawable;
	import android.util.ArrayMap;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.Gravity;
	import android.view.View;
	import android.view.ViewDebug;

	import androidx.annotation.Nullable;

	import com.android.launcher3.AbstractFloatingView;
	import com.android.launcher3.BubbleTextView;
	import com.android.launcher3.CellLayout;
	import com.android.launcher3.DeviceProfile;
	import com.android.launcher3.PagedView;
	import com.android.launcher3.R;
	import com.android.launcher3.ShortcutAndWidgetContainer;
	import com.android.launcher3.Utilities;
	import com.android.launcher3.celllayout.CellLayoutLayoutParams;
	import com.android.launcher3.keyboard.ViewGroupFocusHelper;
	import com.android.launcher3.model.data.ItemInfo;
	import com.android.launcher3.model.data.WorkspaceItemInfo;
	import com.android.launcher3.pageindicators.PageIndicatorDots;
	import com.android.launcher3.util.LauncherBindableItemsContainer.ItemOperator;
	import com.android.launcher3.util.Thunk;
	import com.android.launcher3.util.ViewCache;
	import com.android.launcher3.views.ActivityContext;
	import com.android.launcher3.views.ClipPathView;

	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.function.ToIntFunction;
	import java.util.stream.Collectors;

	public class FolderPagedView extends PagedView<PageIndicatorDots> implements ClipPathView {

	private static final String TAG = "FolderPagedView";

	private static final int REORDER_ANIMATION_DURATION = 230;
	private static final int START_VIEW_REORDER_DELAY = 30;
	private static final float VIEW_REORDER_DELAY_FACTOR = 0.9f;

	/**
	* Fraction of the width to scroll when showing the next page hint.
	*/
	private static final float SCROLL_HINT_FRACTION = 0.07f;

	private static final int[] sTmpArray = new int[2];

	public final boolean mIsRtl;

	private final ViewGroupFocusHelper mFocusIndicatorHelper;

	@Thunk final ArrayMap<View, Runnable> mPendingAnimations = new ArrayMap<>();

	private final FolderGridOrganizer mOrganizer;
	private final ViewCache mViewCache;

	private int mAllocatedContentSize;
	@ViewDebug.ExportedProperty(category = "launcher")
	private int mGridCountX;
	@ViewDebug.ExportedProperty(category = "launcher")
	private int mGridCountY;

	private Folder mFolder;

	private Path mClipPath;

	// If the views are attached to the folder or not. A folder should be bound when its
	// animating or is open.
	private boolean mViewsBound = false;

	public FolderPagedView(Context context, AttributeSet attrs) {
	super(context, attrs);
	ActivityContext activityContext = ActivityContext.lookupContext(context);
	DeviceProfile profile = activityContext.getDeviceProfile();
	mOrganizer = new FolderGridOrganizer(profile);

	mIsRtl = Utilities.isRtl(getResources());
	setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);

	mFocusIndicatorHelper = new ViewGroupFocusHelper(this);
	mViewCache = activityContext.getViewCache();
	}

	public void setFolder(Folder folder) {
	mFolder = folder;
	mPageIndicator = folder.findViewById(R.id.folder_page_indicator);
	initParentViews(folder);
	}

	/**
	* Sets up the grid size such that {@param count} items can fit in the grid.
	*/
	private void setupContentDimensions(int count) {
	mAllocatedContentSize = count;
	mOrganizer.setContentSize(count);
	mGridCountX = mOrganizer.getCountX();
	mGridCountY = mOrganizer.getCountY();

	// Update grid size
	for (int i = getPageCount() - 1; i >= 0; i--) {
	getPageAt(i).setGridSize(mGridCountX, mGridCountY);
	}
	}

	@Override
	protected void dispatchDraw(Canvas canvas) {
	if (mClipPath != null) {
	int count = canvas.save();
	canvas.clipPath(mClipPath);
	mFocusIndicatorHelper.draw(canvas);
	super.dispatchDraw(canvas);
	canvas.restoreToCount(count);
	} else {
	mFocusIndicatorHelper.draw(canvas);
	super.dispatchDraw(canvas);
	}
	}

	/**
	* Binds items to the layout.
	*/
	public void bindItems(List<WorkspaceItemInfo> items) {
	if (mViewsBound) {
	unbindItems();
	}
	arrangeChildren(items.stream().map(this::createNewView).collect(Collectors.toList()));
	mViewsBound = true;
	}

	/**
	* Removes all the icons from the folder
	*/
	public void unbindItems() {
	for (int i = getChildCount() - 1; i >= 0; i--) {
	CellLayout page = (CellLayout) getChildAt(i);
	ShortcutAndWidgetContainer container = page.getShortcutsAndWidgets();
	for (int j = container.getChildCount() - 1; j >= 0; j--) {
	container.getChildAt(j).setVisibility(View.VISIBLE);
	mViewCache.recycleView(R.layout.folder_application, container.getChildAt(j));
	}
	page.removeAllViews();
	mViewCache.recycleView(R.layout.folder_page, page);
	}
	removeAllViews();
	mViewsBound = false;
	}

	/**
	* Returns true if the icons are bound to the folder
	*/
	public boolean areViewsBound() {
	return mViewsBound;
	}

	/**
	* Creates and adds an icon corresponding to the provided rank
	* @return the created icon
	*/
	public View createAndAddViewForRank(WorkspaceItemInfo item, int rank) {
	View icon = createNewView(item);
	if (!mViewsBound) {
	return icon;
	}
	ArrayList<View> views = new ArrayList<>(mFolder.getIconsInReadingOrder());
	views.add(rank, icon);
	arrangeChildren(views);
	return icon;
	}

	/**
	* Adds the {@param view} to the layout based on {@param rank} and updated the position
	* related attributes. It assumes that {@param item} is already attached to the view.
	*/
	public void addViewForRank(View view, WorkspaceItemInfo item, int rank) {
	int pageNo = rank / mOrganizer.getMaxItemsPerPage();

	CellLayoutLayoutParams lp = (CellLayoutLayoutParams) view.getLayoutParams();
	lp.setCellXY(mOrganizer.getPosForRank(rank));
	getPageAt(pageNo).addViewToCellLayout(view, -1, item.getViewId(), lp, true);
	}

	@SuppressLint("InflateParams")
	public View createNewView(WorkspaceItemInfo item) {
	if (item == null) {
	return null;
	}
	final BubbleTextView textView = mViewCache.getView(
	R.layout.folder_application, getContext(), null);
	textView.applyFromWorkspaceItem(item);
	textView.setOnClickListener(mFolder.mActivityContext.getItemOnClickListener());
	textView.setOnLongClickListener(mFolder);
	textView.setOnFocusChangeListener(mFocusIndicatorHelper);
	CellLayoutLayoutParams lp = (CellLayoutLayoutParams) textView.getLayoutParams();
	if (lp == null) {
	textView.setLayoutParams(new CellLayoutLayoutParams(
	item.cellX, item.cellY, item.spanX, item.spanY));
	} else {
	lp.setCellX(item.cellX);
	lp.setCellY(item.cellY);
	lp.cellHSpan = lp.cellVSpan = 1;
	}
	return textView;
	}

	@Nullable
	@Override
	public CellLayout getPageAt(int index) {
	return (CellLayout) getChildAt(index);
	}

	@Nullable
	public CellLayout getCurrentCellLayout() {
	return getPageAt(getNextPage());
	}

	private CellLayout createAndAddNewPage() {
	DeviceProfile grid = mFolder.mActivityContext.getDeviceProfile();
	CellLayout page = mViewCache.getView(R.layout.folder_page, getContext(), this);
	page.setCellDimensions(grid.folderCellWidthPx, grid.folderCellHeightPx);
	page.getShortcutsAndWidgets().setMotionEventSplittingEnabled(false);
	page.setInvertIfRtl(true);
	page.setGridSize(mGridCountX, mGridCountY);

	addView(page, -1, generateDefaultLayoutParams());
	return page;
	}

	@Override
	protected int getChildGap(int fromIndex, int toIndex) {
	return getPaddingLeft() + getPaddingRight();
	}

	public void setFixedSize(int width, int height) {
	width -= (getPaddingLeft() + getPaddingRight());
	height -= (getPaddingTop() + getPaddingBottom());
	for (int i = getChildCount() - 1; i >= 0; i --) {
	((CellLayout) getChildAt(i)).setFixedSize(width, height);
	}
	}

	public void removeItem(View v) {
	for (int i = getChildCount() - 1; i >= 0; i --) {
	getPageAt(i).removeView(v);
	}
	}

	@Override
	protected void onScrollChanged(int l, int t, int oldl, int oldt) {
	super.onScrollChanged(l, t, oldl, oldt);
	if (mMaxScroll > 0) mPageIndicator.setScroll(l, mMaxScroll);
	}

	/**
	* Updates position and rank of all the children in the view.
	* It essentially removes all views from all the pages and then adds them again in appropriate
	* page.
	*
	* @param list the ordered list of children.
	*/
	@SuppressLint("RtlHardcoded")
	public void arrangeChildren(List<View> list) {
	int itemCount = list.size();
	ArrayList<CellLayout> pages = new ArrayList<>();
	for (int i = 0; i < getChildCount(); i++) {
	CellLayout page = (CellLayout) getChildAt(i);
	page.removeAllViews();
	pages.add(page);
	}
	mOrganizer.setFolderInfo(mFolder.getInfo());
	setupContentDimensions(itemCount);

	Iterator<CellLayout> pageItr = pages.iterator();
	CellLayout currentPage = null;

	int position = 0;
	int rank = 0;

	for (int i = 0; i < itemCount; i++) {
	View v = list.size() > i ? list.get(i) : null;
	if (currentPage == null \|\| position >= mOrganizer.getMaxItemsPerPage()) {
	// Next page
	if (pageItr.hasNext()) {
	currentPage = pageItr.next();
	} else {
	currentPage = createAndAddNewPage();
	}
	position = 0;
	}

	if (v != null) {
	CellLayoutLayoutParams lp = (CellLayoutLayoutParams) v.getLayoutParams();
	ItemInfo info = (ItemInfo) v.getTag();
	lp.setCellXY(mOrganizer.getPosForRank(rank));
	currentPage.addViewToCellLayout(v, -1, info.getViewId(), lp, true);

	if (mOrganizer.isItemInPreview(rank) && v instanceof BubbleTextView) {
	((BubbleTextView) v).verifyHighRes();
	}
	}

	rank++;
	position++;
	}

	// Remove extra views.
	boolean removed = false;
	while (pageItr.hasNext()) {
	removeView(pageItr.next());
	removed = true;
	}
	if (removed) {
	setCurrentPage(0);
	}

	setEnableOverscroll(getPageCount() > 1);

	// Update footer
	mPageIndicator.setVisibility(getPageCount() > 1 ? View.VISIBLE : View.GONE);
	// Set the gravity as LEFT or RIGHT instead of START, as START depends on the actual text.
	mFolder.mFolderName.setGravity(getPageCount() > 1 ?
	(mIsRtl ? Gravity.RIGHT : Gravity.LEFT) : Gravity.CENTER_HORIZONTAL);
	}

	public int getDesiredWidth() {
	return getPageCount() > 0 ?
	(getPageAt(0).getDesiredWidth() + getPaddingLeft() + getPaddingRight()) : 0;
	}

	public int getDesiredHeight() {
	return getPageCount() > 0 ?
	(getPageAt(0).getDesiredHeight() + getPaddingTop() + getPaddingBottom()) : 0;
	}

	/**
	* @return the rank of the cell nearest to the provided pixel position.
	*/
	public int findNearestArea(int pixelX, int pixelY) {
	int pageIndex = getNextPage();
	CellLayout page = getPageAt(pageIndex);
	page.findNearestAreaIgnoreOccupied(pixelX, pixelY, 1, 1, sTmpArray);
	if (mFolder.isLayoutRtl()) {
	sTmpArray[0] = page.getCountX() - sTmpArray[0] - 1;
	}
	return Math.min(mAllocatedContentSize - 1,
	pageIndex * mOrganizer.getMaxItemsPerPage()
	+ sTmpArray[1] * mGridCountX + sTmpArray[0]);
	}

	public View getFirstItem() {
	return getViewInCurrentPage(c -> 0);
	}

	public View getLastItem() {
	return getViewInCurrentPage(c -> c.getChildCount() - 1);
	}

	private View getViewInCurrentPage(ToIntFunction<ShortcutAndWidgetContainer> rankProvider) {
	if (getChildCount() < 1 \|\| getCurrentCellLayout() == null) {
	return null;
	}
	ShortcutAndWidgetContainer container = getCurrentCellLayout().getShortcutsAndWidgets();
	int rank = rankProvider.applyAsInt(container);
	if (mGridCountX > 0) {
	return container.getChildAt(rank % mGridCountX, rank / mGridCountX);
	} else {
	return container.getChildAt(rank);
	}
	}

	/**
	* Iterates over all its items in a reading order.
	* @return the view for which the operator returned true.
	*/
	public View iterateOverItems(ItemOperator op) {
	for (int k = 0 ; k < getChildCount(); k++) {
	CellLayout page = getPageAt(k);
	for (int j = 0; j < page.getCountY(); j++) {
	for (int i = 0; i < page.getCountX(); i++) {
	View v = page.getChildAt(i, j);
	if ((v != null) && op.evaluate((ItemInfo) v.getTag(), v)) {
	return v;
	}
	}
	}
	}
	return null;
	}

	public String getAccessibilityDescription() {
	return getContext().getString(R.string.folder_opened, mGridCountX, mGridCountY);
	}

	/**
	* Sets the focus on the first visible child.
	*/
	public void setFocusOnFirstChild() {
	CellLayout currentCellLayout = getCurrentCellLayout();
	if (currentCellLayout == null) {
	return;
	}
	View firstChild = currentCellLayout.getChildAt(0, 0);
	if (firstChild == null) {
	return;
	}
	firstChild.requestFocus();
	}

	@Override
	protected void notifyPageSwitchListener(int prevPage) {
	super.notifyPageSwitchListener(prevPage);
	if (mFolder != null) {
	mFolder.updateTextViewFocus();
	}
	}

	/**
	* Scrolls the current view by a fraction
	*/
	public void showScrollHint(int direction) {
	float fraction = (direction == Folder.SCROLL_LEFT) ^ mIsRtl
	? -SCROLL_HINT_FRACTION : SCROLL_HINT_FRACTION;
	int hint = (int) (fraction * getWidth());
	int scroll = getScrollForPage(getNextPage()) + hint;
	int delta = scroll - getScrollX();
	if (delta != 0) {
	mScroller.startScroll(getScrollX(), 0, delta, 0, Folder.SCROLL_HINT_DURATION);
	invalidate();
	}
	}

	public void clearScrollHint() {
	if (getScrollX() != getScrollForPage(getNextPage())) {
	snapToPage(getNextPage());
	}
	}

	/**
	* Finish animation all the views which are animating across pages
	*/
	public void completePendingPageChanges() {
	if (!mPendingAnimations.isEmpty()) {
	ArrayMap<View, Runnable> pendingViews = new ArrayMap<>(mPendingAnimations);
	for (Map.Entry<View, Runnable> e : pendingViews.entrySet()) {
	e.getKey().animate().cancel();
	e.getValue().run();
	}
	}
	}

	public boolean rankOnCurrentPage(int rank) {
	int p = rank / mOrganizer.getMaxItemsPerPage();
	return p == getNextPage();
	}

	@Override
	protected void onPageBeginTransition() {
	super.onPageBeginTransition();
	// Ensure that adjacent pages have high resolution icons
	verifyVisibleHighResIcons(getCurrentPage() - 1);
	verifyVisibleHighResIcons(getCurrentPage() + 1);
	}

	/**
	* Ensures that all the icons on the given page are of high-res
	*/
	public void verifyVisibleHighResIcons(int pageNo) {
	CellLayout page = getPageAt(pageNo);
	if (page != null) {
	ShortcutAndWidgetContainer parent = page.getShortcutsAndWidgets();
	for (int i = parent.getChildCount() - 1; i >= 0; i--) {
	BubbleTextView icon = ((BubbleTextView) parent.getChildAt(i));
	icon.verifyHighRes();
	// Set the callback back to the actual icon, in case
	// it was captured by the FolderIcon
	Drawable d = icon.getIcon();
	if (d != null) {
	d.setCallback(icon);
	}
	}
	}
	}

	public int getAllocatedContentSize() {
	return mAllocatedContentSize;
	}

	/**
	* Reorders the items such that the {@param empty} spot moves to {@param target}
	*/
	public void realTimeReorder(int empty, int target) {
	if (!mViewsBound) {
	return;
	}
	completePendingPageChanges();
	int delay = 0;
	float delayAmount = START_VIEW_REORDER_DELAY;

	// Animation only happens on the current page.
	int pageToAnimate = getNextPage();
	int maxItemsPerPage = mOrganizer.getMaxItemsPerPage();

	int pageT = target / maxItemsPerPage;
	int pagePosT = target % maxItemsPerPage;

	if (pageT != pageToAnimate) {
	Log.e(TAG, "Cannot animate when the target cell is invisible");
	}
	int pagePosE = empty % maxItemsPerPage;
	int pageE = empty / maxItemsPerPage;

	int startPos, endPos;
	int moveStart, moveEnd;
	int direction;

	if (target == empty) {
	// No animation
	return;
	} else if (target > empty) {
	// Items will move backwards to make room for the empty cell.
	direction = 1;

	// If empty cell is in a different page, move them instantly.
	if (pageE < pageToAnimate) {
	moveStart = empty;
	// Instantly move the first item in the current page.
	moveEnd = pageToAnimate * maxItemsPerPage;
	// Animate the 2nd item in the current page, as the first item was already moved to
	// the last page.
	startPos = 0;
	} else {
	moveStart = moveEnd = -1;
	startPos = pagePosE;
	}

	endPos = pagePosT;
	} else {
	// The items will move forward.
	direction = -1;

	if (pageE > pageToAnimate) {
	// Move the items immediately.
	moveStart = empty;
	// Instantly move the last item in the current page.
	moveEnd = (pageToAnimate + 1) * maxItemsPerPage - 1;

	// Animations start with the second last item in the page
	startPos = maxItemsPerPage - 1;
	} else {
	moveStart = moveEnd = -1;
	startPos = pagePosE;
	}

	endPos = pagePosT;
	}

	// Instant moving views.
	while (moveStart != moveEnd) {
	int rankToMove = moveStart + direction;
	int p = rankToMove / maxItemsPerPage;
	int pagePos = rankToMove % maxItemsPerPage;
	int x = pagePos % mGridCountX;
	int y = pagePos / mGridCountX;

	final CellLayout page = getPageAt(p);
	final View v = page.getChildAt(x, y);
	if (v != null) {
	if (pageToAnimate != p) {
	page.removeView(v);
	addViewForRank(v, (WorkspaceItemInfo) v.getTag(), moveStart);
	} else {
	// Do a fake animation before removing it.
	final int newRank = moveStart;
	final float oldTranslateX = v.getTranslationX();

	Runnable endAction = new Runnable() {

	@Override
	public void run() {
	mPendingAnimations.remove(v);
	v.setTranslationX(oldTranslateX);
	((CellLayout) v.getParent().getParent()).removeView(v);
	addViewForRank(v, (WorkspaceItemInfo) v.getTag(), newRank);
	}
	};
	v.animate()
	.translationXBy((direction > 0 ^ mIsRtl) ? -v.getWidth() : v.getWidth())
	.setDuration(REORDER_ANIMATION_DURATION)
	.setStartDelay(0)
	.withEndAction(endAction);
	mPendingAnimations.put(v, endAction);
	}
	}
	moveStart = rankToMove;
	}

	if ((endPos - startPos) * direction <= 0) {
	// No animation
	return;
	}

	CellLayout page = getPageAt(pageToAnimate);
	for (int i = startPos; i != endPos; i += direction) {
	int nextPos = i + direction;
	View v = page.getChildAt(nextPos % mGridCountX, nextPos / mGridCountX);
	if (page.animateChildToPosition(v, i % mGridCountX, i / mGridCountX,
	REORDER_ANIMATION_DURATION, delay, true, true)) {
	delay += delayAmount;
	delayAmount *= VIEW_REORDER_DELAY_FACTOR;
	}
	}
	}

	@Override
	protected boolean canScroll(float absVScroll, float absHScroll) {
	return AbstractFloatingView.getTopOpenViewWithType(mFolder.mActivityContext,
	TYPE_ALL & ~TYPE_FOLDER) == null;
	}

	public int itemsPerPage() {
	return mOrganizer.getMaxItemsPerPage();
	}

	@Override
	public void setClipPath(Path clipPath) {
	mClipPath = clipPath;
	invalidate();
	}
	}