content: /*
   * 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 android.annotation.SuppressLint;
  import android.content.Context;
  import android.graphics.Canvas;
  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 com.android.launcher3.BaseActivity;
  import com.android.launcher3.BubbleTextView;
  import com.android.launcher3.CellLayout;
  import com.android.launcher3.DeviceProfile;
  import com.android.launcher3.InvariantDeviceProfile;
  import com.android.launcher3.ItemInfo;
  import com.android.launcher3.Launcher;
  import com.android.launcher3.LauncherAppState;
  import com.android.launcher3.PagedView;
  import com.android.launcher3.R;
  import com.android.launcher3.ShortcutAndWidgetContainer;
  import com.android.launcher3.Utilities;
  import com.android.launcher3.Workspace.ItemOperator;
  import com.android.launcher3.WorkspaceItemInfo;
  import com.android.launcher3.anim.Interpolators;
  import com.android.launcher3.keyboard.ViewGroupFocusHelper;
  import com.android.launcher3.pageindicators.PageIndicatorDots;
  import com.android.launcher3.touch.ItemClickHandler;
  import com.android.launcher3.util.Thunk;
  import com.android.launcher3.util.ViewCache;
  
  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> {
  
      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;
  
      // 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);
          InvariantDeviceProfile profile = LauncherAppState.getIDP(context);
          mOrganizer = new FolderGridOrganizer(profile);
  
          mIsRtl = Utilities.isRtl(getResources());
          setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);
  
          mFocusIndicatorHelper = new ViewGroupFocusHelper(this);
          mViewCache = BaseActivity.fromContext(context).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) {
          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--) {
                  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();
  
          CellLayout.LayoutParams lp = (CellLayout.LayoutParams) view.getLayoutParams();
          lp.setXY(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(ItemClickHandler.INSTANCE);
          textView.setOnLongClickListener(mFolder);
          textView.setOnFocusChangeListener(mFocusIndicatorHelper);
          CellLayout.LayoutParams lp = (CellLayout.LayoutParams) textView.getLayoutParams();
          if (lp == null) {
              textView.setLayoutParams(new CellLayout.LayoutParams(
                      item.cellX, item.cellY, item.spanX, item.spanY));
          } else {
              lp.cellX = item.cellX;
              lp.cellY = item.cellY;
              lp.cellHSpan = lp.cellVSpan = 1;
          }
          return textView;
      }
  
      @Override
      public CellLayout getPageAt(int index) {
          return (CellLayout) getChildAt(index);
      }
  
      public CellLayout getCurrentCellLayout() {
          return getPageAt(getNextPage());
      }
  
      private CellLayout createAndAddNewPage() {
          DeviceProfile grid = Launcher.getLauncher(getContext()).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() {
          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);
          mPageIndicator.setScroll(l, mMaxScrollX);
      }
  
      /**
       * 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) {
                  CellLayout.LayoutParams lp = (CellLayout.LayoutParams) v.getLayoutParams();
                  ItemInfo info = (ItemInfo) v.getTag();
                  lp.setXY(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.findNearestArea(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) {
              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() {
          View firstChild = getCurrentCellLayout().getChildAt(0, 0);
          if (firstChild != null) {
              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.setInterpolator(Interpolators.DEACCEL);
              mScroller.startScroll(getScrollX(), delta, 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.getCompoundDrawables()[1];
                  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) {
          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;
              }
          }
      }
  
      public int itemsPerPage() {
          return mOrganizer.getMaxItemsPerPage();
      }
  }
  