Merge "Slide in first page preview items in FolderIcon after Folder closes." into ub-launcher3-dorval-polish
diff --git a/src/com/android/launcher3/folder/Folder.java b/src/com/android/launcher3/folder/Folder.java
index afbf9f2..3184d6d 100644
--- a/src/com/android/launcher3/folder/Folder.java
+++ b/src/com/android/launcher3/folder/Folder.java
@@ -791,12 +791,14 @@
         if (mFolderIcon != null) {
             mFolderIcon.setVisibility(View.VISIBLE);
             if (FeatureFlags.LAUNCHER3_NEW_FOLDER_ANIMATION) {
-                mFolderIcon.mFolderName.setTextVisibility(true);
                 mFolderIcon.setBackgroundVisible(true);
-                mFolderIcon.mBackground.fadeInBackgroundShadow();
             }
             if (wasAnimated) {
-                mFolderIcon.mBackground.animateBackgroundStroke();
+                if (FeatureFlags.LAUNCHER3_NEW_FOLDER_ANIMATION) {
+                    mFolderIcon.mBackground.fadeInBackgroundShadow();
+                    mFolderIcon.mBackground.animateBackgroundStroke();
+                    mFolderIcon.onFolderClose(mContent.getCurrentPage());
+                }
                 if (mFolderIcon.hasBadge()) {
                     mFolderIcon.createBadgeScaleAnimator(0f, 1f).start();
                 }
@@ -818,6 +820,7 @@
         mSuppressFolderDeletion = false;
         clearDragInfo();
         mState = STATE_SMALL;
+        mContent.setCurrentPage(0);
     }
 
     public boolean acceptDrop(DragObject d) {
@@ -1516,18 +1519,17 @@
         return itemsInReadingOrder;
     }
 
-    public List<BubbleTextView> getItemsOnCurrentPage() {
+    public List<BubbleTextView> getItemsOnPage(int page) {
         ArrayList<View> allItems = getItemsInRankOrder();
-        int currentPage = mContent.getCurrentPage();
         int lastPage = mContent.getPageCount() - 1;
         int totalItemsInFolder = allItems.size();
         int itemsPerPage = mContent.itemsPerPage();
-        int numItemsOnCurrentPage = currentPage == lastPage
-                ? totalItemsInFolder - (itemsPerPage * currentPage)
+        int numItemsOnCurrentPage = page == lastPage
+                ? totalItemsInFolder - (itemsPerPage * page)
                 : itemsPerPage;
 
-        int startIndex = currentPage * itemsPerPage;
-        int endIndex = startIndex + numItemsOnCurrentPage;
+        int startIndex = page * itemsPerPage;
+        int endIndex = Math.min(startIndex + numItemsOnCurrentPage, allItems.size());
 
         List<BubbleTextView> itemsOnCurrentPage = new ArrayList<>(numItemsOnCurrentPage);
         for (int i = startIndex; i < endIndex; ++i) {
diff --git a/src/com/android/launcher3/folder/FolderAnimationManager.java b/src/com/android/launcher3/folder/FolderAnimationManager.java
index 7e8d0c7..26a2c89 100644
--- a/src/com/android/launcher3/folder/FolderAnimationManager.java
+++ b/src/com/android/launcher3/folder/FolderAnimationManager.java
@@ -119,7 +119,7 @@
     public AnimatorSet getAnimator() {
         final DragLayer.LayoutParams lp = (DragLayer.LayoutParams) mFolder.getLayoutParams();
         FolderIcon.PreviewLayoutRule rule = mFolderIcon.getLayoutRule();
-        final List<BubbleTextView> itemsInPreview = mFolderIcon.getItemsToDisplay();
+        final List<BubbleTextView> itemsInPreview = mFolderIcon.getPreviewItems();
 
         // Match position of the FolderIcon
         final Rect folderIconPos = new Rect();
@@ -186,7 +186,7 @@
         PropertyResetListener colorResetListener = new PropertyResetListener<>(
                 BubbleTextView.TEXT_ALPHA_PROPERTY,
                 Color.alpha(Themes.getAttrColor(mContext, android.R.attr.textColorSecondary)));
-        for (BubbleTextView icon : mFolder.getItemsOnCurrentPage()) {
+        for (BubbleTextView icon : mFolder.getItemsOnPage(mFolder.mContent.getCurrentPage())) {
             if (mIsOpening) {
                 icon.setTextVisibility(false);
             }
@@ -237,13 +237,19 @@
     }
 
     /**
-     * Animate the items that are displayed in the preview.
+     * Animate the items on the current page.
      */
     private void addPreviewItemAnimators(AnimatorSet animatorSet, final float folderScale,
             int previewItemOffsetX) {
         FolderIcon.PreviewLayoutRule rule = mFolderIcon.getLayoutRule();
-        final List<BubbleTextView> itemsInPreview = mFolderIcon.getItemsToDisplay();
+        boolean isOnFirstPage = mFolder.mContent.getCurrentPage() == 0;
+        final List<BubbleTextView> itemsInPreview = isOnFirstPage
+                ? mFolderIcon.getPreviewItems()
+                : mFolderIcon.getPreviewItemsOnPage(mFolder.mContent.getCurrentPage());
         final int numItemsInPreview = itemsInPreview.size();
+        final int numItemsInFirstPagePreview = isOnFirstPage
+                ? numItemsInPreview
+                : FolderIcon.NUM_ITEMS_IN_PREVIEW;
 
         TimeInterpolator previewItemInterpolator = getPreviewItemInterpolator();
 
@@ -256,8 +262,8 @@
             btvLp.isLockedToGrid = true;
             cwc.setupLp(btv);
 
-            // Match scale of icons in the preview.
-            float previewScale = rule.scaleForItem(i, numItemsInPreview);
+            // Match scale of icons in the preview of the items on the first page.
+            float previewScale = rule.scaleForItem(i, numItemsInFirstPagePreview);
             float previewSize = rule.getIconSize() * previewScale;
             float iconScale = previewSize / itemsInPreview.get(i).getIconSize();
 
@@ -268,7 +274,7 @@
             btv.setScaleY(scale);
 
             // Match positions of the icons in the folder with their positions in the preview
-            rule.computePreviewItemDrawingParams(i, numItemsInPreview, mTmpParams);
+            rule.computePreviewItemDrawingParams(i, numItemsInFirstPagePreview, mTmpParams);
             // The PreviewLayoutRule assumes that the icon size takes up the entire width so we
             // offset by the actual size.
             int iconOffsetX = (int) ((btvLp.width - btv.getIconSize()) * iconScale) / 2;
diff --git a/src/com/android/launcher3/folder/FolderIcon.java b/src/com/android/launcher3/folder/FolderIcon.java
index 7fdacc0..ae6a0e8 100644
--- a/src/com/android/launcher3/folder/FolderIcon.java
+++ b/src/com/android/launcher3/folder/FolderIcon.java
@@ -471,15 +471,25 @@
         return mFolderName.getVisibility() == VISIBLE;
     }
 
-    public List<BubbleTextView> getItemsToDisplay() {
+    /**
+     * Returns the list of preview items displayed in the icon.
+     */
+    public List<BubbleTextView> getPreviewItems() {
+        return getPreviewItemsOnPage(0);
+    }
+
+    /**
+     * Returns the list of "preview items" on {@param page}.
+     */
+    public List<BubbleTextView> getPreviewItemsOnPage(int page) {
         mPreviewVerifier.setFolderInfo(mFolder.getInfo());
 
         List<BubbleTextView> itemsToDisplay = new ArrayList<>();
-        List<View> allItems = mFolder.getItemsInRankOrder();
-        int numItems = allItems.size();
+        List<BubbleTextView> itemsOnPage = mFolder.getItemsOnPage(page);
+        int numItems = itemsOnPage.size();
         for (int rank = 0; rank < numItems; ++rank) {
-            if (mPreviewVerifier.isItemInPreview(rank)) {
-                itemsToDisplay.add((BubbleTextView) allItems.get(rank));
+            if (mPreviewVerifier.isItemInPreview(page, rank)) {
+                itemsToDisplay.add(itemsOnPage.get(rank));
             }
 
             if (itemsToDisplay.size() == FolderIcon.NUM_ITEMS_IN_PREVIEW) {
@@ -639,6 +649,10 @@
         }
     }
 
+    public void onFolderClose(int currentPage) {
+        mPreviewItemManager.onFolderClose(currentPage);
+    }
+
     interface PreviewLayoutRule {
         PreviewItemDrawingParams computePreviewItemDrawingParams(int index, int curNumItems,
             PreviewItemDrawingParams params);
diff --git a/src/com/android/launcher3/folder/FolderIconPreviewVerifier.java b/src/com/android/launcher3/folder/FolderIconPreviewVerifier.java
index d0d8e79..eb415b9 100644
--- a/src/com/android/launcher3/folder/FolderIconPreviewVerifier.java
+++ b/src/com/android/launcher3/folder/FolderIconPreviewVerifier.java
@@ -25,15 +25,45 @@
  */
 public class FolderIconPreviewVerifier {
 
+    private final int mMaxGridCountX;
+    private final int mMaxGridCountY;
+    private final int mMaxItemsPerPage;
+    private final int[] mGridSize = new int[2];
+
+    private int mGridCountX;
+
     public FolderIconPreviewVerifier(InvariantDeviceProfile profile) {
-        // b/37570804
+        mMaxGridCountX = profile.numFolderColumns;
+        mMaxGridCountY = profile.numFolderRows;
+        mMaxItemsPerPage = mMaxGridCountX * mMaxGridCountY;
     }
 
     public void setFolderInfo(FolderInfo info) {
-        // b/37570804
+        FolderPagedView.calculateGridSize(info.contents.size(), 0, 0, mMaxGridCountX,
+                mMaxGridCountY, mMaxItemsPerPage, mGridSize);
+        mGridCountX = mGridSize[0];
     }
 
+    /**
+     * Returns whether the item with {@param rank} is in the default Folder icon preview.
+     */
     public boolean isItemInPreview(int rank) {
+        return isItemInPreview(0, rank);
+    }
+
+    /**
+     * @param page The page the item is on.
+     * @param rank The rank of the item.
+     * @return True iff the icon is in the 2x2 upper left quadrant of the Folder.
+     */
+    public boolean isItemInPreview(int page, int rank) {
+        if (page > 0) {
+            // First page items are laid out such that the first 4 items are always in the upper
+            // left quadrant. For all other pages, we need to check the row and col.
+            int col = rank % mGridCountX;
+            int row = rank / mGridCountX;
+            return col < 2 && row < 2;
+        }
         return rank < FolderIcon.NUM_ITEMS_IN_PREVIEW;
     }
 }
diff --git a/src/com/android/launcher3/folder/PreviewItemManager.java b/src/com/android/launcher3/folder/PreviewItemManager.java
index 2524a6d..74c2102 100644
--- a/src/com/android/launcher3/folder/PreviewItemManager.java
+++ b/src/com/android/launcher3/folder/PreviewItemManager.java
@@ -16,6 +16,9 @@
 
 package com.android.launcher3.folder;
 
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ValueAnimator;
 import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
@@ -48,10 +51,19 @@
 
     // These hold the first page preview items
     private ArrayList<PreviewItemDrawingParams> mFirstPageParams = new ArrayList<>();
+    // These hold the current page preview items. It is empty if the current page is the first page.
+    private ArrayList<PreviewItemDrawingParams> mCurrentPageParams = new ArrayList<>();
+
+    private float mCurrentPageItemsTransX = 0;
+    private boolean mShouldSlideInFirstPage;
 
     static final int INITIAL_ITEM_ANIMATION_DURATION = 350;
     private static final int FINAL_ITEM_ANIMATION_DURATION = 200;
 
+    private static final int SLIDE_IN_FIRST_PAGE_ANIMATION_DURATION_DELAY = 200;
+    private static final int SLIDE_IN_FIRST_PAGE_ANIMATION_DURATION = 300;
+    private static final int ITEM_SLIDE_IN_OUT_DISTANCE_PX = 200;
+
     public PreviewItemManager(FolderIcon icon) {
         mIcon = icon;
     }
@@ -116,15 +128,30 @@
         return params;
     }
 
-    public void draw(Canvas canvas) {
-        computePreviewDrawingParams(mReferenceDrawable);
+    public void drawParams(Canvas canvas, ArrayList<PreviewItemDrawingParams> params,
+            float transX) {
+        canvas.translate(transX, 0);
         // The first item should be drawn last (ie. on top of later items)
-        for (int i = mFirstPageParams.size() - 1; i >= 0; i--) {
-            PreviewItemDrawingParams p = mFirstPageParams.get(i);
+        for (int i = params.size() - 1; i >= 0; i--) {
+            PreviewItemDrawingParams p = params.get(i);
             if (!p.hidden) {
                 drawPreviewItem(canvas, p);
             }
         }
+        canvas.translate(-transX, 0);
+    }
+
+    public void draw(Canvas canvas) {
+        computePreviewDrawingParams(mReferenceDrawable);
+
+        float firstPageItemsTransX = 0;
+        if (mShouldSlideInFirstPage) {
+            drawParams(canvas, mCurrentPageParams, mCurrentPageItemsTransX);
+
+            firstPageItemsTransX = -ITEM_SLIDE_IN_OUT_DISTANCE_PX + mCurrentPageItemsTransX;
+        }
+
+        drawParams(canvas, mFirstPageParams, firstPageItemsTransX);
     }
 
     public void onParamsChanged() {
@@ -156,21 +183,21 @@
         }
     }
 
-    void updateItemDrawingParams(boolean animate) {
-        List<BubbleTextView> items = mIcon.getItemsToDisplay();
-        int numItemsInPreview = items.size();
-        int prevNumItems = mFirstPageParams.size();
+    void buildParamsForPage(int page, ArrayList<PreviewItemDrawingParams> params, boolean animate) {
+        List<BubbleTextView> items = mIcon.getPreviewItemsOnPage(page);
+        int prevNumItems = params.size();
 
-        // We adjust the size of the list to match the number of items in the preview
-        while (numItemsInPreview < mFirstPageParams.size()) {
-            mFirstPageParams.remove(mFirstPageParams.size() - 1);
+        // We adjust the size of the list to match the number of items in the preview.
+        while (items.size() < params.size()) {
+            params.remove(params.size() - 1);
         }
-        while (numItemsInPreview > mFirstPageParams.size()) {
-            mFirstPageParams.add(new PreviewItemDrawingParams(0, 0, 0, 0));
+        while (items.size() > params.size()) {
+            params.add(new PreviewItemDrawingParams(0, 0, 0, 0));
         }
 
-        for (int i = 0; i < mFirstPageParams.size(); i++) {
-            PreviewItemDrawingParams p = mFirstPageParams.get(i);
+        int numItemsInFirstPagePreview = page == 0 ? items.size() : FolderIcon.NUM_ITEMS_IN_PREVIEW;
+        for (int i = 0; i < params.size(); i++) {
+            PreviewItemDrawingParams p = params.get(i);
             p.drawable = items.get(i).getCompoundDrawables()[1];
 
             if (p.drawable != null && !mIcon.mFolder.isOpen()) {
@@ -180,13 +207,13 @@
             }
 
             if (!animate || FeatureFlags.LAUNCHER3_LEGACY_FOLDER_ICON) {
-                computePreviewItemDrawingParams(i, numItemsInPreview, p);
+                computePreviewItemDrawingParams(i, numItemsInFirstPagePreview, p);
                 if (mReferenceDrawable == null) {
                     mReferenceDrawable = p.drawable;
                 }
             } else {
                 FolderPreviewItemAnim anim = new FolderPreviewItemAnim(this, p, i, prevNumItems, i,
-                        numItemsInPreview, DROP_IN_ANIMATION_DURATION, null);
+                        numItemsInFirstPagePreview, DROP_IN_ANIMATION_DURATION, null);
 
                 if (p.anim != null) {
                     if (p.anim.hasEqualFinalState(anim)) {
@@ -201,6 +228,39 @@
         }
     }
 
+    void onFolderClose(int currentPage) {
+        // If we are not closing on the first page, we animate the current page preview items
+        // out, and animate the first page preview items in.
+        mShouldSlideInFirstPage = currentPage != 0;
+        if (mShouldSlideInFirstPage) {
+            mCurrentPageItemsTransX = 0;
+            buildParamsForPage(currentPage, mCurrentPageParams, false);
+            onParamsChanged();
+
+            ValueAnimator slideAnimator = ValueAnimator.ofFloat(0, ITEM_SLIDE_IN_OUT_DISTANCE_PX);
+            slideAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+                @Override
+                public void onAnimationUpdate(ValueAnimator valueAnimator) {
+                    mCurrentPageItemsTransX = (float) valueAnimator.getAnimatedValue();
+                    onParamsChanged();
+                }
+            });
+            slideAnimator.addListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mCurrentPageParams.clear();
+                }
+            });
+            slideAnimator.setStartDelay(SLIDE_IN_FIRST_PAGE_ANIMATION_DURATION_DELAY);
+            slideAnimator.setDuration(SLIDE_IN_FIRST_PAGE_ANIMATION_DURATION);
+            slideAnimator.start();
+        }
+    }
+
+    void updateItemDrawingParams(boolean animate) {
+        buildParamsForPage(0, mFirstPageParams, animate);
+    }
+
     boolean verifyDrawable(@NonNull Drawable who) {
         for (int i = 0; i < mFirstPageParams.size(); i++) {
             if (mFirstPageParams.get(i).drawable == who) {