From 81cec527e902e035d1b342be0624c888740e10d0 Mon Sep 17 00:00:00 2001
From: Sebastian Franco <fransebas@google.com>
Date: Mon, 23 May 2022 16:33:38 -0700
Subject: [PATCH] Fix folder preview animation when adding or removing icons.

The functions PreviewItemManager.updatePreviewItems calls
PreviewItemManager.buildParamsForPage using mFirstPageParams and it
expects that mFirstPageParams contains the values before the reoredering
but they get updated in a previous call to updatePreviewItems(false),
so when doing the animation, the icons are animated to their current
position and nothing changes.

Fix: 233401274
Test: Add icons to a folder 1 to 5 without expanding the folder and
make sure they animate to their new position. Make sure they animate
when removing items as well.

Change-Id: Ia3e1393d8fb2b30eb107e8b2c6eefdf9e50e9f70
---
 .../android/launcher3/folder/PreviewItemManager.java   | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/com/android/launcher3/folder/PreviewItemManager.java b/src/com/android/launcher3/folder/PreviewItemManager.java
index 6355b62e27..2e5f2e5d60 100644
--- a/src/com/android/launcher3/folder/PreviewItemManager.java
+++ b/src/com/android/launcher3/folder/PreviewItemManager.java
@@ -79,6 +79,8 @@ public class PreviewItemManager {
     private int mPrevTopPadding = -1;
     private Drawable mReferenceDrawable = null;
 
+    private int mNumOfPrevItems = 0;
+
     // 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.
@@ -254,7 +256,6 @@ public class PreviewItemManager {
 
     void buildParamsForPage(int page, ArrayList<PreviewItemDrawingParams> params, boolean animate) {
         List<WorkspaceItemInfo> 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 (items.size() < params.size()) {
@@ -278,8 +279,9 @@ public class PreviewItemManager {
                     mReferenceDrawable = p.drawable;
                 }
             } else {
-                FolderPreviewItemAnim anim = new FolderPreviewItemAnim(this, p, i, prevNumItems, i,
-                        numItemsInFirstPagePreview, DROP_IN_ANIMATION_DURATION, null);
+                FolderPreviewItemAnim anim = new FolderPreviewItemAnim(this, p, i,
+                        mNumOfPrevItems, i, numItemsInFirstPagePreview, DROP_IN_ANIMATION_DURATION,
+                        null);
 
                 if (p.anim != null) {
                     if (p.anim.hasEqualFinalState(anim)) {
@@ -318,7 +320,9 @@ public class PreviewItemManager {
     }
 
     void updatePreviewItems(boolean animate) {
+        int numOfPrevItemsAux = mFirstPageParams.size();
         buildParamsForPage(0, mFirstPageParams, animate);
+        mNumOfPrevItems = numOfPrevItemsAux;
     }
 
     void updatePreviewItems(Predicate<WorkspaceItemInfo> itemCheck) {