From 800c0b59ed96d9cd44e2118878cdf5b0fb9d357f Mon Sep 17 00:00:00 2001
From: Harlan <luoxwen@gmail.com>
Date: Fri, 9 Sep 2016 08:58:35 +0800
Subject: [PATCH] Expand and collapse can be done with animation or not.

---
 .../ExpandableUseActivity.java                |  2 +-
 .../adapter/ExpandableItemAdapter.java        |  4 +-
 .../adapter/base/BaseQuickAdapter.java        | 49 +++++++++++++++++--
 3 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/app/src/main/java/com/chad/baserecyclerviewadapterhelper/ExpandableUseActivity.java b/app/src/main/java/com/chad/baserecyclerviewadapterhelper/ExpandableUseActivity.java
index 6a8b78715..6afc51610 100644
--- a/app/src/main/java/com/chad/baserecyclerviewadapterhelper/ExpandableUseActivity.java
+++ b/app/src/main/java/com/chad/baserecyclerviewadapterhelper/ExpandableUseActivity.java
@@ -72,7 +72,7 @@ private ArrayList<MultiItemEntity> generateData() {
         for (int i = 0; i < lv0Count; i++) {
             Level0Item lv0 = new Level0Item("This is " + i + "th item in Level 0", "subtitle of " + i);
             for (int j = 0; j < lv1Count; j++) {
-                Level1Item lv1 = new Level1Item("Level 1 item: " + j, "just subtitle");
+                Level1Item lv1 = new Level1Item("Level 1 item: " + j, "(no animation)");
                 for (int k = 0; k < personCount; k++) {
                     lv1.addSubItem(new Person(nameList[k], random.nextInt(40)));
                 }
diff --git a/app/src/main/java/com/chad/baserecyclerviewadapterhelper/adapter/ExpandableItemAdapter.java b/app/src/main/java/com/chad/baserecyclerviewadapterhelper/adapter/ExpandableItemAdapter.java
index d0934a254..5407a9304 100644
--- a/app/src/main/java/com/chad/baserecyclerviewadapterhelper/adapter/ExpandableItemAdapter.java
+++ b/app/src/main/java/com/chad/baserecyclerviewadapterhelper/adapter/ExpandableItemAdapter.java
@@ -68,9 +68,9 @@ public void onClick(View v) {
                         int pos = holder.getAdapterPosition();
                         Log.d(TAG, "Level 1 item pos: " + pos);
                         if (lv1.isExpanded()) {
-                            collapse(pos);
+                            collapse(pos, false);
                         } else {
-                            expand(pos);
+                            expand(pos, false);
                         }
                     }
                 });
diff --git a/library/src/main/java/com/chad/library/adapter/base/BaseQuickAdapter.java b/library/src/main/java/com/chad/library/adapter/base/BaseQuickAdapter.java
index fdd281f07..798dfea2e 100755
--- a/library/src/main/java/com/chad/library/adapter/base/BaseQuickAdapter.java
+++ b/library/src/main/java/com/chad/library/adapter/base/BaseQuickAdapter.java
@@ -973,9 +973,11 @@ private int recursiveExpand(int position, @NonNull List list) {
      * Expand an expandable item
      *
      * @param position position of the item
+     * @param animate expand items with animation
+     * @param shouldNotify notify the RecyclerView to rebind items, <strong>false</strong> if you want to do it yourself.
      * @return the number of items that have been added.
      */
-    public int expand(@IntRange(from = 0) int position) {
+    public int expand(@IntRange(from = 0) int position, boolean animate, boolean shouldNotify) {
         position -= getHeaderLayoutCount();
 
         T item = getItem(position);
@@ -997,10 +999,39 @@ public int expand(@IntRange(from = 0) int position) {
             expandable.setExpanded(true);
             subItemCount += list.size();
         }
-        notifyItemRangeInserted(position + 1 + getHeaderLayoutCount(), subItemCount);
+        int parentPos = position + getHeaderLayoutCount();
+        if (shouldNotify) {
+            if (animate) {
+                notifyItemChanged(parentPos);
+                notifyItemRangeInserted(parentPos + 1, subItemCount);
+            } else {
+                notifyDataSetChanged();
+            }
+        }
         return subItemCount;
     }
 
+    /**
+     * Expand an expandable item
+     *
+     * @param position position of the item
+     * @param animate expand items with animation
+     * @return the number of items that have been added.
+     */
+    public int expand(@IntRange(from = 0) int position, boolean animate) {
+        return expand(position, animate, true);
+    }
+
+    /**
+     * Expand an expandable item with animation.
+     *
+     * @param position position of the item
+     * @return the number of items that have been added.
+     */
+    public int expand(@IntRange(from = 0) int position) {
+        return expand(position, true, true);
+    }
+
     private int recursiveCollapse(@IntRange(from = 0) int position) {
         T item = getItem(position);
         if (!isExpandable(item)) {
@@ -1032,7 +1063,7 @@ private int recursiveCollapse(@IntRange(from = 0) int position) {
      * @param position the position of the item
      * @return the number of subItems collapsed.
      */
-    public int collapse(@IntRange(from = 0) int position) {
+    public int collapse(@IntRange(from = 0) int position, boolean animate) {
         position -= getHeaderLayoutCount();
         T item = getItem(position);
         if (!isExpandable(item)) {
@@ -1041,10 +1072,20 @@ public int collapse(@IntRange(from = 0) int position) {
         IExpandable expandable = (IExpandable) item;
         int subItemCount = recursiveCollapse(position);
         expandable.setExpanded(false);
-        notifyItemRangeRemoved(position + 1 + getHeaderLayoutCount(), subItemCount);
+        int parentPos = position + getHeaderLayoutCount();
+        if (animate) {
+            notifyItemChanged(parentPos);
+            notifyItemRangeRemoved(parentPos + 1, subItemCount);
+        } else {
+            notifyDataSetChanged();
+        }
         return subItemCount;
     }
 
+    public int collapse(@IntRange(from = 0) int position) {
+        return collapse(position, true);
+    }
+
     private int getItemPosition(T item) {
         return item != null && mData != null && !mData.isEmpty() ? mData.indexOf(item) : -1;
     }