From 0ae44923e9667457a5134ef36c73ab1716dcec18 Mon Sep 17 00:00:00 2001
From: M66B <M66B@users.noreply.github.com>
Date: Sat, 3 Aug 2019 16:49:46 +0200
Subject: [PATCH] Fixed losing selection on adding items

---
 .../selection/DefaultSelectionTracker.java    | 14 ++++-
 .../recyclerview/selection/Range.java         |  5 ++
 patches/selection-updated.patch               | 56 +++++++++++++++++++
 3 files changed, 72 insertions(+), 3 deletions(-)
 create mode 100644 patches/selection-updated.patch

diff --git a/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java b/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java
index a513f5725a..aa523514bc 100644
--- a/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java
+++ b/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java
@@ -348,6 +348,10 @@ public class DefaultSelectionTracker<K> extends SelectionTracker<K> {
         return mRange != null;
     }
 
+    boolean isOverlapping(int position, int count) {
+        return (mRange != null && mRange.isOverlapping(position, count));
+    }
+
     private boolean canSetState(@NonNull K key, boolean nextState) {
         return mSelectionPredicate.canSetStateForKey(key, nextState);
     }
@@ -578,17 +582,21 @@ public class DefaultSelectionTracker<K> extends SelectionTracker<K> {
 
         @Override
         public void onItemRangeInserted(int startPosition, int itemCount) {
-            mSelectionTracker.endRange();
+            if (mSelectionTracker.isOverlapping(startPosition, itemCount))
+                mSelectionTracker.endRange();
         }
 
         @Override
         public void onItemRangeRemoved(int startPosition, int itemCount) {
-            mSelectionTracker.endRange();
+            if (mSelectionTracker.isOverlapping(startPosition, itemCount))
+                mSelectionTracker.endRange();
         }
 
         @Override
         public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
-            mSelectionTracker.endRange();
+            if (mSelectionTracker.isOverlapping(fromPosition, itemCount) ||
+                    mSelectionTracker.isOverlapping(toPosition, itemCount))
+                mSelectionTracker.endRange();
         }
     }
 }
diff --git a/app/src/main/java/androidx/recyclerview/selection/Range.java b/app/src/main/java/androidx/recyclerview/selection/Range.java
index 35fb3a8ba5..b11a14a9ad 100644
--- a/app/src/main/java/androidx/recyclerview/selection/Range.java
+++ b/app/src/main/java/androidx/recyclerview/selection/Range.java
@@ -170,6 +170,11 @@ final class Range {
         mCallbacks.updateForRange(begin, end, selected, type);
     }
 
+    boolean isOverlapping(int position, int count) {
+        return (position >= mBegin && position <= mEnd) ||
+                (position + count >= mBegin && position + count <= mEnd);
+    }
+
     @Override
     public String toString() {
         return "Range{begin=" + mBegin + ", end=" + mEnd + "}";
diff --git a/patches/selection-updated.patch b/patches/selection-updated.patch
new file mode 100644
index 0000000000..e6f05267ca
--- /dev/null
+++ b/patches/selection-updated.patch
@@ -0,0 +1,56 @@
+diff --git a/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java b/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java
+index a513f5725..d8845a0b0 100644
+--- a/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java
++++ b/app/src/main/java/androidx/recyclerview/selection/DefaultSelectionTracker.java
+@@ -348,6 +348,10 @@ public class DefaultSelectionTracker<K> extends SelectionTracker<K> {
+         return mRange != null;
+     }
+ 
++    boolean isOverlapping(int position, int count) {
++        return (mRange != null && mRange.isOverlapping(position, count));
++    }
++
+     private boolean canSetState(@NonNull K key, boolean nextState) {
+         return mSelectionPredicate.canSetStateForKey(key, nextState);
+     }
+@@ -578,17 +582,21 @@ public class DefaultSelectionTracker<K>
+ 
+         @Override
+         public void onItemRangeInserted(int startPosition, int itemCount) {
+-            mSelectionTracker.endRange();
++            if (mSelectionTracker.isOverlapping(startPosition, itemCount))
++                mSelectionTracker.endRange();
+         }
+ 
+         @Override
+         public void onItemRangeRemoved(int startPosition, int itemCount) {
+-            mSelectionTracker.endRange();
++            if (mSelectionTracker.isOverlapping(startPosition, itemCount))
++                mSelectionTracker.endRange();
+         }
+ 
+         @Override
+         public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
+-            mSelectionTracker.endRange();
++            if (mSelectionTracker.isOverlapping(fromPosition, itemCount) ||
++                    mSelectionTracker.isOverlapping(toPosition, itemCount))
++                mSelectionTracker.endRange();
+         }
+     }
+ }
+diff --git a/app/src/main/java/androidx/recyclerview/selection/Range.java b/app/src/main/java/androidx/recyclerview/selection/Range.java
+index 35fb3a8ba..b11a14a9a 100644
+--- a/app/src/main/java/androidx/recyclerview/selection/Range.java
++++ b/app/src/main/java/androidx/recyclerview/selection/Range.java
+@@ -170,6 +170,11 @@ final class Range {
+         mCallbacks.updateForRange(begin, end, selected, type);
+     }
+ 
++    boolean isOverlapping(int position, int count) {
++        return (position >= mBegin && position <= mEnd) ||
++                (position + count >= mBegin && position + count <= mEnd);
++    }
++
+     @Override
+     public String toString() {
+         return "Range{begin=" + mBegin + ", end=" + mEnd + "}";