Minimal default RecyclerView animations support

library/src/main/java/com/timehop/stickyheadersrecyclerview/HeaderPositionCalculator.java

@@ -105,14 +105,14 @@ private Rect getDefaultHeaderOffset(RecyclerView recyclerView, View header, View
     int translationX, translationY;
     Rect headerMargins = mDimensionCalculator.getMargins(header);
     if (orientation == LinearLayoutManager.VERTICAL) {
-      translationX = firstView.getLeft() + headerMargins.left;
+      translationX = (int) firstView.getX() + headerMargins.left;
       translationY = Math.max(
-          firstView.getTop() - header.getHeight() - headerMargins.bottom,
+          (int) firstView.getY() - header.getHeight() - headerMargins.bottom,
           getListTop(recyclerView) + headerMargins.top);
     } else {
-      translationY = firstView.getTop() + headerMargins.top;
+      translationY = (int) firstView.getY() + headerMargins.top;
       translationX = Math.max(
-          firstView.getLeft() - header.getWidth() - headerMargins.right,
+          (int) firstView.getX() - header.getWidth() - headerMargins.right,
           getListLeft(recyclerView) + headerMargins.left);
     }
 

sample/src/main/java/com/timehop/stickyheadersrecyclerview/sample/DividerDecoration.java

@@ -60,7 +60,7 @@ public void drawVertical(Canvas c, RecyclerView parent) {
       final View child = parent.getChildAt(i);
       final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
           .getLayoutParams();
-      final int top = Math.max(recyclerViewTop, child.getBottom() + params.bottomMargin);
+      final int top = Math.max(recyclerViewTop, child.getBottom() + (int) child.getTranslationY() + params.bottomMargin);
       final int bottom = Math.min(recyclerViewBottom, top + mDivider.getIntrinsicHeight());
       mDivider.setBounds(left, top, right, bottom);
       mDivider.draw(c);
@@ -77,7 +77,7 @@ public void drawHorizontal(Canvas c, RecyclerView parent) {
       final View child = parent.getChildAt(i);
       final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
           .getLayoutParams();
-      final int left = Math.max(recyclerViewLeft, child.getRight() + params.rightMargin);
+      final int left = Math.max(recyclerViewLeft, child.getRight() + (int) child.getTranslationX() + params.rightMargin);
       final int right = Math.min(recyclerViewRight, left + mDivider.getIntrinsicHeight());
       mDivider.setBounds(left, top, right, bottom);
       mDivider.draw(c);

sample/src/main/java/com/timehop/stickyheadersrecyclerview/sample/MainActivity.java

@@ -25,13 +25,16 @@
 
 public class MainActivity extends Activity {
 
+  public static final String ANIMALS_BELOW = "Animals below!";
+
   @Override
   protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
 
     final RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
     Button button = (Button) findViewById(R.id.button_update);
+    Button buttonAdd = (Button) findViewById(R.id.button_add);
     final ToggleButton isReverseButton = (ToggleButton) findViewById(R.id.button_is_reverse);
 
     // Set adapter populated with example dummy data
@@ -57,6 +60,18 @@ public void run() {
       }
     });
 
+    // Add/remove item to the top of list (Test animations)
+      buttonAdd.setOnClickListener(new View.OnClickListener() {
+          @Override
+          public void onClick(View v) {
+              if (ANIMALS_BELOW.equals(mAdapter.getItem(0))) {
+                  mAdapter.remove(ANIMALS_BELOW);
+              } else {
+                  mAdapter.add(0, ANIMALS_BELOW);
+              }
+          }
+      });
+
     // Set layout manager
     int orientation = getLayoutManagerOrientation(getResources().getConfiguration().orientation);
     final LinearLayoutManager layoutManager = new LinearLayoutManager(this, orientation, isReverseButton.isChecked());
@@ -122,7 +137,7 @@ private class SampleArrayHeadersAdapter extends RecyclerArrayAdapter<String, Rec
     @Override
     public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
       View view = LayoutInflater.from(parent.getContext())
-          .inflate(R.layout.view_item, parent, false);
+              .inflate(R.layout.view_item, parent, false);
       return new RecyclerView.ViewHolder(view) {
       };
     }
@@ -145,7 +160,7 @@ public long getHeaderId(int position) {
     @Override
     public RecyclerView.ViewHolder onCreateHeaderViewHolder(ViewGroup parent) {
       View view = LayoutInflater.from(parent.getContext())
-          .inflate(R.layout.view_header, parent, false);
+              .inflate(R.layout.view_header, parent, false);
       return new RecyclerView.ViewHolder(view) {
       };
     }

sample/src/main/java/com/timehop/stickyheadersrecyclerview/sample/RecyclerArrayAdapter.java

@@ -52,7 +52,7 @@ public M getItem(int position) {
 
   @Override
   public long getItemId(int position) {
-    return position;
+    return getItem(position).hashCode();
   }
 
   @Override

sample/src/main/res/layout/activity_main.xml

@@ -19,6 +19,14 @@
             android:layout_weight="1"
             android:text="@string/button_update"/>
 
+        <Button
+            android:id="@+id/button_add"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:textSize="14sp"
+            android:text="@string/button_add"/>
+
         <ToggleButton
             android:id="@+id/button_is_reverse"
             android:layout_width="0dp"

sample/src/main/res/values/strings.xml

@@ -2,7 +2,8 @@
 <resources>
 
     <string name="app_name">StickyHeadersRecyclerView</string>
-    <string name="button_update">Start Update</string>
+    <string name="button_update">Update</string>
     <string name="button_reverse">Is reverse</string>
+    <string name="button_add">Add/Remove</string>
 
 </resources>