Merge pull request #163 from yuyakaido/issue/140

Add callback methods to notify appeared/disappeared card

README.md

@@ -274,6 +274,8 @@ CardStackLayoutManager.setCanScrollVertical(true);
 | CardStackListener.onCardSwiped(Direction direction) | This method is called when the card is swiped. |
 | CardStackListener.onCardRewound() | This method is called when the card is rewinded. |
 | CardStackListener.onCardCanceled() | This method is called when the card is dragged less than threshold. |
+| CardStackListener.onCardAppeared(View view, int position) | This method is called when the card appeared. |
+| CardStackListener.onCardDisappeared(View view, int position) | This method is called when the card disappeared. |
 
 # Migration Guide
 

cardstackview/src/main/java/com/yuyakaido/android/cardstackview/CardStackLayoutManager.java

@@ -45,8 +45,11 @@ public RecyclerView.LayoutParams generateDefaultLayoutParams() {
     }
 
     @Override
-    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
+    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State s) {
         update(recycler);
+        if (s.didStructureChange()) {
+            listener.onCardAppeared(getTopView(), state.topPosition);
+        }
     }
 
     @Override
@@ -179,6 +182,7 @@ private void update(RecyclerView.Recycler recycler) {
                     @Override
                     public void run() {
                         listener.onCardSwiped(direction);
+                        listener.onCardAppeared(getTopView(), state.topPosition);
                     }
                 });
                 state.dx = 0;
@@ -397,6 +401,8 @@ private void smoothScrollToNext(int position) {
     }
 
     private void smoothScrollToPrevious(int position) {
+        listener.onCardDisappeared(getTopView(), state.topPosition);
+
         state.proportion = 0.0f;
         state.targetPosition = position;
         state.topPosition--;
@@ -405,6 +411,10 @@ private void smoothScrollToPrevious(int position) {
         startSmoothScroll(scroller);
     }
 
+    public View getTopView() {
+        return findViewByPosition(state.topPosition);
+    }
+
     public int getTopPosition() {
         return state.topPosition;
     }

cardstackview/src/main/java/com/yuyakaido/android/cardstackview/CardStackListener.java

@@ -1,10 +1,14 @@
 package com.yuyakaido.android.cardstackview;
 
+import android.view.View;
+
 public interface CardStackListener {
     void onCardDragging(Direction direction, float ratio);
     void onCardSwiped(Direction direction);
     void onCardRewound();
     void onCardCanceled();
+    void onCardAppeared(View view, int position);
+    void onCardDisappeared(View view, int position);
 
     CardStackListener DEFAULT = new CardStackListener() {
         @Override
@@ -15,5 +19,9 @@ public void onCardSwiped(Direction direction) {}
         public void onCardRewound() {}
         @Override
         public void onCardCanceled() {}
+        @Override
+        public void onCardAppeared(View view, int position) {}
+        @Override
+        public void onCardDisappeared(View view, int position) {}
     };
 }

cardstackview/src/main/java/com/yuyakaido/android/cardstackview/internal/CardStackSmoothScroller.java

@@ -89,16 +89,19 @@ protected void onTargetFound(View targetView, RecyclerView.State state, Action a
 
     @Override
     protected void onStart() {
+        CardStackListener listener = manager.getCardStackListener();
         CardStackState state = manager.getCardStackState();
         switch (type) {
             case AutomaticSwipe:
                 state.next(CardStackState.Status.PrepareSwipeAnimation);
+                listener.onCardDisappeared(manager.getTopView(), manager.getTopPosition());
                 break;
             case AutomaticRewind:
                 state.next(CardStackState.Status.RewindAnimating);
                 break;
             case ManualSwipe:
                 state.next(CardStackState.Status.PrepareSwipeAnimation);
+                listener.onCardDisappeared(manager.getTopView(), manager.getTopPosition());
                 break;
             case ManualCancel:
                 state.next(CardStackState.Status.RewindAnimating);
@@ -115,6 +118,7 @@ protected void onStop() {
                 break;
             case AutomaticRewind:
                 listener.onCardRewound();
+                listener.onCardAppeared(manager.getTopView(), manager.getTopPosition());
                 break;
             case ManualSwipe:
                 // Notify callback from CardStackLayoutManager

sample/src/main/java/com/yuyakaido/android/cardstackview/sample/MainActivity.java

@@ -14,6 +14,7 @@
 import android.view.View;
 import android.view.animation.AccelerateInterpolator;
 import android.view.animation.DecelerateInterpolator;
+import android.widget.TextView;
 
 import com.yuyakaido.android.cardstackview.CardStackLayoutManager;
 import com.yuyakaido.android.cardstackview.CardStackListener;
@@ -75,6 +76,18 @@ public void onCardCanceled() {
         Log.d("CardStackView", "onCardCanceled:" + manager.getTopPosition());
     }
 
+    @Override
+    public void onCardAppeared(View view, int position) {
+        TextView textView = view.findViewById(R.id.item_name);
+        Log.d("CardStackView", "onCardAppeared: (" + position + ") " + textView.getText());
+    }
+
+    @Override
+    public void onCardDisappeared(View view, int position) {
+        TextView textView = view.findViewById(R.id.item_name);
+        Log.d("CardStackView", "onCardDisappeared: (" + position + ") " + textView.getText());
+    }
+
     private void setupNavigation() {
         // Toolbar
         Toolbar toolbar = findViewById(R.id.toolbar);