Update deprecated RecyclerView.OnScrollListener

Changed calculation of proportion value for smooth and correct Bubble and Handle position

Author: dimbslmh

app/src/main/java/com/lb/lollipop_contacts_recyclerview_fast_scroller/FastScroller.java

@@ -17,16 +17,13 @@
 
 import com.lb.lollipopcontactsrecyclerviewfastscroller.R;
 
-import static android.support.v7.widget.RecyclerView.OnScrollListener;
-
 public class FastScroller extends LinearLayout{
   private static final int BUBBLE_ANIMATION_DURATION=100;
   private static final int TRACK_SNAP_RANGE=5;
 
   private TextView bubble;
   private View handle;
   private RecyclerView recyclerView;
-  private final ScrollListener scrollListener=new ScrollListener();
   private int height;
 
   private ObjectAnimator currentAnimator=null;
@@ -98,7 +95,20 @@ public boolean onTouchEvent(@NonNull MotionEvent event)
   public void setRecyclerView(RecyclerView recyclerView)
     {
     this.recyclerView=recyclerView;
-    recyclerView.setOnScrollListener(scrollListener);
+    RecyclerView.OnScrollListener onScrollListener = new RecyclerView.OnScrollListener() 
+      {
+      @Override
+      public void onScrolled(final RecyclerView recyclerView, final int dx, final int dy) 
+        {
+        if (handle.isSelected())
+          return;
+        int verticalScrollOffset = recyclerView.computeVerticalScrollOffset();
+        int verticalScrollRange = recyclerView.computeVerticalScrollRange();
+        float proportion = (float) verticalScrollOffset / ((float) verticalScrollRange - height);
+        setBubbleAndHandlePosition(height * proportion);
+      }
+    };
+    recyclerView.addOnScrollListener(onScrollListener);
     }
 
   private void setRecyclerViewPosition(float y)
@@ -115,7 +125,6 @@ else if(handle.getY()+handle.getHeight()>=height-TRACK_SNAP_RANGE)
         proportion=y/(float)height;
       int targetPos=getValueInRange(0,itemCount-1,(int)(proportion*(float)itemCount));
       ((LinearLayoutManager)recyclerView.getLayoutManager()).scrollToPositionWithOffset(targetPos,0);
-//      recyclerView.oPositionWithOffset(targetPos);
       String bubbleText=((BubbleTextGetter)recyclerView.getAdapter()).getTextToShowInBubble(targetPos);
       bubble.setText(bubbleText);
       }
@@ -169,25 +178,4 @@ public void onAnimationCancel(Animator animation)
     });
     currentAnimator.start();
     }
-
-  private class ScrollListener extends OnScrollListener{
-    @Override
-    public void onScrolled(RecyclerView rv,int dx,int dy)
-      {
-      View firstVisibleView=recyclerView.getChildAt(0);
-      int firstVisiblePosition=recyclerView.getChildPosition(firstVisibleView);
-      int visibleRange=recyclerView.getChildCount();
-      int lastVisiblePosition=firstVisiblePosition+visibleRange;
-      int itemCount=recyclerView.getAdapter().getItemCount();
-      int position;
-      if(firstVisiblePosition==0)
-        position=0;
-      else if(lastVisiblePosition==itemCount)
-        position=itemCount;
-      else
-        position=(int)(((float)firstVisiblePosition/(((float)itemCount-(float)visibleRange)))*(float)itemCount);
-      float proportion=(float)position/(float)itemCount;
-      setBubbleAndHandlePosition(height*proportion);
-      }
-  }
 }