fixed scroll issue

Author: alexey.chernenko

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.1.0'
+        classpath 'com.android.tools.build:gradle:2.2.0'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

library/src/main/java/com/yalantis/pulltomakesoup/PullToRefreshView.java

@@ -161,7 +161,6 @@ private void ensureTarget() {
 
     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
-
         if (!isEnabled() || canChildScrollUp() || mRefreshing) {
             return false;
         }
@@ -180,7 +179,14 @@ public boolean onInterceptTouchEvent(MotionEvent ev) {
                 mInitialMotionY = initialMotionY;
                 break;
             case MotionEvent.ACTION_MOVE:
-                final float yDiff = getMotionEventY(ev, mActivePointerId);
+                if (mActivePointerId == INVALID_POINTER) {
+                    return false;
+                }
+                final float y = getMotionEventY(ev, mActivePointerId);
+                if (y == -1) {
+                    return false;
+                }
+                final float yDiff = y - mInitialMotionY;
                 if (yDiff > mTouchSlop && !mIsBeingDragged) {
                     mIsBeingDragged = true;
                 }