Merge "Revert "Exception if receive move withouth down"" into rvc-dev am: b1d2c79448

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11694777

Change-Id: I84c1bd4e1a48269e979df3f2fe3432b4516ee0d2

core/java/android/view/GestureDetector.java

@@ -288,11 +288,6 @@ public class GestureDetector {
      */
     private VelocityTracker mVelocityTracker;
 
-    /**
-     * True if the detector can throw exception when touch steam is unexpected .
-     */
-    private boolean mExceptionForTouchStream;
-
     /**
      * Consistency verifier for debugging purposes.
      */
@@ -472,8 +467,6 @@ public class GestureDetector {
         mTouchSlopSquare = touchSlop * touchSlop;
         mDoubleTapTouchSlopSquare = doubleTapTouchSlop * doubleTapTouchSlop;
         mDoubleTapSlopSquare = doubleTapSlop * doubleTapSlop;
-        mExceptionForTouchStream = context != null
-                && context.getApplicationInfo().targetSdkVersion >= Build.VERSION_CODES.R;
     }
 
     /**
@@ -646,13 +639,6 @@ public class GestureDetector {
                 break;
 
             case MotionEvent.ACTION_MOVE:
-                if (mExceptionForTouchStream && !mStillDown) {
-                    throw new IllegalStateException("Incomplete event stream received: "
-                            + "Received ACTION_MOVE before ACTION_DOWN. ACTION_DOWN must precede "
-                            + "ACTION_MOVE following ACTION_UP or ACTION_CANCEL, or when this "
-                            + "GestureDetector has not yet received any events.");
-                }
-
                 if (mInLongPress || mInContextClick) {
                     break;
                 }