180 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			Java
		
	
	
	
	
	
			
		
		
	
	
			180 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			Java
		
	
	
	
	
	
| package androidx.recyclerview.widget;
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| 
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| import android.graphics.PointF;
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| import android.util.DisplayMetrics;
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| import android.view.View;
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| import androidx.recyclerview.widget.RecyclerView;
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| 
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| /* loaded from: classes.dex */
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| public class PagerSnapHelper extends SnapHelper {
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|     private static final int MAX_SCROLL_ON_FLING_DURATION = 100;
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|     private OrientationHelper mHorizontalHelper;
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|     private OrientationHelper mVerticalHelper;
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| 
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|     @Override // androidx.recyclerview.widget.SnapHelper
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|     public int[] calculateDistanceToFinalSnap(RecyclerView.LayoutManager layoutManager, View view) {
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|         int[] iArr = new int[2];
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|         if (layoutManager.canScrollHorizontally()) {
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|             iArr[0] = distanceToCenter(layoutManager, view, getHorizontalHelper(layoutManager));
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|         } else {
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|             iArr[0] = 0;
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|         }
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|         if (layoutManager.canScrollVertically()) {
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|             iArr[1] = distanceToCenter(layoutManager, view, getVerticalHelper(layoutManager));
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|         } else {
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|             iArr[1] = 0;
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|         }
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|         return iArr;
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|     }
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| 
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|     @Override // androidx.recyclerview.widget.SnapHelper
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|     public View findSnapView(RecyclerView.LayoutManager layoutManager) {
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|         if (layoutManager.canScrollVertically()) {
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|             return findCenterView(layoutManager, getVerticalHelper(layoutManager));
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|         }
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|         if (layoutManager.canScrollHorizontally()) {
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|             return findCenterView(layoutManager, getHorizontalHelper(layoutManager));
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|         }
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|         return null;
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|     }
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| 
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|     @Override // androidx.recyclerview.widget.SnapHelper
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|     public int findTargetSnapPosition(RecyclerView.LayoutManager layoutManager, int i, int i2) {
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|         OrientationHelper orientationHelper;
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|         int itemCount = layoutManager.getItemCount();
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|         if (itemCount == 0 || (orientationHelper = getOrientationHelper(layoutManager)) == null) {
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|             return -1;
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|         }
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|         int childCount = layoutManager.getChildCount();
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|         View view = null;
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|         View view2 = null;
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|         int i3 = Integer.MIN_VALUE;
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|         int i4 = Integer.MAX_VALUE;
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|         for (int i5 = 0; i5 < childCount; i5++) {
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|             View childAt = layoutManager.getChildAt(i5);
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|             if (childAt != null) {
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|                 int distanceToCenter = distanceToCenter(layoutManager, childAt, orientationHelper);
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|                 if (distanceToCenter <= 0 && distanceToCenter > i3) {
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|                     view2 = childAt;
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|                     i3 = distanceToCenter;
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|                 }
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|                 if (distanceToCenter >= 0 && distanceToCenter < i4) {
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|                     view = childAt;
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|                     i4 = distanceToCenter;
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|                 }
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|             }
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|         }
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|         boolean isForwardFling = isForwardFling(layoutManager, i, i2);
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|         if (isForwardFling && view != null) {
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|             return layoutManager.getPosition(view);
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|         }
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|         if (!isForwardFling && view2 != null) {
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|             return layoutManager.getPosition(view2);
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|         }
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|         if (isForwardFling) {
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|             view = view2;
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|         }
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|         if (view == null) {
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|             return -1;
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|         }
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|         int position = layoutManager.getPosition(view) + (isReverseLayout(layoutManager) == isForwardFling ? -1 : 1);
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|         if (position < 0 || position >= itemCount) {
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|             return -1;
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|         }
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|         return position;
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|     }
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| 
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|     private boolean isForwardFling(RecyclerView.LayoutManager layoutManager, int i, int i2) {
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|         return layoutManager.canScrollHorizontally() ? i > 0 : i2 > 0;
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|     }
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| 
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|     /* JADX WARN: Multi-variable type inference failed */
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|     private boolean isReverseLayout(RecyclerView.LayoutManager layoutManager) {
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|         PointF computeScrollVectorForPosition;
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|         int itemCount = layoutManager.getItemCount();
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|         if (!(layoutManager instanceof RecyclerView.SmoothScroller.ScrollVectorProvider) || (computeScrollVectorForPosition = ((RecyclerView.SmoothScroller.ScrollVectorProvider) layoutManager).computeScrollVectorForPosition(itemCount - 1)) == null) {
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|             return false;
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|         }
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|         return computeScrollVectorForPosition.x < 0.0f || computeScrollVectorForPosition.y < 0.0f;
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|     }
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| 
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|     @Override // androidx.recyclerview.widget.SnapHelper
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|     protected LinearSmoothScroller createSnapScroller(RecyclerView.LayoutManager layoutManager) {
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|         if (layoutManager instanceof RecyclerView.SmoothScroller.ScrollVectorProvider) {
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|             return new LinearSmoothScroller(this.mRecyclerView.getContext()) { // from class: androidx.recyclerview.widget.PagerSnapHelper.1
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|                 @Override // androidx.recyclerview.widget.LinearSmoothScroller, androidx.recyclerview.widget.RecyclerView.SmoothScroller
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|                 protected void onTargetFound(View view, RecyclerView.State state, RecyclerView.SmoothScroller.Action action) {
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|                     PagerSnapHelper pagerSnapHelper = PagerSnapHelper.this;
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|                     int[] calculateDistanceToFinalSnap = pagerSnapHelper.calculateDistanceToFinalSnap(pagerSnapHelper.mRecyclerView.getLayoutManager(), view);
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|                     int i = calculateDistanceToFinalSnap[0];
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|                     int i2 = calculateDistanceToFinalSnap[1];
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|                     int calculateTimeForDeceleration = calculateTimeForDeceleration(Math.max(Math.abs(i), Math.abs(i2)));
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|                     if (calculateTimeForDeceleration > 0) {
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|                         action.update(i, i2, calculateTimeForDeceleration, this.mDecelerateInterpolator);
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|                     }
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|                 }
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| 
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|                 @Override // androidx.recyclerview.widget.LinearSmoothScroller
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|                 protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
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|                     return 100.0f / displayMetrics.densityDpi;
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|                 }
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| 
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|                 @Override // androidx.recyclerview.widget.LinearSmoothScroller
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|                 protected int calculateTimeForScrolling(int i) {
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|                     return Math.min(100, super.calculateTimeForScrolling(i));
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|                 }
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|             };
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|         }
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|         return null;
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|     }
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| 
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|     private int distanceToCenter(RecyclerView.LayoutManager layoutManager, View view, OrientationHelper orientationHelper) {
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|         return (orientationHelper.getDecoratedStart(view) + (orientationHelper.getDecoratedMeasurement(view) / 2)) - (orientationHelper.getStartAfterPadding() + (orientationHelper.getTotalSpace() / 2));
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|     }
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| 
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|     private View findCenterView(RecyclerView.LayoutManager layoutManager, OrientationHelper orientationHelper) {
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|         int childCount = layoutManager.getChildCount();
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|         View view = null;
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|         if (childCount == 0) {
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|             return null;
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|         }
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|         int startAfterPadding = orientationHelper.getStartAfterPadding() + (orientationHelper.getTotalSpace() / 2);
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|         int i = Integer.MAX_VALUE;
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|         for (int i2 = 0; i2 < childCount; i2++) {
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|             View childAt = layoutManager.getChildAt(i2);
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|             int abs = Math.abs((orientationHelper.getDecoratedStart(childAt) + (orientationHelper.getDecoratedMeasurement(childAt) / 2)) - startAfterPadding);
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|             if (abs < i) {
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|                 view = childAt;
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|                 i = abs;
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|             }
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|         }
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|         return view;
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|     }
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| 
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|     private OrientationHelper getOrientationHelper(RecyclerView.LayoutManager layoutManager) {
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|         if (layoutManager.canScrollVertically()) {
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|             return getVerticalHelper(layoutManager);
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|         }
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|         if (layoutManager.canScrollHorizontally()) {
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|             return getHorizontalHelper(layoutManager);
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|         }
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|         return null;
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|     }
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| 
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|     private OrientationHelper getVerticalHelper(RecyclerView.LayoutManager layoutManager) {
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|         OrientationHelper orientationHelper = this.mVerticalHelper;
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|         if (orientationHelper == null || orientationHelper.mLayoutManager != layoutManager) {
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|             this.mVerticalHelper = OrientationHelper.createVerticalHelper(layoutManager);
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|         }
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|         return this.mVerticalHelper;
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|     }
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| 
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|     private OrientationHelper getHorizontalHelper(RecyclerView.LayoutManager layoutManager) {
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|         OrientationHelper orientationHelper = this.mHorizontalHelper;
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|         if (orientationHelper == null || orientationHelper.mLayoutManager != layoutManager) {
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|             this.mHorizontalHelper = OrientationHelper.createHorizontalHelper(layoutManager);
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|         }
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|         return this.mHorizontalHelper;
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|     }
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| }
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