private float calculateTranslationPhase(
RecyclerView.ViewHolder draggingItem, RecyclerView.ViewHolder swapTargetItem) {
final View swapItemView = swapTargetItem.itemView;
final int pos1 = draggingItem.getLayoutPosition();
final int pos2 = swapTargetItem.getLayoutPosition();
CustomRecyclerViewUtils.getDecorationOffsets(
mRecyclerView.getLayoutManager(), swapItemView, mSwapTargetDecorationOffsets);
CustomRecyclerViewUtils.getLayoutMargins(swapItemView, mSwapTargetItemMargins);
final Rect m2 = mSwapTargetItemMargins;
final Rect d2 = mSwapTargetDecorationOffsets;
final int h2 = swapItemView.getHeight() + m2.top + m2.bottom + d2.top + d2.bottom;
final float offsetPx =
draggingItem.itemView.getTop()
- mTranslationY; // == -(ViewCompat.getTranslationY(draggingItem.itemView)
final float phase = (h2 != 0) ? (offsetPx / h2) : 0.0f;
float translationPhase;
if (pos1 > pos2) {
// dragging item moving to upward
translationPhase = phase;
} else {
// dragging item moving to downward
translationPhase = 1.0f + phase;
}
return Math.min(Math.max(translationPhase, 0.0f), 1.0f);
}
public SwapTargetItemOperator(
RecyclerView recyclerView, RecyclerView.ViewHolder draggingItem, ItemDraggableRange range) {
super(recyclerView, draggingItem);
mDraggingItemId = mDraggingItem.getItemId();
mRange = range;
CustomRecyclerViewUtils.getLayoutMargins(mDraggingItem.itemView, mDraggingItemMargins);
CustomRecyclerViewUtils.getDecorationOffsets(
mRecyclerView.getLayoutManager(), mDraggingItem.itemView, mDraggingItemDecorationOffsets);
}