1 /* 2 * Copyright 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package androidx.recyclerview.selection; 18 19 import static androidx.core.util.Preconditions.checkArgument; 20 21 import android.view.MotionEvent; 22 23 import androidx.annotation.Nullable; 24 import androidx.recyclerview.widget.RecyclerView; 25 import androidx.recyclerview.widget.RecyclerView.OnItemTouchListener; 26 27 /** 28 * OnItemTouchListener that delegates drag events to a drag listener, 29 * else sends event to fallback {@link OnItemTouchListener}. 30 * 31 * <p>See {@link OnDragInitiatedListener} for details on implementing drag and drop. 32 */ 33 final class PointerDragEventInterceptor implements OnItemTouchListener { 34 35 private final ItemDetailsLookup mEventDetailsLookup; 36 private final OnDragInitiatedListener mDragListener; 37 private @Nullable OnItemTouchListener mDelegate; 38 39 PointerDragEventInterceptor( 40 ItemDetailsLookup eventDetailsLookup, 41 OnDragInitiatedListener dragListener, 42 @Nullable OnItemTouchListener delegate) { 43 44 checkArgument(eventDetailsLookup != null); 45 checkArgument(dragListener != null); 46 47 mEventDetailsLookup = eventDetailsLookup; 48 mDragListener = dragListener; 49 mDelegate = delegate; 50 } 51 52 @Override 53 public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) { 54 if (MotionEvents.isPointerDragEvent(e) && mEventDetailsLookup.inItemDragRegion(e)) { 55 return mDragListener.onDragInitiated(e); 56 } else if (mDelegate != null) { 57 return mDelegate.onInterceptTouchEvent(rv, e); 58 } 59 return false; 60 } 61 62 @Override 63 public void onTouchEvent(RecyclerView rv, MotionEvent e) { 64 if (mDelegate != null) { 65 mDelegate.onTouchEvent(rv, e); 66 } 67 } 68 69 @Override 70 public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) { 71 if (mDelegate != null) { 72 mDelegate.onRequestDisallowInterceptTouchEvent(disallowIntercept); 73 } 74 } 75 } 76
