| /* |
| * Copyright 2017 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.recyclerview.selection; |
| |
| import static android.support.v4.util.Preconditions.checkArgument; |
| |
| import android.support.annotation.NonNull; |
| import android.support.v7.widget.RecyclerView; |
| import android.util.Log; |
| import android.view.MotionEvent; |
| |
| import androidx.recyclerview.selection.ItemDetailsLookup.ItemDetails; |
| import androidx.recyclerview.selection.SelectionTracker.SelectionPredicate; |
| |
| /** |
| * A MotionInputHandler that provides the high-level glue for touch driven selection. This class |
| * works with {@link RecyclerView}, {@link GestureRouter}, and {@link GestureSelectionHelper} to |
| * to implement the primary policies around touch input. |
| * |
| * @param <K> Selection key type. @see {@link StorageStrategy} for supported types. |
| */ |
| final class TouchInputHandler<K> extends MotionInputHandler<K> { |
| |
| private static final String TAG = "TouchInputDelegate"; |
| private static final boolean DEBUG = false; |
| |
| private final ItemDetailsLookup<K> mDetailsLookup; |
| private final SelectionPredicate<K> mSelectionPredicate; |
| private final OnItemActivatedListener<K> mOnItemActivatedListener; |
| private final OnDragInitiatedListener mOnDragInitiatedListener; |
| private final Runnable mGestureStarter; |
| private final Runnable mHapticPerformer; |
| |
| TouchInputHandler( |
| @NonNull SelectionTracker<K> selectionTracker, |
| @NonNull ItemKeyProvider<K> keyProvider, |
| @NonNull ItemDetailsLookup<K> detailsLookup, |
| @NonNull SelectionPredicate<K> selectionPredicate, |
| @NonNull Runnable gestureStarter, |
| @NonNull OnDragInitiatedListener onDragInitiatedListener, |
| @NonNull OnItemActivatedListener<K> onItemActivatedListener, |
| @NonNull FocusDelegate<K> focusDelegate, |
| @NonNull Runnable hapticPerformer) { |
| |
| super(selectionTracker, keyProvider, focusDelegate); |
| |
| checkArgument(detailsLookup != null); |
| checkArgument(selectionPredicate != null); |
| checkArgument(gestureStarter != null); |
| checkArgument(onItemActivatedListener != null); |
| checkArgument(onDragInitiatedListener != null); |
| checkArgument(hapticPerformer != null); |
| |
| mDetailsLookup = detailsLookup; |
| mSelectionPredicate = selectionPredicate; |
| mGestureStarter = gestureStarter; |
| mOnItemActivatedListener = onItemActivatedListener; |
| mOnDragInitiatedListener = onDragInitiatedListener; |
| mHapticPerformer = hapticPerformer; |
| } |
| |
| @Override |
| public boolean onSingleTapUp(@NonNull MotionEvent e) { |
| if (!mDetailsLookup.overItemWithSelectionKey(e)) { |
| if (DEBUG) Log.d(TAG, "Tap not associated w/ model item. Clearing selection."); |
| mSelectionTracker.clearSelection(); |
| return false; |
| } |
| |
| ItemDetails<K> item = mDetailsLookup.getItemDetails(e); |
| // Should really not be null at this point, but... |
| if (item == null) { |
| return false; |
| } |
| |
| if (mSelectionTracker.hasSelection()) { |
| if (isRangeExtension(e)) { |
| extendSelectionRange(item); |
| } else if (mSelectionTracker.isSelected(item.getSelectionKey())) { |
| mSelectionTracker.deselect(item.getSelectionKey()); |
| } else { |
| selectItem(item); |
| } |
| |
| return true; |
| } |
| |
| // Touch events select if they occur in the selection hotspot, |
| // otherwise they activate. |
| return item.inSelectionHotspot(e) |
| ? selectItem(item) |
| : mOnItemActivatedListener.onItemActivated(item, e); |
| } |
| |
| @Override |
| public void onLongPress(@NonNull MotionEvent e) { |
| if (!mDetailsLookup.overItemWithSelectionKey(e)) { |
| if (DEBUG) Log.d(TAG, "Ignoring LongPress on non-model-backed item."); |
| return; |
| } |
| |
| ItemDetails<K> item = mDetailsLookup.getItemDetails(e); |
| // Should really not be null at this point, but... |
| if (item == null) { |
| return; |
| } |
| |
| boolean handled = false; |
| |
| if (isRangeExtension(e)) { |
| extendSelectionRange(item); |
| handled = true; |
| } else { |
| if (!mSelectionTracker.isSelected(item.getSelectionKey()) |
| && mSelectionPredicate.canSetStateForKey(item.getSelectionKey(), true)) { |
| // If we cannot select it, we didn't apply anchoring - therefore should not |
| // start gesture selection |
| if (selectItem(item)) { |
| // And finally if the item was selected && we can select multiple |
| // we kick off gesture selection. |
| if (mSelectionPredicate.canSelectMultiple()) { |
| mGestureStarter.run(); |
| } |
| handled = true; |
| } |
| } else { |
| // We only initiate drag and drop on long press for touch to allow regular |
| // touch-based scrolling |
| mOnDragInitiatedListener.onDragInitiated(e); |
| handled = true; |
| } |
| } |
| |
| if (handled) { |
| mHapticPerformer.run(); |
| } |
| } |
| } |