DisallowInterceptFilter.java
/*
* Copyright 2020 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 android.view.MotionEvent;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.RecyclerView.OnItemTouchListener;
/**
* Wrapper class that regulates delivery of MotionEvents to delegate listeners, uniformly
* honoring requests to onRequestDisallowInterceptTouchEvent.
* Wrap this class around other OnItemTouchListeners to bestow them with
* proper support for onRequestDisallowInterceptTouchEvent.
*/
// TODO: Replace in-situ "disallow" implementation in EventRouter, ResetManager,
// BandSelectionHelper, GestureSelectionHelper by wrapping w/ this class.
class DisallowInterceptFilter implements
OnItemTouchListener, Resettable {
private final OnItemTouchListener mDelegate;
private boolean mDisallowIntercept;
DisallowInterceptFilter(@NonNull OnItemTouchListener delegate) {
mDelegate = delegate;
}
@Override
public boolean onInterceptTouchEvent(@NonNull RecyclerView rv, @NonNull MotionEvent e) {
// Reset disallow when the event is down as advised in http://b/139141511#comment20.
if (mDisallowIntercept && MotionEvents.isActionDown(e)) {
mDisallowIntercept = false;
}
return !mDisallowIntercept && mDelegate.onInterceptTouchEvent(rv, e);
}
@Override
public void onTouchEvent(@NonNull RecyclerView rv, @NonNull MotionEvent e) {
mDelegate.onInterceptTouchEvent(rv, e);
}
@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
mDisallowIntercept = true;
}
@Override
public boolean isResetRequired() {
return mDisallowIntercept;
}
@Override
public void reset() {
mDisallowIntercept = false;
}
}