Java tutorial
/* * Copyright 2016 Hippo Seven * * 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 com.hippo.ehviewer.gallery.gl; import android.content.Context; import android.os.SystemClock; import android.support.v4.view.GestureDetectorCompat; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.ScaleGestureDetector; // This class aggregates three gesture detectors: GestureDetector, // ScaleGestureDetector, and DownUpDetector. public class GestureRecognizer { @SuppressWarnings("unused") private static final String TAG = "GestureRecognizer"; public interface Listener { boolean onSingleTapUp(float x, float y); boolean onSingleTapConfirmed(float x, float y); boolean onDoubleTap(float x, float y); boolean onDoubleTapConfirmed(float x, float y); void onLongPress(float x, float y); boolean onScroll(float dx, float dy, float totalX, float totalY, float x, float y); /** * @param velocityX Finger from top to bottom is positive * @param velocityY Finger from left to right is positive */ boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY); boolean onScaleBegin(float focusX, float focusY); boolean onScale(float focusX, float focusY, float scale); void onScaleEnd(); void onDown(float x, float y); void onUp(); void onPointerDown(float x, float y); void onPointerUp(); } private final GestureDetectorCompat mGestureDetector; private final ScaleGestureDetector mScaleDetector; private final DownUpDetector mDownUpDetector; private final Listener mListener; public GestureRecognizer(Context context, Listener listener) { mListener = listener; MyGestureListener gestureListener = new MyGestureListener(); mGestureDetector = new GestureDetectorCompat(context, gestureListener, null /* ignoreMultitouch */); mGestureDetector.setOnDoubleTapListener(gestureListener); mScaleDetector = new ScaleGestureDetector(context, new MyScaleListener()); mDownUpDetector = new DownUpDetector(new MyDownUpListener()); } public void onTouchEvent(MotionEvent event) { mScaleDetector.onTouchEvent(event); mGestureDetector.onTouchEvent(event); mDownUpDetector.onTouchEvent(event); } public boolean isDown() { return mDownUpDetector.isDown(); } public void cancelScale() { long now = SystemClock.uptimeMillis(); MotionEvent cancelEvent = MotionEvent.obtain(now, now, MotionEvent.ACTION_CANCEL, 0, 0, 0); mScaleDetector.onTouchEvent(cancelEvent); cancelEvent.recycle(); } private class MyGestureListener extends GestureDetector.SimpleOnGestureListener { @Override public boolean onSingleTapUp(MotionEvent e) { return mListener.onSingleTapUp(e.getX(), e.getY()); } @Override public boolean onSingleTapConfirmed(MotionEvent e) { return mListener.onSingleTapConfirmed(e.getX(), e.getY()); } @Override public boolean onDoubleTapEvent(MotionEvent e) { if (e.getAction() == MotionEvent.ACTION_UP) { return mListener.onDoubleTapConfirmed(e.getX(), e.getY()); } else { return true; } } @Override public boolean onDoubleTap(MotionEvent e) { return mListener.onDoubleTap(e.getX(), e.getY()); } @Override public void onLongPress(MotionEvent e) { mListener.onLongPress(e.getX(), e.getY()); } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float dx, float dy) { return mListener.onScroll(dx, dy, e2.getX() - e1.getX(), e2.getY() - e1.getY(), e2.getX(), e2.getY()); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { return mListener.onFling(e1, e2, velocityX, velocityY); } } private class MyScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener { @Override public boolean onScaleBegin(ScaleGestureDetector detector) { return mListener.onScaleBegin(detector.getFocusX(), detector.getFocusY()); } @Override public boolean onScale(ScaleGestureDetector detector) { return mListener.onScale(detector.getFocusX(), detector.getFocusY(), detector.getScaleFactor()); } @Override public void onScaleEnd(ScaleGestureDetector detector) { mListener.onScaleEnd(); } } private class MyDownUpListener implements DownUpDetector.DownUpListener { @Override public void onDown(MotionEvent e) { mListener.onDown(e.getX(), e.getY()); } @Override public void onUp(MotionEvent e) { mListener.onUp(); } @Override public void onPointerDown(MotionEvent e) { mListener.onPointerDown(e.getX(), e.getY()); } @Override public void onPointerUp(MotionEvent e) { mListener.onPointerUp(); } } }