Java tutorial
/* * Copyright (c) 2013 Menny Even-Danan * * 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.anysoftkeyboard.devicespecific; import android.annotation.TargetApi; import android.content.Context; import android.support.annotation.NonNull; import android.support.v4.view.MotionEventCompat; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import com.anysoftkeyboard.utils.Log; @TargetApi(8) public class AskV8GestureDetector extends GestureDetector { private static final String TAG = "AskV8GestureDetector"; private static final int NOT_A_POINTER_ID = -1; protected final ScaleGestureDetector mScaleGestureDetector; private final AskOnGestureListener mListener; private int mSingleFingerEventPointerId = NOT_A_POINTER_ID; public AskV8GestureDetector(Context context, AskOnGestureListener listener) { super(context, listener, null, true/*ignore multi-touch*/); mListener = listener; mScaleGestureDetector = new ScaleGestureDetector(context, new ScaleGestureDetector.SimpleOnScaleGestureListener() { @Override public boolean onScale(ScaleGestureDetector detector) { final float factor = detector.getScaleFactor(); Log.d(TAG, "onScale factor " + factor); if (factor > 1.1) return mListener.onSeparate(factor); else if (factor < 0.9) return mListener.onPinch(factor); return false; } }); } @Override public boolean onTouchEvent(@NonNull MotionEvent ev) { int singleFingerEventPointerId = mSingleFingerEventPointerId; //I want to keep track on the first finger (https://github.com/AnySoftKeyboard/AnySoftKeyboard/issues/300) switch (MotionEventCompat.getActionMasked(ev)) { case MotionEvent.ACTION_DOWN: if (ev.getPointerCount() == 1) { mSingleFingerEventPointerId = ev.getPointerId(0); singleFingerEventPointerId = mSingleFingerEventPointerId; } break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: if (ev.getPointerCount() == 1) mSingleFingerEventPointerId = NOT_A_POINTER_ID; } try { //https://github.com/AnySoftKeyboard/AnySoftKeyboard/issues/26 mScaleGestureDetector.onTouchEvent(ev); } catch (IllegalArgumentException e) { //I have nothing I can do here. } catch (ArrayIndexOutOfBoundsException e) { //I have nothing I can do here. } //I'm going to pass the event to the super, only if it is a single touch, and the event is for the first finger //https://github.com/AnySoftKeyboard/AnySoftKeyboard/issues/300 if (ev.getPointerCount() == 1 && ev.getPointerId(0) == singleFingerEventPointerId) return super.onTouchEvent(ev); else return false; } }