AskV8GestureDetector.java

/*
 * 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;
    }

}