com.google.android.apps.forscience.whistlepunk.MultiTouchDrawerLayout.java Source code

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Here is the source code for com.google.android.apps.forscience.whistlepunk.MultiTouchDrawerLayout.java

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/*
 *  Copyright 2016 Google Inc. All Rights Reserved.
 *
 *  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.google.android.apps.forscience.whistlepunk;

import android.content.Context;
import android.support.v4.widget.DrawerLayout;
import android.util.AttributeSet;
import android.view.MotionEvent;

/**
 * This is a workaround to a multi-touch bug in DrawerLayout as described in
 * https://code.google.com/p/android/issues/detail?id=60464.
 * This is taken nearly verbatum from a solution in that thread,
 * https://code.google.com/p/android/issues/detail?id=60464#c5.
 */
public class MultiTouchDrawerLayout extends DrawerLayout {
    public MultiTouchDrawerLayout(Context context) {
        super(context);
    }

    public MultiTouchDrawerLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public MultiTouchDrawerLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    private boolean mIsDisallowIntercept = false;

    @Override
    public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
        // keep the info about if the innerViews do requestDisallowInterceptTouchEvent
        mIsDisallowIntercept = disallowIntercept;
        super.requestDisallowInterceptTouchEvent(disallowIntercept);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        // the incorrect array size will only happen in the multi-touch scenario.
        if (ev.getPointerCount() > 1 && mIsDisallowIntercept) {
            requestDisallowInterceptTouchEvent(false);
            boolean handled = super.dispatchTouchEvent(ev);
            requestDisallowInterceptTouchEvent(true);
            return handled;
        } else {
            return super.dispatchTouchEvent(ev);
        }
    }
}