com.awen.codebase.ui.VerticalViewPager.java Source code

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Here is the source code for com.awen.codebase.ui.VerticalViewPager.java

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/*
 *     Spruce
 *     Copyright (c) 2017 WillowTree, Inc.
 *     Permission is hereby granted, free of charge, to any person obtaining a copy
 *     of this software and associated documentation files (the "Software"), to deal
 *     in the Software without restriction, including without limitation the rights
 *     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *     copies of the Software, and to permit persons to whom the Software is
 *     furnished to do so, subject to the following conditions:
 *     The above copyright notice and this permission notice shall be included in
 *     all copies or substantial portions of the Software.
 *     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *     THE SOFTWARE.
 *
 */

package com.awen.codebase.ui;

import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class VerticalViewPager extends ViewPager {

    public VerticalViewPager(Context context) {
        super(context);
        init();
    }

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

    private void init() {
        setPageTransformer(true, new VerticalPageTransformer());
        setOverScrollMode(OVER_SCROLL_NEVER);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
        swapXY(ev);
        return intercepted;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return super.onTouchEvent(swapXY(ev));
    }

    private MotionEvent swapXY(MotionEvent ev) {
        float width = getWidth();
        float height = getHeight();

        float newX = (ev.getY() / height) * width;
        float newY = (ev.getX() / width) * height;

        ev.setLocation(newX, newY);

        return ev;
    }

    private class VerticalPageTransformer implements ViewPager.PageTransformer {

        @Override
        public void transformPage(View view, float position) {
            if (position < -1) {
                view.setAlpha(0);
            } else if (position <= 1) {
                view.setAlpha(1);
                view.setTranslationX(view.getWidth() * -position);
                float yPosition = position * view.getHeight();
                view.setTranslationY(yPosition);
            } else {
                view.setAlpha(0);
            }
        }
    }

}