co.carlosandresjimenez.android.gotit.TabLayoutOnPageChangeListener.java Source code

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Here is the source code for co.carlosandresjimenez.android.gotit.TabLayoutOnPageChangeListener.java

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/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Carlos Andres Jimenez <apps@carlosandresjimenez.co>
 *
 * 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 co.carlosandresjimenez.android.gotit;

import android.support.design.widget.TabLayout;
import android.support.v4.view.ViewPager;

import java.lang.ref.WeakReference;

/**
 * Created by carlosjimenez on 10/30/15.
 */
public class TabLayoutOnPageChangeListener implements ViewPager.OnPageChangeListener {

    private final WeakReference<TabLayout> mTabLayoutRef;
    private int mPreviousScrollState;
    private int mScrollState;

    public TabLayoutOnPageChangeListener(TabLayout tabLayout) {
        mTabLayoutRef = new WeakReference<>(tabLayout);
    }

    @Override
    public void onPageScrollStateChanged(int state) {
        mPreviousScrollState = mScrollState;
        mScrollState = state;
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        final TabLayout tabLayout = mTabLayoutRef.get();
        if (tabLayout != null) {
            final boolean updateText = (mScrollState == ViewPager.SCROLL_STATE_DRAGGING)
                    || (mScrollState == ViewPager.SCROLL_STATE_SETTLING
                            && mPreviousScrollState == ViewPager.SCROLL_STATE_DRAGGING);
            tabLayout.setScrollPosition(position, positionOffset, updateText);
        }
    }

    @Override
    public void onPageSelected(int position) {
        final TabLayout tabLayout = mTabLayoutRef.get();
        if (tabLayout != null) {
            tabLayout.getTabAt(position).select();
        }
    }
}