/**
 * openHAB, the open Home Automation Bus.
 * Copyright (C) 2010-2012, openHAB.org <admin@openhab.org>
 *
 * See the contributors.txt file in the distribution for a
 * full listing of individual contributors.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses>.
 *
 * Additional permission under GNU GPL version 3 section 7
 *
 * If you modify this Program, or any covered work, by linking or
 * combining it with Eclipse (or a modified version of that library),
 * containing parts covered by the terms of the Eclipse Public License
 * (EPL), the licensors of this Program grant you additional permission
 * to convey the resulting work.
 */

package org.openhab.habdroid.ui;

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

import java.lang.reflect.Field;

public class OpenHABViewPager extends ViewPager {

    // Disable page swiping by default
    private boolean mSwipeEnabled = false;
    // A custom scroller to lower the scroll speed a little bit
    private ScrollerCustomDuration mScroller = null;

    public OpenHABViewPager(Context context) {
        super(context);
        postInitViewPager();
    }

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

    /**
     * Override the Scroller instance with our own class so we can change the
     * duration
     */

    private void postInitViewPager() {
        try {
            Class<?> viewpager = ViewPager.class;
            Field scroller = viewpager.getDeclaredField("mScroller");
            scroller.setAccessible(true);
            Field interpolator = viewpager.getDeclaredField("sInterpolator");
            interpolator.setAccessible(true);

            mScroller = new ScrollerCustomDuration(getContext(),
                    (Interpolator) interpolator.get(null));
            scroller.set(this, mScroller);
        } catch (Exception e) {
        }
    }

    /**
     * Set the factor by which the duration will change
     */
    public void setScrollDurationFactor(double scrollFactor) {
        mScroller.setScrollDurationFactor(scrollFactor);
    }

    /*
        onTouchEvent and onInterceptTouchEvent are needed to prevent swiping
        sitemap pages (OpenHABWidgetListFragments) to keep navigation as usual
        (press item to drill down, press 'back' to get to previous page)
     */

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (this.mSwipeEnabled) {
            return super.onTouchEvent(event);
        }

        return false;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        if (this.mSwipeEnabled) {
            return super.onInterceptTouchEvent(event);
        }

        return false;
    }

    /*
        For flexibility or future use you can enable swiping pages (disabled by default)
     */

    public void setSwipeEnabled(boolean swipe) {
        mSwipeEnabled = swipe;
    }
}