org.xbmc.android.view.RelativePagerAdapter.java Source code

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Here is the source code for org.xbmc.android.view.RelativePagerAdapter.java

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/*
 *      Copyright (C) 2005-2015 Team XBMC
 *      http://xbmc.org
 *
 *  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 2, 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 XBMC Remote; see the file license.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

package org.xbmc.android.view;

import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

import static org.xbmc.android.view.RelativePagerFragment.OnStatusChangeListener;

/**
 * A pager adapter that relies on the currently displayed fragment to deliver the
 * next or previous page, as opposed to a global list of fragments.
 *
 * It does this by keeping only three pages in the stack and moving them to the left
 * or right depending on how the user swipes. In order to do that, it must always be
 * used with a {@link RelativeViewPager}.
 *
 * @author freezy <freezy@xbmc.org>
 */
public class RelativePagerAdapter extends FragmentStatePagerAdapter implements OnStatusChangeListener {

    public static final int PAGE_POSITION_LEFT = 0;
    public static final int PAGE_POSITION_CENTER = 1;
    public static final int PAGE_POSITION_RIGHT = 2;

    public static final int NUM_ITEMS = 3;

    private RelativePagerFragment currFragment;
    private RelativeViewPager pager;

    private final FragmentStateManager fragmentStateManager;

    private final FragmentManager fragmentManager;

    public RelativePagerAdapter(FragmentManager fm, FragmentStateManager fsm) {
        super(fm);
        fragmentManager = fm;
        fragmentStateManager = fsm;
        fragmentStateManager.setOnStatusChangeListener(this);
    }

    public void setInitialFragment(RelativePagerFragment fragment) {
        currFragment = fragment;
    }

    public void setPager(RelativeViewPager p) {
        pager = p;
    }

    @Override
    public int getItemPosition(Object object) {
        return POSITION_NONE;
    }

    public void move(int direction) {
        if (direction == 1) {
            currFragment = currFragment.hasPrev() ? currFragment.getPrev(fragmentStateManager) : currFragment;
        } else {
            currFragment = currFragment.hasNext() ? currFragment.getNext(fragmentStateManager) : currFragment;
        }
        notifyDataSetChanged();
    }

    public RelativePagerFragment getCurrentFragment() {
        return currFragment;
    }

    @Override
    public int getCount() {
        return NUM_ITEMS;
    }

    @Override
    public Fragment getItem(int position) {
        if (currFragment == null) {
            throw new RuntimeException("Must set initial fragment before view is rendered.");
        }
        if (position == PAGE_POSITION_RIGHT) {
            return currFragment.hasNext() ? currFragment.getNext(fragmentStateManager) : new Fragment();
        } else if (position == PAGE_POSITION_LEFT) {
            return currFragment.hasPrev() ? currFragment.getPrev(fragmentStateManager) : new Fragment();
        } else {
            return currFragment;
        }
    }

    @Override
    public Parcelable saveState() {
        final Bundle state = (Bundle) super.saveState();
        fragmentManager.putFragment(state, "currentFragment", currFragment);
        return state;
    }

    @Override
    public void restoreState(Parcelable state, ClassLoader loader) {
        super.restoreState(state, loader);
        final Bundle bundle = (Bundle) state;
        bundle.setClassLoader(loader);
        currFragment = (RelativePagerFragment) fragmentManager.getFragment(bundle, "currentFragment");
    }

    @Override
    public void onNextPage() {
        if (!currFragment.onNextClicked()) {
            notifyDataSetChanged();
            pager.setCurrentItem(PAGE_POSITION_RIGHT, true);
        }
    }

    @Override
    public void onPrevPage() {
        if (!currFragment.onPrevClicked()) {
            notifyDataSetChanged();
            pager.setCurrentItem(PAGE_POSITION_LEFT, true);
        }
    }

    @Override
    public void onStatusUpdated() {
        pager.onStatusUpdate();
    }
}