ca.mymenuapp.ui.widgets.SwipeableActionBarTabsAdapter.java Source code

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Here is the source code for ca.mymenuapp.ui.widgets.SwipeableActionBarTabsAdapter.java

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/*
 * Copyright (C) 2014 MyMenu, Inc.
 *
 * 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/].
 */

package ca.mymenuapp.ui.widgets;

import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.support.v13.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import java.util.ArrayList;

/**
 * This is a helper class that implements the management of tabs and all
 * details of connecting a ViewPager with associated TabHost.  It relies on a
 * trick.  Normally a tab host has a simple API for supplying a View or
 * Intent that each tab will show.  This is not sufficient for switching
 * between pages.  So instead we make the content part of the tab host
 * 0dp high (it is not shown) and the TabsAdapter supplies its own dummy
 * view to show as the tab content.  It listens to changes in tabs, and takes
 * care of switch to the correct paged in the ViewPager whenever the selected
 * tab changes.
 */
public class SwipeableActionBarTabsAdapter extends FragmentPagerAdapter
        implements ActionBar.TabListener, ViewPager.OnPageChangeListener {
    private final Context context;
    private final ActionBar actionBar;
    private final ViewPager viewPager;
    private final ArrayList<TabInfo> tabs = new ArrayList<TabInfo>();

    static final class TabInfo {
        private final Class<?> clss;
        private final Bundle args;

        TabInfo(Class<?> clss, Bundle args) {
            this.clss = clss;
            this.args = args;
        }
    }

    public SwipeableActionBarTabsAdapter(Activity activity, ViewPager pager,
            DelegateOnPageChangeListener delegate) {
        super(activity.getFragmentManager());
        context = activity;
        actionBar = activity.getActionBar();
        viewPager = pager;
        viewPager.setAdapter(this);
        delegate.addOnPageChangeListener(this);
    }

    public void addTab(ActionBar.Tab tab, Class<?> clss, Bundle args) {
        TabInfo info = new TabInfo(clss, args);
        tab.setTag(info);
        tab.setTabListener(this);
        tabs.add(info);
        actionBar.addTab(tab);
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return tabs.size();
    }

    @Override
    public Fragment getItem(int position) {
        TabInfo info = tabs.get(position);
        return Fragment.instantiate(context, info.clss.getName(), info.args);
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    }

    @Override
    public void onPageSelected(int position) {
        actionBar.setSelectedNavigationItem(position);
    }

    @Override
    public void onPageScrollStateChanged(int state) {
    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
        Object tag = tab.getTag();
        for (int i = 0; i < tabs.size(); i++) {
            if (tabs.get(i) == tag) {
                viewPager.setCurrentItem(i);
            }
        }
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
    }
}