DungeonManager/app/src/main/java/com/kauron/dungeonmanager/Display.java

package com.kauron.dungeonmanager;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TabHost;
import android.widget.TabHost.TabContentFactory;
import android.widget.Toast;

import java.util.HashMap;
import java.util.List;
import java.util.Vector;

/**
 * The <code>Display</code> class implements the Fragment activity that maintains a TabHost using a ViewPager.
 */
public class Display extends ActionBarActivity implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {

    private TabHost mTabHost;
    private ViewPager mViewPager;
    private HashMap<String, TabInfo> mapTabInfo = new HashMap<String, Display.TabInfo>();
    private PagerAdapter mPagerAdapter;
    /**
     *
     * Maintains extrinsic info of a tab's construct
     */
    private class TabInfo {
        private String tag;
        private Class<?> clss;
        private Bundle args;
        private Fragment fragment;
        TabInfo(String tag, Class<?> clazz, Bundle args) {
            this.tag = tag;
            this.clss = clazz;
            this.args = args;
        }

    }
    /**
     * A simple factory that returns dummy views to the Tabhost
     */
    class TabFactory implements TabContentFactory {

        private final Context mContext;

        /**
         * @param context
         */
        public TabFactory(Context context) {
            mContext = context;
        }

        /** (non-Javadoc)
         * @see android.widget.TabHost.TabContentFactory#createTabContent(java.lang.String)
         */
        public View createTabContent(String tag) {
            View v = new View(mContext);
            v.setMinimumWidth(0);
            v.setMinimumHeight(0);
            return v;
        }

    }
    /** (non-Javadoc)
     * @see android.support.v4.app.FragmentActivity#onCreate(android.os.Bundle)
     */
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Inflate the layout
        setContentView(R.layout.display);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Kauron");
        toolbar.setSubtitle("Brujo Tiflin");
        setSupportActionBar(toolbar);
        getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(true);
        // Initialise the TabHost
        this.initialiseTabHost(savedInstanceState);
        if (savedInstanceState != null) {
            mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab")); //set the tab as per the saved state
        }
        // Initialise ViewPager
        this.intialiseViewPager();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        if ( mTabHost.getCurrentTabTag().equals("Stats") ) {
            getMenuInflater().inflate(R.menu.menu_welcome, menu);
        } else if ( mTabHost.getCurrentTabTag().equals("Powers") ) {
            getMenuInflater().inflate(R.menu.menu_show_player, menu);
        }
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if ( id == R.id.action_add_player ) {
            Toast.makeText(getApplicationContext(), "it works", Toast.LENGTH_LONG).show();
        }

        return super.onOptionsItemSelected(item);
    }

    /** (non-Javadoc)
     * @see android.support.v4.app.FragmentActivity#onSaveInstanceState(android.os.Bundle)
     */
    protected void onSaveInstanceState(Bundle outState) {
        outState.putString("tab", mTabHost.getCurrentTabTag()); //save the tab selected
        super.onSaveInstanceState(outState);
    }

    /**
     * Initialise ViewPager
     */
    private void intialiseViewPager() {

        List<Fragment> fragments = new Vector<>();
        fragments.add(Fragment.instantiate(this, PlayerDisplay.class.getName()));
        fragments.add(Fragment.instantiate(this, PowerDisplay.class.getName()));
        this.mPagerAdapter  = new PagerAdapter(super.getSupportFragmentManager(), fragments);
        //
        this.mViewPager = (ViewPager)super.findViewById(R.id.viewpager);
        this.mViewPager.setAdapter(this.mPagerAdapter);
        this.mViewPager.setOnPageChangeListener(this);
    }

    /**
     * Initialise the Tab Host
     */
    private void initialiseTabHost(Bundle args) {
        mTabHost = (TabHost)findViewById(android.R.id.tabhost);
        mTabHost.setup();
        TabInfo tabInfo = null;
        Display.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Stats").setIndicator("Stats"), (tabInfo = new TabInfo("Stats", PlayerDisplay.class, args)));
        this.mapTabInfo.put(tabInfo.tag, tabInfo);
        Display.AddTab(this, this.mTabHost, this.mTabHost.newTabSpec("Powers").setIndicator("Powers"), (tabInfo = new TabInfo("Powers", PowerDisplay.class, args)));
        this.mapTabInfo.put(tabInfo.tag, tabInfo);
        // Default to first tab
        //this.onTabChanged("Tab1");
        //
        mTabHost.setOnTabChangedListener(this);
    }

    /**
     * Add Tab content to the Tabhost
     * @param activity
     * @param tabHost
     * @param tabSpec
     */
    private static void AddTab(Display activity, TabHost tabHost, TabHost.TabSpec tabSpec, TabInfo tabInfo) {
        // Attach a Tab view factory to the spec
        tabSpec.setContent(activity.new TabFactory(activity));
        tabHost.addTab(tabSpec);
    }

    /** (non-Javadoc)
     * @see android.widget.TabHost.OnTabChangeListener#onTabChanged(java.lang.String)
     */
    public void onTabChanged(String tag) {
        //TabInfo newTab = this.mapTabInfo.get(tag);
        int pos = this.mTabHost.getCurrentTab();
        this.mViewPager.setCurrentItem(pos);
    }

    /* (non-Javadoc)
     * @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrolled(int, float, int)
     */
    @Override
    public void onPageScrolled(int position, float positionOffset,
                               int positionOffsetPixels) {
        // TODO Auto-generated method stub

    }

    /* (non-Javadoc)
     * @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageSelected(int)
     */
    @Override
    public void onPageSelected(int position) {
        // TODO Auto-generated method stub
        this.mTabHost.setCurrentTab(position);
    }

    /* (non-Javadoc)
     * @see android.support.v4.view.ViewPager.OnPageChangeListener#onPageScrollStateChanged(int)
     */
    @Override
    public void onPageScrollStateChanged(int state) {
        // TODO Auto-generated method stub

    }
}