/*
 * Tint Browser for Android
 * 
 * Copyright (C) 2012 - to infinity and beyond J. Devauchelle and contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 3 as published by the Free Software Foundation.
 *
 * 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.
 */

package com.seal.ui.tabs;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;

public class GenericTabListener<T extends Fragment> implements ActionBar.TabListener {

	private Fragment mFragment;
	private Activity mActivity;
	private String mTag;
	private Class<T> mClass;

	/**
	 * Constructor used each time a new tab is created.
	 * 
	 * @param activity
	 *            The host Activity, used to instantiate the fragment
	 * @param tag
	 *            The identifier tag for the fragment
	 * @param clz
	 *            The fragment's Class, used to instantiate the fragment
	 */
	public GenericTabListener(Activity activity, String tag, Class<T> clz) {
		this(activity, tag, clz, null);
	}

	public GenericTabListener(Activity activity, String tag, Class<T> clz, Bundle args) {
		mFragment = null;
		mActivity = activity;
		mTag = tag;
		mClass = clz;

		// Check to see if we already have a fragment for this tab, probably
		// from a previously saved state. If so, deactivate it, because our
		// initial state is that a tab isn't shown.
		mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
		if (mFragment != null && !mFragment.isDetached()) {
			FragmentTransaction ft = mActivity.getFragmentManager().beginTransaction();
			ft.detach(mFragment);
			ft.commit();
		}

	}

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

	@Override
	public void onTabSelected(Tab tab, FragmentTransaction ft) {
		// Check if the fragment is already initialized
		if (mFragment == null) {
			// If not, instantiate and add it to the activity
			mFragment = Fragment.instantiate(mActivity, mClass.getName());
			ft.add(android.R.id.content, mFragment, mTag);
		} else {
			// If it exists, simply attach it in order to show it
			ft.attach(mFragment);
		}
	}

	@Override
	public void onTabUnselected(Tab tab, FragmentTransaction ft) {
		if (mFragment != null) {
			// Detach the fragment, because another one is being attached
			ft.detach(mFragment);
		}
	}
}