open-keychain/OpenPGP-Keychain/src/org/sufficientlysecure/keychain/ui/HelpActivity.java

/*
 * Copyright (C) 2012-2013 Dominik Schürmann <dominik@dominikschuermann.de>
 *
 * 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 org.sufficientlysecure.keychain.ui;

import org.sufficientlysecure.keychain.R;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.widget.TextView;

import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.ActionBar.Tab;
import com.actionbarsherlock.view.MenuItem;

import java.util.ArrayList;

import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;

import com.actionbarsherlock.app.SherlockFragmentActivity;

public class HelpActivity extends SherlockFragmentActivity {
    public static final String EXTRA_SELECTED_TAB = "selectedTab";

    ViewPager mViewPager;
    TabsAdapter mTabsAdapter;
    TextView tabCenter;
    TextView tabText;

    /**
     * Menu Items
     */
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case android.R.id.home:
            // app icon in Action Bar clicked; go home
            Intent intent = new Intent(this, MainActivity.class);
            intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            startActivity(intent);
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mViewPager = new ViewPager(this);
        mViewPager.setId(R.id.pager);

        setContentView(mViewPager);
        ActionBar bar = getSupportActionBar();
        bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        bar.setDisplayShowTitleEnabled(true);
        bar.setDisplayHomeAsUpEnabled(true);

        mTabsAdapter = new TabsAdapter(this, mViewPager);

        int selectedTab = 0;
        Intent intent = getIntent();
        if (intent.getExtras() != null && intent.getExtras().containsKey(EXTRA_SELECTED_TAB)) {
            selectedTab = intent.getExtras().getInt(EXTRA_SELECTED_TAB);
        }

        Bundle startBundle = new Bundle();
        startBundle.putInt(HelpFragmentHtml.ARG_HTML_FILE, R.raw.help_start);
        mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.help_tab_start)),
                HelpFragmentHtml.class, startBundle, (selectedTab == 0 ? true : false));

        Bundle nfcBundle = new Bundle();
        nfcBundle.putInt(HelpFragmentHtml.ARG_HTML_FILE, R.raw.help_nfc_beam);
        mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.help_tab_nfc_beam)),
                HelpFragmentHtml.class, nfcBundle, (selectedTab == 1 ? true : false));

        Bundle changelogBundle = new Bundle();
        changelogBundle.putInt(HelpFragmentHtml.ARG_HTML_FILE, R.raw.help_changelog);
        mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.help_tab_changelog)),
                HelpFragmentHtml.class, changelogBundle, (selectedTab == 2 ? true : false));

        mTabsAdapter.addTab(bar.newTab().setText(getString(R.string.help_tab_about)),
                HelpFragmentAbout.class, null, (selectedTab == 3 ? true : false));
    }

    public static class TabsAdapter extends FragmentPagerAdapter implements ActionBar.TabListener,
            ViewPager.OnPageChangeListener {
        private final Context mContext;
        private final ActionBar mActionBar;
        private final ViewPager mViewPager;
        private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();

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

            TabInfo(Class<?> _class, Bundle _args) {
                clss = _class;
                args = _args;
            }
        }

        public TabsAdapter(SherlockFragmentActivity activity, ViewPager pager) {
            super(activity.getSupportFragmentManager());
            mContext = activity;
            mActionBar = activity.getSupportActionBar();
            mViewPager = pager;
            mViewPager.setAdapter(this);
            mViewPager.setOnPageChangeListener(this);
        }

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

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

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

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

        public void onPageSelected(int position) {
            mActionBar.setSelectedNavigationItem(position);
        }

        public void onPageScrollStateChanged(int state) {
        }

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

        public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        }

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