MainActivity.java

package com.orisider.gdfs.ui.activity;

import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.view.Menu;
import com.actionbarsherlock.view.MenuItem;
import com.github.rtyley.android.sherlock.roboguice.activity.RoboSherlockFragmentActivity;
import com.ipaulpro.afilechooser.FileChooserFragment;
import com.orisider.gdfs.R;
import com.orisider.gdfs.ui.event.GDFSDialogConfirmEvent;
import com.orisider.gdfs.ui.fragment.MainF;
import com.orisider.gdfs.ui.fragment.diag.AboutFragment;
import com.orisider.gdfs.ui.fragment.diag.ConfirmFragment;
import com.orisider.gdfs.util.Constant;
import roboguice.event.Observes;
import roboguice.inject.InjectView;

import java.io.File;
import java.util.List;

public class MainActivity extends RoboSherlockFragmentActivity implements FileChooserFragment.FileChooserListener {
    private static final String BUNDLE_KEY_SELECTED_TAB = "selected_tab";
    private static final String BUNDLE_KEY_SELECTED_FILE = "selected_file";
    private static final String DEFAULT_TITLE = "GDFS";

    private int selectedTabIndex = 0;
    private File selectedFile = null;

    @InjectView(R.id.pager)
    private ViewPager pager;
    private TabPagerAdapter adapter;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActionBar ab = getSupportActionBar();
        ab.setDisplayHomeAsUpEnabled(false);
        ab.setDisplayShowHomeEnabled(true);


        setTitle(DEFAULT_TITLE);
        setContentView(R.layout.a_main);

		initTab();

		if (savedInstanceState != null) {
			selectedTabIndex = savedInstanceState.getInt(BUNDLE_KEY_SELECTED_TAB, 0);
			selectedFile = (File) savedInstanceState.getSerializable(BUNDLE_KEY_SELECTED_FILE);

			FileChooserFragment f = getFileChooseFragment();
			if (f != null) {
				f.setListener(this);
			}
		}
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getSupportMenuInflater().inflate(R.menu.a_main, menu);

        MenuItem launchItem = menu.findItem(R.id.launch_gdrive);
        launchItem.setVisible(isGdriveInstalled());

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.launch_gdrive:
                startActivity(new Intent().setComponent(new ComponentName(Constant.PKG_GDRIVE,
                        "com.google.android.apps.docs.app.NewMainProxyActivity")).setFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
                break;
            case R.id.about:
                new AboutFragment().show(getSupportFragmentManager(), Constant.FRAG_TAG_DIALOG);
                break;
            default:
        }
        return true;
    }

    private boolean isGdriveInstalled() {
        List<ApplicationInfo> packages;
        PackageManager pm = getPackageManager();
        packages = pm.getInstalledApplications(0);
        for (ApplicationInfo packageInfo : packages) {
            if (packageInfo.packageName.equals(Constant.PKG_GDRIVE))
                return true;
        }
        return false;
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(BUNDLE_KEY_SELECTED_TAB, selectedTabIndex);
        outState.putSerializable(BUNDLE_KEY_SELECTED_FILE, selectedFile);
    }

    private void initTab() {
        final ActionBar ab = getSupportActionBar();
        ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        ViewPager.SimpleOnPageChangeListener pageChangeListener = new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                super.onPageSelected(position);
                ab.setSelectedNavigationItem(position);
            }
        };

        pager.setOnPageChangeListener(pageChangeListener);

        adapter = new TabPagerAdapter(this);
        pager.setAdapter(adapter);


        ab.addTab(
                getSupportActionBar().newTab().setText(R.string.tab_home).setTabListener(new CustomTabListener(pager,
                        this)));
        ab.addTab(
                getSupportActionBar().newTab().setText(R.string.tab_explorer).setTabListener(new CustomTabListener
                        (pager, this)));
    }

    @Override
    public void onUpRequestedOnRoot() {
        finish();
    }

    private String filePath;

    @Override
    public void onFilePathChanged(String newFilePath) {
        filePath = newFilePath;
        if (pager.getCurrentItem() == 1) {
            setTitle(filePath);
        }
    }

    @Override
    public void onMediaUnmounted() {
    }


    @Override
    public void onFileSelected(File file) {
        selectedFile = file;
        ConfirmFragment.newInstance(getString(R.string.confirm_upload, file.getName())).show
                (getSupportFragmentManager(),
                        Constant.FRAG_TAG_DIALOG);
    }

    @SuppressWarnings("UnusedDeclaration")
    private void onConfirmed(@Observes GDFSDialogConfirmEvent confirmResult) {
        if (confirmResult.confirm && selectedFile != null) {
            startService(new Intent().setAction(Constant.ACTION_DRIVE_UPLOAD).putExtra(Constant.FILE_URI
                    , Uri.fromFile(selectedFile)));
        }
    }

    @Override
    public void onBackPressed() {
        if (getSupportActionBar().getSelectedNavigationIndex() == 0) {
            super.onBackPressed();
        } else {
            getFileChooseFragment().updateBreadcrumb(false);
        }
    }

    private FileChooserFragment getFileChooseFragment() {

        return (FileChooserFragment) getSupportFragmentManager().findFragmentByTag("android:switcher:" + pager.getId
                () + ":1");
    }

    private static class CustomTabListener implements ActionBar.TabListener {

        private final ViewPager pager;
        private final MainActivity act;

        CustomTabListener(ViewPager pager, MainActivity act) {
            this.pager = pager;
            this.act = act;
        }

        @Override
        public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fakeFt) {
            pager.setCurrentItem(tab.getPosition());
            if (tab.getPosition() == 0) {
                act.setTitle(DEFAULT_TITLE);
            } else {
                act.setTitle(act.filePath);
            }
        }

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

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

    private static class TabPagerAdapter extends FragmentPagerAdapter {
        final int PAGE_COUNT = 2;
        private final MainActivity act;


        public TabPagerAdapter(MainActivity act) {
            super(act.getSupportFragmentManager());
            this.act = act;

        }

        @Override
        public Fragment getItem(int i) {
            switch (i) {
                case 0:
                    return new MainF();
                case 1:
                    FileChooserFragment f = new FileChooserFragment();
                    f.setListener(act);
                    return f;
                default:
                    return null;
            }
        }


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