ViewKeyAdvSubkeysFragment.java

/*
 * Copyright (C) 2014-2015 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 android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;

import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.provider.KeychainContract;
import org.sufficientlysecure.keychain.ui.adapter.SubkeysAdapter;
import org.sufficientlysecure.keychain.util.Log;

public class ViewKeyAdvSubkeysFragment extends LoaderFragment implements
        LoaderManager.LoaderCallbacks<Cursor> {

    public static final String ARG_DATA_URI = "data_uri";

    private ListView mSubkeysList;
    private SubkeysAdapter mSubkeysAdapter;

    private Uri mDataUriSubkeys;

    /**
     * Creates new instance of this fragment
     */
    public static ViewKeyAdvSubkeysFragment newInstance(Uri dataUri) {
        ViewKeyAdvSubkeysFragment frag = new ViewKeyAdvSubkeysFragment();

        Bundle args = new Bundle();
        args.putParcelable(ARG_DATA_URI, dataUri);

        frag.setArguments(args);
        return frag;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup superContainer, Bundle savedInstanceState) {
        View root = super.onCreateView(inflater, superContainer, savedInstanceState);
        View view = inflater.inflate(R.layout.view_key_adv_subkeys_fragment, getContainer());

        mSubkeysList = (ListView) view.findViewById(R.id.keys);

        return root;
    }

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

        Uri dataUri = getArguments().getParcelable(ARG_DATA_URI);
        if (dataUri == null) {
            Log.e(Constants.TAG, "Data missing. Should be Uri of key!");
            getActivity().finish();
            return;
        }

        loadData(dataUri);
    }

    private void loadData(Uri dataUri) {
        mDataUriSubkeys = KeychainContract.Keys.buildKeysUri(dataUri);

        // Create an empty adapter we will use to display the loaded data.
        mSubkeysAdapter = new SubkeysAdapter(getActivity(), null, 0);
        mSubkeysList.setAdapter(mSubkeysAdapter);

        // Prepare the loaders. Either re-connect with an existing ones,
        // or start new ones.
        getLoaderManager().initLoader(0, null, this);
    }

    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        setContentShown(false);

        return new CursorLoader(getActivity(), mDataUriSubkeys,
                SubkeysAdapter.SUBKEYS_PROJECTION, null, null, null);
    }

    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        // Avoid NullPointerExceptions, if we get an empty result set.
        if (data.getCount() == 0) {
            return;
        }

        // Swap the new cursor in. (The framework will take care of closing the
        // old cursor once we return.)
        mSubkeysAdapter.swapCursor(data);

        // TODO: maybe show not before both are loaded!
        setContentShown(true);
    }

    /**
     * This is called when the last Cursor provided to onLoadFinished() above is about to be closed.
     * We need to make sure we are no longer using it.
     */
    public void onLoaderReset(Loader<Cursor> loader) {
        mSubkeysAdapter.swapCursor(null);
    }

}