Android example source code file (LoginActivity.java)

This example Android source code file (LoginActivity.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, bitmap, content, contentvalues, cursor, drawable, drawing, hashmap, intent, listview, menu_id_delete, menu_id_show, override, string, textview, ui, userdescription, usersadapter, view, widget

The LoginActivity.java Android example source code

/*
 * Copyright (C) 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.photostream;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.LayoutInflater;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.Menu;
import android.view.KeyEvent;
import android.view.animation.AnimationUtils;
import android.view.animation.Animation;
import android.widget.TextView;
import android.widget.ListView;
import android.widget.CursorAdapter;
import android.widget.AdapterView;
import android.widget.ProgressBar;
import android.content.Intent;
import android.content.Context;
import android.content.ContentValues;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import java.util.HashMap;

/**
 * Activity used to login the user. The activity asks for the user name and then add
 * the user to the users list upong successful login. If the login is unsuccessful,
 * an error message is displayed. Clicking any stored user launches PhotostreamActivity.
 *
 * This activity is also used to create Home shortcuts. When the intent
 * {@link Intent#ACTION_CREATE_SHORTCUT} is used to start this activity, sucessful login
 * returns a shortcut Intent to Home instead of proceeding to PhotostreamActivity.
 *
 * The shortcut Intent contains the real name of the user, his buddy icon, the action
 * {@link android.content.Intent#ACTION_VIEW} and the URI flickr://photos/nsid.
 */
public class LoginActivity extends Activity implements View.OnKeyListener,
        AdapterView.OnItemClickListener {

    private static final int MENU_ID_SHOW = 1;
    private static final int MENU_ID_DELETE = 2;

    private boolean mCreateShortcut;

    private TextView mUsername;
    private ProgressBar mProgress;

    private SQLiteDatabase mDatabase;
    private UsersAdapter mAdapter;

    private UserTask<String, Void, Flickr.User> mTask;

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

        schedule();

        // If the activity was started with the "create shortcut" action, we
        // remember this to change the behavior upon successful login
        if (Intent.ACTION_CREATE_SHORTCUT.equals(getIntent().getAction())) {
            mCreateShortcut = true;
        }

        mDatabase = new UserDatabase(this).getWritableDatabase();

        setContentView(R.layout.screen_login);
        setupViews();
    }

    private void schedule() {
        //SharedPreferences preferences = getSharedPreferences(Preferences.NAME, MODE_PRIVATE);
        //if (!preferences.getBoolean(Preferences.KEY_ALARM_SCHEDULED, false)) {
        CheckUpdateService.schedule(this);
        //    preferences.edit().putBoolean(Preferences.KEY_ALARM_SCHEDULED, true).commit();
        //}
    }

    private void setupViews() {
        mUsername = (TextView) findViewById(R.id.input_username);
        mUsername.setOnKeyListener(this);
        mUsername.requestFocus();

        mAdapter = new UsersAdapter(this, initializeCursor());

        final ListView userList = (ListView) findViewById(R.id.list_users);
        userList.setAdapter(mAdapter);
        userList.setOnItemClickListener(this);

        registerForContextMenu(userList);

        mProgress = (ProgressBar) findViewById(R.id.progress);
    }

    private Cursor initializeCursor() {
        Cursor cursor = mDatabase.query(UserDatabase.TABLE_USERS,
                new String[] { UserDatabase._ID, UserDatabase.COLUMN_REALNAME,
                UserDatabase.COLUMN_NSID, UserDatabase.COLUMN_BUDDY_ICON },
                null, null, null, null, UserDatabase.SORT_DEFAULT);

        startManagingCursor(cursor);

        return cursor;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.login, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onMenuItemSelected(int featureId, MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_item_settings:
                SettingsActivity.show(this);
                return true;
            case R.id.menu_item_info:
                Eula.showDisclaimer(this);
                return true;
        }

        return super.onMenuItemSelected(featureId, item);
    }

    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_UP) {
            switch (v.getId()) {
                case R.id.input_username:
                    if (keyCode == KeyEvent.KEYCODE_ENTER ||
                            keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
                        onAddUser(mUsername.getText().toString());
                        return true;
                    }
                    break;
            }
        }
        return false;
    }

    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        final Flickr.User user = Flickr.User.fromId(((UserDescription) view.getTag()).nsid);

        if (!mCreateShortcut) {
            onShowPhotostream(user);
        } else {
            onCreateShortcut(user);
        }
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
            ContextMenu.ContextMenuInfo menuInfo) {

        super.onCreateContextMenu(menu, v, menuInfo);

        AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) menuInfo;
        menu.setHeaderTitle(((TextView) info.targetView).getText());

        menu.add(0, MENU_ID_SHOW, 0, R.string.context_menu_show_photostream);
        menu.add(0, MENU_ID_DELETE, 0, R.string.context_menu_delete_user);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        final AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)
                item.getMenuInfo();
        final UserDescription description = (UserDescription) info.targetView.getTag();

        switch (item.getItemId()) {
            case MENU_ID_SHOW:
                final Flickr.User user = Flickr.User.fromId(description.nsid);
                onShowPhotostream(user);
                return true;
            case MENU_ID_DELETE:
                onRemoveUser(description.id);
                return true;
        }

        return super.onContextItemSelected(item);
    }

    @Override
    protected void onResume() {
        super.onResume();

        if (mProgress.getVisibility() == View.VISIBLE) {
            mProgress.setVisibility(View.GONE);
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        if (mTask != null && mTask.getStatus() == UserTask.Status.RUNNING) {
            mTask.cancel(true);
        }

        mAdapter.cleanup();
        mDatabase.close();
    }

    private void onAddUser(String username) {
        // When the user enters his user name, we need to find his NSID before
        // adding it to the list.
        mTask = new FindUserTask().execute(username);
    }

    private void onRemoveUser(String id) {
        int rows = mDatabase.delete(UserDatabase.TABLE_USERS, UserDatabase._ID + "=?",
                new String[] { id });
        if (rows > 0) {
            mAdapter.refresh();
        }
    }

    private void onError() {
        hideProgress();
        mUsername.setError(getString(R.string.screen_login_error));
    }

    private void hideProgress() {
        if (mProgress.getVisibility() != View.GONE) {
            final Animation fadeOut = AnimationUtils.loadAnimation(this, R.anim.fade_out);
            mProgress.setVisibility(View.GONE);
            mProgress.startAnimation(fadeOut);
        }
    }

    private void showProgress() {
        if (mProgress.getVisibility() != View.VISIBLE) {
            final Animation fadeIn = AnimationUtils.loadAnimation(this, R.anim.fade_in);
            mProgress.setVisibility(View.VISIBLE);
            mProgress.startAnimation(fadeIn);
        }
    }

    private void onShowPhotostream(Flickr.User user) {
        PhotostreamActivity.show(this, user);
    }

    /**
     * Creates the shortcut Intent to send back to Home. The intent is a view action
     * to a flickr://photos/nsid URI, with a title (real name or user name) and a
     * custom icon (the user's buddy icon.)
     *
     * @param user The user to create a shortcut for.
     */
    private void onCreateShortcut(Flickr.User user) {
        final Cursor cursor = mDatabase.query(UserDatabase.TABLE_USERS,
                new String[] { UserDatabase.COLUMN_REALNAME, UserDatabase.COLUMN_USERNAME,
                UserDatabase.COLUMN_BUDDY_ICON }, UserDatabase.COLUMN_NSID + "=?",
                new String[] { user.getId() }, null, null, UserDatabase.SORT_DEFAULT);
        cursor.moveToFirst();

        final Intent shortcutIntent = new Intent(PhotostreamActivity.ACTION);
        shortcutIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        shortcutIntent.putExtra(PhotostreamActivity.EXTRA_NSID, user.getId());

        // Sets the custom shortcut's title to the real name of the user. If no
        // real name was found, use the user name instead.
        final Intent intent = new Intent();
        intent.putExtra(Intent.EXTRA_SHORTCUT_INTENT, shortcutIntent);
        String name = cursor.getString(cursor.getColumnIndexOrThrow(UserDatabase.COLUMN_REALNAME));
        if (name == null || name.length() == 0) {
            name = cursor.getString(cursor.getColumnIndexOrThrow(UserDatabase.COLUMN_USERNAME));
        }
        intent.putExtra(Intent.EXTRA_SHORTCUT_NAME, name);

        // Sets the custom shortcut icon to the user's buddy icon. If no buddy
        // icon was found, use a default local buddy icon instead.
        byte[] data = cursor.getBlob(cursor.getColumnIndexOrThrow(UserDatabase.COLUMN_BUDDY_ICON));
        Bitmap icon = BitmapFactory.decodeByteArray(data, 0, data.length);
        if (icon != null) {
            intent.putExtra(Intent.EXTRA_SHORTCUT_ICON, icon);
        } else {
            intent.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE,
                    Intent.ShortcutIconResource.fromContext(this, R.drawable.default_buddyicon));
        }

        setResult(RESULT_OK, intent);
        finish();
    }

    /**
     * Background task used to load the user's NSID. The task begins by showing the
     * progress bar, then loads the user NSID from the network and finally open
     * PhotostreamActivity.
     */
    private class FindUserTask extends UserTask<String, Void, Flickr.User> {
        @Override
        public void onPreExecute() {
            showProgress();
        }

        public Flickr.User doInBackground(String... params) {
            final String name = params[0].trim();
            if (name.length() == 0) return null;

            final Flickr.User user = Flickr.get().findByUserName(name);
            if (isCancelled() || user == null) return null;

            Flickr.UserInfo info = Flickr.get().getUserInfo(user);
            if (isCancelled() || info == null) return null;

            String realname = info.getRealName();
            if (realname == null) realname = name;

            final ContentValues values = new ContentValues();
            values.put(UserDatabase.COLUMN_USERNAME, name);
            values.put(UserDatabase.COLUMN_REALNAME, realname);
            values.put(UserDatabase.COLUMN_NSID, user.getId());
            values.put(UserDatabase.COLUMN_LAST_UPDATE, System.currentTimeMillis());
            UserDatabase.writeBitmap(values, UserDatabase.COLUMN_BUDDY_ICON,
                    info.loadBuddyIcon());

            long result = -1;
            if (!isCancelled()) {
                result = mDatabase.insert(UserDatabase.TABLE_USERS,
                        UserDatabase.COLUMN_REALNAME, values);
            }

            return result != -1 ? user : null;
        }

        @Override
        public void onPostExecute(Flickr.User user) {
            if (user == null) {
                onError();
            } else {
                mAdapter.refresh();
                hideProgress();
            }
        }
    }

    private class UsersAdapter extends CursorAdapter {
        private final LayoutInflater mInflater;
        private final int mRealname;
        private final int mId;
        private final int mNsid;
        private final int mBuddyIcon;
        private final Drawable mDefaultIcon;
        private final HashMap<String, Drawable> mIcons = new HashMap();

        public UsersAdapter(Context context, Cursor cursor) {
            super(context, cursor, true);

            mInflater = LayoutInflater.from(context);
            mDefaultIcon = context.getResources().getDrawable(R.drawable.default_buddyicon);

            mRealname = cursor.getColumnIndexOrThrow(UserDatabase.COLUMN_REALNAME);
            mId = cursor.getColumnIndexOrThrow(UserDatabase._ID);
            mNsid = cursor.getColumnIndexOrThrow(UserDatabase.COLUMN_NSID);
            mBuddyIcon = cursor.getColumnIndexOrThrow(UserDatabase.COLUMN_BUDDY_ICON);
        }

        public View newView(Context context, Cursor cursor, ViewGroup parent) {
            final View view = mInflater.inflate(R.layout.list_item_user, parent, false);
            final UserDescription description = new UserDescription();
            view.setTag(description);
            return view;
        }

        public void bindView(View view, Context context, Cursor cursor) {
            final UserDescription description = (UserDescription) view.getTag();
            description.id = cursor.getString(mId);
            description.nsid = cursor.getString(mNsid);

            final TextView textView = (TextView) view;
            textView.setText(cursor.getString(mRealname));

            Drawable icon = mIcons.get(description.nsid);
            if (icon == null) {
                final byte[] data = cursor.getBlob(mBuddyIcon);

                Bitmap bitmap = null;
                if (data != null) bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

                if (bitmap != null) {
                    icon = new FastBitmapDrawable(bitmap);
                } else {
                    icon = mDefaultIcon;
                }

                mIcons.put(description.nsid, icon);
            }

            textView.setCompoundDrawablesWithIntrinsicBounds(icon, null, null, null);
        }

        void cleanup() {
            for (Drawable icon : mIcons.values()) {
                icon.setCallback(null);
            }
        }

        void refresh() {
            getCursor().requery();
        }
    }

    private static class UserDescription {
        String id;
        String nsid;
    }
}