tasks/astrid/plugin-src/com/todoroo/astrid/gtasks/auth/AccountChooser.java

/*
 * Copyright 2010 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.todoroo.astrid.gtasks.auth;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;

/**
 * Choose which account to upload track information to.
 *
 * @author Sandor Dornbush
 */
public class AccountChooser {

    /**
     * The last selected account.
     */
    private int selectedAccountIndex = -1;
    private Account selectedAccount = null;

    /**
     * An interface for receiving updates once the user has selected the account.
     */
    public interface AccountHandler {
        /**
         * Handle the account being selected.
         *
         * @param account The selected account or null if none could be found
         */
        public void handleAccountSelected(Account account);
    }

    /**
     * Chooses the best account to upload to.
     * If no account is found the user will be alerted.
     * If only one account is found that will be used.
     * If multiple accounts are found the user will be allowed to choose.
     *
     * @param activity The parent activity
     * @param handler  The handler to be notified when an account has been selected
     */
    public void chooseAccount(final Activity activity,
                              final AccountHandler handler) {
        final Account[] accounts = AccountManager.get(activity)
                .getAccountsByType("com.google"); //$NON-NLS-1$
        if (accounts.length < 1) {
            alertNoAccounts(activity, handler);
            return;
        }
        if (accounts.length == 1) {
            handler.handleAccountSelected(accounts[0]);
            return;
        }

        // TODO This should be read out of a preference.
        if (selectedAccount != null) {
            handler.handleAccountSelected(selectedAccount);
            return;
        }

        // Let the user choose.
        final AlertDialog.Builder builder = new AlertDialog.Builder(activity);
        builder.setCancelable(false);
        builder.setPositiveButton(android.R.string.ok,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        selectedAccount = accounts[selectedAccountIndex];
                        handler.handleAccountSelected(selectedAccount);
                    }
                });
        builder.setNegativeButton(android.R.string.cancel,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        handler.handleAccountSelected(null);
                    }
                });
        String[] choices = new String[accounts.length];
        for (int i = 0; i < accounts.length; i++) {
            choices[i] = accounts[i].name;
        }
        builder.setSingleChoiceItems(choices, selectedAccountIndex,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        selectedAccountIndex = which;
                    }
                });
        builder.show();
    }

    /**
     * Puts up a dialog alerting the user that no suitable account was found.
     */
    private void alertNoAccounts(final Activity activity,
                                 final AccountHandler handler) {
        final AlertDialog.Builder builder = new AlertDialog.Builder(activity);
        builder.setMessage("No Accounts Found."); //$NON-NLS-1$
        builder.setCancelable(true);
        builder.setNegativeButton(android.R.string.ok,
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        handler.handleAccountSelected(null);
                    }
                });
        builder.show();
    }
}