com.google.drive.samples.crossclientoauth2.MainActivity.java Source code

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Here is the source code for com.google.drive.samples.crossclientoauth2.MainActivity.java

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/**
 * Copyright 2013 Google Inc. All Rights Reserved.
 *
 * 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.drive.samples.crossclientoauth2;

import java.util.Arrays;
import java.util.List;

import android.accounts.AccountManager;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.TextUtils;
import android.widget.EditText;

import com.google.android.gms.auth.GoogleAuthUtil;
import com.google.android.gms.auth.UserRecoverableAuthException;
import com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential;
import com.google.api.client.googleapis.extensions.android.gms.auth.UserRecoverableAuthIOException;

public class MainActivity extends Activity {

    final private String CLIENT_ID = "abc123.apps.googleusercontent.com";
    final private List<String> SCOPES = Arrays.asList(
            new String[] { "https://www.googleapis.com/auth/plus.login", "https://www.googleapis.com/auth/drive" });

    private GoogleAccountCredential mCredential;

    private EditText mExchangeCodeEditText;
    private EditText mIdTokenEditText;

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

        setContentView(R.layout.activity_main);
        mExchangeCodeEditText = (EditText) findViewById(R.id.editTextExchangeCode);
        mIdTokenEditText = (EditText) findViewById(R.id.editTextIdToken);

        // initiate a credential object with drive and plus.login scopes
        // cross identity is only available for tokens retrieved with plus.login
        mCredential = GoogleAccountCredential.usingOAuth2(this, null);

        // user needs to select an account, start account picker
        startActivityForResult(mCredential.newChooseAccountIntent(), REQUEST_ACCOUNT_PICKER);
    }

    /**
     * Handles the callbacks from result returning
     * account picker and permission requester activities.
     */
    @Override
    protected void onActivityResult(final int requestCode, final int resultCode, final Intent data) {
        switch (requestCode) {
        // user has  returned back from the account picker,
        // initiate the rest of the flow with the account he/she has chosen.
        case REQUEST_ACCOUNT_PICKER:
            String accountName = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
            if (accountName != null) {
                mCredential.setSelectedAccountName(accountName);
                new RetrieveExchangeCodeAsyncTask().execute();
                new RetrieveJwtAsyncTask().execute();
            }
            break;
        // user has returned back from the permissions screen,
        // if he/she has given enough permissions, retry the the request.
        case REQUEST_AUTHORIZATION:
            if (resultCode == Activity.RESULT_OK) {
                // replay the same operations
                new RetrieveExchangeCodeAsyncTask().execute();
                new RetrieveJwtAsyncTask().execute();
            }
            break;
        }
    }

    /**
     * Retrieves the exchange code to be sent to the
     * server-side component of the app.
     */
    public class RetrieveExchangeCodeAsyncTask extends AsyncTask<Void, Boolean, String> {

        @Override
        protected String doInBackground(Void... params) {
            String scope = String.format("oauth2:server:client_id:%s:api_scope:%s", CLIENT_ID,
                    TextUtils.join(" ", SCOPES));
            try {
                return GoogleAuthUtil.getToken(MainActivity.this, mCredential.getSelectedAccountName(), scope);
            } catch (UserRecoverableAuthException e) {
                startActivityForResult(e.getIntent(), REQUEST_AUTHORIZATION);
            } catch (Exception e) {
                e.printStackTrace(); // TODO: handle the exception
            }
            return null;
        }

        @Override
        protected void onPostExecute(String code) {
            // exchange code with server-side to retrieve an additional
            // access token on the server-side.
            mExchangeCodeEditText.setText(code);
        }
    }

    /**
     * Retrieves a JWT to identify the user without the
     * regular client-side authorization flow. The jwt payload needs to be
     * sent to the server-side component.
     */
    public class RetrieveJwtAsyncTask extends AsyncTask<Void, Boolean, String> {

        @Override
        protected String doInBackground(Void... params) {
            String scope = "audience:server:client_id:" + CLIENT_ID;
            try {
                return GoogleAuthUtil.getToken(MainActivity.this, mCredential.getSelectedAccountName(), scope);
            } catch (UserRecoverableAuthIOException e) {
                startActivityForResult(e.getIntent(), REQUEST_AUTHORIZATION);
            } catch (Exception e) {
                e.printStackTrace(); // TODO: handle the exception
            }
            return null;
        }

        @Override
        protected void onPostExecute(String idToken) {
            // exchange encrypted idToken with server-side to identify the user
            mIdTokenEditText.setText(idToken);
        }
    }

    private static final int REQUEST_ACCOUNT_PICKER = 100;
    private static final int REQUEST_AUTHORIZATION = 200;

}