グーグルのAPIを使うときに欠かせないGoogle OAuthの作り方と使い方：Androidで動く携帯Javaアプリ作成入門（59）（3/3 ページ）

private static final int REQUEST_ACCOUNT_CHOOSER = 1;
private static final int REQUEST_AUTHORIZATION_FROM_DRIVE = 2;
private static final int REQUEST_AUTHORIZATION_FROM_PLUS = 3;
 
private GoogleAccountCredential mCredential;
private Drive mDrive;
private Plus mPlus;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    initializeLogging();
    showAccountChooser();
}

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    boolean isSelectedAccount = mCredential != null && mCredential.getSelectedAccountName() != null;
    menu.getItem(0).setEnabled(!isSelectedAccount);
    menu.getItem(1).setEnabled(isSelectedAccount);
    menu.getItem(2).setEnabled(isSelectedAccount);
    return true;
}
 
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    switch (id) {
        case R.id.action_oauth:
            Log.i(TAG, "--- Authentication ---");
            showAccountChooser();
            return true;
        case R.id.action_drive:
            Log.i(TAG, "--- List Drive files ---");
            listDriveFiles();
            return true;
        case R.id.action_plus:
            Log.i(TAG, "--- Show Plus user ---");
            showPlusUser();
            return true;
    }
 
    return super.onOptionsItemSelected(item);
}

@NonNull
private GoogleAccountCredential makeCredential() {
    Collection<String> scopes = Arrays.asList(
            DriveScopes.DRIVE_READONLY,
            PlusScopes.USERINFO_PROFILE);
    return GoogleAccountCredential.usingOAuth2(getApplicationContext(), scopes);
}
 
private void showAccountChooser() {
    if (mCredential == null) {
        mCredential = makeCredential();
    }
    startActivityForResult(mCredential.newChooseAccountIntent(), REQUEST_ACCOUNT_CHOOSER);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    switch (requestCode) {
        case REQUEST_ACCOUNT_CHOOSER:
            if (resultCode == RESULT_OK && data != null) {
                String accountName = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
                Log.i(TAG, "Account Name:" + accountName);
                if (accountName != null) {
                    mCredential.setSelectedAccountName(accountName);
                }
            }
            break;
        case REQUEST_AUTHORIZATION_FROM_DRIVE:
        case REQUEST_AUTHORIZATION_FROM_PLUS:
            if (resultCode == RESULT_OK) {
                if (requestCode == REQUEST_AUTHORIZATION_FROM_DRIVE) {
                    listDriveFiles();
                } else if (requestCode == REQUEST_AUTHORIZATION_FROM_PLUS) {
                    showPlusUser();
                }
            }
            break;
    }
}

private void listDriveFiles() {
    if (mDrive == null) {
        mDrive = buildDrive();
    }
    new ListDriveFilesTask().execute();
}
 
private void showPlusUser() {
    if (mPlus == null) {
        mPlus = buildPlus();
    }
    new ShowPlusUserTask().execute();
}
 
@NonNull
private Drive buildDrive() {
    HttpTransport transport = AndroidHttp.newCompatibleTransport();
    GsonFactory factory = new GsonFactory();
    return new Drive.Builder(transport, factory, mCredential).build();
}
 
@NonNull
private Plus buildPlus() {
    HttpTransport transport = AndroidHttp.newCompatibleTransport();
    GsonFactory factory = new GsonFactory();
    return new Plus.Builder(transport, factory, mCredential).build();
}

@Override
protected Void doInBackground(Void... unused) {
    mList = new ArrayList<>();
    try {
        Drive.Files.List request = mDrive.files().list();
        request.setQ("mimeType = 'application/vnd.google-apps.document'");
        do {
            FileList files = request.execute();
            mList.addAll(files.getItems());
            request.setPageToken(files.getNextPageToken());
        } while (request.getPageToken() != null &&
                request.getPageToken().length() > 0);
    } catch (UserRecoverableAuthIOException e) {
       mIntent = e.getIntent();
    } catch (IOException e) {
        Log.e(TAG, e.getMessage(), e);
    }
    return null;
}

@Override
protected void onPostExecute(Void unused) {
    if (mIntent != null) {
        startActivityForResult(mIntent, REQUEST_AUTHORIZATION_FROM_DRIVE);
    } else {
        for (File file : mList) {
            Log.d(TAG, file.getTitle() + " " + file.getOwnerNames() + "");
        }
    }
}

@Override
protected Void doInBackground(Void... unused) {
    try {
        mPerson = mPlus.people().get("me").execute();
    } catch (UserRecoverableAuthIOException e) {
        mIntent = e.getIntent();
    } catch (IOException e) {
        Log.e(TAG, e.getMessage(), e);
    }
    return null;
}

@Override
protected void onPostExecute(Void unused) {
    if (mIntent != null) {
        startActivityForResult(mIntent, REQUEST_AUTHORIZATION_FROM_PLUS);
    } else {
        Log.d(TAG, "Display Name:" + mPerson.getDisplayName());
        Log.d(TAG, "Birthday:" + mPerson.getBirthday());
        Log.d(TAG, "Gender:" + mPerson.getGender());
        Log.d(TAG, "toString():" + mPerson.toString());
    }
}