Project Development¶

Development Environment¶

Dr. Tinder was developed entirely in Android Studio. We highly recommend Android studio as IDE for further develop. It can be downloaded from here.

Anyway, you could use any IDE with which you feel comfortable. Dr. Tinder has an automated build system thanks to Gradle build tool (Build script and gradle wrapper included).

Architecture¶

The app architecture is organized as follows:

The main activities are:

• Login Activity: Acts as entry point to the system. Users can log in into the system or create a new user.

• Main Activity: The main activity contains two fragments and is responsable for switching between them:

  • Selection Fragment: User selection screen
  • Chat list Fragment: List of all matches

  Also, main activity contains a menu from which is accessible Profile Activity

• Profile Activity: Allows the user add or modify his data

• User Details Activity: Shows the public user data of a candidate

• Chat Session: Allows the user to chat with a contact.

There are three utility classes that provides access to the online resources. Every activity uses them to connect to the server via REST.

• String Resources Handler
• Images Resources Handler
• User Data Handler

User Data Handler also provides a store place of the common user data (which is fetched from the server) to all the activities, such as the username or the session token.

Data Policy¶

Dr. Tinder stores no user data. Every information is fetched from the server dynamically and stored in RAM during the app execution. Even if data transfer rates are low, the data payload is small enough. If there is no network connection, the app can’t send likes or messages, so there is no need to maintain data to work offline.

The images are cached locally to improve network usage in some cases, for example in the chats where if there where no cache, the same image would be fetch multiple times, slowing down the app. This cache is forced to clean up all cached files in local storage when the main activity closes.

Errors Display¶

User errors are shown via snackbar. A snackbar wrapper is present in the “Utility” class. Errors that are irrelevant to the user such as some image failed to fetch are handled internally (and in a transparent way to user, like adding a “not found” image).

Every error is logged using the DrTinderLogger class, which is merely a wrapper of the log class. The class is used to add automatically an common tag to all the app logs (from our sourcecode).

Code¶

Here are some snippets that uses the most relevant features

• Filling an ImageView with an external resource using Image Resource Handler

//UserDetailsActivity.java
private void setUserImage(Intent intent) {

    ImageView imageView = (ImageView) findViewById(R.id.backdrop);
    String userId = intent.getStringExtra(EXTRA_USER_ID);

    ImageResourcesHandler.fillImageResource(userId, ImageResourcesHandler.RES_USER_IMG, mToken,
            imageView, getBaseContext());

}

• Using Dr. Tinder logger to log an error

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode == RESULT_OK && requestCode == PICK_IMAGE) {
        Uri imageUri = data.getData();
        try {
            mProfileImage = MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
        } catch (IOException e) {
            DrTinderLogger.writeLog(DrTinderLogger.ERRO, "The impossible happen. Image IOError");
            return; //No image to display (cant upload)
        }
        mProfilePic.setImageURI(imageUri);
    }
}

• Making a query with String Resource Handler. Showing snackbar error

StringResourcesHandler.executeQuery(mUsername, StringResourcesHandler.USER_INFO, mToken,
    data -> {
        if (data == null) {
            Utility.showMessage("Error de conexion con el servidor", Utility.getViewgroup(this), "Ok");
            return;
        }
        String username = data.get(0)[0];
        String age = data.get(0)[1];
        String sex = data.get(0)[2];
        String lookingFor = data.get(0)[3];
        String interest = data.get(0)[4];

        TextView usernameView = (TextView) findViewById(R.id.profUsername);
        assert usernameView != null; //DEBUG Assert
        usernameView.setText(username);

        mAge.setText(age);
        mSexMale.setChecked(sex.equals(MALE));
        mSexFemale.setChecked(sex.equals(FEMALE));
        mSearchingMale.setChecked(lookingFor.equals(MALE) || lookingFor.equals(BOTH));
        mSearchingFemale.setChecked(lookingFor.equals(FEMALE) || lookingFor.equals(BOTH));


        String[] interests = interest.split(StringResourcesHandler.INTEREST_DIVIDER);
        for (String interest1 : interests) {
            String[] params = interest1.split(StringResourcesHandler.INTEREST_DATA_DIVIDER);
            addInterest(params[0], params[1]);
        }

    });

• Clearing cached resource

DrTinderLogger.writeLog(DrTinderLogger.INFO, "Rejected " + data.get(USER_NAME));
ImageResourcesHandler.freeCachedResource(data.get(USER_ID),
        ImageResourcesHandler.RES_USER_IMG, getContext());

• Clearing all cache

@Override
public void onDestroy() {
    super.onDestroy();
    ImageResourcesHandler.clearCache(this);
}

Code Style¶

Dr. Tinder follows a strict code style guide to ensure code quality. Before making a pull request, please check the following rules:

• Code builds without errors at Travis.
• New code does not add errors at style checks performed by Checkstyle, Findbugs, PMD and Lint. You could check this locally using the Gradle check target as follows:

.\gradlew check

Dependencies¶

Dr. Tinder depends on the following External libraries

Classes API¶

The classes API can be found at javadoc section.