Add MQTT dependencies, settings UI, and test coverage (CATROID-1670, CATROID-1672) by Paras-ydv · Pull Request #5220 · Catrobat/Catroid

Paras-ydv · 2026-06-21T09:33:46Z

Summary

This PR introduces the initial MQTT foundation for Catroid by combining:

CATROID-1670: Eclipse Paho MQTT dependency and Android configuration
CATROID-1672: MQTT settings UI, persistence layer, validation, and automated tests

CATROID-1670 — MQTT Dependency and Android Configuration

Changes Implemented

catroid/build.gradle

Added org.eclipse.paho.client.mqttv3:1.2.5
Added org.eclipse.paho.android.service:1.1.1
Added FEATURE_MQTT_ENABLED build config flag

AndroidManifest.xml

Registered org.eclipse.paho.android.service.MqttService
Verified existing permissions:
- INTERNET
- ACCESS_NETWORK_STATE

Testing

Added dependency sanity tests verifying:

MqttClient
MqttConnectOptions
MqttMessage
MqttException
MqttCallback

are available on the test classpath.

CATROID-1672 — MQTT Settings UI and Persistence

UI Demo

Watch UI Demo

Features Implemented

Added MQTT settings screen with:

MQTT enable toggle
Broker host
Broker port
TLS option
Username
Password
Client ID

Persistence

Implemented persistent storage using SharedPreferences.

Added accessor APIs:

isMqttSharedPreferenceEnabled()
getMqttHost()
getMqttPort()
isMqttTlsEnabled()
getMqttUsername()
getMqttPassword()
getMqttClientId()

Password Storage Refactor (MqttPasswordRepository)

Following a discussion with Harsh and Prof. Wolfgang's review feedback, the MQTT password is no longer stored in plain SharedPreferences.

Instead, a MqttPasswordRepository interface was introduced (modelled after LocalHashVersionRepository) with a
DefaultMqttPasswordRepository implementation backed by EncryptedSharedPreferences. It is registered as a Koin singleton and injected wherever the password is read or written.

This keeps SettingsFragment.getMqttPassword(Context) as the existing public API — it now delegates to the injected repository internally. Unit tests mock the interface via a Koin test module, so no Android
Keystore is required in the test environment.

Validation

Port range: 1–65535
Invalid values rejected with UI feedback

Testing

Added automated tests covering:

Default values
Persistence
Validation
Edge cases
UI integration

28 unit tests added.

Followed TDD workflow:

Red
Green
Refactor

Your Checklist

Add the Eclipse Paho MQTT Java library dependency to the Catroid module's build configuration. This lays the groundwork for the connection manager and the new MQTT bricks. - Declare org.eclipse.paho.client.mqttv3:1.2.5 via Maven Central (Eclipse Paho repo not required) - Declare org.eclipse.paho.android.service:1.1.1 via Maven Central - Add FEATURE_MQTT_ENABLED build config flag in build.gradle - Register MqttService in AndroidManifest.xml - Add MqttDependencySanityTest to verify Paho classes are accessible on the test classpath INTERNET and ACCESS_NETWORK_STATE permissions were already present in the manifest — no changes required.

harshsomankar123-tech

Thanks, @Paras-ydv. I only gave this a quick first pass, but I’ll do a full review ASAP. PTAL at the comments in the meantime.

…d default host, disable MQTT settings if feature is not enabled

… strings.xml

harshsomankar123-tech

@Paras-ydv PTAL the review and questions!
Thanks!

wslany

Many thanks!!

MQTT password is stored in default SharedPreferences
mqtt_preferences.xml (line 63) defines the broker password as an EditTextPreference, and SettingsFragment.java (line 456) reads it from default shared preferences. That means broker credentials are persisted in plaintext app prefs. Since Catroid already has androidx.security:security-crypto and an EncryptedSharedPreferences pattern, this should either move to encrypted storage or avoid persisting the password.

MQTT Espresso smoke test toggles the navigation entry instead of the actual checkbox
In SettingsFragmentTest.java (line 264), the first click opens the MQTT settings screen using the title preference_title_enable_mqtt_bricks (“MQTT extension”). Then line 268 (line 268) passes the same title into checkPreference, whose helper expects a checkbox row to toggle. Inside the MQTT screen, the checkbox title is preference_title_mqtt_enabled (“Enable MQTT bricks”), so the test either fails to find the row or does not verify SETTINGS_SHOW_MQTT_BRICKS. It should navigate once, then call checkPreference(R.string.preference_title_mqtt_enabled, SETTINGS_SHOW_MQTT_BRICKS).

…encrypt password storage - Fix mqttSettingsTest() to use preference_title_mqtt_enabled instead of preference_title_enable_mqtt_bricks so Espresso finds the actual checkbox inside MqttSettingsFragment - Remove redundant password onPreferenceChangeListener that only returned true - Store MQTT password in EncryptedSharedPreferences (AES256) instead of plaintext default SharedPreferences

Paras-ydv · 2026-07-10T00:31:52Z

Hi @harshsomankar123-tech and @wslany,

I've addressed the review comments:

Updated the Espresso test to use R.string.preference_title_mqtt_enabled for the actual checkbox in MqttSettingsFragment.
Removed the redundant password preference listener that only returned true.
Changed MQTT password storage to use EncryptedSharedPreferences instead of the default SharedPreferences, and updated SettingsFragment.getMqttPassword() accordingly.

PTAL. Thanks!

Paras-ydv · 2026-07-13T00:28:30Z

Hi @wslany and @harshsomankar123-tech ,

I've implemented the MqttPasswordRepository approach we discussed.

Here's a summary of what was done:

Added MqttPasswordRepository interface with getPassword(), setPassword(), and clearPassword()
DefaultMqttPasswordRepository wraps EncryptedSharedPreferences (lazy-initialised), following the same pattern as LocalHashVersionRepository
Registered as a Koin singleton in repositoryModules inside CatroidKoinHelper
MqttSettingsFragment injects it via by inject() - password preference is non-persistent and reads/writes through the repository
SettingsFragment.getMqttPassword(Context) retains its existing signature but delegates to the injected repository internally, so no other callers needed to change
Unit tests mock the interface via a Koin test module (no mockkStatic, no Android Keystore dependency) and use verify(exactly = 1) to assert both the read and write paths

Let me know if you'd like any adjustments!!!

harshsomankar123-tech

@Paras-ydv Thanks! Sorry for the delay. I was actually a bit busy working on a new feature for the organization. I just have a few final comments; otherwise, this PR is good to go from my side.

sonarqubecloud · 2026-07-18T10:10:20Z

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

harshsomankar123-tech

@Paras-ydv Thanks! LGTM
cc @wslany @reichli

Paras-ydv added 7 commits March 31, 2026 11:52

test: add MQTT settings tests (defaults, persistence, validation)

1f49480

feat: add MQTT settings constants and accessor methods

3ce2096

feat: add MQTT settings fragment with port validation logic

638bd54

feat: add MQTT settings UI resources and preferences

4995ba8

feat: integrate MQTT settings screen into SettingsFragment navigation

222dd13

test: add UI test for MQTT settings entry

cc34243

github-advanced-security Bot found potential problems Jun 21, 2026

View reviewed changes

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/MqttSettingsFragment.kt Fixed

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/MqttSettingsFragment.kt Fixed

github-advanced-security Bot found potential problems Jun 21, 2026

View reviewed changes

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/MqttSettingsFragment.kt Fixed

harshsomankar123-tech added the GSoC-2026 This ticket is assigned to the GSoC contributor. label Jun 21, 2026

CATROID-1672 Fix: address static analysis warnings

ddc7440

harshsomankar123-tech requested review from ratschillerp, reichli and wslany June 21, 2026 22:07

harshsomankar123-tech requested changes Jun 21, 2026

View reviewed changes

Comment thread catroid/src/main/AndroidManifest.xml Outdated

Comment thread catroid/build.gradle Outdated

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/SettingsFragment.java

CATROID-1670, CATROID-1672 Fix: remove unused MQTT android service an…

3eb0c8d

…d default host, disable MQTT settings if feature is not enabled

github-advanced-security Bot found potential problems Jun 22, 2026

View reviewed changes

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/SettingsFragment.java Fixed

harshsomankar123-tech reviewed Jun 28, 2026

View reviewed changes

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/SettingsFragment.java Outdated

CATROID-1670 fix checkstyle blank lines and move default MQTT host to…

a066366

… strings.xml

harshsomankar123-tech self-requested a review July 2, 2026 19:46

harshsomankar123-tech requested changes Jul 8, 2026

View reviewed changes

Comment thread ...d/src/androidTest/java/org/catrobat/catroid/uiespresso/ui/activity/SettingsFragmentTest.java Outdated

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/MqttSettingsFragment.kt

wslany requested changes Jul 8, 2026

View reviewed changes

github-advanced-security Bot found potential problems Jul 10, 2026

View reviewed changes

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/MqttSettingsFragment.kt Fixed

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/MqttSettingsFragment.kt Fixed

CATROID-1672 refactor: secure MQTT password via Koin-injected repository

08d4e78

github-advanced-security Bot found potential problems Jul 13, 2026

View reviewed changes

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/settingsfragments/SettingsFragment.java Fixed

fixed import order

5a9d4cf

harshsomankar123-tech requested changes Jul 15, 2026

View reviewed changes

Comment thread catroid/src/test/java/org/catrobat/catroid/test/mqtt/MqttSettingsTest.kt Outdated

Comment thread catroid/src/main/java/org/catrobat/catroid/ui/recyclerview/repository/MqttPasswordRepository.kt Outdated

harshsomankar123-tech requested a review from wslany July 15, 2026 20:41

switch to idiomatic Koin generic binding for MqttPasswordRepository

53fa7ed

harshsomankar123-tech approved these changes Jul 18, 2026

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wslany approved these changes Aug 3, 2026

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wslany merged commit f634463 into Catrobat:develop Aug 3, 2026
16 checks passed

Paras-ydv mentioned this pull request Aug 23, 2026

Add MQTT publish and receive bricks with broker integration (CATROID-1669) #5240

Draft

14 tasks

This was referenced Sep 2, 2026

Implement MQTT Message Publishing in MqttManager (CATROID-1673) #5225

Open

Implement MQTT Topic Subscription in MqttManager (CATROID-1674) #5233

Open

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Paras-ydv commented Jun 21, 2026 • edited by harshsomankar123-tech Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

CATROID-1670 — MQTT Dependency and Android Configuration

Changes Implemented

catroid/build.gradle

AndroidManifest.xml

Testing

CATROID-1672 — MQTT Settings UI and Persistence

UI Demo

Features Implemented

Persistence

Password Storage Refactor (MqttPasswordRepository)

Validation

Testing

Your Checklist

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Paras-ydv commented Jul 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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sonarqubecloud Bot commented Jul 18, 2026

Quality Gate passed

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Paras-ydv commented Jun 21, 2026 •

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