MVVM Refactor - Main UI by Kteja03 · Pull Request #45 · grey-box/Project-Mesh

Kteja03 · 2026-03-05T08:32:27Z

Added MainViewModel to manage UI logic
Added MeshUiState for centralized UI state handling
Updated MainActivity to observe ViewModel state

- Added MainViewModel with StateFlow - Moved logic from MainActivity into ViewModel - Updated Activity to observe ViewModel state

gemini-code-assist · 2026-03-05T08:32:46Z

Summary of Changes

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This pull request significantly refactors the application's main user interface by implementing the MVVM architectural pattern. The primary goal is to decouple the UI from its logic, making the codebase more modular, testable, and easier to maintain. This is achieved by introducing a dedicated ViewModel to manage UI state and handle user interactions, centralizing all UI-related data in a single state object, and transforming the MainActivity into a reactive observer of this state.

Highlights

MVVM Architecture Implementation: The main UI logic and state management have been refactored to adhere to the MVVM (Model-View-ViewModel) architectural pattern, improving separation of concerns and maintainability.
MainViewModel Introduction: A new MainViewModel has been added to encapsulate all UI-related business logic and manage the state for the MainActivity.
Centralized UI State with MeshUiState: A MeshUiState data class was introduced to represent the complete UI state of the main screen, providing a single source of truth for UI elements and data.
MainActivity Refactoring: The MainActivity has been updated to observe the MainViewModel's state via StateFlow and dispatch UI events to the ViewModel, removing direct state management from the Activity.
SharedPreferences Binding: A new SharedPreferences binding with the tag 'mesh' has been added to GlobalApp.kt for managing application-specific preferences.

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Changelog

.idea/misc.xml
- Added XML declaration and ExternalStorageConfigurationManager component.
app/src/main/java/com/greybox/projectmesh/GlobalApp.kt
- Added a new SharedPreferences binding for 'mesh' related preferences.
app/src/main/java/com/greybox/projectmesh/MainActivity.kt
- Imported MainViewModel, MeshUiState, and MeshUiEvent.
- Replaced numerous local state variables with observed state from MainViewModel.
- Updated navigation logic to dispatch events to MainViewModel.
- Modified callbacks for OnboardingScreen and BottomNavApp to use MainViewModel events.
app/src/main/java/com/greybox/projectmesh/ViewModelFactory.kt
- Added a blank line for formatting.
app/src/main/java/com/greybox/projectmesh/mainscreen/MainViewModel.kt
- Added MainViewModel to manage UI state and logic for the main screen.
- Implemented methods to load initial state from SharedPreferences and observe mesh network changes.
- Defined event handlers for various UI interactions like navigation, theme updates, and permission handling.
app/src/main/java/com/greybox/projectmesh/mainscreen/MeshUiState.kt
- Added MeshUiState data class to define the complete UI state for MainActivity.
- Added MeshUiEvent sealed class to represent all possible UI actions and events.

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Code Review

This pull request effectively refactors the MainActivity to use the MVVM pattern by introducing MainViewModel and MeshUiState. This greatly improves the separation of concerns and makes the UI logic more manageable. I've left a few comments with suggestions to further improve consistency with the MVVM pattern and enhance code clarity. Specifically, some logic still remains in the MainActivity that should be moved to the ViewModel, and some methods in the new ViewModel could be made clearer.

app/src/main/java/com/greybox/projectmesh/MainActivity.kt

gemini-code-assist · 2026-03-05T08:35:03Z

app/src/main/java/com/greybox/projectmesh/mainscreen/MainViewModel.kt

+    private fun startMeshNetwork() {
+        viewModelScope.launch {
+            try {
+                _uiState.update { it.copy(isLoading = true, statusMessage = "Starting mesh...") }
+                // Node starting happens automatically via observeMeshNetwork
+                Log.d(TAG, "Mesh network start requested")
+            } catch (e: Exception) {
+                Log.e(TAG, "Failed to start mesh", e)
+                _uiState.update {
+                    it.copy(
+                        isLoading = false,
+                        error = "Failed to start mesh: ${e.message}"
+                    )
+                }
+            }
+        }
+    }


The startMeshNetwork method (and stopMeshNetwork as well) is currently misleading. It updates the UI state to indicate loading but does not contain any logic to actually start the network. The comment // Node starting happens automatically via observeMeshNetwork points to an implicit behavior that makes the code harder to understand and maintain.

If an action is required to start the network (e.g., calling a method on the node instance), it should be done within this try block. This would make the method's purpose explicit and the try-catch block would be effective in handling potential errors.

If no action is needed, consider renaming the method and the corresponding UI event to better reflect what they do (e.g., ShowStartingMeshStatus).

Right now, these methods don’t actually start or stop the mesh node. They just update the UI to show the status, while the real mesh state is handled through observeMeshNetwork(). Since there isn’t a direct start/stop call here yet, I’ve kept the behaviour as is for this PR. I can rename these methods later to make their purpose clearer if needed.

@Kteja03 Can you just add a comment to this function saying something about this function name being a bit misleading.

ccameron-gb · 2026-03-07T02:55:27Z

@Kteja03 Can you address the 3 items Gemini brings up? If you don't think they're legit, just comment under the comment why that is.

app/src/main/java/com/greybox/projectmesh/MainActivity.kt

app/src/main/java/com/greybox/projectmesh/mainscreen/MainViewModel.kt

taimuradam

The PR looks good, there are just 2 small changes that could cause incorrect behavior. Removing the RequestPermissionScreen() from MainActivity could cause the app to never ask for wifi/bluetooth permissions and the hasRunBefore() logic in MainViewModel is slightly wrong, since it reads the default values at the start which could cause it to show the wrong screen, for example an onboarding screen to someone that has already been onboarded.

Kteja03 · 2026-03-30T22:33:43Z

I’ve addressed both of the MainActivity comments here. I removed the unused meshPrefs variable, and moved the autoFinish / saveToFolder preference updates to ViewModel events so the Activity only forwards user actions.

…ed unused code

flow733

After going through the changes made, I was only able to dig up the issues already mentioned by Taimur. Since it looks like you just fixed these issues, I have nothing else to comment on. I apologize for the slow turnaround to the pr review; I'm still learning how to do these correctly. Your work appears solid and ready to me.

taimuradam

Looks good to me, the mentioned problems were fixed.

- Added MeshUiState for UI state handling.

36acf16

- Added MainViewModel with StateFlow - Moved logic from MainActivity into ViewModel - Updated Activity to observe ViewModel state

gemini-code-assist bot reviewed Mar 5, 2026

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ccameron-gb requested review from flow733 and taimuradam March 17, 2026 00:26

taimuradam reviewed Mar 23, 2026

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app/src/main/java/com/greybox/projectmesh/MainActivity.kt Show resolved Hide resolved

taimuradam reviewed Mar 23, 2026

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app/src/main/java/com/greybox/projectmesh/mainscreen/MainViewModel.kt Show resolved Hide resolved

taimuradam requested changes Mar 23, 2026

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Fix MVVM issues: moved SharedPreferences logic to ViewModel and remov…

1c3edbd

…ed unused code

flow733 approved these changes Mar 30, 2026

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ccameron-gb requested a review from taimuradam March 31, 2026 00:05

taimuradam approved these changes Apr 6, 2026

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MVVM Refactor - Main UI#45

MVVM Refactor - Main UI#45
Kteja03 wants to merge 2 commits intomainfrom
mvvm-refactor-asu2025F

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