Add basic logcat viewer

[SamratB8]

Summary

Create a basic logcat viewer in WinDroid Studio for streaming Android system and application logs from the selected device or emulator.

The first version should provide start, stop, clear, and simple text-filter controls while preventing unlimited memory growth.

This is an initial developer-tool implementation and does not need advanced log parsing or query features.

Background

Android logcat is an important tool for:

• Application debugging
• Runtime diagnostics
• Device troubleshooting
• ADB verification
• Future WinDroid runtime research

Because logcat is a continuous stream, it must be handled differently from short ADB commands.

Dependencies

This issue depends on:

• Issue Implement ADB path detection service #3 — Implement ADB path detection service
• Issue Create process runner for executing ADB commands #4 — Create process runner for executing ADB commands
• Issue Display connected ADB devices in the WinUI dashboard #7 — Display connected ADB devices in the WinUI dashboard
• Issue Add basic logging/output panel #8 — Add basic logging/output panel

The existing process runner may need a carefully scoped streaming extension.

ADB Command

The basic command is:

adb -s <device-serial> logcat

The command must explicitly target the selected device.

Streaming Requirements

The implementation should:

• Start logcat asynchronously
• Read output incrementally
• Avoid waiting for the process to exit before displaying output
• Support cancellation
• Stop the process cleanly
• Handle device disconnection
• Avoid blocking the WinUI thread
• Avoid leaving orphaned ADB processes
• Stop streaming when the relevant page or application closes

Memory-Safety Requirements

Logcat can produce an unlimited amount of output.

The viewer must limit retained logs using a strategy such as:

• Maximum number of retained lines
• Circular buffer
• Removal of oldest entries after reaching a cap

The initial line cap may be fixed and documented.

The UI must not keep an unlimited string containing the complete session output.

UI Requirements

Create a developer-tools page or panel with:

• Selected-device indicator
• Start button
• Stop button
• Clear button
• Text-filter field
• Scrollable log view
• Streaming status
• Error state
• Line-count or retained-line indicator where practical

Filtering Requirements

The initial filter should:

• Match text locally
• Be case-insensitive
• Avoid restarting logcat
• Support clearing the filter
• Avoid discarding the underlying capped log buffer

Advanced Android log priorities and tags can be added later.

Lifecycle Requirements

When streaming starts:

• Start should become disabled
• Stop should become enabled
• The selected device should be captured for that stream

When streaming stops:

• The process should terminate
• Start should become available again
• Existing captured logs may remain visible

When the device selection changes:

• Stop any active stream first, or
• Require the user to stop before switching

The viewer must not silently continue streaming from one device while showing another as selected.

Tasks

• Add streaming-process support where required
• Add logcat service
• Explicitly target the selected device
• Add cancellation and process termination
• Create a capped in-memory log buffer
• Create the logcat viewer UI
• Add Start, Stop, and Clear controls
• Add local text filtering
• Add device-disconnection handling
• Stop streaming during application shutdown
• Add useful status and error messages
• Add tests for buffer behavior
• Add tests for filtering logic
• Document any fixed line cap

Security and Privacy Requirements

Logcat may contain sensitive information.

The first version should:

• Avoid automatically uploading logs
• Avoid writing logs permanently to disk
• Avoid including log contents in telemetry
• Clearly treat exported logs as a future separate feature
• Avoid displaying secrets elsewhere in the application

Out of Scope

This issue does not need to:

• Add advanced tag filtering
• Add log-priority dropdowns
• Parse every logcat format
• Colour-code priorities
• Export logs
• Search with regular expressions
• Add bookmarks
• Add timeline visualization
• Add multiple simultaneous device streams
• Persist logs between sessions
• Upload diagnostic reports

Acceptance Criteria

• The user can start logcat for the selected device.
• Log lines appear incrementally.
• The UI remains responsive during streaming.
• The user can stop the stream.
• Stopping does not leave an orphaned process.
• Closing the application stops the stream.
• Device disconnection is handled visibly.
• Retained logs have a defined maximum size.
• Old entries are removed safely after the cap is reached.
• The user can clear visible logs.
• Local text filtering works.
• No logs are uploaded or permanently stored automatically.
• Relevant buffer and filtering tests pass.
• The full solution builds successfully in Debug and Release configurations.
• No new compiler warnings are introduced.