CAMEL-23635: camel-jbang - Add shell panel to TUI

[gnodet]

CAMEL-23635

Summary

Embeds a JLine interactive shell inside the TUI, accessible via F6 or F2 → Shell.

Architecture

Uses JLine's virtual terminal infrastructure (same pattern as WebTerminal):

• LineDisciplineTerminal — master/slave virtual terminal
• ScreenTerminal — VT100 emulator with readable screen buffer
• ScreenTerminalOutputStream — bridges terminal output to screen buffer
• Shell runs in a background thread via ShellBuilder + PicocliCommandRegistry
• Screen buffer dumped each TUI frame, converted to TamboUI Span/Line widgets
• Key events encoded as ANSI escape sequences and forwarded to the virtual terminal

Features

• F6 toggles the shell panel open/close (shell persists in background)
• Shift+F6 cycles shell height (25% → 50% → 75%)
• F2 → Shell also opens it
• Split-screen layout with monitoring tabs on top
• Full JLine shell with tab completion, history, command highlighting
• All Camel CLI commands available (get, catalog, ask, etc.)
• POSIX commands (cd, ls, pwd) with working directory support
• Color and text attribute support (bold, underline, reverse, italic, dim)
• Resize handling (terminal resize propagated to virtual terminal via SIGWINCH)
• Process auto-selection: TUI's selected integration propagated to camel ask
• list_processes / select_process tools for runtime process switching
• Printer output redirected through virtual terminal (command output renders in panel)

Additional fixes

• EndpointsTab: null guard for history LinkedList entries (NPE fix)
• ActionsPopup: explicit action list in resolveAction() (fixes F2→Shell mapping when MCP is disabled)

Test plan

• F6 opens shell panel with prompt and separator line
• Type commands (e.g., catalog component --filter=kafka) — output with colors
• Arrow keys work (Up/Down for history, Left/Right for cursor)
• Tab completion works
• F6 closes shell panel (shell persists)
• F6 reopens — previous session preserved
• Shift+F6 cycles height (25% → 50% → 75%)
• cd, ls, pwd work
• ask auto-targets the TUI's selected integration
• F2 → Shell also opens the panel
• Resize terminal window — shell reflows

Claude Code on behalf of Guillaume Nodet

[github-actions]

🌟 Thank you for your contribution to the Apache Camel project! 🌟
🤖 CI automation will test this PR automatically.

🐫 Apache Camel Committers, please review the following items:

• First-time contributors require MANUAL approval for the GitHub Actions to run
• You can use the command /component-test (camel-)component-name1 (camel-)component-name2.. to request a test from the test bot although they are normally detected and executed by CI.
• You can label PRs using skip-tests and test-dependents to fine-tune the checks executed by this PR.
• Build and test logs are available in the summary page. Only Apache Camel committers have access to the summary.

⚠️ Be careful when sharing logs. Review their contents before sharing them publicly.

[davsclaus]

Oh can the toggle be 25%/50%/100% or does that not work to well ?

[gnodet]

Updated — the toggle now cycles through three sizes:

• F11 grows: 25% → 50% → 100%
• Escape shrinks: 100% → 50% → 25% → close

The split uses Constraint.percentage() so it adapts to any terminal height.

Claude Code on behalf of Guillaume Nodet

[davsclaus]

There is a merge conflict, thanks

[gnodet]

Merge conflict resolved — rebased on latest main which added the ACTION_RUN_INFRA action. Action IDs and group sizes updated accordingly.

Claude Code on behalf of Guillaume Nodet

[github-actions]

🧪 CI tested the following changed modules:

• dsl/camel-jbang/camel-jbang-core
• dsl/camel-jbang/camel-jbang-plugin-tui

⚠️ Some tests are disabled on GitHub Actions (@DisabledIfSystemProperty(named = "ci.env.name")) and require manual verification:

• dsl/camel-jbang/camel-jbang-core: 1 test(s) disabled on GitHub Actions

💡 Manual integration tests recommended:

You modified dsl/camel-jbang/camel-jbang-core. The related integration tests in dsl/camel-jbang/camel-jbang-it are excluded from CI. Consider running them manually:

mvn verify -f dsl/camel-jbang/camel-jbang-it -Djbang-it-test

All tested modules (6 modules)

• Camel :: JBang :: Core
• Camel :: JBang :: MCP
• Camel :: JBang :: Plugin :: Route Parser
• Camel :: JBang :: Plugin :: TUI
• Camel :: JBang :: Plugin :: Validate
• Camel :: Launcher :: Container

---

⚙️ View full build and test results

[davsclaus]

Nice feature — the JLine ScreenTerminal + LineDisciplineTerminal wiring is solid, and the convertAttrToStyle() bit extraction correctly matches JLine's own generateSpanTag(). A couple of minor observations below.

This review does not replace specialized AI review tools (CodeRabbit, Sourcery) or static analysis (SonarCloud).

This review was generated by an AI agent and may contain inaccuracies. Please verify all suggestions before applying.

[davsclaus]

Are we waiting for a tamboui fix ?

[davsclaus]

Camel JBang has been renamed to Camel CLI so there are some stale doc files you need to regen

[gnodet]

No, we don't need a TamboUI fix. TamboUI 0.3.0 is the latest release and works fine for this feature.

Claude Code on behalf of Guillaume Nodet

[gnodet]

Our branch is rebased on top of the latest main which already includes the Camel JBang → Camel CLI rename. No stale doc files in our diff.

Claude Code on behalf of Guillaume Nodet

[davsclaus]

Late follow-up review against project conventions — the PR is already approved and comments addressed.

Findings (all low severity)

1. ShellPanel.destroy() never called — CamelMonitor never calls destroy() on TUI exit. The shell thread is daemon so the JVM won't hang, but the virtual terminal won't be cleanly shut down. Minor resource leak if TUI is restarted within the same JVM.

2. Overlays suppressed when shell is open — draw overlay, kill confirm, caption, and help overlay (F1) don't render while the shell panel is visible. Likely intentional (keyboard focus goes to shell), but worth confirming users know to close the shell first for F1 help.

3. No tests — consistent with the current coverage pattern for TUI and Ask.java modules. The EndpointsTab NPE fix is a straightforward null-guard. The list_processes/select_process tools could be tested in isolation but would require mocking RuntimeHelper.

What looks good

• ScreenTerminal → TamboUI convertAttrToStyle() bit extraction is correct
• DelegateOutputStream cleanly breaks the LineDisciplineTerminal ↔ ScreenTerminalOutputStream circular dependency
• ActionsPopup.resolveAction() refactor from index arithmetic to explicit buildVisualActionList() is much more maintainable
• EndpointsTab.unbox() NPE fix is correct and minimal
• encodeKeyEvent() ANSI encoding covers all standard keys

No blocking issues found.

This review does not replace specialized AI review tools (CodeRabbit, Sourcery) or static analysis (SonarCloud).

This review was generated by an AI agent and may contain inaccuracies. Please verify all suggestions before applying.

[gnodet]

Thanks for the review. All 3 findings addressed:

1. destroy() never called — fixed: shellPanel.destroy() now called in CamelMonitor.doCall() finally block on TUI exit.

2. Overlays suppressed — fixed: overlays (help, caption, kill confirm, draw, actions popup) now render on top of the full content area regardless of shell panel state. F1 help works even when shell is open.

3. No tests — acknowledged. The TUI module has no test infrastructure for interactive rendering. The EndpointsTab.unbox() fix and Ask process discovery are straightforward. Will add tests if/when a test harness is available.

Claude Code on behalf of Guillaume Nodet