Reclaim the tmux viewport during active Remux use by h3nock · Pull Request #62 · h3nock/remux

h3nock · 2026-08-11T14:25:49Z

Summary

Reclaim Remux’s viewport when returning to the foreground or switching back to a retained session.
Reclaim a mismatched viewport before terminal input and relevant tmux interactions, including opening Windows or Panes.
Coalesce repeated claims while one is settling and batch the claim with the user action in the same outbound write.
Publish viewport-size changes and the corresponding claim together without polling or additional tmux queries.

Testing

Ran 68 focused controller and adapter tests covering exact outbound bytes, batching, duplicate suppression, command completion, and topology settlement.
Verified on a physical iPhone.
Verified end to end in the iOS Simulator against the existing Mac mini tmux session: after a desktop client changed the server window to 189×49, interacting from Remux restored it to 50×41.

Summary by CodeRabbit

Bug Fixes
- Improved terminal session recovery when the app returns to the foreground.
- Kept the active terminal viewport aligned when switching selected terminals or presenting window and pane selectors.
- Improved viewport handling during resizing, navigation, input, copy mode, and other terminal actions.
- Added recovery for viewport mismatches and prevented duplicate viewport requests.
Tests
- Added coverage for viewport claiming, reclaiming, resizing, ordering, and stale responses.

coderabbitai · 2026-08-11T14:26:00Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Run ID: a43c746c-a2bf-4c9e-aa84-8287717d8bc6

📥 Commits

Reviewing files that changed from the base of the PR and between 3edd122 and eb39225.

📒 Files selected for processing (2)

RemuxApp/Sources/Tmux/TmuxScreenModel.swift
RemuxAppTests/TmuxScreenModelForegroundActiveCheckTests.swift

🚧 Files skipped from review as they are similar to previous changes (1)

RemuxApp/Sources/Tmux/TmuxScreenModel.swift

📝 Walkthrough

Walkthrough

The change adds active tmux viewport claim and reclaim operations. Claims propagate through viewport sizing, input, navigation, mutation, and selection commands. Lifecycle and selection events reclaim or claim the viewport. Tests cover ordering, deduplication, stale replies, resizing, and cleanup.

Changes

Active viewport ownership

Layer / File(s)	Summary
Controller claim admission and settlement `RemuxApp/Sources/Tmux/TmuxSessionController.swift`	The controller tracks pending viewport claims, admits claims before relevant commands, settles claims from topology updates, and resets claim state during cleanup.
Viewport claim API and lifecycle wiring `RemuxApp/Sources/Ghostty/GhosttyTerminalScreenModeling.swift`, `RemuxApp/Sources/Ghostty/GhosttySurfaceScreen.swift`, `RemuxApp/Sources/Tmux/TmuxScreenModel.swift`, `RemuxApp/Sources/Tmux/TmuxTerminalScreenAdapter.swift`, `RemuxApp/Sources/App/RemuxRootModel.swift`	The viewport APIs accept claim flags and expose claim and reclaim actions. Screen selection, scene activation, lifecycle activation, and sheet presentation invoke the required viewport operation.
Viewport claim behavior tests `RemuxAppTests/TmuxSessionControllerClientSizeTests.swift`, `RemuxAppTests/TmuxTerminalScreenAdapterTests.swift`, `RemuxAppTests/TmuxScreenModelForegroundActiveCheckTests.swift`	Tests cover claim and reclaim behavior, command ordering, duplicate suppression, stale replies, resize handling, unchanged-size claims, and updated callback signatures.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant RemuxRootModel
  participant GhosttySurfaceScreen
  participant TmuxTerminalScreenAdapter
  participant TmuxSessionController
  participant tmux
  RemuxRootModel->>TmuxTerminalScreenAdapter: reclaimActiveTmuxViewport()
  GhosttySurfaceScreen->>TmuxTerminalScreenAdapter: prepareInitialViewport(..., claimActiveViewport)
  TmuxTerminalScreenAdapter->>TmuxSessionController: setClientSize(..., claimActiveViewport)
  TmuxSessionController->>tmux: refresh-client and select-window
  tmux-->>TmuxSessionController: topology update

Possibly related PRs

h3nock/remux#21: Related session-switching and terminal-sheet changes invoke active viewport claim and reclaim operations.
h3nock/remux#23: Related terminal input and viewport lifecycle handling changes the same screen and session-control paths.
h3nock/remux#49: Related multi-pane viewport and client-size handling uses the same screen model, adapter, and session controller paths.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 12.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the PR's main change: reclaiming the tmux viewport during active Remux use.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches 💡 1

📝 Generate docstrings 💡

Create stacked PR
Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch fix/client-viewport-claim

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cloudflare-workers-and-pages · 2026-08-11T14:26:01Z

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chatgpt-codex-connector · 2026-08-11T14:58:04Z

+        _ size: TmuxSessionController.ClientSize,
+        claimActiveViewport: Bool = false
    ) -> Bool {
        guard !stopped, let controller = session?.controller else { return false }
        guard size != lastSubmittedClientSize else { return false }


Honor same-size viewport claims

When an active viewport observation resolves to the previously submitted grid, this guard drops claimActiveViewport before it reaches the controller. For example, if another tmux client has enlarged the active window and a Remux geometry update does not cross a cell boundary, prepareInitialViewport(..., claimActiveViewport: true) returns here and the window remains at the other client's size until some later input or topology action triggers a claim. Forward the request when claimActiveViewport is true even if no refresh-client size change is required; setClientSize now explicitly supports that same-size claim path.

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cloudflare-workers-and-pages · 2026-08-11T17:51:16Z

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reclaim tmux viewport during active use

3edd122

h3nock marked this pull request as ready for review August 11, 2026 14:52

chatgpt-codex-connector Bot reviewed Aug 11, 2026

View reviewed changes

preserve explicit viewport claims

eb39225

h3nock merged commit d661591 into main Aug 11, 2026
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coderabbitai Bot mentioned this pull request Aug 14, 2026

Fix tmux startup resize failure #67

Merged

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Reclaim the tmux viewport during active Remux use - #62

Reclaim the tmux viewport during active Remux use#62
h3nock merged 2 commits into
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fix/client-viewport-claim

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