Repository navigation
Fix panel drag hover terminal flicker - #1213
Merged
Merged
Conversation
|
The latest updates on your projects. Learn more about Vercel for GitHub.
|
|
Caution Review failedThe pull request is closed. ℹ️ Recent review info⚙️ Run configurationConfiguration used: defaults Review profile: CHILL Plan: Pro Run ID: 📒 Files selected for processing (2)
📝 WalkthroughWalkthroughDrop-hover and drag handling were updated so drop-zone overlays are attached to parent containers (not hosted terminal views), overlay lifecycle and logging were extended, and terminal surface resize deferral and a pixel-size debug helper were added to avoid surface re-layout during active drags/overlays. Changes
Sequence Diagram(s)mermaid Estimated code review effort🎯 3 (Moderate) | ⏱️ ~25 minutes Possibly related issues
Possibly related PRs
Poem
🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✏️ Tip: You can configure your own custom pre-merge checks in the settings. ✨ Finishing Touches
🧪 Generate unit tests (beta)
Comment |
![coderabbitai[bot]](https://avatars.githubusercontent.com/in/347564?s=60&v=4){kind=small}
There was a problem hiding this comment.
Actionable comments posted: 1
🤖 Prompt for all review comments with AI agents
Verify each finding against the current code and only fix it if needed.
Inline comments:
In `@Sources/GhosttyTerminalView.swift`:
- Around line 6730-6732: The predicate hasActiveDropZoneOverlay returns false as
soon as activeDropZone is cleared, but setDropZoneOverlay(zone: nil) only hides
the view and clears state after the hide animation completes, so keep the
predicate true until the hide completes: either delay clearing activeDropZone
until the completion handler in setDropZoneOverlay(zone: nil), or introduce a
transient flag (e.g. isHidingDropZoneOverlay) set when the hide animation starts
and cleared in its completion, and include that flag in hasActiveDropZoneOverlay
alongside activeDropZone and pendingDropZone; this ensures updateSurfaceSize()
retries won't think the overlay is gone while the hide animation is still
visible.
ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro
Run ID: cfe74648-96c1-4193-878e-887cf2f83fe1
📒 Files selected for processing (2)
Sources/GhosttyTerminalView.swiftcmuxTests/CmuxWebViewKeyEquivalentTests.swift
Comment on lines
+6730
to
+6732
| fileprivate var hasActiveDropZoneOverlay: Bool { | ||
| activeDropZone != nil || pendingDropZone != nil | ||
| } |
There was a problem hiding this comment.
Keep the overlay predicate true until the hide animation finishes.
activeDropZone is cleared at the start of setDropZoneOverlay(zone: nil), but the overlay view remains visible until the completion handler runs. If a deferred updateSurfaceSize() retry lands during that gap, Ghostty can resize under a still-visible hover overlay and reintroduce the flicker this patch is trying to remove.
💡 Suggested fix
fileprivate var hasActiveDropZoneOverlay: Bool {
- activeDropZone != nil || pendingDropZone != nil
+ activeDropZone != nil || pendingDropZone != nil || !dropZoneOverlayView.isHidden
}🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed.
In `@Sources/GhosttyTerminalView.swift` around lines 6730 - 6732, The predicate
hasActiveDropZoneOverlay returns false as soon as activeDropZone is cleared, but
setDropZoneOverlay(zone: nil) only hides the view and clears state after the
hide animation completes, so keep the predicate true until the hide completes:
either delay clearing activeDropZone until the completion handler in
setDropZoneOverlay(zone: nil), or introduce a transient flag (e.g.
isHidingDropZoneOverlay) set when the hide animation starts and cleared in its
completion, and include that flag in hasActiveDropZoneOverlay alongside
activeDropZone and pendingDropZone; this ensures updateSurfaceSize() retries
won't think the overlay is gone while the hide animation is still visible.
![cubic-dev-ai[bot]](https://avatars.githubusercontent.com/in/1082092?s=60&v=4){kind=small}
There was a problem hiding this comment.
2 issues found across 2 files
Prompt for AI agents (unresolved issues)
Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.
<file name="Sources/GhosttyTerminalView.swift">
<violation number="1" location="Sources/GhosttyTerminalView.swift:3673">
P2: The new `dropOverlay` deferral path can spin a continuous main-queue retry loop while the overlay is active, causing avoidable CPU churn during drag hover.</violation>
<violation number="2" location="Sources/GhosttyTerminalView.swift:6731">
P2: Keep the drop-overlay deferral predicate true until the overlay view is actually hidden. As written, this can flip to false before the hide animation completes, allowing a surface resize under a still-visible overlay and causing flicker.</violation>
</file>
Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.
Contributor
Greptile SummaryThis PR fixes a terminal content flicker/reflow bug (#1209) that occurred when dragging a panel over a Ghostty terminal: the drop-zone hover overlay caused layout changes that triggered unwanted Ghostty surface resizes mid-drag. Key changes:
Confidence Score: 5/5
Important Files Changed
Sequence DiagramsequenceDiagram
participant DragSession
participant GhosttySurfaceScrollView
participant GhosttyNSView
participant TerminalSurface
DragSession->>GhosttySurfaceScrollView: setDropZoneOverlay(zone: .left)
Note over GhosttySurfaceScrollView: activeDropZone = .left<br/>hasActiveDropZoneOverlay = true
GhosttySurfaceScrollView->>GhosttyNSView: layout() [frame resize]
GhosttyNSView->>GhosttyNSView: updateSurfaceSize()
GhosttyNSView->>GhosttyNSView: activeSurfaceResizeDeferralReason()
GhosttyNSView-->>GhosttyNSView: "dropOverlay" (deferred)
GhosttyNSView->>GhosttyNSView: scheduleDeferredSurfaceSizeRetryIfNeeded()
Note over GhosttyNSView: pendingSurfaceSize = newSize<br/>resize blocked
DragSession->>GhosttySurfaceScrollView: setDropZoneOverlay(zone: nil)
Note over GhosttySurfaceScrollView: activeDropZone = nil<br/>hasActiveDropZoneOverlay = false
GhosttyNSView->>GhosttyNSView: deferred retry fires (DispatchQueue.main.async)
GhosttyNSView->>GhosttyNSView: updateSurfaceSize()
GhosttyNSView->>GhosttyNSView: activeSurfaceResizeDeferralReason() → nil
GhosttyNSView->>TerminalSurface: ghostty_surface_set_size(newWidth, newHeight)
Note over TerminalSurface: lastPixelWidth/Height updated
Last reviewed commit: 90ca636 |
bn-l
pushed a commit
to bn-l/cmux
that referenced
this pull request
Apr 3, 2026
…hover-flicker Fix panel drag hover terminal flicker
This was referenced May 8, 2026
This branch was successfully deployed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Closes #1209.
Summary by cubic
Stops terminal flicker during panel drag-hover by deferring terminal surface resize and rendering the hover overlay outside the hosted terminal so layout stays stable. Closes #1209.
Written for commit 379150a. Summary will update on new commits.
Summary by CodeRabbit
New Features
Bug Fixes
Tests