Resolve the dragged window by name when reordering a dock

[sproctor]

Problem

Fixes crash DESKTOP-3J (IndexOutOfBoundsException: Index: 2, Size: 1 in changeWindowPositions, fatal on desktop, seen in production on 3.1.0-beta.27).

A same-dock drag crashed when the dock changed under the gesture. The drop's indices are snapshots: sourceIndex is frozen at drag start, and insertionIndex comes from item bounds cached at the dock's last recomposition - while the dock list is live. The game closing a panel mid-drag (a transient's closeDialog) shrinks the list, and the unguarded removeAt/add then throw inside the drag-gesture coroutine, which has no handler, taking the whole app down. The crash math matched exactly: the drag layer believed the dock had 3 items while the live list had 2.

There was also a quieter sibling: a stale-but-still-in-bounds sourceIndex would reorder whatever window now sat at that index instead of the one the user dragged.

Fix

• changeWindowPositions takes the dragged window's name (which DropResult already carried), resolves its current index inside the update {} - dropping the gesture when the window is gone - and clamps the insertion index to the shrunken list, mirroring the clamp moveWindowToPosition already had.
• Both drop handlers (desktop and mobile) pass result.name.
• The stale-snapshot trap is removed from the API: DropResult.sourceIndex, DragDropState.sourceIndex, and startDrag's index parameter are deleted so nothing can consume a drag-start index snapshot again.

Testing

./gradlew jvmTest passes and compose compiles for Android. The crash path is gesture-timing dependent (drop landing in the same frame a window leaves the dock), so it has no unit harness; the fix is defensive resolution against the live list at the single choke point.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved window drag-and-drop reordering for more reliable positioning.
  • Safely handles missing windows and prevents unnecessary layout updates.
  • Correctly adjusts destination positions when moving windows within the same location.

[coderabbitai]

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Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 6255ea92-80c5-4b42-a943-bfeeb685431e

📥 Commits

Reviewing files that changed from the base of the PR and between de5d26a and 69028fd.

📒 Files selected for processing (3)

• compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/game/GameViewModel.kt
• compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/window/DesktopWindowsAtLocation.kt
• compose/src/mobileMain/kotlin/warlockfe/warlock3/compose/ui/window/WindowsAtLocation.kt

📝 Walkthrough

Walkthrough

changeWindowPositions now identifies dragged windows by name, resolves their current index, handles missing windows, clamps destination indices, and avoids unnecessary persistence. Drag state and desktop/mobile call sites no longer pass source indices.

Changes

Window reordering

Layer / File(s)	Summary
Remove source index from drag state compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/window/DragDropState.kt	DragDropState.startDrag, DropResult, endDrag, and clearState no longer track sourceIndex.
Resolve and persist reordered windows compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/game/GameViewModel.kt	changeWindowPositions resolves the dragged window by name, handles missing windows, clamps the destination index, and skips persistence when no reorder occurs.
Update desktop and mobile drag wiring compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/game/DesktopGameView.kt, compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/window/DesktopWindowsAtLocation.kt, compose/src/mobileMain/kotlin/warlockfe/warlock3/compose/ui/game/GameView.kt, compose/src/mobileMain/kotlin/warlockfe/warlock3/compose/ui/window/WindowsAtLocation.kt	Desktop and mobile drag initiation and same-location reorder callbacks use window names instead of source indices.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: resolving the dragged window by name during dock reordering.

✨ Finishing Touches

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In
`@compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/game/GameViewModel.kt`:
- Line 1338: Update the persistence flow containing the names collection and
setPositions so it returns immediately when the filtered names list is empty,
before performing any database query or transaction; preserve the existing
return behavior when reordered is null.

In
`@compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/window/DesktopWindowsAtLocation.kt`:
- Line 319: Remove index from the pointerInput keys in both
DesktopWindowsAtLocation.kt (lines 319-319) and WindowsAtLocation.kt (lines
311-311). Use uiState.name and location as the keys in both implementations
while leaving the dragDropState.startDrag behavior unchanged.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: f789526f-ee29-4712-a8b1-b536816d45a3

📥 Commits

Reviewing files that changed from the base of the PR and between b2831a0 and de5d26a.

📒 Files selected for processing (6)

• compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/game/GameViewModel.kt
• compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/window/DragDropState.kt
• compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/game/DesktopGameView.kt
• compose/src/jvmMain/kotlin/warlockfe/warlock3/compose/desktop/ui/window/DesktopWindowsAtLocation.kt
• compose/src/mobileMain/kotlin/warlockfe/warlock3/compose/ui/game/GameView.kt
• compose/src/mobileMain/kotlin/warlockfe/warlock3/compose/ui/window/WindowsAtLocation.kt

💤 Files with no reviewable changes (1)

• compose/src/commonMain/kotlin/warlockfe/warlock3/compose/ui/window/DragDropState.kt

[sproctor]

Both review comments addressed in 69028fd.

pointerInput keyed on the index (major) — fixed, and it turned out to matter more than a restart nuisance. Each window in the dock is wrapped in key(uiState.name), so its composition identity survives a neighbor being removed; the index in the pointerInput key was therefore the only thing killing an in-flight drag when a window ahead of the dragged one left the dock. That is the same mid-drag dock change this PR exists to handle, so it was cancelling exactly the drags that most needed to complete. Both handlers now key on uiState.name and location, with a comment on why the index must stay out.

This is also the flip side of the crash: with the index keyed, a window removed before the dragged one silently cancelled the gesture, while one removed after left the index untouched, let the gesture finish, and fed stale bounds into removeAt/add — the Index: 2, Size: 1 in the report.

Since that key was the last use of the parameter, WindowViewSlot no longer takes an index at all, in the same spirit as dropping DropResult.sourceIndex.

Skip persistence when the savable order is empty (minor) — fixed; changeWindowPositions now returns before the transaction when the dock holds nothing savable. Worth noting the DAO call was not a pure no-op in that case: with an empty names, setPositions still walked the dock and compacted any sparse positions, so a reorder of transient-only panels could rewrite saved rows (including closed windows' remembered slots) that the user never touched. Returning early avoids the round trip and that side effect.

./gradlew jvmTest passes and compose compiles for Android.