feat: keep automatic stacks within application size constraints by qeude · Pull Request #148 · qeude/Defi

qeude · 2026-10-19T21:51:39Z

Why

Stacked windows got equal slots even when an app could not shrink that far. The app refused the height, Defi retried it on every desktop sync, and the window overflowed its slot. With the proxy overlay from #150 the refusal is also visible: the overlay draws the picture at the asked height, then fades to a native window of another height.

Closes #93.

What changed

This PR stacks on #150 (feat/window-proxy-ribbon).

Window keeps a verified minimumTiledHeight from the existing optional private constraint read. Without that read, stacks behave as before.
Sources/DefiCore/StackConstraints.swift splits a column by water-filling within each window's verified minimum and maximum height. Unconstrained stacks are split exactly as before.
join-window refuses a stack that cannot fit and leaves the workspace untouched. The CLI prints cannot join: stack needs 1650pt but only 1367pt is available.
When a stack stops fitting after a monitor, reserved-area or constraint change, the longest top run stays and the rest moves into new columns to its right. Columns never merge back on their own.
A single window taller than the viewport is targeted at its minimum, top-aligned, and listed as oversized-stack-windows= in defi status.
New on top of feat(ribbon): animate windows through a proxy overlay #150: a mouse drag only offers a stack when that stack fits. Otherwise the drop reorders the column. The overlay's stack preview uses the same slot heights the layout will apply.

Scope

Stack heights, join-window, and the drag-to-stack target from #150. Overview drops into a stack are unchanged. If such a stack cannot fit, the separation rule splits it on the next sync.

Tradeoffs

Targets now match what the app accepts, so the overlay's per-window settle learning only sees small residual adjustments. It never has to absorb a refused height.
Allocation ignores per-request TiledSizeAcceptance. Changing a request from it would start a resize battle.
The window server reports a minimum no larger than the current frame. A window that opens below its own minimum is read with a smaller minimum until the next topology read. Separation then catches up.

Blast Radius

Pure layout and runtime code, plus one more field from a constraint read that already ran. No new Accessibility writes, no per-frame work, no overlay or border code. The drag change only adds a feasibility check and a slot-height computation per pointer update, both pure math over one column.

Verification

python3 script/verify.py local passes on this head. One earlier run failed FrameGeometryReadTests on a 3 s timing wait outside this diff. The suite passed alone and the full rerun passed.
On the previous feat(ribbon): animate windows through a proxy overlay #150 head (7f6d7608), python3 script/verify.py desktop <run> --wait --filter 'DesktopE2ETests/(testAppliedTargetConvergesWithRealWindowFrame|testManagedResizeAnimationConvergesWithAdaptiveSizeWrites|testReenteringWindowJoinsFirstAnimatedRibbonSample|testHorizontalAnimationFrameWritesPositionWithoutSize)' ran 4 tests, 4 passed, 0 skipped. Accessibility was available, and the session restore passed. One earlier run passed the same 4 tests but its restore hit a LaunchServices open error -600. A manual restore under the desktop lock then succeeded.
On that same head, python3 script/desktop_lock.py --wait python3 .agents/skills/verify-defi/stacks_check.py on the installed build: all six scenarios passed, with one daemon left afterwards.
New unit tests cover a drag into a stack that cannot fit and a preview that keeps the dragged window's minimum.
Not done: Computer Use with a real drag over constrained apps.
The latest feat(ribbon): animate windows through a proxy overlay #150 commits only change AGENTS.md and the duration_ms = 0 workspace switch. They do not touch stacks or drag, so the desktop checks were not repeated on this head.

Note

Add automatic stack separation and window height constraints to Defi layout

Windows now carry a discovered minimumTiledHeight (Window.swift, WindowBorderPrivateProviders.swift), and stack slots are allocated with a water-filling algorithm that honors minimum and maximum heights per window (StackConstraints.swift).
Stacks that cannot fit are handled at three points: joinFocusedWindow rejects infeasible joins with a StackRejection error before mutating state, mouse drops hide stack targets that cannot fit, and synchronizeScrollOffsets automatically separates infeasible columns into right-adjacent columns while preserving window order, focus, and scroll anchors (ScrollReconciliation.swift).
Separated columns are never re-merged, even after the viewport grows. Single windows whose minimum exceeds the viewport remain unchanged and are reported as oversized-stack-windows in defi status.
Adds an executable end-to-end verifier (stacks_check.py) with a ClampFixture DEFI_FIXTURE_MIN mode, plus unit tests for allocation, rejection, separation, and mouse previews.
Risk: existing workspaces with height-constrained windows may separate on first reconciliation after this change; check separateInfeasibleStacks in StackConstraints.swift and the computeLayout / acceptedTiledSizes changes in Layout.swift, which now use constrained slot geometry instead of equal-height slots.

^{Macroscope summarized 488a223.}

macroscopeapp · 2026-10-19T21:54:44Z

Approvability

Verdict: Needs Human Approval

Macroscope's review found this PR requires human approval — This PR introduces substantial production behavior: constraint-aware stack sizing, rejected joins, drag-target changes, and automatic splitting of existing stacks when a viewport or app constraint changes. Because it adds a new user-facing workflow and changes multiple existing runtime paths, the scope warrants human review.

No code changes detected at 488a223. Prior analysis still applies.

^{You can add or adjust custom eligibility rules. Learn more.}

Count each unconstrained window's gaps and 1pt drawable height in a stack's lower bound, so stackFit no longer accepts a stack that squeezes a sibling below the frame applyGaps emits.

cubic-dev-ai

Review completed against the latest diff

_{Reply with feedback, questions, or to request a fix.

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cubic-dev-ai

2 issues found across 18 files

Confidence score: 3/5

In stacks_check.py, the unscoped calls change every monitor, but the journey selects only the first; cleanup can also overwrite every monitor’s bottom edge with one restore value. Scope the changes to the test monitor and restore its original bottom edge.
In ScrollReconciliation.swift, splitting stacks on every monitor can leave monitors with no submitted layout in the old arrangement. Propagate the changed monitor IDs and include them in the layout.

Prompt for AI agents (unresolved issues)


Check if these issues are valid — if so, understand the root cause of each and fix them. When an issue isn't valid or won't be fixed in this PR, reply in its thread with the reason and then resolve the thread. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="Sources/DefiRuntime/ScrollReconciliation.swift">

<violation number="1" location="Sources/DefiRuntime/ScrollReconciliation.swift:57">
P2: This splits stacks on every monitor, but callers can submit layout for only a subset, leaving other monitors' native frames in the old stack arrangement. Propagate the changed monitor IDs and include them in the layout submission.</violation>
</file>

<file name=".agents/skills/verify-defi/stacks_check.py">

<violation number="1" location=".agents/skills/verify-defi/stacks_check.py:186">
P1: These unscoped calls change every monitor, although the journey selects only the first; cleanup then replaces every bottom edge with one `--restore-bottom` value. Scope the changes to the test monitor and restore its saved edge.</violation>
</file>

_{Requires human review: Auto-approval blocked because this review re-detected 5 unresolved issues already reported by Cubic.

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- format stack rejection heights as Double so an extreme minimum cannot trap - make WindowSizeConstraints.minimumHeight a let so callers cannot drop it - exclude native fullscreen windows from oversized-stack-windows - stacks journey: exact window ID matching, every completion kind, require the stack-constraint error, and fail unless exactly one daemon remains

cubic-dev-ai

1 issue found across 6 files (changes from recent commits).

_{Reply with feedback, questions, or to request a fix.

View guided diff | Turn on auto-fix | Re-trigger cubic}

Prompt for AI agents (unresolved issues)


Check if these issues are valid — if so, understand the root cause of each and fix them. When an issue isn't valid or won't be fixed in this PR, reply in its thread with the reason and then resolve the thread. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="Sources/DefiCore/StackConstraints.swift">

<violation number="1" location="Sources/DefiCore/StackConstraints.swift:15">
P3: `StackConstraints.swift` now uses Foundation's `formatted(...)` but does not import Foundation. It compiles only because `DefiModel` imports Foundation and Swift leaks that import. Add `import Foundation` explicitly.</violation>
</file>

- compute accepted-size slot offsets in one pass - describe viewport-based limits and capped-maximum centring in CONFIGURATION.md - stacks journey: require one monitor, validate --restore-bottom, and close a fixture whose setup fails

Import Foundation explicitly where StackRejection formats heights.

Enforce a window's verified maximum height on its final gapped frame, since applyGaps shrinks gaps wider than half a frame after the slot-level cap.

cubic-dev-ai

All reported issues were addressed across 3 files (changes from recent commits).