Avoid scrolling whole selections to keep undo responsive#108
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brandonbloom wants to merge 1 commit intokrzyzanowskim:mainfrom
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Avoid scrolling whole selections to keep undo responsive#108brandonbloom wants to merge 1 commit intokrzyzanowskim:mainfrom
brandonbloom wants to merge 1 commit intokrzyzanowskim:mainfrom
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Undoing a delete after selecting a very large range can become slow on AppKit. The expensive work happens in STTextView.layout() when the view tries to make the restored selection visible. The existing code always asks TextKit for the frame of the entire current selection, so undoing Cmd+A/Delete effectively requests geometry for the whole document. Make the scroll-to-selection path target only the geometry that is needed: - if the selection already intersects the current viewport, do not scroll - if the selection is outside the viewport, scroll only the nearest selection edge instead of the entire selection range - share the same gutter-aware rect adjustment logic for range-based and location-based scrolling Add focused AppKit tests for the selection-to-scroll-target logic in UndoTests so this behavior is covered on the branch without depending on any other test harness changes. This keeps undo responsive for large selection restores while preserving the existing selection visibility behavior.
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Optimize scroll-to-selection logic in layout() to avoid unnecessary viewport jumps: - Skip scrolling if selection already intersects visible viewport - Scroll to nearest selection edge instead of entire range - Extract adjustedScrollRect() to deduplicate gutter-aware rect logic Based on PR krzyzanowskim#108 by brandonbloom. Co-Authored-By: Claude Opus 4.6 <[email protected]>
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Undoing a delete after selecting a very large range can become slow on AppKit. The expensive work happens in STTextView.layout() when the view tries to make the restored selection visible. The existing code always asks TextKit for the frame of the entire current selection, so undoing Cmd+A/Delete effectively requests geometry for the whole document.
Make the scroll-to-selection path target only the geometry that is needed:
Add focused AppKit tests for the selection-to-scroll-target logic in UndoTests so this behavior is covered on the branch without depending on any other test harness changes.
This keeps undo responsive for large selection restores while preserving the existing selection visibility behavior.