Core: Viewport UX fixes by ghengeveld · Pull Request #33557 · storybookjs/storybook

ghengeveld · 2026-01-15T22:37:52Z

What I did

Ensure values on drag handles respect minimum viewport size
Update values on drag handles to account for zoom scale factor
Fix scrollIntoView when dragging
Prevent panel drag handle from rendering outside of container
Prevent floating point numbers on drag handles

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

stories
unit tests
integration tests
end-to-end tests

Manual testing

Caution

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

Add or update documentation reflecting your changes
If you are deprecating/removing a feature, make sure to update
MIGRATION.MD

Checklist for Maintainers

When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts
Make sure this PR contains one of the labels below:
Available labels
- bug: Internal changes that fixes incorrect behavior.
- maintenance: User-facing maintenance tasks.
- dependencies: Upgrading (sometimes downgrading) dependencies.
- build: Internal-facing build tooling & test updates. Will not show up in release changelog.
- cleanup: Minor cleanup style change. Will not show up in release changelog.
- documentation: Documentation only changes. Will not show up in release changelog.
- feature request: Introducing a new feature.
- BREAKING CHANGE: Changes that break compatibility in some way with current major version.
- other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook publish.yml --field pr=<PR_NUMBER>

Summary by CodeRabbit

Bug Fixes
- Resizing enforces minimum dimensions, aborts invalid drags early, and applies correct final size when dragging ends.
Improvements
- Edge-drag behavior and auto-scrolling are more reliable with edge tracking; drag handles show scaled, rounded dimensions and react to canvas scale changes.
- Overlapping resizer behavior refined for panel placements.
Refactor
- Layout sizing centralized via CSS-variable driven styles, simplifying component props.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

nx-cloud · 2026-01-15T22:38:26Z

View your CI Pipeline Execution ↗ for commit 8fba269

Command	Status	Duration	Result
`nx run-many -t compile,check,knip,test,pretty-d...`	✅ Succeeded	10m 42s	View ↗

☁️ Nx Cloud last updated this comment at 2026-01-19 08:59:24 UTC

coderabbitai · 2026-01-15T22:43:18Z

📝 Walkthrough

Walkthrough

Per-dimension, scale-aware viewport drag/resize with guarded drag-target tracking and clamped sizing; layout refactor to drive nav/right/bottom sizes via CSS custom properties and add overlapping-aware resizer behavior.

Changes

Cohort / File(s)	Summary
Viewport resize & drag flow `code/core/src/manager/components/preview/Viewport.tsx`	Adds `dragScrollTarget` to track dragged edge; early guards in `onDrag`; per-dimension clamped width/height updates with scale-aware `data-value` on handles; computes final size from element dims × `scale` on drag end; introduces memoized `dimensions` (frame & display) and uses it for styling/attributes; includes `scale` in deps.
Layout sizing & resizer behavior `code/core/src/manager/components/layout/Layout.tsx`	Replaces numeric prop drilling with CSS custom properties (`--nav-width`, `--right-panel-width`, `--bottom-panel-height`) passed via `style`; narrows `LayoutContainer` and `Drag` props; computes grid sizing via CSS vars; adds `overlapping` flag affecting resizer geometry/behavior; updates `PanelContainer`/`Drag` styling and grid-area logic; imports `CSSProperties`.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

UI: Keep preview frame stable in overall layout #33447 — modifies Layout.tsx rendering/structure (PanelContainer/Drag/LayoutContainer), likely related to the layout refactor.

✨ Finishing touches

📝 Generate docstrings

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

coderabbitai

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@code/core/src/manager/components/preview/Viewport.tsx`:
- Around line 233-242: Clamp the minimums in logical (unscaled) units before
applying scale: when computing width/height in the drag handlers (use symbols
dragSide, dragStart, scale, targetRef, dragRefX, dragRefY, VIEWPORT_MIN_WIDTH,
VIEWPORT_MIN_HEIGHT), convert the raw pixel measurement to logical units by
dividing by scale, apply Math.max with VIEWPORT_MIN_*, then multiply back by
scale for the DOM size; set targetRef.current.style.width/height using the
scaled value and set dragRefX.current.dataset.value /
dragRefY.current.dataset.value to the logical value. Apply the same pattern to
the other drag blocks referenced (around the other occurrences noted).

📜 Review details

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 8486c72 and 4f956a4.

📒 Files selected for processing (1)

code/core/src/manager/components/preview/Viewport.tsx

🧰 Additional context used

📓 Path-based instructions (5)

**/*.{js,jsx,ts,tsx,json,md,html,css,scss}