[vector_graphics_compiler] Handle coordinate lists on text and tspan by mackings · Pull Request #13287 · flutter/packages

mackings · 2026-10-16T06:41:00Z

SVG allows x, y, dx and dy on text and tspan to be a list, one value per character. The compiler parsed them as a single number, so a list like x="0 4.86 10.01" threw a confusing FormatException: Invalid double.

Lists aren't supported, so it now throws an UnimplementedError that names the attribute and value. Single values work as before.

Fixes flutter/flutter#165490

Pre-Review Checklist

If you need help, consider asking for advice on the #hackers-new channel on Discord.

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling. ↩ ↩²

gemini-code-assist

Code Review

This pull request updates the SVG parser in vector_graphics_compiler to extract and use only the first coordinate when text or tspan elements contain a list of coordinates, preventing potential crashes. A review comment suggests optimizing the _firstListValue helper by caching the RegExp instance and using indexOf and substring instead of split to avoid unnecessary string allocations.

gemini-code-assist · 2026-10-16T06:42:09Z

+  // Text and tspan can list one coordinate per character. Per-character
+  // positioning isn't supported, so only the first coordinate is used.
+  String? _firstListValue(String? raw) => raw?.trim().split(RegExp(r'[\s,]+')).first;
+


Using split on the entire coordinate string is inefficient because it allocates a list of all substrings, which can be quite large for long coordinate lists (e.g., one coordinate per character in a long text block). Additionally, creating a new RegExp instance on every call of _firstListValue adds unnecessary overhead.\n\nInstead, we can reuse a single static RegExp instance and use indexOf and substring to efficiently extract only the first coordinate without splitting the rest of the string. This also safely handles empty or whitespace-only strings by returning null.

static final RegExp _coordinateSeparator = RegExp(r'[\\s,]');\n\n // Text and tspan can list one coordinate per character. Per-character\n // positioning isn't supported, so only the first coordinate is used.\n String? _firstListValue(String? raw) {\n if (raw == null) {\n return null;\n }\n final String trimmed = raw.trim();\n if (trimmed.isEmpty) {\n return null;\n }\n final int index = trimmed.indexOf(_coordinateSeparator);\n return index == -1 ? trimmed : trimmed.substring(0, index);\n }\n

Good point, thank you! x/y are parsed for every element, so I moved the RegExp to a static field and switched to indexOf/substring. The suggested snippet came through escaped (r'[\\s,]' would match a backslash), so I used r'[\s,]' instead.

gaaclarke

I think it's better to throw an exception to say lists aren't implemented instead of just throwing away the other values

…rst value

mackings · 2026-10-20T07:21:04Z

That makes sense, thanks! It now throws an UnimplementedError that names the attribute, e.g. A list of values for "x" is not supported: "0 4.86 10.01".

…gc-text-coordinate-list

gaaclarke

lgtm, thanks

gaaclarke · 2026-10-20T15:55:35Z

@walley892 can you be a secondary reviewer here please

flutter/packages@23a05b6...a8549ae 2026-10-27 [email protected] [material_ui] Deprecate the black/white parameters in `Typography.material2021` (flutter/packages#13443) 2026-10-27 [email protected] [shared_preferences] Defer SharedPreferences fetch in `LegacySharedPreferencesPlugin` until first use on Android (flutter/packages#13431) 2026-10-27 [email protected] [material_ui] Fix MenuAnchor non-Unicode shortcut labels on JS web (flutter/packages#13370) 2026-10-27 [email protected] [material_ui] Add Checkbox.markInsets (flutter/packages#12690) 2026-10-27 [email protected] [vector_graphics_compiler] Handle coordinate lists on text and tspan (flutter/packages#13287) 2026-10-27 [email protected] [cupertino_ui] Unskip web tests that pass on CanvasKit and Skwasm: nav_bar_transition_test, refresh_test, route_test, text_field_cursor_test (flutter/packages#13439) 2026-10-27 [email protected] [material_ui] Fix `TextTheme` and `Typography` `debugFillProperties` defaults (flutter/packages#13374) 2026-10-27 [email protected] [material_ui] Update out-of-date typography documentation (flutter/packages#13372) 2026-10-27 [email protected] [shared_preferences_foundation] Fix web compilation of apps that import the package (flutter/packages#13447) 2026-10-26 [email protected] Fix AI guidelines link in PR template (flutter/packages#13411) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages-flutter-autoroll Please CC [email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

[vector_graphics_compiler] Handle coordinate lists on text and tspan

ffb837e

github-actions Bot added p: vector_graphics triage-engine Should be looked at in engine triage labels Oct 16, 2026

gemini-code-assist Bot reviewed Oct 16, 2026

View reviewed changes

mackings and others added 2 commits October 16, 2026 07:55

Reuse one RegExp and avoid split when reading coordinate lists

46ccaf3

Merge branch 'main' into vgc-text-coordinate-list

0abd0e6

gaaclarke added the CICD Run CI/CD label Oct 19, 2026

gaaclarke self-requested a review October 19, 2026 20:02

gaaclarke requested changes Oct 19, 2026

View reviewed changes

Throw UnimplementedError for coordinate lists instead of using the fi…

54adeb1

…rst value

Merge remote-tracking branch 'origin/vgc-text-coordinate-list' into v…

502cf2a

…gc-text-coordinate-list

flutter-dashboard Bot removed the CICD Run CI/CD label Oct 20, 2026

mackings requested a review from gaaclarke October 20, 2026 07:31

gaaclarke approved these changes Oct 20, 2026

View reviewed changes

gaaclarke added the CICD Run CI/CD label Oct 20, 2026

gaaclarke requested a review from walley892 October 20, 2026 15:55

walley892 approved these changes Oct 26, 2026

View reviewed changes

gaaclarke added the autosubmit Merge PR when tree becomes green via auto submit App label Oct 26, 2026

auto-submit Bot merged commit e71b3fd into flutter:main Oct 27, 2026
14 checks passed

This was referenced Oct 27, 2026

Roll Packages from 23a05b6ad5d5 to 587ee23a639b (9 revisions) flutter/flutter#195422

Closed

Roll Packages from 23a05b6ad5d5 to a8549ae8080b (10 revisions) flutter/flutter#195434

Merged

Navigation Menu

Repository navigation

[vector_graphics_compiler] Handle coordinate lists on text and tspan - #13287

[vector_graphics_compiler] Handle coordinate lists on text and tspan#13287
auto-submit[bot] merged 5 commits into
flutter:mainfrom
mackings:vgc-text-coordinate-list

mackings commented Oct 16, 2026 •

edited

Loading

Uh oh!

gemini-code-assist Bot left a comment

Uh oh!

gemini-code-assist Bot Oct 16, 2026

Uh oh!

mackings Oct 16, 2026

Uh oh!

gaaclarke left a comment

Uh oh!

mackings commented Oct 20, 2026

Uh oh!

gaaclarke left a comment

Uh oh!

gaaclarke commented Oct 20, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

mackings commented Oct 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Pre-Review Checklist

Footnotes

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

gemini-code-assist Bot Oct 16, 2026

Choose a reason for hiding this comment

Uh oh!

mackings Oct 16, 2026

Choose a reason for hiding this comment

Uh oh!

gaaclarke left a comment

Choose a reason for hiding this comment

Uh oh!

mackings commented Oct 20, 2026

Uh oh!

gaaclarke left a comment

Choose a reason for hiding this comment

Uh oh!

gaaclarke commented Oct 20, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

mackings commented Oct 16, 2026 •

edited

Loading