[google_maps_flutter_ios] Fix kCGImageAlphaPremultipliedLast implicit conversion from enumeration type

[jmagman]

Docs for CGBitmapContextCreate bitmapInfo parameter say:

The constants for specifying the alpha channel information are declared with the CGImageAlphaInfo type but can be passed to this parameter safely. You can also pass the other constants associated with the CGBitmapInfo type.

The docs still show kCGImageAlphaPremultipliedLast being passed in directly.

Instead of casting to CGBitmapInfo (which would also work I believe), use kCGBitmapAlphaInfoMask.

Further explanation at inkling/Subliminal#23 (comment).

Tested here:

packages/packages/google_maps_flutter/google_maps_flutter_ios/example/ios14/ios/RunnerTests/GoogleMapsTests.m

Line 81 in b2aef15

UIImage *downsampledImage = [controller handleResultTile:wideGamutImage];

Fixes flutter/flutter#170440

Pre-Review Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter.
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or I have commented below to indicate which version change exemption this PR falls under¹.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style, or I have commented below to indicate which CHANGELOG exemption this PR falls under¹.
• I updated/added any relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or I have commented below to indicate which test exemption this PR falls under¹.
• All existing and new tests are passing.

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.

Footnotes

1. 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 ↩³

[gemini-code-assist]

Code Review

This pull request fixes a compiler warning in the iOS implementation related to an implicit enum conversion when creating a bitmap context. The change correctly uses kCGBitmapAlphaInfoMask to avoid the warning. The pubspec.yaml version and CHANGELOG.md are updated accordingly. I have one suggestion to align the changelog entry with the repository's style guide.

[gemini-code-assist]

Per the repository's contribution guide¹, which specifies the CHANGELOG style, entries should be in the past tense and be a complete sentence ending with a period. Please update this entry to align with the guide.

Style Guide References

Suggested change

	* Fixes `kCGImageAlphaPremultipliedLast` implicit conversion from enumeration type warning.
	* Fixed `kCGImageAlphaPremultipliedLast` implicit conversion from enumeration type warning.

Footnotes

1. PR descriptions should include the Pre-Review Checklist from the PR template, with all of the steps completed. (link) ↩

[jmagman]

This advice is wrong, the CHANGELOG style says:

Entries should use present tense indicative for verbs, with "this version" as an implied subject. For example, "Adds cool new feature.", not "Add", "Added", or "Adding".

[stuartmorgan-g]

LGTM