Upgrade dependencies, fix EPSG:3413 example

[JosefWN]

Upgrades the project to the latest compatible dependencies.

Also adds assets/ path prefix to a broken Image.asset() in the EPSG:3413 example.

Tested on all examples, seems to work except for #1360.

[JaffaKetchup]

Hi @JosefWN,
flutter pub outdated says that all dependencies are up to date without this PR:


However, I can see that your versions in this PR are the latest.
Do you have an idea why this might be?
Many thanks.

[JosefWN]

Ah: https://dart.dev/tools/pub/dependencies

For example, ^1.2.3 is equivalent to >=1.2.3 <2.0.0, and ^0.1.2 is equivalent to >=0.1.2 <0.2.0.

I assumed ^ would only allow patch version bumps regardless of major version, so I've effectively only made the dependency spec a little stricter.

Two things which might be good:

• Bumped to Dart 2.18 for example/ just to align with the flutter_map spec.
• If I got it right, flutter_lints: ">=1.0.4" will allow any version greater than or equal to 1.0.4 (including future 3.0.0), so it might be safer to use the caret syntax there too like I did in my PR?

[JaffaKetchup]

Good spot on the example project!

Still not sure why they would be showing differences on our systems, as they almost all use carat syntax anyway?

But I think your second point is an issue: I would prefer carat syntax, like you've changed to.

[JosefWN]

Still not sure why they would be showing differences on our systems, as they almost all use carat syntax anyway?

I think it will depend on when we last ran flutter pub upgrade or equivalent, so by bumping dependency versions in the spec we ensure that everyone using flutter_map are using these later versions.

[JaffaKetchup]

Ok, I'm happy with this. Can someone else (@ibrierley, @TesteurManiak, @moonag) give this a check to make sure it runs fine on their system? (Note the SDK version change)

[TesteurManiak]

LGTM

[JaffaKetchup]

LGTM. Thanks for your changes!