Refactor GeoAxes gridliner handling and format flow; remove cartopy monkey patches

[cvanelteren]

Summary

• Replace cartopy gridliner monkey-patching with local _CartopyGridliner/_CartopyLabel subclasses and a gridlines() override.
• Unify cartopy/basemap gridliner behavior via adapters, shared side-mapping, and adapter-owned tick positions.
• Split GeoAxes.format into focused helpers for clarity and extensibility; add format flow comment.
• Preserve legacy gridliner toggle behavior for empty label arrays (fixes test_cartesian_and_geo).

User API is the same.

[Copilot]

Pull request overview

This PR refactors the GeoAxes gridliner handling to eliminate cartopy monkey-patching in favor of local subclasses and introduces a unified adapter pattern for both cartopy and basemap backends. The core changes improve code maintainability and extensibility by creating clear abstraction boundaries.

Changes:

• Replaced cartopy monkey-patching with _CartopyGridliner and _CartopyLabel subclasses
• Introduced _GridlinerAdapter protocol with backend-specific implementations (_CartopyGridlinerAdapter and _BasemapGridlinerAdapter)
• Split the large GeoAxes.format() method into focused helper methods for improved clarity
• Added comprehensive type hints throughout the geographic axes implementation

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
ultraplot/tests/test_geographic.py	Added comprehensive tests for gridliner label handling, adapter refresh, tick positions, and tick_params updates across both cartopy and basemap backends
ultraplot/axes/geo.py	Major refactoring: introduced adapter pattern, removed monkey patches, split format() into focused helpers, added type hints, and unified backend handling

Comments suppressed due to low confidence (4)

ultraplot/axes/geo.py:3141

• For loop variable 'obj' is not used in the loop body.

                        for obj in feat:

ultraplot/axes/geo.py:24

• Import of 'mtransforms' is not used.

import matplotlib.transforms as mtransforms

ultraplot/axes/geo.py:29

• Import of 'pticker' is not used.

from .. import ticker as pticker

ultraplot/axes/geo.py:39

• Import of 'ic' is not used.

from ..internals import (
    _not_none,
    _pop_rc,
    _version_cartopy,
    docstring,
    ic,  # noqa: F401
    labels,
    warnings,
)

---

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[Copilot]

This initialization method calls GeoAxes.init multiple times, via this call and this call.

[cvanelteren]

@copilot open a new pull request to apply changes based on this feedback

[cvanelteren]

@cvanelteren I've opened a new pull request, #455, to work on those changes. Once the pull request is ready, I'll request review from you.

Bad copilot, you messed things up

[codecov]

Codecov Report

❌ Patch coverage is 95.19231% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
ultraplot/tests/test_geographic.py	95.19%	0 Missing and 5 partials ⚠️

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