FIX: gridliner auto-updates by default (and always in future)

lib/cartopy/mpl/geoaxes.py

@@ -1359,7 +1359,7 @@ def gridlines(self, crs=None, draw_labels=False,
                   xformatter=None, yformatter=None, xlim=None, ylim=None,
                   rotate_labels=None, xlabel_style=None, ylabel_style=None,
                   labels_bbox_style=None, xpadding=5, ypadding=5,
-                  offset_angle=25, auto_update=False, formatter_kwargs=None,
+                  offset_angle=25, auto_update=None, formatter_kwargs=None,
                   **kwargs):
         """
         Automatically add gridlines to the axes, in the given coordinate
@@ -1464,9 +1464,13 @@ def gridlines(self, crs=None, draw_labels=False,
             a label must be flipped to be more readable.
             For example, a value of 10 makes a vertical top label to be
             flipped only at 100 degrees.
-        auto_update: bool
-            Whether to update the grilines and labels when the plot is
+        auto_update: bool, default=True
+            Whether to update the gridlines and labels when the plot is
             refreshed.
+
+            .. deprecated:: 0.23
+               In future the gridlines and labels will always be updated.
+
         formatter_kwargs: dict, optional
             Options passed to the default formatters.
             See :class:`~cartopy.mpl.ticker.LongitudeFormatter` and

lib/cartopy/mpl/gridliner.py

@@ -114,7 +114,7 @@ def __init__(self, axes, crs, draw_labels=False, xlocator=None,
                  xlim=None, ylim=None, rotate_labels=None,
                  xlabel_style=None, ylabel_style=None, labels_bbox_style=None,
                  xpadding=5, ypadding=5, offset_angle=25,
-                 auto_update=False, formatter_kwargs=None):
+                 auto_update=None, formatter_kwargs=None):
         """
         Artist used by :meth:`cartopy.mpl.geoaxes.GeoAxes.gridlines`
         to add gridlines and tick labels to a map.
@@ -218,9 +218,13 @@ def __init__(self, axes, crs, draw_labels=False, xlocator=None,
             a label must be flipped to be more readable.
             For example, a value of 10 makes a vertical top label to be
             flipped only at 100 degrees.
-        auto_update: bool
+        auto_update: bool, default=True
             Whether to redraw the gridlines and labels when the figure is
             updated.
+
+            .. deprecated:: 0.23
+               In future the gridlines and labels will always be redrawn.
+
         formatter_kwargs: dict, optional
             Options passed to the default formatters.
             See :class:`~cartopy.mpl.ticker.LongitudeFormatter` and
@@ -444,6 +448,13 @@ def __init__(self, axes, crs, draw_labels=False, xlocator=None,
 
         # Draw status
         self._drawn = False
+        if auto_update is None:
+            auto_update = True
+        else:
+            warnings.warn(
+                "The auto_update parameter was deprecated at Cartopy 0.23.  In future "
+                "the gridlines and labels will always be updated.",
+                DeprecationWarning)
         self._auto_update = auto_update
 
     def has_labels(self):

lib/cartopy/tests/mpl/test_gridliner.py

@@ -216,7 +216,7 @@ def test_grid_labels():
 @pytest.mark.skipif(geos_version == (3, 9, 0), reason="GEOS intersection bug")
 @pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='gridliner_labels_tight.png',
-                               tolerance=2.92)
+                               tolerance=2.9)
 def test_grid_labels_tight():
     # Ensure tight layout accounts for gridlines
     fig = plt.figure(figsize=(7, 5))
@@ -290,8 +290,7 @@ def test_gridliner_constrained_adjust_datalim():
     ax.autoscale()
 
     # Add some gridlines
-    ax.gridlines(draw_labels=["bottom", "left"], auto_update=True,
-                 linestyle="-")
+    ax.gridlines(draw_labels=["bottom", "left"], linestyle="-")
 
     return fig
 
@@ -515,11 +514,11 @@ def test_gridliner_remove():
 
 
 def test_gridliner_save_tight_bbox():
-    # Smoke test for save with auto_update=True and bbox_inches=Tight (gh2246).
+    # Smoke test for save with bbox_inches=Tight (gh2246).
     fig = plt.figure()
     ax = fig.add_subplot(1, 1, 1, projection=ccrs.PlateCarree())
     ax.set_global()
-    ax.gridlines(draw_labels=True, auto_update=True)
+    ax.gridlines(draw_labels=True)
     fig.savefig(io.BytesIO(), bbox_inches='tight')
 
 
@@ -569,7 +568,7 @@ def test_gridliner_labels_zoom():
 
     # Start with a global map.
     ax.set_global()
-    gl = ax.gridlines(draw_labels=True, auto_update=True)
+    gl = ax.gridlines(draw_labels=True)
 
     fig.draw_without_rendering()  # Generate child artists
     labels = [a.get_text() for a in gl.bottom_label_artists if a.get_visible()]