Make coasts and gridlines optional on plots

There are currently a number of problems with gridlines on plots in
Jupyter notebooks. There are different solutions that depend on whether
you want an interactive plot, a static plot in a notebook, or are
saving the plot to a file. Unfortunately there is no single solution
that works in all cases currently. Until a proper solution is found,
users can disable gridlines and then re-enable them in the way that
works for their current environment.

SciTools/cartopy#2245
SciTools/cartopy#2246
SciTools/cartopy#2247

docs/releases/development.rst

@@ -5,3 +5,11 @@ Next release (in development)
 * Fix transect plot title and units.
   All attributes were being dropped accidentally in `prepare_data_array_for_transect()`.
   (:pr:`114`).
+* Add `coast` and `gridlines` parameters to :func:`emsarray.plot.plot_on_figure()`,
+  allowing users to disable these components of a plot.
+  Currently gridlines can cause issues in interactive Jupyter notebooks
+  and some other environments.
+  There is no one solution to every situation.
+  Allowing users to disable gridlines is a temporary work around
+  while other solutions are being sought.
+  (:pr:`115`, :issue:`SciTools/cartopy#2245`, :issue:`SciTools/cartopy#2246`, :issue:`SciTools/cartopy#2247`).

src/emsarray/plot.py

@@ -62,7 +62,12 @@ def add_coast(axes: Axes, **kwargs: Any) -> None:
     axes.add_feature(coast, **kwargs)
 
 
-def add_gridlines(axes: Axes) -> gridliner.Gridliner:
+def add_gridlines(
+    axes: Axes,
+    draw_labels={'left', 'bottom'},
+    auto_update=True,
+    **kwargs: Any,
+) -> gridliner.Gridliner:
     """
     Add some gridlines to the axes.
 
@@ -75,9 +80,11 @@ def add_gridlines(axes: Axes) -> gridliner.Gridliner:
     -------
     cartopy.mpl.gridliner.Gridliner
     """
-    gridlines = axes.gridlines(draw_labels=True, auto_update=True)
-    gridlines.top_labels = False
-    gridlines.right_labels = False
+    gridlines = axes.gridlines(
+        draw_labels=draw_labels,
+        auto_update=auto_update,
+        **kwargs,
+    )
     return gridlines
 
 
@@ -270,6 +277,8 @@ def plot_on_figure(
     title: Optional[str] = None,
     projection: Optional[cartopy.crs.Projection] = None,
     landmarks: Optional[Iterable[Landmark]] = None,
+    gridlines: bool = True,
+    coast: bool = True,
 ) -> None:
     """
     Plot a :class:`~xarray.DataArray`
@@ -298,6 +307,10 @@ def plot_on_figure(
         which is defined in :attr:`.Convention.data_crs`.
     landmarks : list of :data:`landmarks <emsarray.types.Landmark>`, optional
         Landmarks to add to the plot. These are tuples of (name, point).
+    gridlines : bool, default True
+        Whether to add gridlines to the plot using :func:`add_gridlines()`.
+    coast : bool, default True
+        Whether to add coastlines to the plot using :func:`add_coast()`.
     """
     if projection is None:
         projection = cartopy.crs.PlateCarree()
@@ -331,10 +344,19 @@ def plot_on_figure(
     if landmarks:
         add_landmarks(axes, landmarks)
 
-    add_coast(axes)
-    add_gridlines(axes)
+    if coast:
+        add_coast(axes)
+    if gridlines:
+        add_gridlines(axes)
+
     axes.autoscale()
 
+    # Work around for gridline positioning issues
+    # https://github.com/SciTools/cartopy/issues/2245#issuecomment-1732313921
+    layout_engine = figure.get_layout_engine()
+    if layout_engine is not None:
+        layout_engine.execute(figure)
+
 
 @_requires_plot
 def animate_on_figure(
@@ -347,6 +369,8 @@ def animate_on_figure(
     title: Optional[Union[str, Callable[[Any], str]]] = None,
     projection: Optional[cartopy.crs.Projection] = None,
     landmarks: Optional[Iterable[Landmark]] = None,
+    gridlines: bool = True,
+    coast: bool = True,
     interval: int = 1000,
     repeat: Union[bool, Literal['cycle', 'bounce']] = True,
 ) -> animation.FuncAnimation:
@@ -392,6 +416,10 @@ def animate_on_figure(
         which is defined in :attr:`.Convention.data_crs`.
     landmarks : list of :data:`landmarks <emsarray.types.Landmark>`, optional
         Landmarks to add to the plot. These are tuples of (name, point).
+    gridlines : bool, default True
+        Whether to add gridlines to the plot using :func:`add_gridlines()`.
+    coast : bool, default True
+        Whether to add coastlines to the plot using :func:`add_coast()`.
     interval : int
         The interval between frames of animation
     repeat : {True, False, 'cycle', 'bounce'}
@@ -442,8 +470,10 @@ def animate_on_figure(
         axes.add_collection(quiver)
 
     # Draw a coast overlay
-    add_coast(axes)
-    gridlines = add_gridlines(axes)
+    if coast:
+        add_coast(axes)
+    if gridlines:
+        gridliner = add_gridlines(axes)
     if landmarks:
         add_landmarks(axes, landmarks)
     axes.autoscale()
@@ -470,8 +500,9 @@ def animate(index: int) -> Iterable[Artist]:
         coordinate_value = coordinate.values[index]
         axes.title.set_text(coordinate_callable(coordinate_value))
         changes.append(axes.title)
-        changes.extend(gridlines.xline_artists)
-        changes.extend(gridlines.yline_artists)
+        if gridlines:
+            changes.extend(gridliner.xline_artists)
+            changes.extend(gridliner.yline_artists)
 
         if collection is not None:
             collection.set_array(scalar_values[index])