Feature labels on top of map

lib/cartopy/mpl/geoaxes.py

@@ -42,7 +42,6 @@
 from cartopy.mpl.slippy_image_artist import SlippyImageArtist
 from cartopy.vector_transform import vector_scalar_to_grid
 
-
 assert mpl.__version__ >= '1.5.1', ('Cartopy is only supported with '
                                     'Matplotlib 1.5.1 or greater.')
 
@@ -301,6 +300,7 @@ def set_position(self, position):
 
 def _add_transform(func):
     """A decorator that adds and validates the transform keyword argument."""
+
     @functools.wraps(func)
     def wrapper(self, *args, **kwargs):
         transform = kwargs.get('transform', None)
@@ -314,6 +314,7 @@ def wrapper(self, *args, **kwargs):
 
         kwargs['transform'] = transform
         return func(self, *args, **kwargs)
+
     return wrapper
 
 
@@ -450,7 +451,7 @@ def hold_limits(self, hold=True):
                 self.dataLim.set_points(data_lim)
                 self.viewLim.set_points(view_lim)
                 (self.ignore_existing_data_limits,
-                    self._autoscaleXon, self._autoscaleYon) = other
+                 self._autoscaleXon, self._autoscaleYon) = other
 
     def _draw_preprocess(self, renderer):
         """
@@ -654,7 +655,7 @@ def tissot(self, rad_km=500, lons=None, lats=None, n_samples=80, **kwargs):
             raise ValueError('lons and lats must have the same shape.')
 
         for lon, lat in zip(lons, lats):
-            circle = geod.circle(lon, lat, rad_km*1e3, n_samples=n_samples)
+            circle = geod.circle(lon, lat, rad_km * 1e3, n_samples=n_samples)
             geoms.append(sgeom.Polygon(circle))
 
         feature = cartopy.feature.ShapelyFeature(geoms, ccrs.Geodetic(),
@@ -1349,13 +1350,13 @@ def imshow(self, img, *args, **kwargs):
                 # kwargs['alpha'] is guaranteed to be either 1D, 2D, or None
                 alpha = kwargs.pop('alpha')
                 old_img = img[:, :, 0:3]
-                img = np.zeros(img.shape[:2] + (4, ), dtype=img.dtype)
+                img = np.zeros(img.shape[:2] + (4,), dtype=img.dtype)
                 img[:, :, 0:3] = old_img
                 # Put an alpha channel in if the image was masked.
                 if not np.any(alpha):
                     alpha = 1
-                img[:, :, 3] = np.ma.filled(alpha, fill_value=0) * \
-                    (~np.any(old_img.mask, axis=2))
+                img[:, :, 3] = np.ma.filled(alpha, fill_value=0) * (
+                    ~np.any(old_img.mask, axis=2))
                 if img.dtype.kind == 'u':
                     img[:, :, 3] *= 255
 
@@ -1700,7 +1701,7 @@ def _pcolormesh_patched(self, *args, **kwargs):
         collection.set_alpha(alpha)
         collection.set_array(C)
         if norm is not None:
-            assert(isinstance(norm, mcolors.Normalize))
+            assert (isinstance(norm, mcolors.Normalize))
         collection.set_cmap(cmap)
         collection.set_norm(norm)
         collection.set_clim(vmin, vmax)
@@ -1782,7 +1783,7 @@ def _pcolormesh_patched(self, *args, **kwargs):
                     #       projection which will help with curved boundaries
                     size_limit = (abs(self.projection.x_limits[1] -
                                       self.projection.x_limits[0]) /
-                                  (2*np.sqrt(2)))
+                                  (2 * np.sqrt(2)))
                     to_mask = (np.isnan(diagonal0_lengths) |
                                (diagonal0_lengths > size_limit) |
                                np.isnan(diagonal1_lengths) |

lib/cartopy/mpl/gridliner.py

@@ -714,6 +714,16 @@ def _segment_angle_to_text_specs(self, angle, lonlat):
                 x=dx, y=dy, units='points')
             kw.update(transform=transform)
 
+            if self.xpadding < 0 or self.ypadding < 0:
+                if kw['ha'] == 'left':
+                    kw['ha'] = 'right'
+                elif kw['ha'] == 'right':
+                    kw['ha'] = 'left'
+                if kw['va'] == 'top':
+                    kw['va'] = 'bottom'
+                elif kw['va'] == 'bottom':
+                    kw['va'] = 'top'
+
         return kw, loc
 
     def _update_labels_visibility(self, renderer):
@@ -783,6 +793,7 @@ def remove_path_dupes(path):
                 this_patch = artist.get_bbox_patch()
                 this_path = this_patch.get_path().transformed(
                     this_patch.get_transform())
+
                 if '3.1.0' <= matplotlib.__version__ <= '3.1.2':
                     this_path = remove_path_dupes(this_path)
                 center = artist.get_transform().transform_point(
@@ -803,17 +814,27 @@ def remove_path_dupes(path):
                                         .transformed(self.axes.transData))
                         if '3.1.0' <= matplotlib.__version__ <= '3.1.2':
                             outline_path = remove_path_dupes(outline_path)
+
                     # Inline must be within the map.
                     if ((lonlat == 'lon' and self.x_inline) or
                             (lonlat == 'lat' and self.y_inline)):
                         # TODO: When Matplotlib clip path works on text, this
                         # clipping can be left to it.
                         if outline_path.contains_point(center):
                             visible = True
-                    # Non-inline must not run through the outline.
-                    elif not outline_path.intersects_path(this_path):
+                    elif not outline_path.intersects_path(this_path,
+                                                          False if
+                                                          self.xpadding < 0 or
+                                                          self.ypadding < 0
+                                                          else True):
                         visible = True
 
+                    # labels must be within map bbox
+                    if (self.xpadding < 0 or self.ypadding < 0) and (
+                            not this_path.intersects_path(
+                                outline_path)):
+                        visible = False
+
                     # Good
                     if visible:
                         break

lib/cartopy/tests/mpl/test_gridliner.py

@@ -129,11 +129,16 @@ def test_gridliner_specified_lines():
     TOL = 15
 else:
     TOL = 0.5
-grid_label_tol = grid_label_inline_tol = grid_label_inline_usa_tol = TOL
+grid_label_tol = \
+    grid_label_inline_tol = \
+    grid_label_inline_usa_tol = \
+    grid_label_intersect_map_tol = TOL
+
 grid_label_inline_tol += 1.1
 grid_label_image = 'gridliner_labels'
 grid_label_inline_image = 'gridliner_labels_inline'
 grid_label_inline_usa_image = 'gridliner_labels_inline_usa'
+grid_label_intersect_map_image = 'gridliner_labels_intersect_map'
 
 
 @pytest.mark.natural_earth
@@ -388,3 +393,51 @@ def test_gridliner_line_limits():
     for path in paths:
         assert (np.min(path.vertices, axis=0) >= (xlim[0], ylim[0])).all()
         assert (np.max(path.vertices, axis=0) <= (xlim[1], ylim[1])).all()
+
+
+@pytest.mark.natural_earth
+@ImageTesting([grid_label_intersect_map_image],
+              tolerance=grid_label_intersect_map_tol)
+def test_grid_labels_intersect_map():
+    top = 49.3457868  # north lat
+    left = -124.7844079  # west long
+    right = -66.9513812  # east long
+    bottom = 24.7433195  # south lat
+    plt.figure(figsize=(35, 35))
+    for i, proj in enumerate(TEST_PROJS, 1):
+        if isinstance(proj, tuple):
+            proj, kwargs = proj
+        else:
+            kwargs = {}
+        ax = plt.subplot(7, 4, i, projection=proj(**kwargs))
+        try:
+            ax.set_extent([left, right, bottom, top], crs=ccrs.PlateCarree())
+        except Exception:
+            pass
+        ax.set_title(proj, y=1.075)
+        if ccrs.PROJ4_VERSION[:2] == (5, 0) and proj in (
+                ccrs.Orthographic,
+                ccrs.AlbersEqualArea,
+                ccrs.Geostationary,
+                ccrs.NearsidePerspective,
+        ):
+            # Above projections are broken, so skip labels.
+            # Add gridlines anyway to minimize image differences.
+            ax.gridlines()
+        else:
+            gl = ax.gridlines(draw_labels=True, clip_on=True)
+            gl.xpadding = -5
+            gl.ypadding = -5
+        ax.coastlines(resolution="110m")
+    plt.subplots_adjust(wspace=0.35, hspace=0.35)
+
+
+def test_setting_padding_values():
+    plt.figure()
+    ax = plt.subplot(1, 1, 1, projection=ccrs.PlateCarree())
+    gl = ax.gridlines()
+    assert gl.xpadding == 5 and gl.ypadding == 5
+    gl.xpadding = gl.ypadding = 10
+    assert gl.xpadding == 10 and gl.ypadding == 10
+    gl.xpadding = gl.ypadding = -5
+    assert gl.xpadding == -5 and gl.ypadding == -5