fix outline width parameter, add unittests (#139)

Co-authored-by: Sonja Stockhaus <stockhaus@cip.ifi.lmu.de>

Author: Sonja-Stockhaus

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning][].
 
 -   Multi-scale images/labels are now correctly substituted and the action is logged (#131).
 -   Empty geometries among the shapes can be handeled (#133).
+-   `outline_width` parameter in render_shapes is now a float that actually determines the line width (#139).
 
 ## [0.0.2] - 2023-06-25
 

src/spatialdata_plot/pl/basic.py

@@ -145,7 +145,7 @@ def render_shapes(
         groups: str | Sequence[str] | None = None,
         size: float = 1.0,
         outline: bool = False,
-        outline_width: tuple[float, float] = (0.3, 0.05),
+        outline_width: float = 1.5,
         outline_color: str | list[float] = "#000000ff",
         alt_var: str | None = None,
         layer: str | None = None,
@@ -198,6 +198,7 @@ def render_shapes(
         Notes
         -----
             Empty geometries will be removed at the time of plotting.
+            An ``outline_width`` of 0.0 leads to no border being plotted.
 
         Returns
         -------
@@ -538,7 +539,7 @@ def show(
                 render_cmds[cmd] = params
 
         if len(render_cmds.keys()) == 0:
-            raise TypeError("Please specify what to plot using the 'render_*' functions before calling 'imshow().")
+            raise TypeError("Please specify what to plot using the 'render_*' functions before calling 'imshow()'.")
 
         if title is not None:
             if isinstance(title, str):

src/spatialdata_plot/pl/render.py

@@ -156,7 +156,7 @@ def _get_collection_shape(
             patches,
             snap=False,
             # zorder=4,
-            lw=1.5,
+            lw=render_params.outline_params.linewidth,
             facecolor=fill_c,
             edgecolor=outline_c,
             **kwargs,

src/spatialdata_plot/pl/utils.py

@@ -485,31 +485,36 @@ class OutlineParams:
 
     outline: bool
     outline_color: str | list[float]
-    gap_size: float
-    bg_size: float
+    linewidth: float
 
 
 def _set_outline(
     size: float,
     outline: bool = False,
-    outline_width: tuple[float, float] = (0.3, 0.05),
+    outline_width: float = 1.5,
     outline_color: str | list[float] = "#0000000ff",  # black, white
     **kwargs: Any,
 ) -> OutlineParams:
-    bg_width, gap_width = outline_width
-    point = np.sqrt(size)
-    gap_size = (point + (point * gap_width) * 2) ** 2
-    bg_size = (np.sqrt(gap_size) + (point * bg_width) * 2) ** 2
-    # the default black and white colors can be changes using the contour_config parameter
-
+    # Type checks for outline_width
+    if isinstance(outline_width, int):
+        outline_width = float(outline_width)
+    if not isinstance(outline_width, float):
+        raise TypeError(f"Invalid type of `outline_width`: {type(outline_width)}, expected `float`.")
+    if outline_width == 0.0:
+        outline = False
+    if outline_width < 0.0:
+        logging.warning(f"Negative line widths are not allowed, changing {outline_width} to {(-1)*outline_width}")
+        outline_width = (-1) * outline_width
+
+    # the default black and white colors can be changed using the contour_config parameter
     if (len(outline_color) == 3 or len(outline_color) == 4) and all(isinstance(c, float) for c in outline_color):
         outline_color = matplotlib.colors.to_hex(outline_color)
 
     if outline:
         kwargs.pop("edgecolor", None)  # remove edge from kwargs if present
         kwargs.pop("alpha", None)  # remove alpha from kwargs if present
 
-    return OutlineParams(outline, outline_color, gap_size, bg_size)
+    return OutlineParams(outline, outline_color, outline_width)
 
 
 def _get_subplots(num_images: int, ncols: int = 4, width: int = 4, height: int = 3) -> plt.Figure | plt.Axes:

tests/_images/Shapes_can_render_circles_with_default_outline_width.png

@@ -51,3 +51,9 @@ def test_plot_can_render_polygons_with_rgba_colored_outline(self, sdata_blobs: S
     def test_plot_can_render_empty_geometry(self, sdata_blobs: SpatialData):
         sdata_blobs.shapes["blobs_circles"].at[0, "geometry"] = gpd.points_from_xy([None], [None])[0]
         sdata_blobs.pl.render_shapes().pl.show()
+
+    def test_plot_can_render_circles_with_default_outline_width(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(elements="blobs_circles", outline=True).pl.show()
+
+    def test_plot_can_render_circles_with_specified_outline_width(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(elements="blobs_circles", outline=True, outline_width=3.0).pl.show()