Generalise stylesheet parsing to extract colours for light/dark theme callback.

src/napari_matplotlib/tests/test_util.py

@@ -18,29 +18,37 @@ def test_interval():
 
 def test_get_size_from_css(mocker):
     """Test getting the max-width and max-height from something in css"""
+    # some weird (but valid) css to check we can skip things correctly
     test_css = """
         Flibble {
+            padding: 0 0 1px 2px;
+            color: rgb(3, 4, 555);
             min-width : 0;
             max-width : 123px;
-            min-height : 0px;
+            min-height : 0%;
             max-height : 456px;
-            padding: 0px;
         }
         """
     mocker.patch("napari.qt.get_current_stylesheet").return_value = test_css
-    assert from_napari_css_get_size_of("Flibble", (1, 2)) == QSize(123, 456)
+    assert from_napari_css_get_size_of("Flibble", fallback=(1, 2)) == QSize(
+        123, 456
+    )
 
 
 def test_fallback_if_missing_dimensions(mocker):
     """Test fallback if given something that doesn't have dimensions"""
     test_css = " Flobble { background-color: rgb(0, 97, 163); } "
     mocker.patch("napari.qt.get_current_stylesheet").return_value = test_css
     with pytest.warns(RuntimeWarning, match="Unable to find DimensionToken"):
-        assert from_napari_css_get_size_of("Flobble", (1, 2)) == QSize(1, 2)
+        assert from_napari_css_get_size_of(
+            "Flobble", fallback=(1, 2)
+        ) == QSize(1, 2)
 
 
 def test_fallback_if_prelude_not_in_css():
     """Test fallback if given something not in the css"""
     doesntexist = "AQButtonThatDoesntExist"
     with pytest.warns(RuntimeWarning, match=f"Unable to find {doesntexist}"):
-        assert from_napari_css_get_size_of(doesntexist, (1, 2)) == QSize(1, 2)
+        assert from_napari_css_get_size_of(
+            doesntexist, fallback=(1, 2)
+        ) == QSize(1, 2)

src/napari_matplotlib/util.py

@@ -1,4 +1,4 @@
-from typing import List, Optional, Tuple, Union
+from typing import Generator, List, Optional, Tuple, Union
 from warnings import warn
 
 import napari.qt
@@ -47,6 +47,21 @@ def __contains__(self, val: int) -> bool:
         return True
 
 
+def _logical_lines(
+    nodes: List[tinycss2.ast.Node],
+) -> Generator[Tuple[tinycss2.ast.Node, tinycss2.ast.Node], None, None]:
+    """Generator to provide logical lines (thing: value) of css (terminated by ';')"""
+    ident, dimension = None, None
+    for node in nodes:
+        if node == ";":
+            yield (ident, dimension)
+            ident, dimension = None, None
+        elif node.type == "ident":
+            ident = node
+        elif node.type == "dimension":
+            dimension = node
+
+
 def _has_id(nodes: List[tinycss2.ast.Node], id_name: str) -> bool:
     """
     Is `id_name` in IdentTokens in the list of CSS `nodes`?
@@ -66,13 +81,8 @@ def _get_dimension(
     -------
         None if no IdentToken is found.
     """
-    cleaned_nodes = [node for node in nodes if node.type != "whitespace"]
-    for name, _, value, _ in zip(*(iter(cleaned_nodes),) * 4):
-        if (
-            name.type == "ident"
-            and value.type == "dimension"
-            and name.value == id_name
-        ):
+    for name, value in _logical_lines(nodes):
+        if name.value == id_name:
             return value.int_value
     warn(f"Unable to find DimensionToken for {id_name}", RuntimeWarning)
     return None