Issue #62: refactor MapCSS generation.

roentgen/mapcss.py

@@ -0,0 +1,68 @@
+"""
+MapCSS scheme creation.
+"""
+from pathlib import Path
+from typing import Dict, List
+
+import logging
+from colour import Color
+
+from roentgen.grid import IconCollection
+from roentgen.icon import ShapeExtractor
+from roentgen.scheme import Scheme
+
+
+def construct_selectors(scheme: Scheme, icon_directory_name: str):
+    """
+    Construct icon selectors for MapCSS 0.2 scheme.
+    """
+    selectors: Dict[str, List[str]] = {}
+    for matcher in scheme.node_matchers:
+        if matcher.shapes and not matcher.location_restrictions:
+            # TODO: support location restrictions
+            selectors[matcher.get_mapcss_selector()] = [
+                (x if isinstance(x, str) else x["shape"]) for x in matcher.shapes
+            ]
+
+    s = ""
+    for selector in selectors:
+        for target in ["node", "area"]:
+            s += (
+                target + selector + " {\n"
+                f'    icon-image: "{icon_directory_name}/'
+                + "___".join(selectors[selector])
+                + '.svg";\n}\n'
+            )
+    return s
+
+
+def write_mapcss() -> None:
+    """
+    Write MapCSS 0.2 scheme.
+    """
+    icon_directory_name: str = "icons"
+
+    out_path: Path = Path("out")
+    directory: Path = out_path / "roentgen_icons_mapcss"
+    directory.mkdir(exist_ok=True)
+    icons_with_outline_path: Path = directory / icon_directory_name
+
+    icons_with_outline_path.mkdir(parents=True, exist_ok=True)
+
+    scheme: Scheme = Scheme(Path("scheme/default.yml"))
+    extractor: ShapeExtractor = ShapeExtractor(
+        Path("icons/icons.svg"), Path("icons/config.json")
+    )
+    collection: IconCollection = IconCollection.from_scheme(scheme, extractor)
+    collection.draw_icons(
+        icons_with_outline_path, color=Color("black"), outline=True
+    )
+    with Path("data/roentgen_icons_part.mapcss").open() as input_file:
+        header = input_file.read()
+
+    with (directory / "roentgen_icons.mapcss").open("w+") as output_file:
+        output_file.write(header)
+        output_file.write("\n")
+        output_file.write(construct_selectors(scheme, icon_directory_name))
+
+    logging.info(f"MapCSS 0.2 scheme is written to {directory}.")