Add support for CSS styles

gtkblueprinttool/ast.py

@@ -266,14 +266,23 @@ class Child(AstNode):
 
 class ObjectContent(AstNode):
     child_type = "object_content"
-    def __init__(self, properties=[], signals=[], children=[]):
+    def __init__(self, properties=[], signals=[], children=[], style=[]):
         super().__init__()
         self.properties = properties
         self.signals = signals
         self.children = children
+        self.style = style
+
+    @validate()
+    def only_one_style_class(self):
+        if len(self.style) > 1:
+            raise CompileError(
+                f"Only one style directive allowed per object, but this object contains {len(self.style)}",
+                start=self.style[1].group.start,
+            )
 
     def emit_xml(self, xml: XmlEmitter):
-        for x in [*self.properties, *self.signals, *self.children]:
+        for x in [*self.properties, *self.signals, *self.children, *self.style]:
             x.emit_xml(xml)
 
 
@@ -390,3 +399,28 @@ class Signal(AstNode):
         if self.detail_name:
             name += "::" + self.detail_name
         xml.put_self_closing("signal", name=name, handler=self.handler, swapped="true" if self.swapped else None)
+
+
+class Style(AstNode):
+    child_type = "style"
+
+    def __init__(self, style_classes=None):
+        super().__init__()
+        self.style_classes = style_classes or []
+
+    def emit_xml(self, xml: XmlEmitter):
+        xml.start_tag("style")
+        for style in self.style_classes:
+            style.emit_xml(xml)
+        xml.end_tag()
+
+
+class StyleClass(AstNode):
+    child_type = "style_classes"
+
+    def __init__(self, name):
+        super().__init__()
+        self.name = name
+
+    def emit_xml(self, xml):
+        xml.put_self_closing("class", name=self.name)

gtkblueprinttool/parse_tree.py

@@ -319,6 +319,19 @@ class ZeroOrMore(ParseNode):
         return True
 
 
+class Delimited(ParseNode):
+    """ ParseNode that matches its first child any number of times (including zero
+    times) with its second child in between and optionally at the end. """
+    def __init__(self, child, delimiter):
+        self.child = child
+        self.delimiter = delimiter
+
+    def _parse(self, ctx):
+        while self.child.parse(ctx).matched() and self.delimiter.parse(ctx).matched():
+            pass
+        return True
+
+
 class Optional(ParseNode):
     """ ParseNode that matches its child zero or one times. It cannot fail to
     parse. """
@@ -362,6 +375,9 @@ class OpenParen(StaticToken):
 class CloseParen(StaticToken):
     token_type = TokenType.CLOSE_PAREN
 
+class Comma(StaticToken):
+    token_type = TokenType.COMMA
+
 
 class Op(ParseNode):
     """ ParseNode that matches the given operator. """

gtkblueprinttool/parser.py

@@ -137,11 +137,27 @@ def parse(tokens) -> ast.UI:
         )
     )
 
+    style = Group(
+        ast.Style,
+        Sequence(
+            Keyword("style"),
+            Delimited(
+                Group(
+                    ast.StyleClass,
+                    UseQuoted("name")
+                ),
+                Comma(),
+            ),
+            StmtEnd(),
+        )
+    )
+
     object_content = Group(
         ast.ObjectContent,
         Sequence(
             OpenBlock(),
             ZeroOrMore(AnyOf(
+                style,
                 property,
                 binding,
                 signal,

tests/test_parser.py

@@ -45,6 +45,7 @@ class TestParser(unittest.TestCase):
         }
 
         Label {
+            style "dim-label", "my-class";
             label: "Text";
             notify::visible => on_notify_visible();
         }
@@ -109,3 +110,7 @@ class TestParser(unittest.TestCase):
         self.assertEqual(signal.handler, "on_notify_visible")
         self.assertEqual(signal.detail_name, "visible")
         self.assertFalse(signal.swapped)
+        self.assertEqual(len(obj.object_content.style), 1)
+        style = obj.object_content.style[0]
+        self.assertEqual(len(style.style_classes), 2)
+        self.assertEqual([s.name for s in style.style_classes], ["dim-label", "my-class"])