refactor: avoid parsing document twice for figure numbers

renderer/image.py

@@ -0,0 +1,40 @@
+import re
+
+from mistletoe.block_tokenizer import FileWrapper
+
+from renderer.referenced_token import ReferencedToken
+
+
+class Image(ReferencedToken):
+    """
+    Block token for pictures and photos.
+    Examples:
+        [picture:727:amplitude_periode_halbwellen:Positive und negative Halbwellen einer Sinusschwingung]
+        [photo:123:n_wasserfalldiagramm_trx_collage:Ansichten verschiedener Transceiver]
+    """
+
+    pattern = re.compile(r"^\[(?P<kind>picture|photo):(?P<id>\d+):(?P<marker>[^:\]]+):(?P<text>[^:\]]+)\]$")
+
+    @classmethod
+    def start(cls, line: str):
+        return cls.pattern.match(line.strip()) is not None
+
+    @classmethod
+    def check_interrupts_paragraph(cls, lines: FileWrapper):
+        line = lines.peek()
+        if line is not None:
+            return cls.start(line)
+        else:
+            return False
+
+    @classmethod
+    def read(cls, lines: FileWrapper):
+        match = cls.pattern.match(next(lines).strip())
+        return match.group("kind"), match.group("id"), match.group("marker"), match.group("text")
+
+    def __init__(self, match):
+        kind, id, marker, text = match
+        super().__init__(marker)
+        self.kind = kind
+        self.id = id
+        self.text = text