Lay out new client structure

cheuph/attributed_text_widget.py

@@ -0,0 +1,77 @@
+from typing import Any, List, Tuple, Union
+
+import urwid
+
+from ..markup import AttributedText
+
+__all__ = ["AttributedTextWidget", "ATWidget"]
+
+class AttributedTextWidget(urwid.Text):
+    """
+    A widget that works like urwid.Text, but displays AttributedText.
+
+    The AttributedText's "style" attribute is used as the style for urwid.Text,
+    where present.
+    """
+
+    def __init__(self,
+            text: AttributedText,
+            *args: Any,
+            **kwargs: Any
+            ) -> None:
+        """
+        text - an AttributedText object
+
+        All other arguments are passed onto a urwid.Text constructor and thus
+        work the same way.
+        """
+
+        self._attributed_text = text
+        super().__init__(self._convert_to_markup(text), *args, **kwargs)
+
+    @staticmethod
+    def _convert_to_markup(text: AttributedText
+            ) -> List[Union[str, Tuple[str, str]]]:
+
+        # Wonder why mypy can't figure out the type signature of markup on its
+        # own... :P
+        markup: List[Union[str, Tuple[str, str]]]
+        markup = [
+                segment.text if style is None else (style, segment.text)
+                for segment, style in text.split_by("style")
+        ]
+
+        return markup or [""]
+
+    def set_attributed_text(self, text: AttributedText) -> None:
+        """
+        Set the content of the AttributedTextWidget.
+        """
+
+        self._attributed_text = text
+        super().set_text(self._convert_to_markup(text))
+
+    def set_text(self, *args, **kwargs):
+        """
+        This function should not be used directly. Instead, use
+        set_attributed_text().
+        """
+
+        raise NotImplementedError("use set_attributed_text() instead")
+
+    def get_attributed_text(self) -> AttributedText:
+        """
+        Returns the currently used AttributedText.
+
+        urwid.Text's get_text() also returns a run length encoded list of
+        attributes. This is not necessary here because the AttributedText
+        already contains all its attributes.
+        """
+
+        return self._attributed_text
+
+    @property
+    def attributed_text(self) -> AttributedText:
+        return self.get_attributed_text()
+
+ATWidget = AttributedTextWidget