Client: variables resolved in the live editor and reading view

Co-Authored-By: Claude Opus 5.5 <[email protected]>

Client/LiveMarkdown.py

@@ -9,7 +9,9 @@ list, table or quote). The text between blocks (blank lines) is kept
 byte for byte, so editing one block never reformats the rest of the file.
 A ```mermaid block shows as its diagram when MakeDiagram gives one (Diagrams.py),
 and the properties block at the top as its panel (Properties.py). Checkboxes
-(tasks and true/false properties) tick without opening their block."""
+(tasks and true/false properties) tick without opening their block. With
+GetSpans, text and headings show their variables' results (Variables.py);
+opening a block shows what's written."""
 
 import re
 from dataclasses import dataclass
@@ -20,6 +22,7 @@ import flet as ft
 import Core
 from Core import CodeStyleSheet, MarkdownCodeTheme, MarkdownSheet, Palette
 from Properties import ParseProperties, PropertiesView, ToggleLine, WithCheckboxes
+from Variables import Substitute
 
 FenceStart = re.compile(r"^ {0,3}(`{3,}|~{3,})")
 HeadingLine = re.compile(r"^ {0,3}(#{1,6})(\s|$)")
@@ -113,7 +116,8 @@ def SplitBlocks(Document: str) -> list[Block]:
 class LiveMarkdown(ft.Column):
     def __init__(self, Document: str, FontSize: int, OnChange: Callable[[], None],
                  OnFocusChange: Callable[[bool], None], OnTapLink: Callable,
-                 MakeDiagram: Optional[Callable[[str, int], Optional[ft.Control]]] = None):
+                 MakeDiagram: Optional[Callable[[str, int], Optional[ft.Control]]] = None,
+                 GetSpans: Optional[Callable[[str], list[dict]]] = None):
         super().__init__(scroll=ft.ScrollMode.AUTO, expand=True, spacing=0,
                          horizontal_alignment=ft.CrossAxisAlignment.STRETCH)
         self.Document = Document
@@ -122,11 +126,13 @@ class LiveMarkdown(ft.Column):
         self.OnFocusChange = OnFocusChange
         self.OnTapLink = OnTapLink
         self.MakeDiagram = MakeDiagram
+        self.GetSpans = GetSpans
+        self.SpansFor: tuple[str, list[dict]] = ("", [])  # (document, its spans)
         self.Blocks: list[Block] = []
         self.BlockControls: list[ft.Control] = []
         # Rendered blocks by their text, reused when the layout is rebuilt so
         # only the edited part is rendered again.
-        self.RenderCache: dict[tuple[str, str], list[ft.Control]] = {}
+        self.RenderCache: dict[tuple[str, str], list[ft.Control]] = {}  # by (kind, text as shown)
         self.EditingIndex: Optional[int] = None  # len(Blocks) is the new block at the end
         self.Field: Optional[ft.TextField] = None
         self._Layout(Update=False)
@@ -239,7 +245,14 @@ class LiveMarkdown(ft.Column):
             on_tap_link=self.OnTapLink,
         )
 
-    def _Render(self, Text: str, Kind: str) -> ft.Control:
+    def _Spans(self) -> list[dict]:
+        if self.GetSpans is None:
+            return []
+        if self.SpansFor[0] != self.Document:
+            self.SpansFor = (self.Document, self.GetSpans(self.Document))
+        return self.SpansFor[1]
+
+    def _Render(self, Text: str, Kind: str, Shown: Optional[str] = None, LineMap: Optional[list] = None) -> ft.Control:
         Rendered = ft.Container(padding=ft.Padding.symmetric(horizontal=8, vertical=6), border_radius=4)
         # Lines are counted from the block's start, found again when ticked:
         # a rendered block is reused wherever its text ends up (RenderCache).
@@ -250,10 +263,10 @@ class LiveMarkdown(ft.Column):
         elif Kind == "Properties" and (Found := ParseProperties(Text)) is not None:
             Rendered.content = PropertiesView(Found, self.FontSize, self._Markdown, Toggle)
         elif Kind == "Text":
-            Parts = WithCheckboxes(Text, 0, self._Markdown, Toggle, self.FontSize)
+            Parts = WithCheckboxes(Shown if Shown is not None else Text, 0, self._Markdown, Toggle, self.FontSize, LineMap)
             Rendered.content = Parts[0] if len(Parts) == 1 else ft.Column(Parts, spacing=0, tight=True)
         else:
-            Rendered.content = self._Markdown(Text)
+            Rendered.content = self._Markdown(Shown if Shown is not None and Kind == "Heading" else Text)
         Rendered.on_click = lambda e, C=Rendered: self._OnBlockClicked(C)
         Rendered.on_hover = lambda e, C=Rendered: self._OnHover(C, e)
         return Rendered
@@ -276,6 +289,7 @@ class LiveMarkdown(ft.Column):
 
     def _Layout(self, Update: bool = True) -> None:
         self.Blocks = SplitBlocks(self.Document)
+        Spans = self._Spans()
         Cache = self.RenderCache
         self.RenderCache = {}
         self.BlockControls = []
@@ -284,11 +298,12 @@ class LiveMarkdown(ft.Column):
                 self.BlockControls.append(self.Field)
                 continue
             Text = self.Document[Item.Start:Item.End]
-            Reused = Cache.get((Item.Kind, Text))
-            Control = Reused.pop() if Reused else self._Render(Text, Item.Kind)
+            Shown, LineMap = Substitute(Text, Item.Start, Spans) if Item.Kind in ("Text", "Heading") else (Text, None)
+            Reused = Cache.get((Item.Kind, Shown))
+            Control = Reused.pop() if Reused else self._Render(Text, Item.Kind, Shown, LineMap)
             Control.bgcolor = None
             self.BlockControls.append(Control)
-            self.RenderCache.setdefault((Item.Kind, Text), []).append(Control)
+            self.RenderCache.setdefault((Item.Kind, Shown), []).append(Control)
         Controls = list(self.BlockControls)
         if self.EditingIndex == len(self.Blocks):
             Controls.append(self.Field)