Client: Mermaid diagrams, drawn by the server

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

Client/Viewer.py

@@ -2,7 +2,7 @@
 EditorView/ImageView idea, with SaraView's View/Edit/Save toolbar).
 
 - Markdown is rendered in View; the other text types are shown as
-  highlighted code. Edit is a plain monospace field with an explicit Save
+  highlighted code. On a server, ```mermaid blocks show as diagrams (Diagrams.py). Edit is a plain monospace field with an explicit Save
   (Ctrl+S). On a server, saving records line blame for you, like the web view.
 - With Markdown editing set to Live (Settings > General), Markdown opens in
   LiveMarkdown instead: rendered, and click a block to edit it in place.
@@ -20,6 +20,7 @@ import flet as ft
 
 from App import App
 from Core import ChipButton, CodeStyleSheet, HumanSize, MarkdownCodeTheme, MarkdownSheet, Palette
+from Diagrams import MaybeDiagram, WithDiagrams
 from LiveMarkdown import LiveMarkdown
 from Sources import Entry, SourceError, TextFileTypes
 
@@ -121,7 +122,8 @@ class FileView(ft.Container):
                 self.TextField.value = self.Content
                 if self.IsLive:
                     self.Live = LiveMarkdown(self.Content, self.TheApp.Config.FontSize, self._OnTextChanged,
-                                             self.OnFocusChange, self._OnTapLink)
+                                             self.OnFocusChange, self._OnTapLink,
+                                             MakeDiagram=lambda Text, Size: MaybeDiagram(self.TheApp, Text, Size))
                     return self.Live
                 return self._RenderedView()
             if self.FileType == "image":
@@ -133,16 +135,21 @@ class FileView(ft.Container):
 
     def _RenderedView(self) -> ft.Control:
         Text = self.TextField.value or ""
+        Views: Optional[list[ft.Control]] = None
         if self.FileType == "markdown" and len(Text) <= HighlightCharLimit:
-            View: ft.Control = ft.Markdown(
-                value=Text,
-                selectable=True,
-                extension_set=ft.MarkdownExtensionSet.GITHUB_FLAVORED,
-                md_style_sheet=MarkdownSheet(self.TheApp.Config.FontSize),
-                code_theme=MarkdownCodeTheme(),
-                code_style_sheet=CodeStyleSheet(),
-                on_tap_link=self._OnTapLink,
-            )
+            def MakeMarkdown(Part: str) -> ft.Control:
+                return ft.Markdown(
+                    value=Part,
+                    selectable=True,
+                    extension_set=ft.MarkdownExtensionSet.GITHUB_FLAVORED,
+                    md_style_sheet=MarkdownSheet(self.TheApp.Config.FontSize),
+                    code_theme=MarkdownCodeTheme(),
+                    code_style_sheet=CodeStyleSheet(),
+                    on_tap_link=self._OnTapLink,
+                )
+
+            Views = WithDiagrams(self.TheApp, Text, self.TheApp.Config.FontSize, MakeMarkdown)
+            View: ft.Control = Views[0]
         elif self.FileType in ("config", "html") and len(Text) <= HighlightCharLimit:
             Extension = "." + self.Item.Name.rsplit(".", 1)[-1].lower()
             View = ft.Markdown(
@@ -156,8 +163,8 @@ class FileView(ft.Container):
         else:
             View = ft.Text(Text, selectable=True, size=self.TheApp.Config.FontSize)
         if not Text:
-            View = ft.Text("This file is empty.", color=Palette.Overlay0, italic=True)
-        return ft.Column([View], scroll=ft.ScrollMode.AUTO, expand=True)
+            View, Views = ft.Text("This file is empty.", color=Palette.Overlay0, italic=True), None
+        return ft.Column(Views or [View], scroll=ft.ScrollMode.AUTO, expand=True)
 
     def _InfoView(self) -> ft.Control:
         Icon = ft.Icons.MOVIE_OUTLINED if self.FileType == "video" else ft.Icons.INSERT_DRIVE_FILE_OUTLINED