Add graph view

Client/Sources.py

@@ -113,6 +113,7 @@ class Source:
     def Upload(self, Root: str, DirectoryPath: str, LocalFile: Path, OnProgress: Optional[Callable[[float], None]] = None) -> str: ...
     def LocalFile(self, Root: str, RelativePath: str) -> Path: ...
     def Book(self, Root: str, RelativePath: str) -> dict: ...
+    def Graph(self, Root: str, RelativePath: str) -> dict: ...
 
     @property
     def CanWrite(self) -> bool:
@@ -268,6 +269,12 @@ class LocalSource(Source):
     def Book(self, Root: str, RelativePath: str) -> dict:
         return {}  # SaraTag tags are only read through a server for now
 
+    def Graph(self, Root: str, RelativePath: str) -> dict:
+        """The graph view's data, built here the way the server builds it."""
+        from Graph import BuildLocalGraph  # Graph.py imports this module
+
+        return BuildLocalGraph(self, Root, RelativePath)
+
 
 class ServerSource(Source):
     """A SaraView server, through the same /api endpoints the web frontend
@@ -453,6 +460,10 @@ class ServerSource(Source):
         except SourceError:
             return {}  # tags are extra; a file without them still opens
 
+    def Graph(self, Root: str, RelativePath: str) -> dict:
+        # A big root takes the server a while to read through.
+        return self._Json("GET", "/graph", params=self._At(Root, RelativePath), timeout=120)
+
 
 def MakeSource(Config: AppConfig, Token: str = "") -> Source:
     return ServerSource(Config, Token) if Config.Mode == "Server" else LocalSource(Config)