Notify backends of updates to plot render settings

extensions/positron-python/python_files/posit/positron/plot_comm.py

@@ -19,9 +19,20 @@
 
 
 @enum.unique
-class RenderFormat(str, enum.Enum):
+class PlotUnit(str, enum.Enum):
+    """
+    Possible values for PlotUnit
+    """
+
+    Pixels = "pixels"
+
+    Inches = "inches"
+
+
+@enum.unique
+class PlotRenderFormat(str, enum.Enum):
     """
-    Possible values for RenderFormat
+    Possible values for PlotRenderFormat
     """
 
     Png = "png"
@@ -35,17 +46,6 @@ class RenderFormat(str, enum.Enum):
     Tiff = "tiff"
 
 
-@enum.unique
-class PlotUnit(str, enum.Enum):
-    """
-    Possible values for PlotUnit
-    """
-
-    Pixels = "pixels"
-
-    Inches = "inches"
-
-
 class IntrinsicSize(BaseModel):
     """
     The intrinsic size of a plot, if known
@@ -81,9 +81,9 @@ class PlotResult(BaseModel):
         description="The MIME type of the plot data",
     )
 
-    policy: Optional[RenderPolicy] = Field(
+    settings: Optional[PlotRenderSettings] = Field(
         default=None,
-        description="The policy used to render the plot",
+        description="The settings used to render the plot",
     )
 
 
@@ -101,21 +101,21 @@ class PlotSize(BaseModel):
     )
 
 
-class RenderPolicy(BaseModel):
+class PlotRenderSettings(BaseModel):
     """
-    The policy used to render the plot
+    The settings used to render the plot
     """
 
     size: PlotSize = Field(
-        description="Plot size of the render policy",
+        description="Plot size to render the plot to",
     )
 
     pixel_ratio: Union[StrictInt, StrictFloat] = Field(
         description="The pixel ratio of the display device",
     )
 
-    format: RenderFormat = Field(
-        description="Format of the render policy",
+    format: PlotRenderFormat = Field(
+        description="Format in which to render the plot",
     )
 
 
@@ -163,7 +163,7 @@ class RenderParams(BaseModel):
         description="The pixel ratio of the display device",
     )
 
-    format: RenderFormat = Field(
+    format: PlotRenderFormat = Field(
         description="The requested plot format",
     )
 
@@ -215,7 +215,7 @@ class PlotFrontendEvent(str, enum.Enum):
 
 PlotSize.update_forward_refs()
 
-RenderPolicy.update_forward_refs()
+PlotRenderSettings.update_forward_refs()
 
 GetIntrinsicSizeRequest.update_forward_refs()
 

extensions/positron-python/python_files/posit/positron/tests/test_plots.py

@@ -182,7 +182,7 @@ def verify_response(response, filename: str, expected_size: Tuple[float, float],
         assert percent_difference(image.size[1], expected_size[1] * pixel_ratio) <= threshold
 
         # Check the rest of the response.
-        assert response == json_rpc_response({"mime_type": f"image/{format_}", "policy": None})
+        assert response == json_rpc_response({"mime_type": f"image/{format_}", "settings": None})
 
     verify_response(response, "test-mpl-render-0-explicit-size", (size.width, size.height))
 

extensions/positron-python/python_files/posit/positron/ui_comm.py

@@ -17,6 +17,8 @@
 
 from ._vendor.pydantic import BaseModel, Field, StrictBool, StrictFloat, StrictInt, StrictStr
 
+from .plot_comm import PlotRenderSettings
+
 Param = Any
 CallMethodResult = Any
 
@@ -137,10 +139,47 @@ class UiBackendRequest(str, enum.Enum):
     An enumeration of all the possible requests that can be sent to the backend ui comm.
     """
 
+    # Notification that the settings to render a plot (i.e. the plot size)
+    # have changed.
+    DidChangePlotsRenderSettings = "did_change_plots_render_settings"
+
     # Run a method in the interpreter and return the result to the frontend
     CallMethod = "call_method"
 
 
+class DidChangePlotsRenderSettingsParams(BaseModel):
+    """
+    Typically fired when the plot component has been resized by the user.
+    This notification is useful to produce accurate pre-renderings of
+    plots.
+    """
+
+    settings: PlotRenderSettings = Field(
+        description="Plot rendering settings.",
+    )
+
+
+class DidChangePlotsRenderSettingsRequest(BaseModel):
+    """
+    Typically fired when the plot component has been resized by the user.
+    This notification is useful to produce accurate pre-renderings of
+    plots.
+    """
+
+    params: DidChangePlotsRenderSettingsParams = Field(
+        description="Parameters to the DidChangePlotsRenderSettings method",
+    )
+
+    method: Literal[UiBackendRequest.DidChangePlotsRenderSettings] = Field(
+        description="The JSON-RPC method name (did_change_plots_render_settings)",
+    )
+
+    jsonrpc: str = Field(
+        default="2.0",
+        description="The JSON-RPC version specifier",
+    )
+
+
 class CallMethodParams(BaseModel):
     """
     Unlike other RPC methods, `call_method` calls into methods implemented
@@ -180,7 +219,10 @@ class CallMethodRequest(BaseModel):
 
 class UiBackendMessageContent(BaseModel):
     comm_id: str
-    data: CallMethodRequest
+    data: Union[
+        DidChangePlotsRenderSettingsRequest,
+        CallMethodRequest,
+    ] = Field(..., discriminator="method")
 
 
 @enum.unique
@@ -477,6 +519,10 @@ class ShowHtmlFileParams(BaseModel):
 
 Range.update_forward_refs()
 
+DidChangePlotsRenderSettingsParams.update_forward_refs()
+
+DidChangePlotsRenderSettingsRequest.update_forward_refs()
+
 CallMethodParams.update_forward_refs()
 
 CallMethodRequest.update_forward_refs()

extensions/positron-r/src/provider.ts

@@ -279,6 +279,9 @@ export async function makeMetadata(
 		config.get<string>('shutdownTimeout', 'immediately') !== 'immediately' ?
 			positron.LanguageRuntimeSessionLocation.Machine : positron.LanguageRuntimeSessionLocation.Workspace;
 
+	// Subscribe to UI notifications of interest
+	const uiSubscriptions = [positron.UiRuntimeNotifications.DidChangePlotsRenderSettings];
+
 	const metadata: positron.LanguageRuntimeMetadata = {
 		runtimeId,
 		runtimeName,
@@ -295,6 +298,7 @@ export async function makeMetadata(
 			).toString('base64'),
 		sessionLocation,
 		startupBehavior,
+		uiSubscriptions,
 		extraRuntimeData
 	};
 

positron/comms/README.md

@@ -68,10 +68,16 @@ npm install
 If you've already installed dependencies, just run the code generator.
 This will (re-)generate code for all comms.
 
-```
+```sh
 npx ts-node generate-comms.ts
 ```
 
+If you have `just` installed, then just run `just`:
+
+```sh
+just
+```
+
 For each contract, this writes Rust, Python, and Typescript modules using the current contract.
 It also prints each affected filepath.
 
@@ -82,6 +88,12 @@ This will (re-)generate code only for the ui and variables comms.
 npx ts-node generate-comms.ts ui variables
 ```
 
+You can pass arguments via `just` as well but you'll need to explicitly name the `gen` recipe instead of relying on it being the default:
+
+```
+just gen ui variables
+```
+
 Above we've targetted two comms by name, "ui" and "variables".
 It's also acceptable to specify a comm by mentioning any member of its trio of files, i.e. "ui.json", "ui-frontend-openrpc.json", and "ui-backend-openrpc.json" are the same as specifying "ui".