refactor: decouple plot viewers and implement PlotManager for extensibility

Author: randy3k

session.md

@@ -254,17 +254,17 @@ export async function showDataView(source: string, type: string, title: string,
 ```typescript
 case 'httpgd': {
     if (request.url) {
-        await globalHttpgdManager?.showViewer(request.url);
+        await globalPlotManager?.showHttpgdPlot(request.url);
     }
     break;
 }
 ```
 
-**Detail (`httpgd` [-> src/plotViewer/index.ts#L72](src/plotViewer/index.ts#L72)):**
+**Detail (`httpgd` [-> src/plotViewer/index.ts](src/plotViewer/index.ts)):**
 Triggered when an R script opens an `httpgd` graphics device (a modern SVG/HTML-based plotting device for R).
 
 1. **Intercepting the URL**: R tells VS Code the exact local URL/port where the `httpgd` server is streaming the plots.
-2. **Delegation to Manager**: The session handler passes this URL to the `globalHttpgdManager` (an instance of `HttpgdManager` defined in `src/plotViewer/index.ts`).
+2. **Delegation to Manager**: The session handler passes this URL to the `globalPlotManager` (an instance of `CommonPlotManager` defined in `src/plotViewer/index.ts`).
 3. **Viewer Instantiation**: The manager parses the URL, extracting the host and security token. It searches to see if a viewer for that host already exists. If not, it instantiates a new `HttpgdViewer`.
 4. **Webview Rendering**: The `HttpgdViewer` spins up a dedicated `WebviewPanel`. Instead of just embedding the plot as a static image, it loads a full React-based frontend application (bundled in the extension's resources) into the webview. This frontend connects directly to the R `httpgd` server via WebSockets to provide a live, interactive, resizable plot viewer with history tracking and export capabilities.
 

src/extension.ts

@@ -20,7 +20,8 @@ import * as apiImplementation from './apiImplementation';
 import * as rHelp from './helpViewer';
 import * as completions from './completions';
 import * as rShare from './liveShare';
-import * as httpgdViewer from './plotViewer';
+import * as plotViewer from './plotViewer';
+import { PlotManager } from './plotViewer/types';
 import * as languageService from './languageService';
 import { RTaskProvider } from './tasks';
 
@@ -32,7 +33,7 @@ export let rWorkspace: workspaceViewer.WorkspaceDataProvider | undefined = undef
 export let globalRHelp: rHelp.RHelp | undefined = undefined;
 export let extensionContext: vscode.ExtensionContext;
 export let enableSessionWatcher: boolean | undefined = undefined;
-export let globalHttpgdManager: httpgdViewer.HttpgdManager | undefined = undefined;
+export let globalPlotManager: PlotManager | undefined = undefined;
 export let rmdPreviewManager: rmarkdown.RMarkdownPreviewManager | undefined = undefined;
 export let rmdKnitManager: rmarkdown.RMarkdownKnitManager | undefined = undefined;
 export let sessionStatusBarItem: vscode.StatusBarItem | undefined = undefined;
@@ -200,8 +201,8 @@ export async function activate(context: vscode.ExtensionContext): Promise<apiImp
         }
     ));
 
-    // initialize httpgd viewer
-    globalHttpgdManager = httpgdViewer.initializeHttpgd();
+    // initialize plot manager
+    globalPlotManager = plotViewer.initializePlotManager();
 
     // initialize the package/help related functions
     globalRHelp = await rHelp.initializeHelp(context, rExtension);

src/liveShare/shareCommands.ts

@@ -9,7 +9,7 @@ import { forwardCommands, shareWorkspace } from './shareTree';
 import { runTextInTerm } from '../rTerminal';
 import { requestFile, WorkspaceData } from '../session';
 import { HelpFile } from '../helpViewer';
-import { globalHttpgdManager, globalRHelp } from '../extension';
+import { globalPlotManager, globalRHelp } from '../extension';
 
 // used in sending messages to the guest service,
 // distinguishes the type of vscode message to show
@@ -99,7 +99,7 @@ export const Commands: ICommands = {
             void updateGuestPlot(args[0]);
         },
         [Callback.NotifyGuestPlotManager]: (args: [url: string]): void => {
-            void globalHttpgdManager?.showViewer(args[0]);
+            void globalPlotManager?.showHttpgdPlot(args[0]);
         },
         [Callback.OrderDetach]: (): void => {
             void detachGuest();

src/liveShare/shareSession.ts

@@ -1,7 +1,7 @@
 import path = require('path');
 import * as vscode from 'vscode';
 
-import { extensionContext, globalHttpgdManager, globalRHelp, rWorkspace } from '../extension';
+import { extensionContext, globalPlotManager, globalRHelp, rWorkspace } from '../extension';
 import { asViewColumn, config, readContent } from '../util';
 import { showBrowser, showDataView, showWebView, WorkspaceData } from '../session';
 import { liveSession, UUID, rGuestService, _sessionStatusBarItem as sessionStatusBarItem } from '.';
@@ -118,7 +118,7 @@ export async function updateGuestRequest(file: string, force: boolean = false):
             }
             case 'httpgd': {
                 if (request.url) {
-                    await globalHttpgdManager?.showViewer(request.url);
+                    await globalPlotManager?.showHttpgdPlot(request.url);
                 }
                 break;
             }