introduce a command for the code map

fix the issues with duplicate editors being opened
optimize it to do less rendering

package.json

@@ -84,6 +84,13 @@
 					"highContrast": "#99999999"
 				}
 			}
+		],
+		"commands": [
+			{
+				"command": "debug-utils.showCodeMap",
+				"title": "Build a Code Map during debugging",
+				"when": "inDebugMode"
+			}
 		]
 	}
 }

src/codemap.ts

@@ -6,35 +6,42 @@ import * as gv from "ts-graphviz";
 export class CodeMapProvider implements vs.DebugAdapterTracker, vs.TextDocumentContentProvider  {
 	dotDocument?: vs.TextDocument;
 	graph: gv.Digraph;
+	active = false;
 
-	constructor() {
-		this.graph = gv.digraph('Call Graph', { splines: true });
-	}
-
-	/** @override */
-	provideTextDocumentContent(uri: vs.Uri, token: vs.CancellationToken): vs.ProviderResult<string> {
-		// here we update the source .dot document
-		// TODO: actually check uri
-		return gv.toDot(this.graph);
-	}
-
-	// https://code.visualstudio.com/api/extension-guides/virtual-documents#update-virtual-documents
-	onDidChangeEmitter = new vs.EventEmitter<vs.Uri>();
-	onDidChange = this.onDidChangeEmitter.event; // without this the emitter silently doesn't work
-
-	async onWillStartSession() {
-		this.dotDocument = await vs.workspace.openTextDocument(vs.Uri.parse('dot:1.dot', true));
+	async activate() : Promise<void> {
 		this.graph = gv.digraph('Call Graph', { splines: true }); // reset the graph
 
-		// used for debugging
-		vs.window.showTextDocument(this.dotDocument, { preview: false });
+		this.dotDocument = await vs.workspace.openTextDocument(vs.Uri.parse('dot:callgraph.dot', true));
+		this.active = true;
+
+		// save the current editor
+		const activeEditor = vs.window.activeTextEditor;
+		// show the `dot` source
+		vs.window.showTextDocument(this.dotDocument, vs.ViewColumn.Beside, true);
 
 		const args = {
 			document: this.dotDocument,
-			callback: (webpanel: any) => {
-				// The callback function receives the newly created webPanel.
-				// Overload webPanel.handleMessage(message) to receive message events like onClick and onDblClick
-				//console.log(JSON.stringify(webpanel, undefined, 2));
+			callback: (panel: any /* PreviewPanel */) => {
+				// we have to switch back to the original editor group to prevent issues
+				const webpanel: vs.WebviewPanel = panel.panel;
+				const disposable = webpanel.onDidChangeViewState(e => {
+					if (activeEditor)
+						vs.window.showTextDocument(activeEditor.document, activeEditor.viewColumn, false);
+					disposable.dispose();
+				});
+				// handle user closing the graphviz preview
+				webpanel.onDidDispose(e => {
+					this.active = false;
+					// there's no way to close a document, only this
+					// FIXME: if the editor is not in the active view column, this opens a new one and closes it
+					vs.window.showTextDocument(this.dotDocument!, vs.ViewColumn.Active, false)
+						.then(() => {
+							return vs.commands.executeCommand('workbench.action.closeActiveEditor');
+						});
+					this.graph.clear();
+					this.onDidChangeEmitter.fire(this.dotDocument!.uri);
+					this.dotDocument = undefined; // FIXME: does not delete the document
+				});
 			},
 			allowMultiplePanels: false,
 			title: 'Call Graph',
@@ -43,11 +50,24 @@ export class CodeMapProvider implements vs.DebugAdapterTracker, vs.TextDocumentC
 		vs.commands.executeCommand("graphviz-interactive-preview.preview.beside", args);
 	}
 
-	onWillStopSession() {
-		this.dotDocument = undefined;
-		this.graph.clear();
+	/** @override TextDocumentContentProvider */
+	provideTextDocumentContent(uri: vs.Uri, token: vs.CancellationToken): vs.ProviderResult<string> {
+		// here we update the source .dot document
+		if (uri.path != 'callgraph.dot')
+			return;
+		return gv.toDot(this.graph);
 	}
 
+	// https://code.visualstudio.com/api/extension-guides/virtual-documents#update-virtual-documents
+	onDidChangeEmitter = new vs.EventEmitter<vs.Uri>();
+	onDidChange = this.onDidChangeEmitter.event; // without this the emitter silently doesn't work
+
+	/** @override DebugAdapterTracker */
+	// onWillStartSession() {}
+
+	/** @override DebugAdapterTracker */
+	// onWillStopSession() {}
+
 	private getOrCreateNode(name: string) {
 		return this.graph.getNode(name) ?? this.graph.createNode(name, { shape: "box" });
 	}
@@ -64,11 +84,17 @@ export class CodeMapProvider implements vs.DebugAdapterTracker, vs.TextDocumentC
 		if (!r.success || r.body.stackFrames.length < 1)
 			return;
 
+		let lastNode = this.getOrCreateNode(CodeMapProvider.wordwrap(r.body.stackFrames[0].name, 64));
+		// prevent re-rendering if we're still in the same function
+		if (lastNode.attributes.get("color"))
+			return;
+
+		// mark the current function with a red border
 		for (const f of this.graph.nodes)
 			f.attributes.delete("color");
-
-		let lastNode = this.getOrCreateNode(CodeMapProvider.wordwrap(r.body.stackFrames[0].name, 64));
 		lastNode.attributes.set("color", "red");
+
+		// walk up the stack and create nodes/edges
 		for (let i = 1; i < r.body.stackFrames.length; ++i) {
 			const nodeName = CodeMapProvider.wordwrap(r.body.stackFrames[i].name, 64);
 			const node = this.getOrCreateNode(nodeName);
@@ -82,9 +108,11 @@ export class CodeMapProvider implements vs.DebugAdapterTracker, vs.TextDocumentC
 		this.onDidChangeEmitter.fire(this.dotDocument!.uri);
 	}
 
-	/** @override */
+	/** @override DebugAdapterTracker */
 	onDidSendMessage(msg: dap.ProtocolMessage) {
-		console.log(`< ${typeof msg} ${JSON.stringify(msg, undefined, 2)}`);
+		if (!this.active)
+			return;
+
 		if (msg.type !== "response" || (msg as dap.Response).command !== "stackTrace")
 			return;
 

src/extension.ts

@@ -12,10 +12,17 @@ export function activate(context: vs.ExtensionContext) {
 	});
 	context.subscriptions.push(disposable);
 
+	// when the command is run a debug session is already active
+	// then it'd be too late to register the tracker, so do it eagerly
 	const codemap = new CodeMapProvider();
+	disposable =  vs.commands.registerCommand("debug-utils.showCodeMap", () => {
+		codemap.activate();
+	});
+	context.subscriptions.push(disposable);
+
 	disposable = vs.debug.registerDebugAdapterTrackerFactory("*", {
 		createDebugAdapterTracker(_session: vs.DebugSession) {
-			return codemap;
+			return codemap; // null is also possible
 		}
 	});
 	context.subscriptions.push(disposable);