feat: add extension decorations API

Author: sqs

src/extension/api.ts

@@ -1,7 +1,8 @@
 import { Subscription } from 'rxjs'
+import { TextDocumentIdentifier } from 'vscode-languageserver-types'
 import { Context } from '../environment/context/context'
 import { MessageConnection } from '../jsonrpc2/connection'
-import { InitializeParams, Settings } from '../protocol'
+import { InitializeParams, Settings, TextDocumentDecoration } from '../protocol'
 import { URI } from '../types/textDocument'
 
 /**
@@ -159,6 +160,14 @@ export interface Windows extends Observable<Window[]> {
      * @returns The user's input, or null if the user (or the client) canceled the input request.
      */
     showInputBox(message: string, defaultValue?: string): Promise<string | null>
+
+    /**
+     * Sets the decorations for the given document. All previous decorations for the document are cleared.
+     *
+     * @param resource The document to decorate.
+     * @param decorations The decorations to apply to the document.
+     */
+    setDecorations(resource: TextDocumentIdentifier, decorations: TextDocumentDecoration[]): void
 }
 
 /**

src/extension/features/windows.ts

@@ -1,5 +1,13 @@
 import { BehaviorSubject } from 'rxjs'
-import { DidCloseTextDocumentNotification, DidOpenTextDocumentNotification, ShowInputRequest } from '../../protocol'
+import { TextDocumentIdentifier } from 'vscode-languageserver-types'
+import {
+    DidCloseTextDocumentNotification,
+    DidOpenTextDocumentNotification,
+    ShowInputRequest,
+    TextDocumentDecoration,
+    TextDocumentPublishDecorationsNotification,
+    TextDocumentPublishDecorationsParams,
+} from '../../protocol'
 import { CXP, Observable, Window, Windows } from '../api'
 
 class ExtWindows extends BehaviorSubject<Window[]> implements Windows, Observable<Window[]> {
@@ -39,6 +47,13 @@ class ExtWindows extends BehaviorSubject<Window[]> implements Windows, Observabl
         return this.ext.rawConnection.sendRequest(ShowInputRequest.type, { message, defaultValue })
     }
 
+    public setDecorations(resource: TextDocumentIdentifier, decorations: TextDocumentDecoration[]): void {
+        return this.ext.rawConnection.sendNotification(TextDocumentPublishDecorationsNotification.type, {
+            textDocument: resource,
+            decorations,
+        } as TextDocumentPublishDecorationsParams)
+    }
+
     public readonly [Symbol.observable] = () => this
 }