Implement textDocuments RPC method for VS Code host bridge

Adds the `textDocuments` RPC method to the VS Code host bridge. This method allows the client to retrieve a list of currently open text documents in the VS Code workspace, along with their paths, active status, and view column information.

The changes include:

- Adding `textDocuments` RPC method to `WorkspaceService` in `proto/host/workspace.proto`.
- Creating `src/hosts/vscode/hostbridge/workspace/textDocuments.ts` to implement the `textDocuments` method, which retrieves the list of open documents from `vscode.workspace.textDocuments` and their associated metadata.
- Updating `DiffViewProvider.ts` to use the new `textDocuments` RPC method to check if a file is already open and dirty before getting its contents. This ensures that the latest version of the file is used.

proto/host/workspace.proto

@@ -3,11 +3,13 @@ syntax = "proto3";
 package host;
 option java_package = "bot.cline.host.proto";
 option java_multiple_files = true;
+import "host/window.proto";
 
 // Provides methods for working with workspaces/projects.
 service WorkspaceService {
   // Returns a list of the top level directories of the workspace.
   rpc getWorkspacePaths(GetWorkspacePathsRequest) returns (GetWorkspacePathsResponse);
+  rpc textDocuments(TextDocumentsRequest) returns (TextDocumentsResponse);
 }
 
 message GetWorkspacePathsRequest {
@@ -22,3 +24,17 @@ message GetWorkspacePathsResponse {
   optional string id = 1;
   repeated string paths = 2;
 }
+
+message TextDocumentsRequest {
+  // The unique ID for the workspace/project.
+  // This is currently optional in vscode. It is required in other environments where cline is running at
+  // the application level, and the user can open multiple projects.
+  optional string id = 1;
+}
+
+message TextDocumentsResponse {
+  // The unique ID for the workspace/project.
+  optional string id = 1;
+  // The list of text documents in the workspace.
+  repeated TextEditorInfo editors = 2;
+}

src/hosts/vscode/hostbridge/workspace/textDocuments.ts

@@ -0,0 +1,17 @@
+import { TextDocumentsRequest, TextDocumentsResponse, TextEditorInfo } from "@/shared/proto/index.host"
+import * as vscode from "vscode"
+import { ViewColumn } from "vscode"
+
+export async function textDocuments(_: TextDocumentsRequest): Promise<TextDocumentsResponse> {
+	const visibleEditors = vscode.window.visibleTextEditors
+	const editors =
+		vscode.workspace.textDocuments?.map((doc) => ({
+			documentPath: doc.uri.toString(),
+			isActive: visibleEditors.some((editor) => editor.document === doc),
+			viewColumn: visibleEditors.find((editor) => editor.document === doc)?.viewColumn ?? ViewColumn.Active,
+		})) || []
+
+	return TextDocumentsResponse.create({
+		editors: editors.map((editor) => TextEditorInfo.create(editor)),
+	})
+}

src/integrations/editor/DiffViewProvider.ts

@@ -11,6 +11,7 @@ import { detectEncoding } from "../misc/extract-text"
 import * as iconv from "iconv-lite"
 import { getHostBridgeProvider } from "@/hosts/host-providers"
 import { ShowTextDocumentRequest, ShowTextDocumentOptions } from "@/shared/proto/host/window"
+import { TextDocumentsResponse } from "@/shared/proto/index.host"
 
 export const DIFF_VIEW_URI_SCHEME = "cline-diff"
 
@@ -41,11 +42,11 @@ export abstract class DiffViewProvider {
 
 		// if the file is already open, ensure it's not dirty before getting its contents
 		if (fileExists) {
-			const existingDocument = vscode.workspace.textDocuments.find((doc) =>
-				arePathsEqual(doc.uri.fsPath, this.absolutePath),
-			)
-			if (existingDocument && existingDocument.isDirty) {
-				await existingDocument.save()
+			const textDocuments = await getHostBridgeProvider().workspaceClient.textDocuments(TextDocumentsResponse.create({}))
+			const existingEditor = textDocuments?.editors?.find((editor) => arePathsEqual(editor.documentPath, this.absolutePath))
+			const existingDoc = existingEditor ? await vscode.workspace.openTextDocument(existingEditor.documentPath) : undefined
+			if (existingDoc?.isDirty) {
+				await existingDoc.save()
 			}
 
 			const fileBuffer = await fs.readFile(this.absolutePath)