Make LeetCodeTreeDataProvider global variable pattern

Author: Vigilans

src/explorer/LeetCodeTreeDataProvider.ts renamed to src/explorer/leetCodeTreeDataProvider.ts

@@ -12,8 +12,9 @@ import { Category, defaultProblem, IProblem, ProblemState } from "../shared";
 import { getWorkspaceConfiguration } from "../utils/workspaceUtils";
 import { LeetCodeNode } from "./LeetCodeNode";
 
-export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCodeNode> {
+class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCodeNode> {
 
+    private context: vscode.ExtensionContext;
     private problemPool: Map<string, IProblem>; // maintains the ownership of all problems.
 
     private treeData: {
@@ -27,7 +28,9 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
     // tslint:disable-next-line:member-ordering
     public readonly onDidChangeTreeData: vscode.Event<any> = this.onDidChangeTreeDataEvent.event;
 
-    constructor(private context: vscode.ExtensionContext) { }
+    public initialize(context: vscode.ExtensionContext): void {
+        this.context = context;
+    }
 
     public async refresh(): Promise<void> {
         await this.getProblemData();
@@ -274,3 +277,5 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
         }
     }
 }
+
+export const leetCodeTreeDataProvider: LeetCodeTreeDataProvider = new LeetCodeTreeDataProvider();

src/extension.ts

@@ -11,7 +11,7 @@ import * as show from "./commands/show";
 import * as submit from "./commands/submit";
 import * as test from "./commands/test";
 import { LeetCodeNode } from "./explorer/LeetCodeNode";
-import { LeetCodeTreeDataProvider } from "./explorer/LeetCodeTreeDataProvider";
+import { leetCodeTreeDataProvider } from "./explorer/LeetCodeTreeDataProvider";
 import { leetCodeChannel } from "./leetCodeChannel";
 import { leetCodeExecutor } from "./leetCodeExecutor";
 import { leetCodeManager } from "./leetCodeManager";
@@ -28,13 +28,13 @@ export async function activate(context: vscode.ExtensionContext): Promise<void>
             throw new Error("The environment doesn't meet requirements.");
         }
 
+        leetCodeTreeDataProvider.initialize(context);
+
         leetCodeManager.on("statusChanged", () => {
             leetCodeStatusBarController.updateStatusBar(leetCodeManager.getStatus(), leetCodeManager.getUser());
             leetCodeTreeDataProvider.refresh();
         });
 
-        const leetCodeTreeDataProvider: LeetCodeTreeDataProvider = new LeetCodeTreeDataProvider(context);
-
         context.subscriptions.push(
             leetCodeStatusBarController,
             leetCodeChannel,