Add Click the tree explorer should open the topic (LeetCode-OpenSource#132)

Author: xuzaixian

src/explorer/LeetCodeNode.ts

@@ -2,6 +2,7 @@
 // Licensed under the MIT license.
 
 import { IProblem, ProblemState } from "../shared";
+import { Command } from "vscode";
 
 export class LeetCodeNode {
     constructor(private data: IProblem, private parentNodeName: string, private isProblemNode: boolean = true) { }
@@ -48,4 +49,12 @@ export class LeetCodeNode {
     public get parentName(): string {
         return this.parentNodeName;
     }
+
+    public get selectedCommand(): Command {
+        return {
+            title: 'Open Problem',
+            command: 'leetcode.showProblem',
+            arguments: [this]
+        }
+    }
 }

src/explorer/LeetCodeTreeDataProvider.ts

@@ -52,6 +52,7 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
             collapsibleState: element.isProblem ? vscode.TreeItemCollapsibleState.None : vscode.TreeItemCollapsibleState.Collapsed,
             contextValue: element.isProblem ? "problem" : element.id.toLowerCase(),
             iconPath: this.parseIconPathFromProblemState(element),
+            command: element.isProblem ? element.selectedCommand : undefined
         };
     }