Show a popup to reload the window on environment changes

A popup is now shown when the user changes VS Code settings that
affect the environment. This popup asks the user if he wants to
reload the VS Code window to make the Ada extension take into
account the newly set environment.

For eng/ide/ada_language_server#1218

Author: AnthonyLeonardoGracio

integration/vscode/ada/src/ExtensionState.ts

@@ -4,6 +4,7 @@ import { createClient } from './clients';
 import GnatTaskProvider from './gnatTaskProvider';
 import GprTaskProvider from './gprTaskProvider';
 import { registerTaskProviders } from './taskProviders';
+import { getCustomEnvSettingName } from './helpers';
 
 /**
  * This class encapsulates all state that should be maintained throughout the
@@ -71,6 +72,26 @@ export class ExtensionState {
         this.registeredTaskProviders = [];
     };
 
+    /**
+     * Show a popup asking the user to reload the VS Code window after
+     * changes made in the VS Code environment settings
+     * (e.g: terminal.integrated.env.linux).
+     */
+    public showReloadWindowPopup = async () => {
+        const selection = await vscode.window.showWarningMessage(
+            `The workspace environment has changed: the VS Code window needs
+            to be reloaded in order for the Ada Language Server to take the
+            new environment into account.
+            Do you want to reload the VS Code window?`,
+            'Reload Window'
+        );
+
+        // Reload the VS Code window if the user selected 'Yes'
+        if (selection == 'Reload Window') {
+            void vscode.commands.executeCommand('workbench.action.reloadWindow');
+        }
+    };
+
     //  React to changes in configuration to recompute predefined tasks if the user
     //  changes scenario variables' values.
     public configChanged = (e: vscode.ConfigurationChangeEvent) => {
@@ -81,5 +102,14 @@ export class ExtensionState {
             this.unregisterTaskProviders();
             this.registerTaskProviders();
         }
+
+        //  React to changes made in the environment variables, showing
+        //  a popup to reload the VS Code window and thus restart the
+        //  Ada extension.
+        const env_config_name = getCustomEnvSettingName();
+
+        if (e.affectsConfiguration(env_config_name)) {
+            void this.showReloadWindowPopup();
+        }
     };
 }