fix / #75 run checks when changing file open in active text editor

src/extension.ts

@@ -10,6 +10,8 @@ import { looksLikePath, resolvePath, findWorkspaceRoot } from './util/path';
 // To keep track of document changes we save hashed versions of their content to this record
 let documentHashMemory : Record<string, string> = {};
 
+let previewAnalysisTimer: NodeJS.Timeout | undefined;
+let previewedDocument: vscode.TextDocument | undefined;
 let cppcheckProgressIndicator: vscode.StatusBarItem;
 let checksRunning = false;
 
@@ -192,6 +194,39 @@ export async function activate(context: vscode.ExtensionContext) {
     // Run cppcheck when a file is opened
     vscode.workspace.onDidOpenTextDocument(handleDocument, null, context.subscriptions);
 
+    // Run cppcheck when changing files viewed in text editor
+    vscode.window.tabGroups.onDidChangeTabs(async e => {
+        clearTimeout(previewAnalysisTimer);
+        for (const tab of e.changed) {
+            if (tab.input instanceof vscode.TabInputText) {
+                const uri = tab.input.uri;
+                const document =
+                    vscode.workspace.textDocuments.find(
+                        doc => doc.uri.toString() === uri.toString()
+                    ) ?? await vscode.workspace.openTextDocument(uri);
+                // Only analyze previewed files if user stays on them for 10 seconds
+                if (tab && tab.isPreview) {
+                    previewAnalysisTimer = setTimeout(() => {
+                        handleDocument(document);
+                        previewedDocument = document;
+                    }, 10000);
+                } else {
+                    // If file is properly opened we run analysis right away
+                    handleDocument(document);
+                }
+            }
+        }
+    }, null, context.subscriptions);
+
+    // Clear diagnostics of previewed files when no longer viewed
+    vscode.window.onDidChangeActiveTextEditor(() => {
+        if (previewedDocument) {
+            diagnosticCollection.delete(previewedDocument.uri);
+            documentHashMemory[previewedDocument.fileName] = '';
+            previewedDocument = undefined;
+        }
+    });
+
     // Run cppcheck for all open files when the workspace is opened
     vscode.workspace.onDidChangeWorkspaceFolders(() => {
         vscode.workspace.textDocuments.forEach(handleDocument);