checks on input, exceptions, improved contains query performance

gui/mainwindow.cpp

@@ -37,6 +37,7 @@ void MainWindow::connectSignals()
     connect(this, &MainWindow::beginSearch, searchWorker, &SearchWorker::search);
     connect(searchWorker, &SearchWorker::searchResultsReady, this, &MainWindow::handleSearchResults);
     connect(searchWorker, &SearchWorker::searchCancelled, this, &MainWindow::handleCancelledSearch);
+    connect(searchWorker, &SearchWorker::searchError, this, &MainWindow::handleSearchError);
     connect(ui->treeResultsList, &QTreeWidget::itemActivated, this, &MainWindow::treeSearchItemActivated);
     connect(ui->treeResultsList, &QTreeWidget::customContextMenuRequested, this, &MainWindow::showSearchResultsContextMenu);
     connect(ui->tabWidget, &QTabWidget::currentChanged, this, &MainWindow::tabChanged);
@@ -98,6 +99,11 @@ void MainWindow::pdfPreviewReceived(PdfPreview preview)
 void MainWindow::lineEditReturnPressed()
 {
     QString q = ui->txtSearch->text();
+    if(!searchWorker->checkParanthesis(q))
+    {
+        ui->lblSearchResults->setText("Invalid paranthesis");
+        return;
+    }
     //TODO: validate q;
     ui->lblSearchResults->setText("Searching...");
     emit beginSearch(q);
@@ -158,6 +164,11 @@ void MainWindow::handleCancelledSearch()
 
 }
 
+void MainWindow::handleSearchError(QString error)
+{
+    ui->lblSearchResults->setText("Error:"  + error);
+}
+
 void MainWindow::treeSearchItemActivated(QTreeWidgetItem *item, int i)
 {
     QDesktopServices::openUrl(QUrl::fromLocalFile(item->text(1)));