feat: Prevent Tab key from moving focus outside active viewport tools

src/MainWindow.cpp

@@ -17,11 +17,14 @@
 #include <QIcon>
 #include <QInputDialog>
 #include <QStringList>
+#include <QKeyEvent>
+#include <QApplication>
 
 MainWindow::MainWindow(ApplicationController* appController, QWidget *parent)
     : QMainWindow(parent)
     , m_appController(appController)
 {
+    qApp->installEventFilter(this);
     setWindowTitle("OpenCAD");
     resize(1920, 1080);
 
@@ -204,3 +207,19 @@ void MainWindow::updateWindowTitle(const QString& filePath)
         shownName = "Untitled";
     setWindowTitle(tr("%1[*] - %2").arg(QFileInfo(shownName).fileName(), tr("OpenCAD")));
 }
+
+bool MainWindow::eventFilter(QObject *watched, QEvent *event)
+{
+    if (m_appController->activeTool() != ApplicationController::ToolType::None && event->type() == QEvent::KeyPress) {
+        QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
+        if (keyEvent->key() == Qt::Key_Tab || keyEvent->key() == Qt::Key_Backtab) {
+            if (watched == m_viewport) {
+                return false; // Let the viewport handle its own event
+            }
+            // Forward event to viewport and consume it
+            QApplication::sendEvent(m_viewport, keyEvent);
+            return true;
+        }
+    }
+    return QMainWindow::eventFilter(watched, event);
+}