testcon: Show debug log when loading fails

Switch to debug log and point it out in message.

Change-Id: I0809a1da0c6d5dab148705fae32004af0dc8e371
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

tools/testcon/mainwindow.cpp

@@ -130,9 +130,11 @@ bool MainWindow::addControlFromClsid(const QString &clsid)
         updateGUI();
     } else {
         delete container;
-        QMessageBox::information(this,
-                                 tr("Error Loading Control"),
-                                 tr("The control \"%1\" could not be loaded.").arg(clsid));
+        logTabWidget->setCurrentIndex(logTabWidget->count() - 1);
+        const QString message =
+            tr("The control \"%1\" could not be loaded."
+               " See the \"Debug log\" tab for details.").arg(clsid);
+        QMessageBox::information(this, tr("Error Loading Control"), message);
     }
     return result;
 }

tools/testcon/mainwindow.ui

@@ -103,9 +103,9 @@
                     <enum>Raised</enum>
                   </property>
                 </widget>
-                <widget class="QTabWidget" name="TabWidget2" >
+                <widget class="QTabWidget" name="logTabWidget" >
                   <property name="objectName" >
-                    <string notr="true" >TabWidget2</string>
+                    <string notr="true" >logTabWidget</string>
                   </property>
                   <property name="sizePolicy" >
                     <sizepolicy>