Qt: Make IOConsoleDialog a single instance

When opening a console dialog, make it reuse an existing instance
if it is already open. This is required because the output of
the Lua code currently only goes into a single GUI dialog
(the last one open). And in general it feels correct.

This depends on the QAction holding the pointer reference,
which seems reasonable because it is a dynamic menu action.

ui/qt/funnel_statistics.cpp

@@ -224,11 +224,21 @@ FunnelConsoleAction::~FunnelConsoleAction()
 }
 
 void FunnelConsoleAction::triggerCallback() {
-    IOConsoleDialog *dialog = new IOConsoleDialog(*qobject_cast<QWidget *>(parent()),
+    if (!dialog_) {
+        dialog_ = new IOConsoleDialog(*qobject_cast<QWidget *>(parent()),
                                             this->text(),
                                             eval_cb_, open_cb_, close_cb_, callback_data_);
-    dialog->setAttribute(Qt::WA_DeleteOnClose);
-    dialog->show();
+        dialog_->setAttribute(Qt::WA_DeleteOnClose);
+    }
+
+    if (dialog_->isMinimized()) {
+        dialog_->showNormal();
+    }
+    else {
+        dialog_->show();
+    }
+    dialog_->raise();
+    dialog_->activateWindow();
 }
 
 static QHash<int, QList<FunnelAction *> > funnel_actions_;

ui/qt/funnel_statistics.h

@@ -13,8 +13,10 @@
 #include <QObject>
 #include <QAction>
 #include <QSet>
+#include <QPointer>
 
 #include <epan/funnel.h>
+#include "io_console_dialog.h"
 #include "capture_file.h"
 #include <ui/qt/filter_action.h>
 
@@ -111,6 +113,7 @@ private:
     funnel_console_open_cb_t open_cb_;
     funnel_console_close_cb_t close_cb_;
     void *callback_data_;
+    QPointer<IOConsoleDialog> dialog_;
 };
 
 extern "C" {