qt: use singleton in OpenDialog

modules/gui/qt/dialogs/open/open.cpp

@@ -36,16 +36,15 @@
 # define DEBUG_QT 1
 #endif
 
-OpenDialog *OpenDialog::instance = NULL;
-
 OpenDialog* OpenDialog::getInstance(  qt_intf_t *p_intf,
         bool b_rawInstance, int _action_flag, bool b_selectMode )
 {
-    /* Creation */
-    if( !instance )
-        instance = new OpenDialog( nullptr, p_intf, b_selectMode,
-                                   _action_flag );
-    else if( !b_rawInstance )
+    const auto instance = Singleton<OpenDialog>::getInstance(nullptr,
+                                                             p_intf,
+                                                             b_selectMode,
+                                                             _action_flag);
+
+    if( !b_rawInstance )
     {
         /* Request the instance but change small details:
            - Button menu */

modules/gui/qt/dialogs/open/open.hpp

@@ -32,6 +32,7 @@
 
 #include "widgets/native/qvlcframe.hpp"
 #include "dialogs/open/open_panels.hpp"
+#include "util/singleton.hpp"
 
 /* Auto-generated from .ui files */
 #include "ui_open.h"
@@ -55,20 +56,16 @@ enum {
 
 class QString;
 
-class OpenDialog : public QVLCDialog
+class OpenDialog : public QVLCDialog, public Singleton<OpenDialog>
 {
+    friend Singleton<OpenDialog>;
+
     Q_OBJECT
 public:
     static OpenDialog * getInstance(qt_intf_t *p_intf,
                                 bool b_rawInstance = false, int _action_flag = 0,
                                 bool b_selectMode = false );
 
-    static void killInstance()
-    {
-        delete instance;
-        instance = NULL;
-    }
-
     void showTab( int = OPEN_FILE_TAB );
     QString getMRL( bool b = true );
 
@@ -87,8 +84,6 @@ private:
                 int _action_flag = 0 );
     virtual ~OpenDialog();
 
-    static OpenDialog *instance;
-
     QString optionsMRL;
     QString storedMethod;
     QStringList itemsMRL;