Add QDeferredDeleteEvent

Use this to store the loop-level counter needed by QCoreApplication
when determining when it is safe to delete an object.

This removes the hack to hijack the QEvent::d pointer (even though
the pointer is unused).

Change-Id: I91c0b1aa00235ec6e13feb30bf928e56d2f80026
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/src/corelib/kernel/qcoreevent.cpp b/src/corelib/kernel/qcoreevent.cpp
index 1e3f8a2fee..5231f813f4 100644
--- a/src/corelib/kernel/qcoreevent.cpp
+++ b/src/corelib/kernel/qcoreevent.cpp
@@ -116,7 +116,7 @@ QT_BEGIN_NAMESPACE
     \value ContentsRectChange               The margins of the widget's content rect changed.
     \value ContextMenu                      Context popup menu (QContextMenuEvent).
     \value CursorChange                     The widget's cursor has changed.
-    \value DeferredDelete                   The object will be deleted after it has cleaned up.
+    \value DeferredDelete                   The object will be deleted after it has cleaned up (QDeferredDeleteEvent).
     \value DragEnter                        The cursor enters a widget during a drag and drop operation (QDragEnterEvent).
     \value DragLeave                        The cursor leaves a widget during a drag and drop operation (QDragLeaveEvent).
     \value DragMove                         A drag and drop operation is in progress (QDragMoveEvent).
@@ -580,4 +580,24 @@ QDynamicPropertyChangeEvent::~QDynamicPropertyChangeEvent()
     \sa QObject::setProperty(), QObject::dynamicPropertyNames()
 */
 
+/*!
+    Constructs a deferred delete event with an initial loopLevel() of zero.
+*/
+QDeferredDeleteEvent::QDeferredDeleteEvent()
+    : QEvent(QEvent::DeferredDelete)
+    , level(0)
+{ }
+
+/*! \internal */
+QDeferredDeleteEvent::~QDeferredDeleteEvent()
+{ }
+
+/*! \fn int QDeferredDeleteEvent::loopLevel() const
+
+    Returns the loop-level in which the event was posted. The
+    loop-level is set by QCoreApplication::postEvent().
+
+    \sa QObject::deleteLater()
+*/
+
 QT_END_NAMESPACE