QHeaderView - no big update work if updates are disabled

There is no reason to find out where to update the headerview
if updates aren't enabled.  Another approch I considered to skip the
whole calculation and just call update. I seriosly doubt that this
calculation and update of a particular QHeaderView rect will normally(*)
be faster than just updating everything.

However to be safe I have done the conservative fix.

(*) Normally but with many/fragmented spans in the headerview.

Change-Id: Ia812a747ee825653db0345cdc34f9d2f7155ea01
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index 8ecbdeb8bd..76529fcda3 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -887,6 +887,11 @@ void QHeaderView::resizeSection(int logical, int size)
     if (size != oldSize)
         d->createSectionSpan(visual, visual, size, d->headerSectionResizeMode(visual));
 
+    if (!updatesEnabled()) {
+        emit sectionResized(logical, oldSize, size);
+        return;
+    }
+
     int w = d->viewport->width();
     int h = d->viewport->height();
     int pos = sectionViewportPosition(logical);