* Added a BWindow::InViewTransaction() that determines whether or not the

window is currently updating its drawings as suggested by Stippi.
* Add this method to decide whether to call _FontChanged() in
  BListView::SetFont().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34109 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/Window.h

@@ -185,6 +185,7 @@ public:
 			void				EndViewTransaction();
 									// referred as CommitViewTransaction()
 									// in BeBook
+			bool				InViewTransaction() const;
 
 			BRect				Bounds() const;
 			BRect				Frame() const;

src/kits/interface/ListView.cpp

@@ -655,10 +655,9 @@ void
 BListView::SetFont(const BFont* font, uint32 mask)
 {
 	BView::SetFont(font, mask);
-	//_FontChanged();
-		// TODO: this absolutely kills the performance, if a BListItem
-		// changes the font when drawing - if this should be called at all,
-		// it should only be done outside any updates!
+
+	if (Window() != NULL && !Window()->InViewTransaction())
+		_FontChanged();
 }
 
 

src/kits/interface/Window.cpp

@@ -682,6 +682,14 @@ BWindow::EndViewTransaction()
 }
 
 
+bool
+BWindow::InViewTransaction() const
+{
+	BAutolock locker(const_cast<BWindow*>(this));
+	return fInTransaction;
+}
+
+
 bool
 BWindow::IsFront() const
 {