Re: fdo#47907: fix flickering scrolling in Basic IDE

On 02/08/12 15:31, Noel Power wrote:
> Hi János,
>
> On 31/07/12 12:34, János Uray wrote:
> > Again? Oh, yes.
> > Now here it is.
> >
> > On Tue, Jul 31, 2012 at 11:10 AM, Noel Power <nopower@suse.com 
> > <mailto:nopower@suse.com>> wrote:
> >
> >     Hi János
> >     you forgot to attach the patch :-)
> >
> >     On 30/07/12 19:04, János Uray wrote:
> > >     This patch solves this bug:
> > >     https://bugs.freedesktop.org/show_bug.cgi?id=47907
> > >
> > >     The text was flickering because Window::Invalidate() clears the
> > >     client area by default. To prevent this, I've added an
> > >     INVALIDATE_NOERASE parameter to Invalidate() calls.
> > >     On the other hand, the background still needed to be erased
> > >     outside the text: the indentation space and the rest of the line.
> seems to work better :-), imho still is not as smooth as 3.4, I would 
> love to know *why* we get this behaviour now in >=3.5, is something 
> triggering Resize() more often now ( and why indeed is Resize even 
> called when scrolling ). Additionally I am a but nervous about changes 
> to the TextEngine  ( a piece of code I have no familiarity with at all 
> ). Saying that the change you made seems quite small ( despite the 
> confusing diff due to the whitespace changes ) I suppose it is the 
> last part of the patch that is really necessary. But still it just 
> feels wrong that we need to tweak the TextEngine and I wonder are we 
> correcting a side affect rather than fixing the root cause
well it seems that

--- a/basctl/source/basicide/baside2b.cxx
+++ b/basctl/source/basicide/baside2b.cxx
@@ -682,7 +682,6 @@ void EditorWindow::Notify( SfxBroadcaster& /*rBC*/, 
const SfxHint& rHint )
                 ( 0, 
pModulWindow->GetBreakPointWindow().GetCurYOffset() - 
pEditView->GetStartDocPos().Y() );
             pModulWindow->GetLineNumberWindow().DoScroll
                 ( 0, 
pModulWindow->GetLineNumberWindow().GetCurYOffset() - 
pEditView->GetStartDocPos().Y() );
-            pModulWindow->Invalidate();
         }
         else if( rTextHint.GetId() == TEXT_HINT_TEXTHEIGHTCHANGED )
         {


solves the problem, I see no side affects, however since you have proved 
you are quite adept and talented at handling complicated drawing bits, 
notice if you scroll the window ( by dragging the scroll bar ) if you 
have the linenumbers enabled they flash and flicker and even disappear 
while scrolling, it would be great to get than nice and smooth

Noel