"James C. Sutherland" <james.sutherl...@utah.edu> writes:
> When trying to scroll with the mouse, I get many copies of the following
> message:
>
>> /Users/stephan/cvs/lyx/lyx-2.0.0alpha4/src/frontends/qt4/GuiWorkArea.cpp(840):
>> wheelScrollLines = 3 delta = 0 scroll_value = 0 page_step = 734
>>
The problem is "delata = 0". The code reads:
void GuiWorkArea::wheelEvent(QWheelEvent * ev)
{
// Wheel rotation by one notch results in a delta() of 120 (see
// documentation of QWheelEvent)
int const delta = ev->delta() / 120;
On PCs, the mouse wheel clicks, and each wheelEvent corresponds to a
multiple of 120 (unot is eighth of degree, and a click is 15 degrees).
On a mac, the situation is different, since the wheel turns smoothly.
It might be enough to have delta be a double. Could you test the
attached patch?
JMarc
Index: src/frontends/qt4/GuiWorkArea.cpp
===================================================================
--- src/frontends/qt4/GuiWorkArea.cpp (révision 34729)
+++ src/frontends/qt4/GuiWorkArea.cpp (copie de travail)
@@ -816,7 +816,7 @@
{
// Wheel rotation by one notch results in a delta() of 120 (see
// documentation of QWheelEvent)
- int const delta = ev->delta() / 120;
+ double const delta = ev->delta() / 120.0;
if (ev->modifiers() & Qt::ControlModifier) {
docstring arg = convert<docstring>(5 * delta);
lyx::dispatch(FuncRequest(LFUN_BUFFER_ZOOM_IN, arg));
@@ -830,11 +830,8 @@
int scroll_value = lines > page_step
? page_step : lines * verticalScrollBar()->singleStep();
- // Take into account the rotation.
- scroll_value *= delta;
-
- // Take into account user preference.
- scroll_value = int(scroll_value * lyxrc.mouse_wheel_speed);
+ // Take into account the rotation and the user preferences.
+ scroll_value = int(scroll_value * delta * lyxrc.mouse_wheel_speed);
LYXERR(Debug::SCROLLING, "wheelScrollLines = " << lines
<< " delta = " << delta << " scroll_value = " << scroll_value
<< " page_step = " << page_step);
