Slider drags start and end with mouse dragging, and SliderAttachment uses sliderDragStarted() and sliderDragEnded() to determine when to start and end parameter gestures. Because adjusting a slider via mouse wheel doesn’t trigger these drag callbacks it ends up with a lot of automation stuttering in Touch automation (testing on Pro Tools currently) since our value is set without gesture start/end calls.
Our workaround currently is using a custom attachment that determines gesture start and end by starting a timer when the slider receives a mouse wheel.
Are mouse wheel adjustments something that could be supported by the default juce::AudioProcessorValueTreeState::SliderAttachment?
Seems I was slightly off as to the location of the issue, stuttering is because a gesture is started and ended immediately (DragInProgress going out of scope after setValue()) every mouse wheel event in juce_Slider.cpp line 1072:
bool mouseWheelMove (const MouseEvent& e, const MouseWheelDetails& wheel)
{
if (scrollWheelEnabled
&& style != TwoValueHorizontal
&& style != TwoValueVertical)
{
// sometimes duplicate wheel events seem to be sent, so since we're going to
// bump the value by a minimum of the interval, avoid doing this twice..
if (e.eventTime != lastMouseWheelTime)
{
lastMouseWheelTime = e.eventTime;
if (normRange.end > normRange.start && ! e.mods.isAnyMouseButtonDown())
{
if (valueBox != nullptr)
valueBox->hideEditor (false);
auto value = static_cast<double> (currentValue.getValue());
auto delta = getMouseWheelDelta (value, (std::abs (wheel.deltaX) > std::abs (wheel.deltaY)
? -wheel.deltaX : wheel.deltaY)
* (wheel.isReversed ? -1.0f : 1.0f));
if (delta != 0.0)
{
auto newValue = value + jmax (normRange.interval, std::abs (delta)) * (delta < 0 ? -1.0 : 1.0);
DragInProgress drag (*this);
setValue (owner.snapValue (newValue, notDragging), sendNotificationSync);
}
}
}
return true;
}
return false;
}
Hard to say - it works well for moving stepped wheels by a few clicks. On a smooth-wheel mouse trying to adjust sliders, even in small amounts, in Touch automation ends up with some pretty funky curves unless I use a timer to end the gesture
