+1, but I found two little issues:

• The MouseArea's height is quite short, so it's hard to get the cursor into the right place. I would recommend making it span the full height of the player bar rather than simply just filling the area of the slider.
• When scrolled, the handle's movement on the volume slider is instantaneous, but for the playback position slider it lags about half a second. This is not related to this patch here, but it making it scrollable makes this pre-existing issue more prominent.

In D22332#492786, @ngraham wrote:

+1, but I found two little issues:

• The MouseArea's height is quite short, so it's hard to get the cursor into the right place. I would recommend making it span the full height of the player bar rather than simply just filling the area of the slider.
• When scrolled, the handle's movement on the volume slider is instantaneous, but for the playback position slider it lags about half a second. This is not related to this patch here, but it making it scrollable makes this pre-existing issue more prominent.

I have fixed the first issue. The second issue is a lot more difficult since the seeking and the volume change are working differently. The volume property of the actual audio player is bound to the slider value, while the seek works directly on the audio player and the slider is bound to the player. So the latter does a round trip. The fact that it is also done with two connected signals probably does not help.