Sliders instead of spin rows

[bragefuglseth]

The color amount, brightness and contrast settings are currently implemented as spin buttons, but they might make more sense as sliders. For the settings that can be both positive and negative, you can have a snapping point in the center and have the slider be set to 50% by default. See the sound panel in Settings for reference.

From the HIG:

Use a slider when:

• the range of values is fixed and ordered
• adjusting the value relative to its current value is more important than choosing an absolute value
• it is useful for the user to control the rate of change of the value in real time
• the number of potential values is high

[tfuxu]

I feel that this would lead to a worse UX. Sliders are less precise than spin rows, which is important when setting the number of colors, and there is no way for user to insert a specific value, without adding an additional widget that would make the sliders even smaller.

This is how it looks like with sliders: