Projects/Usability/HIG/Slider and Spin Box

Purpose

Spin Boxes allow a user to enter a specific value, and gives users fine control over which value is chosen, but are slow when moving over large ranges of values. Sliders allow for quickly changing values over long ranges, but make it harder to select very specific values. In cases where both are necessary, combing the two is sometimes a good approach.

Guidelines

Is this the right control

• Use both a slider and spin box when the value is constrained at both ends, and when there is a large range of values (more than 20 steps) but precise control over the value is needed nevertheless.
• Consider to use only slider or spin box if a well defined workflow makes the other redundant.

Behavior

• The values of the slider and spin box should be linked so changes to one are immediately reflect in another.
• Make sure that all requirements from slider and spin box are met.

Appearance

• The spin box should be aligned with the long axis of the slider. So if the slider is horizontal, the spin box should be to the right of the slider and aligned vertically with the center of the slider. If the slider is vertical, the spin box should be below the slider and aligned horizontally with the center of the slider.
• Provide a single label using a text label above it or to the left of the widgets, using sentence capitalization. Provide an access key in the label that should give focus directly to the spin box.
• Mark significant values along the length of the slider with text or tick marks.

Implementation

KIntNumInput and KDoubleNumInput. Call setSlideEnabled(true) to show the slider.