Mobile Design Pattern: Slider Control
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This design pattern is part of the Mobile Design Patterns series.
Contents |
Description
A control which enables the user to choose one distinct value within a finite range by dragging (or simulating the dragging) of) one or more sliders along a single axis.
Advantages
- Highly visual and intuitive — especially when representing a familiar scale of values.
Disadvantages
- Only suitable when the list of values is short and there is enough context to make an informed decision regarding the likely impact of the chosen increment.
Use when
- The user’s mental model of a series of values is closely tied to an increasing or decreasing scale and limited amount of discrete values. Ex. Controls to increase/decrease brightness, contrast, intensity or volume.
Use how
Direct manipulation
- The slider works in a similar manner to a real-world physical control. The user presses on the slider handle (to simulate grasping) then (while continuing to press), drags the handle to the desired incremental stop position.
- A two-handle control can also be used (on touch devices only) to set a range of values. In this case, one slider provides the minimum value and the other the maximum value—thereby creating a range.
Indirect manipulation
- The slider handle is either provided with immediate focus or the user can focus the control then manipulate it. (see example below)
- The slider handle is mapped to the Left/Right keys (for a horizontal control) or Up/Down keys (for a vertical control).
- Each click of the keys moves the slider handle by one pre-set increment.
- Holding 'Down' may automatically repeat the adjustment until the key is released.
Figure: The S60 Equalizers must each be focused before they can be manipulated.
Design Tips
- Adding tick marks (or other visual way points) enables users to more accurately gauge the incremental change in values.
- Pairing the slider with a visual representation of the change in value can also be useful. Ex. A Real-time RGB colour picker updates the colour values in real time as you manipulate each slider.
Figure: Various sliders in use within S60; each providing varying degrees of feedback. The ‘Ringing Volume’ control functions in a in a similar manner but does not provide an actual slider—only the accompanying ‘increasing scale’ visualization.
Figure: Examples of Qt embedded widget sliders for touch devices.
03 Sep
2009
The article demonstrates a deep understanding of Mobile Design Patterns : Slider Control, the examples and diagrams provided reflect well the authors thoughts. This article is recommended for reading by everyone who wants to design or implement this pattern. The advantages, disadvantages, when and how to use has been explained properly. It aslo mentions some design tips which could be handly when designing custom control applying the above pattern.