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Motif and CDE 2.1 Style Guide Reference

Selection Models

Reference

Description

Selection models determine which selection techniques are available in a selection scope, the selection modes in which they operate, and the selection policies that control exactly what the techniques do.

There are five standard selection models:

Single selection model
Allows the user to select zero or one element from a scope.

Browse selection model
Allows a user to select one element from a scope and to obtain intermediate feedback while browsing elements to select.

Range selection model
Allows the user to select a single contiguous range of elements.

Extended selection model
Allows the user to select or deselect any set of elements, but it is easiest to select an element or range of elements.

Multiple selection model
Allows the user to select or deselect any set of elements, but is aimed at making it easy to add or remove elements from a currently selected set.

When to Use

Required
If you need to provide other models, or variants of these models (for example, because the elements in the scope are arranged densely, or in hierarchies, or in layers or other 3-D arrangements), do not deviate unnecessarily from the standard models.

Required
Use the single or browse selection models when at most one element in the scope can be selected.

Required
Use the range selection model when only a single contiguous range of elements can be selected.

Required
Use the multiple or extended selection models to allow discontiguous groups of elements to be selected.

Required
Use the browse selection model instead of the single selection model when you want to provide feedback to the user regarding the effect of the possible selection of an element.

Recommended
Use the single selection model instead of the browse selection model when you want to allow the user to select no elements at all.

Recommended
Use the extended selection model instead of the multiple selection model when the user is most likely to make a selection, act on the selection, and then start a new selection from scratch.

Recommended
Use the multiple selection model instead of the extended selection model when the user is most likely to make a selection, act on the selection, and then make small modifications to the previous selection before acting on it again.

Recommended
Use the extended selection model instead of the multiple selection model when the user most likely will to want to select a range of contiguous elements.

Recommended
Use the multiple selection model instead of the extended selection model when the user is as likely to want to deselect a selected element as to want to select an unselected element.

Recommended
Use the extended selection model instead of the multiple selection model when the user will want to be able to switch between normal and add modes or between select and toggle modes.

Guidelines

Required
Use the modes and techniques with the various selection models described in Table 25 and Table 26.

Table 25. Keyboard and Mouse Modes

Model Keyboard Mode Mouse Mode Technique
Single Add Toggle Point
Browse Normal Select Point, browse
Multiple Add Toggle Point, area and/or touch
Range Normal Select Point, range
Range Add Toggle (only for discontiguous ranges) Point, range
Extended Normal Select Point, range and/or area, touch (when needed), browse (keyboard-only)
Extended Add Toggle (only via Ctrl) Point, range and/or area, touch (when needed)

Table 26. Selection Models

Model Select Deselect All? Contiguous? Technique(s) Mode(s)
Single Max of 1 Y N/A Only point Toggle, add
Browse Max of 1 N N/A Browse and point Select, normal
Multiple Any Y Y Point. Touch, range, and/or area may also be used. Toggle, add
Range Any Y Y Point, browse, range. Select, normal (default), add
Discontiguous Any Y Y Point, browse, at least one of touch, range, and/or area. Select (default), toggle, normal (default), add

Required
Make toggle mode available only in the extended selection model through augmentation with the Ctrl modifier key. When Ctrl is not used, use select mode for mouse-based selection techniques.

Required
When using the extended selection model, allow both normal and add modes, but make normal mode the default mode.

Required
Group techniques must be available for the range and extended selection models.

Recommended
Support group techniques for the multiple selection model if the user is likely to need to select a group of elements at a time.

Essential Related Topics

For more information, see the Selection Modes, Selection Policies, and Selection Techniques reference pages.

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