Projects/Usability/HIG/ListView

Purpose

A list view is basically used to show some items. It offers orientation thereby and allows navigation without the need of other controls. Additionally, a list view may be used for single selection (users select one item from a list of mutually exclusive values) or multiple selection (selections in combination with the Shift key or Control key). However, because there is no common visual clue whether a list box’ mode is single or multiple and since other controls are more efficient for single selection, a list box should be used for single selection only.

Guidelines

Subsection 1

• Prefer a list view to show items that belong together and in case of sufficient space.
• Alternate row color (use theme settings). Use different keys (e.g. page up/down) when more lists should be accessible.
• Do not have blank list items; use meta-options, e.g. (None) instead.
• Place options that represent general options (e.g. All, None) at the beginning of the list.
• Sort list items in a logical order. Make sure sorting fits translation.
• For lists with more than one column view, show headers and enable sorting by clicking the header. Show sort order in header.
• Always give list controls a label, positioned above or to the left of the list, in sentence capitalization.
• Make the list control large enough that it can show at least four items at a time without scrolling.
• If the list appears in a dialog or utility window, consider making the window and the list within it resizable so that the user can choose how many list items are visible at a time without scrolling. Each time the user opens this dialog, set its dimensions to those that the user last resized it to.

Selection

• Use the list view for selection if it is easy for users to know which items are checked at any given time, for one or more of these reasons:
  • There are no more than twice the number of options then are visible at a time
  • The options are well-known (for example months of a year or days of a week)
  • Usually the selected options are close to each other in the list
• Provide extended multiple selection with Shift+Click or Ctrl+Click to select groups of contiguous or non-adjacent values, respectively.

Implementation

• QListView, for single-column lists.
• QTreeView, for multi-column lists. Be sure to set the rootIsDecorated property to false if the items in your list do not have children.