Vertical Lists

Vertical lists display to a user a one-dimensional set of items, each occupying one line in the list. Various types of vertical list exist ”Table 7-1 provides an overview of their functionality, with each type described in detail in this section. An example application illustrating each type provides a practical guide to using vertical lists.

Selection Lists

A selection list allows one item at a time to be selected. If you need to enable the user to select multiple items simultaneously , you should use a multiselection list. The items in a selection list represent persistent data ”if the user switches away from the application or closes it, the items will all be the same when the list is next displayed. An example use for a selection list would be for a game to display a list of saved games , as shown in Figure 7-4. Selecting an item allows you to do several other things as well, like opening a more detailed view to show details of the game, which the user could edit. You can also execute a command, such as to play the game or open a context-sensitive menu.

Figure 7-4. Selection list.


Table 7-1. List Types

Type

Example

LISTBOX Flags in Resource File

Selection

SimpleList

EAknListBoxSelectionList

Menu

PopUpList

EAknListBoxMenuList

Markable

MarkableList

EAknListBoxMarkableList

Multiselection

MarkableList

can be easily changed create this functionality

EAknListBoxMultiselectionList


Menu Lists

Menu lists appear in a pop-up window in place of the Options menu and are cancelled by high-priority events (for example, incoming calls). Note that the Options menu itself is a menu list.

The usual way to invoke a menu list is by choosing an item from a selection list ”the menu list then contains further options for the selected item. For example, selecting a saved game from a selection list could invoke a menu list showing levels from a previously saved game, as shown in Figure 7-5. Selecting an item from the pop-up menu invokes a command, such as playing a game at the selected level.

Figure 7-5. Menu list.


Menu lists are very similar to context-sensitive menus invoked by the Selection key. You should use a menu list when you need to provide the same set of actions for a number of items (for example, to play a game at a specific level). A context-sensitive menu should be used when you need to provide alternative actions for a selected item (for example, to play or delete a selected game).

Keys

Scroll Up/Down

Selection Key

Left Soft Key

Right Soft Key

Moves focus

Selects item

Opens options menu

Back-steps

Moves focus

Selects item

Selects item

Cancels list and returns to previous state

With Edit key: Marks or unmarks all items scrolled over

Without Edit key : Moves focus

With Edit key : Marks or unmarks currently focused item

Without Edit key : Selects item

Selects item

Unmarks all items in list and back-steps

Moves focus

Check or uncheck item

Accept list checks

Cancels list and return to previous state


Markable Lists

Markable lists allow a user to mark multiple items and perform an action on all of them. For example, in a markable list of saved games, the user may choose to delete all of the marked games, as shown in Figure 7-6.

Figure 7-6. Markable list.


Selecting Mark, Mark All, Unmark or Unmark All from the Options menu, or using certain keys, marks and unmarks the items graphically. Note that nothing is displayed by a markable list (such as an empty checkbox) to indicate explicitly that an item can be marked. If you need to show explicitly that items should be marked, you should use a multiselection list instead.

When a command is invoked from the Options menu (for example, Delete ), it will be applied to the marked items only ”if an item is focused but not marked, it will not be affected by the command. Pressing the Selection key could invoke a command (for example, Delete ) on the marked items or open a context-sensitive menu. Further details of context-sensitive menus can be found in the Menus section of Chapter 5.

Multiselection Lists

Multiselection lists, as shown in Figure 7-7, allow you to mark a number of items and perform an action on all of them.

Figure 7-7. Multiselection list.


In contrast to markable lists, the ability to mark items in a multiselection list is transparent ”usually it is shown by means of a checkbox. Multiselection lists should be used in preference to markable lists if you need to show that there is a requirement , rather than an option , to perform an action on multiple items.

Items are checked and unchecked using the Selection key. Pressing the left soft key accepts the list of checked items and invokes a command (for example, to play a multi-player game against the checked players). Note that the Options menu is not available in a multiselection list.

Markable and multiselection lists are very useful for speeding up repetitive actions for a user. For example, deleting multiple items from a long list of saved games in a selection list would take a long time and many key presses to perform, but less time and key presses in a markable or multiselection list.

List Items and Fields

As you have seen, a list contains a number of items, which may be individually selected and activated. Items may in turn be made up of smaller components referred to as fields . Fields cannot be individually selected or activated ”they are just the building blocks used to construct list items. Series 60 supports the following types of field:

  • Icons

  • Headings

  • Numbers, or times

  • One or more lines of text

For example, each item in a list of saved games might consist of an icon representing the number of players, and two lines of text ”one for the saved game name, and one for a short description. An item in a list of high scores may have a number indicating the position within the high-score table, and a single line of text indicating the player's name .

Note that, in any given list, every item has exactly the same type and layout of fields.

Finding Items in a List

You can search for items in a list using a search field (also known as a find pane ), as shown in Figure 7-8. This is a particularly useful feature in long lists. You type into the search field part of the text of the item you wish to find. As you type, the list filters to display only those items that start with text you have typed.

Figure 7-8. Search field.




Developing Series 60 Applications. A Guide for Symbian OS C++ Developers
Developing Series 60 Applications: A Guide for Symbian OS C++ Developers: A Guide for Symbian OS C++ Developers
ISBN: 0321227220
EAN: 2147483647
Year: 2003
Pages: 139

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