:: Research Group Embedded Interaction :: Media Informatics :: Ludwig-Maximilians-University Munich

J2ME Command Alignment

While developing a J2ME application I wondered how different mobile devices align commands (javax.microedition.lcdui.Command) according to their types on the screen. It makes sense to align the commands in the same way as it is common on a specific device. The midlet CommandTest creates a series of forms with different commands attached to them to determine the way in which the commands are being arranged and how command type and command priority influence the arrangement.

Used Software

• J2ME (MIDP 2.0, CDLC 1.0)
• J2ME Polish 1.2.4

Used Hardware

• Siemens S65 (software version 12)
• Nokia 6230 (software version 4.44)

Findings

The midlet has been tested on a Siemens S65, a Nokia 6230 and on a Siemens S65 using J2ME Polish. The results for each test is included as a comment into the source code.

General

• The order of adding the commands is only relevant for the positioning within a command type.

Siemens S65

• Priorities can influence the positioning also beyond command types (for example SCREEN and ITEM types; but the priority did not affect the alignment of OK and CANCEL types).
• The middle softkey has always the same command as the right softkey, or - if there is an options menu on the right softkey - the same as the first entry of this menu. It is being labeled with the first letter of the command label.
• If there is a BACK command defined it is possible to use the red button for the BACK action, too.
• Priority of softkeys: middle (and therefore also right, see above), left, right menu.
• Priority of command types: SCREEN, BACK, CANCEL, EXIT, OK, ITEM, HELP.

Nokia 6230

• Priorities cannot influence the positioning beyond command types.
• The right softkey is only bind to a CANCEL, EXIT or BACK command.
• CANCEL, EXIT or BACK commands are never bind to the middle softkey.
• Priority of softkeys: middle, left, (right, only for selected commands).
• Priority of command types: OK, ITEM, SCREEN, HELP, CANCEL, BACK, EXIT.

J2ME Polish (for Siemens S65 device)

• The right softkey is only bind to a CANCEL or BACK command.
• The middle softkey can not be assigned to a command (but it is used for list or menu selection).
• Priority of softkeys: left, (right, only for selected commands).
• Priority of command types: SCREEN, ITEM, OK, HELP (?), BACK, EXIT, CANCEL.

Note: Command types with a high priority will be bind to a softkey with a high priority.

Source code

• CommandTest.java

If you have any comments or questions, please feel free to ask us!