One of the challenges encountered when creating a Windows CE–based application is to design for a small screen. To maximize the screen space available for applications in the client area, the OS supports a new type of control—the command bar. The command bar is unique to Windows CE because it combines a menu bar, toolbar, and an optional address bar. Windows CE supports multiple command bars, each containing gripper controls that enable users to hide buttons and menus. Command bars can contain combo boxes, edit boxes, and buttons, as well as other types of controls. They also can include the Close (X) button, the Help (?) button, and the OK button.
Command bars vary from 240 pixels through 640 pixels in length depending on the screen resolution. It is recommended that you always display a command bar in Windows CE–based applications.
Command bars are composed of bands, separated by gripper controls. Each band can contain up to one child window, which can be a toolbar or any other control. The default is to display a toolbar. Additionally, each band can have its own bitmap, displayed as a background for the toolbar. A user can resize or reposition a band by dragging its gripper bar. If a band has a text label or icon next to its gripper bar, a user can maximize the band and restore it to its previous size by using the pointing device to choose the label or icon. The following screen shot shows a command bar.
A command bar menu includes a list of commands that drops down when a user taps the menu's caption on the command bar. Menu titles on a command bar appear in bold text. If you include a menu bar, always position it as the first (leftmost) element on the command bar. If you provide File, Edit, View, Insert, Format, Tools, and Window menus, place them in this order, from left to right. The menu titles appear as bold text surrounded by a rectangular frame.
Windows CE supports ToolTips for command bar and toolbar buttons, but not for menus or combo boxes on a command bar. ToolTips usually display only the title of a button command, but they can also display the shortcut key for the command.
You can place check boxes or radio buttons on the command bar to enable users to toggle between different views. Moving between views can make windows more readable by eliminating unnecessary scrolling. A command bar button can display both text and images. This enables you to include text as part of a button label to provide descriptions, which eliminates the need for ToolTips.
If you choose to place a label next to your edit control on a command bar, you have two choices. You can insert a static text field above or to the left of the control. Alternatively, you can include an edit control label inside the text field as the default text. In this case, you would enclose the label between angle brackets, as in the following example: <name>. Because the user can no longer see the control label when typing text in the field, it is recommended that you use a static text field.
If you provide individual New, Open, Save, and Print buttons on a command bar, you must position them in this order, from left to right. If you provide individual Bold, Italic, and Underline buttons, you must also place them in this order, from left to right. Always make buttons at least 23 x 23 pixels. If you plan to support touch interaction in which users use a finger rather than a stylus, make all buttons at least 38 x 38 pixels. However, to conserve space, consider creating a
combo-box button instead of three or four separate buttons.