Screen-Based Controls

Screen-Based Controls

Screen-based controls, often simply called controls and sometimes called widgets, are the elements of a screen that constitute its body.

By definition, they are graphic objects that represent the properties or operations of other objects. A control may:

·        Permit the entry or selection of a particular value.

·        Permit the changing or editing of a particular value.

·        Display only a particular piece of text, value, or graphic.

·        Cause a command to be performed.

·        Possess a contextual pop-up window.

Three extremely important principles regarding controls should be noted:

·        A control must:

·        Look the way it works. Work the way it looks.

·        A control must be used exactly as its design intended.

·        A control must be presented in a standard manner.

The look of a control should make it obvious that it is a control. Its design characteristics should signal “enterability” or “clickability.” Microsoft Windows, for example, presents the following simple rules:

·        Raised elements can be pressed.

·        Recessed elements cannot be pressed.

·        Elements on a flat white background can be opened, edited, or moved.