subject: Types of widgets (window objects) [print this page] Types of widgets (window objects) Types of widgets (window objects)
Different interface programming packages support different widget sets. However, a surprising number of them contain similar kinds of widgets, so that one can think of a generic widget set which is applicable to most interfaces. The following widgets are representatives of this generic class.
Label widget. This is probably one of the simplest widgets. A label widget does nothing except to display a label, i.e. it does not have any other interaction capabilities and is not sensitive to mouse clicks. A label widget is often used as a part of other widgets.
Container widget. These widgets do not stand by themselves, but exist merely to contain other widgets. Other widgets are created as children of the container widget. When the container widget is moved or resized, its children widget also get moved or resized. A container widget has no callback routines associated with it.
Pop-up menu. These are transient and task specific. A pop-up menu appears upon pressing the mouse button, irrespective of the mouse position.
Pull-down menu. These are more permanent and general. You have to move the cursor to a specific location and pull down this type of menu.
Dialog boxes. We often need to select multiple elements from a selection list. A dialog box remains visible until explicitly dismissed by the user. A dialog box can include areas for entering text as well as values. If an apply command is supported in a dialog box, the newly entered values can be tried without dismissing the box. Through most dialog boxes ask you to enter some information, there are some dialog boxes which are merely informative, alerting you to a problem with your system or an error you have made. Generally, these boxes ask you to read the information presented and then click OK to dismiss the box.
Push button. A push button contains key words or pictures that describe the action that is triggered when you activate the button. Usually, the action related to a push button occurs immediately when you click a push button unless it contains an ellipsis (). A push button with an ellipsis generally indicates that another dialog box will appear.
Radio buttons. A set of radio buttons is used when only one option has to be selected out of many options. A radio button is a hollow circle followed by text describing the option it stands for. When a radio button is selected, it appears filled and the previously selected radio button from the group is unselected. Only one radio button from a group can be selected at any time. This operation is similar to that of the band selection buttons that were available in old radios.
Combo boxes. A combo box looks like a button until the user interacts with it. When the user presses or clicks it, the combo box displays a menu of items to choose from. Normally a combo box is used to display either one-of-many choices when space is limited, the number of choices is large, or when the menu items are computed at run-time.
