Other Widgets: From Buttons to Seek Bars

The Android system provides some standard graphical widgets that developers can utilize to create a cohesive user experience across applications. The most common ones are

• Button— A rectangular graphic that registers when the screen is touched within its bounds. It can contain user-provided text or images.

• CheckBox— A button with a checkmark graphic and description text that can be toggled on or off when touched. The ToggleButton is similar and also discussed here.

• RadioButton— A button with a dot graphic that can be selected when touched, but cannot then be turned off. Multiple radio buttons can be grouped together into a RadioGroup, which allows only one radio button of the group to be selected at a time.

• Spinner— A button showing the current selection and an arrow graphic to denote a drop-down menu. When the spinner is touched, the list of possible values displays and when a new selection is made, it is displayed in the spinner.

• ProgressBar— A bar that lights up to visually indicate the percentage of progress (and optionally secondary progress) in an operation. It is not interactive. If a quantitative measure of progress cannot be determined, it can be set in indeterminate mode, which shows a rotating circular motion instead.

• SeekBar— An interactive progress bar that allows progress to be dragged and changed. This is useful to show media playback, for example. It can show how much of the media has been played, and a user can drag to move to an earlier or later place in the file.