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QProgressBar Class Reference
[com.trolltech.qt.gui module]

The QProgressBar widget provides a horizontal or vertical progress bar. More...

Inherits QWidget.


Detailed Description

The QProgressBar widget provides a horizontal or vertical progress bar.

A progress bar is used to give the user an indication of the progress of an operation and to reassure them that the application is still running.

The progress bar uses the concept of steps. You set it up by specifying the minimum and maximum possible step values, and it will display the percentage of steps that have been completed when you later give it the current step value. The percentage is calculated by dividing the progress (value - minimum) divided by maximum - minimum.

You can specify the minimum and maximum number of steps with setMinimum and setMaximum. The current number of steps is set with setValue. The progress bar can be rewound to the beginning with reset.

If minimum and maximum both are set to 0, the bar shows a busy indicator instead of a percentage of steps. This is useful, for example, when using QFtp or QHttp to download items when they are unable to determine the size of the item being downloaded.

Screenshot of a Macintosh style progress barA progress bar shown in the Macintosh widget style.
Screenshot of a Windows XP style progress barA progress bar shown in the Windows XP widget style.
Screenshot of a Plastique style progress barA progress bar shown in the Plastique widget style.

See also QTimeLine, QProgressDialog, and GUI Design Handbook: Progress Indicator.


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Qt Jambi 4.3.5_01