The left section of the status bar contains a progress indicator. This indicator is used to inform the user what is taking place for certain operations. It displays the kind of operation by printing a text string in the bar (eg, reading...) and a progress value.
Any operation that uses the indicator can be interrupted by the user. This is done by one of the following operations:
Pressing (any mouse button) on the progress bar.
Clicking on the "Cancel Operation" toolbar button.
Selecting the "Cancel Operation" entry in the File menu.
The user will then be prompted to confirm the cancellation.