Displaying a progress bar

A progress bar is a dynamic dialog that displays the percentage complete bar for a running process that the user must wait for before continuing. A progress bar is more advanced than a simple dialog because it needs to be updated continuously. In this recipe, we'll create a simple progress dialog based on a timer.

Getting ready

No groundwork is required for this recipe.

How to do it...

The steps for this recipe include creating a custom class based on the QProgressBar, initializing the dialog and setting its size and title, creating a timer, connecting the progress bar to the timer, starting the time, and displaying the progress. To do this, we need to perform the following steps:

1. First, we must import both the GUI and QGIS core libraries:

   from PyQt4.QtGui import *
   from PyQt4.QtCore import *
   

2. Next, we create a custom class for our progress bar, including a method to increase the value of the progress bar:

   class Bar(QProgressBar):
     value = 0
     def increaseValue(self...