Introduction
Progress bars are great for giving feedback to the user during lengthy
operations. However, sometimes a percentage completion is not enough, so I came
up with this little class to display an estimation of the length of time
remaining to complete the operation.
The class uses a simple linear time calculation to predict the estimated time
remaining. For example, if the progress is at 10% complete and it has taken 5
seconds so far, then it predicts that it will take another 45 seconds to get to
100%
The prediction is repeated every time the control is drawn, therefore
assuming that the progress percentage is accurate, then the prediction should be
reasonably so too.
TProgressTimeToComplete is provided ready to go and can be used
as a direct replacement for the MFC CProgressCtrl class. The start
time is taken from when the class is instantiated, but can be reset if the
control is instantiated long before the processing by calling the
ResetStartTime() member function.
There is one virtual function that can be overloaded in order to customise
the display. GetRemainingText is called to format the text string
which is written over the top of the progress bar. There are two parameters
given the percentage complete and the estimated time to complete - in seconds.
The default implementation of the function looks like this:
CString TProgressTimeToComplete::GetRemainingText(double lfPercent,
double lfSecsRemaining)
{
CString str;
int nSeconds = (int)fmod(lfSecsRemaining, 60.0);
if (lfSecsRemaining < 60)
{
if (nSeconds < 1)
str = "Less than a second";
else
str.Format("%d second%s remaining", nSeconds,
nSeconds==1? "":"s");
}
else
{
int nMinutes = (int)(lfSecsRemaining/60.0);
str.Format("%d minute%s, %d second%s remaining",
nMinutes, nMinutes==1? "":"s",
nSeconds, nSeconds==1? "":"s");
}
return str;
}
Features
- Horizontal and vertical progress bars are supported
- Smooth and Blocked progress bars are supported
- Expandable for custom text formatting
- Interchangeable with MFC's
CProgressCtrl
- It's free !
Notes
The progress control uses Keith Rule's memory DC
class for smooth painting. Enjoy!
