Catch Error for invalid bin range in setBinRange()

[Mike Thomas]

Entering bin range values outside the range of the data yields an error from MantidPlot about the scrollbar. It would be more useful to identify that the bin range is wrong. The current error message reads:

Sorry, MantidPlot has caught an unexpected exception:

XIntegrationScrollBar : minimum and maximum must be between 0 and 1

Would you like to terminate MantidPlot or try to continue working?
If you choose to continue it is advisable to save your data and restart the application.

Terminate     Continue

The error was caused in the python command line with the lines

 instrument_view = getInstrumentView("Small_Angle")
 instrument_view.setBinRange(10000,15000)

where Small_Angle is a workspace of data in units of wavelength with a min of 2.2 and max of 10. Hence the range 10000,15000 is unsuitable

[Andrei Savici]

Check if set maximum less than allowed minimum. Refs #7864

Changeset: 806b1f1e22401c01a5018864c66520d1cd9a3f65

[Arturs Bekasovs]

An exception thrown was definitely an over-reaction. It isn't happening any more.

However, as it works now, it might not be entirely obvious what the function is doing when you specify unreasonable values. I think a log-warning saying something like "Specified range start is too small, set to min value" would make it much better.

Another option might be not to change values if arguments are unreasonable, returning an appropriate error (not an exception of course). This way usually helps to avoid lots of user mistakes. (​http://en.wikipedia.org/wiki/Fail-fast).

[Andrei Savici]

There are other things users are not warned about (such as swapping minimum and maximum if they are in the wrong order). If someone wants some big notices, a new ticket should be opened.

[Arturs Bekasovs]

Merge remote-tracking branch 'origin/feature/7864_XIntegrationRange'

Full changeset: ​020cf106d0867f18e9eda26a18cdfb5ff6cf1ac3

[Arturs Bekasovs]

As discussed, that's not the only occasion when it does something silently, so if that's really important - new ticket would be more appropriate.

[Stuart Campbell]

This ticket has been transferred to github issue ​8709