ColorBarWidget: do not limit user's entry for min/max range

[Owen Arnold]

If you modify the minimum on the colour scale in the slice viewer, it immediately replaces this value with it's default. Modifications are remembered for maximum, but not for the minimum.

[Janik Zikovsky]

I have the color bar widget limit the user's entry of min/max to the min/max of the full data range calculated when setting the workspace. That means that if you set min < overall minimum, it will reset. If you set it larger than that, it will stick.

I'm thinking that maybe I should NOT limit the min/max this way but allow the user to put whatever. What do you think?

[Owen Arnold]

I think that the users should be able to set it lower than the overall range. That way they have more control over the scaling.

[Janik Zikovsky]

Modified ticket title...

[Janik Zikovsky]

Refs #4088 : Color map not limited

It seems to act funny if min < 1e-8 but I think this is an issue with QwtPlot, not my code.

Changeset: f76d2e4c086cf387a074fcce7b6bede2a76ba950

[Janik Zikovsky]

Note to testers: This widget is used inside the SliceViewer.

[Owen Arnold]

This works. Defaults to the range of real values, but can specify these boundaries to be outside the pre-set limits.

[Stuart Campbell]

This ticket has been transferred to github issue ​4935