Add More Colormap Functionality (Set Extrema)

[Hovden]

There should be a user friendly way in which the user can select the minimum and maximum of the colormap being applied. Right now the user can set these values after clicking an icon and typing values. At our last meeting we discussed a more interactive possibility that is more intuitive to the user.

[mathturtle]

This is going to require we pretty much rewrite the color map editor. I don't think there is a good way to extend the existing one to do this.

[cryos]

It will require a new widget, but there is a fair bit we can reuse from the charting that underlies the color map editor. Not a trivial amount of work, but I think it will be worth it.

[mathturtle]

If I'm going to be writing a new widget for this, can we get a list of all the things we would like it to do and iterate a bit on the general design before I jump into working on it?

[cryos]

Yes, but not today. There are lots of other things to do first anyway.

[Hovden]

Is this currently addressed with the "Specify Data Range" button?

[cryos]

I would like to add the graphical equivalent to the chart, I really just moved the button closer to the central widget.

[cquammen]

I experimented with preliminaries for this, and this is mostly a note to whoever implements this. You may want to override the member functions

vtkChartHistogram::MouseButtonPressEvent(const vtkContextMouseEvent &m) vtkChartHistogram::MouseButtonReleaseEvent(const vtkContextMouseEvent &m)

For instance, you may want to set some state that you have selected a data range marker in the button press event, then unset it in the release event. The MouseButtonPressEvent() is called okay when you click in the histogram, but MouseButtonReleaseEvent() never seems to be called.

I dug a little to see that vtkContextScene::ButtonReleaseEvent(const vtkContextMouseEvent &e) is called, but it never seems to invoke vtkChartHistogram::MouseButtonReleaseEvent(const vtkContextMouseEvent &m). I didn't yet track down why.

[Hovden]

I'm cool with moving this to next release.