Adding the Ability to Control Line Drawing in X-Y Graphs
This afternoon a couple of developers stopped by trying to do something in the graphs I've built on VantagePoint, and I'll admit - it wasn't going to be easy. Basically, they wanted a multi-variable scatter graph - just like the TwoDimCrossScatterViewer, but with all the GUI widgets to make it easy to use by the target audience.
The first step was to be able to easily control the visibility of the lines on the x-y graph, because if I could do that, then I could easily build on that and just use it in the "no lines" mode and be ready to go. But in order to do that, I needed to have a clean way to turn on and off the lines in all pairs, and a pair at a time.
What I came up with was the simple applet PARAM tag showxylines. If that guy is true, then the graph will show the lines, if it's false, then it won't. If it's missing, then they will be shown, by default. The neat addition to that was to add the PARAM tag showxylines:columnName and if that's true, the lines with that column in their definition will be shown, and not otherwise. This makes it very easy to turn all lines off and then some select few on, or vice versa.
This doesn't mean I'm done, but it's a great stepping-stone. From here, I need to add in the GUI widgets to control the graph, make sure the lines are "off", and then put it all together. Not trivial, but I've done this several times and it's not as hard as all that.