No parameter attribute for number formats

[etadobson]

This issue was recently brought up on the forum... currently, if for example, you want to display the a default value of 0.0178 in the dialog for a user…

#@Double(label="Distance", value=0.01780, persist=false) distance

When the code runs… you get a pre-set value of 0.018 popping up and there is no current method to set the number of decimal places for that input.

As stated by @imagejan on the forum:

"The spinner created in SwingNumberWidget is using the default DecimalFormat which apparently has a maximum of three decimal places.

You can somehow work around the issue by using a slider or scroll bar (within a defined range). But while the actual values can contain more decimal places (as shown by the println statement, there’s still no visual feedback inside the spinner text field:

#@ Double (label="Distance", min=0, max=0.05, value=0.01780, persist=false, stepSize=0.0001, style=slider) distance
println distance

There’s no parameter attribute for number formats, but we could maybe use the style attribute for this; in any case we should try to guess a suitable spinner number format from the combination of min, max and stepSize, or from the default value…"

[BoudewijnvanLangerak]

Added code for formatting numerical values in the @parameter annotation.
Code in the pullrequests:
scijava/scijava-common#399
#50