Extend Legend Options

[Daniel Marsh-Patrick]

Meagan Longoria wrote a really nice post about the visual, and one of the things she did to improve readability was to overlay her own legend, explaining the points within the violin:

This could be really useful for end-users and we should try to incorporate such a feature.

Current behaviour is as follows:

• If the plot contains categories, and the user opts to apply colours by category, then the Legend menu becomes available.
• Legend will display colour and name of each category.
• There is no interactivity or cross-filtering to consider at this time.

The intended solution is to use the existing legend space and functionality, so behaviour will be modified to the following logic:

• Legend will be enabled by default.
• Note that the legend utils do not support shapes other than circles very well; other visuals with different shapes do some post-processing on them prior to render. We'll do the same thing.
• Category behaviour:
  • An option will be added to toggle categories on and off.
  • For a single category or multiple categories with the same colour, the legend will display the measure name and the colour as a normal legend item.
  • For multiple categories with individual colours, the legend will work as it does currently.
  • The category shape will be replaced with a simple 'violin' rather than a circle.
• Statistical Data Indicators behaviour:
  • An option will be added to toggle stat indicators on and off.
  • Properties will be provided to customise the displayed text for each data point.
  • Only the intended data points for the relevant combo plot will be shown.
  • Barcode Data Point:
    • If the barcode plot is enabled, the barcode line stying will be used as the legend icon
    • We will use Individual Data Point as the default name, but we'll add a property to allow the user to override with their own description.
  • Mean:
    • If the mean is enabled, the circle will be replicated in the legend as formatted in the plot, i.e. circle with inner/outer colouring
    • The shape will be surrounded with a fill matching the fill of the box plot.
  • Median:
    • If the median is enabled, the legend icon will be the line and styling used for the median as per the properties
    • The shape will be surrounded with a fill matching the fill of the box plot. If using a barcode plot then this will be the fisrt used category colour for the violin.
  • Quartiles:
    • If quartiles are enabled, and both are the same colour and line style, then we will display 1st & 3rd Quartiles, with the line styling. Same rules for median in terms of background colour.
    • If quartiles have different styling to each other, then we'll display individual legend points for 1st Quartile and 3rd Quartile respectively.

[Daniel Marsh-Patrick]

I'm some way towards getting this done, but I'm going to bump it to 1.3.0, particularly given that #67 is ready to go and needs wrapping up

[Daniel Marsh-Patrick]

Some examples of how this looks:

Legend Oriented On Left

Legend Oriented At Top (With Multiple Categories and Different Quartile Configuration)

Editing Properties

[Daniel Marsh-Patrick]

I've passed to Meagan to have a look and she's had some suggestions which have been resolved, so this one's good to go.