AbstractPlotting: inconsistent attributes in basic_recipes (e.g. no visible attribute for barplot)

[kragol]

Some of the plot recipes in basic_recipes/ do not implement basic functionality such as visible on/off behaviour.

Should there be a standard set of attributes implemented by all recipes ?

• a visible attribute seems useful for any plot type, but I am not sure that every low-level plot type already implements it.
• perhaps a transparency attribute which is implemented by at least some low-level plot types already?
• an attribute deciding whether mouse_selection / pick should be able to "see" the object or ignore it (and look at what is "behind"). For instance, it may be rare to need to see grid lines, so these could default to "ignored".
• ...

Clearly, I have not thought about all possibilities, but this issue could be used to discuss that.

At the risk of being excommunicated, I thought some of the matlab standard interaction features could also be considered for inspiration, see e.g. https://www.mathworks.com/help/matlab/ref/matlab.graphics.chart.primitive.line-properties.html, those from the Interactivity, or Callback Execution Control sections in particular. PickableParts and HitTest for instance could also make sense for mouse interaction in Makie.

[kragol]

Just a bit of context:

I am designing some datatip function for a BarPlot (I did Scatter before, which was a bit easier) and I am facing a few issues right now:

• I want to be able to highlight the current hovered bar (or a selection of several bars through code). For that I plan to have a ghost BarPlot that draws some contours over the highlighted bars and turns invisible when not hovering the BarPlot. Right now, there is no visible attribute for BarPlot (see PR added a visible attribute to BarPlot JuliaPlots/AbstractPlotting.jl#539)
• In order to highlight one bar, the ghost BarPlot would only have one bar. Turns out that this throws an error (after a warning):

julia> barplot!([1],[1])
Warning: No strict ticks found
└ @ PlotUtils ~/.julia/packages/PlotUtils/3Ttrk/src/ticks.jl:283
ArgumentError: At least one finite value must be provided to formatter.with ticks: [-Inf, Inf]

• When hovering over a bar, I use the mouse_selection function to get which bar I am hovering. A mild issue is that mouse_selection only returns the low-level plot objects constituting the BarPlot (mesh and lines) instead of the BarPlot itself. While it is possible to figure out that the BarPlot is a parent of the low-level objects, the index of the plot element returned by mouse_selection may not be the same as the index of the hovered bar. Having a PickableParts attribute could simplify the identification of the BarPlot by returning the first parent object with PickableParts=false instead of the low-level objects. However, there would also be a need to convert the indices of the low-level plot elements (e.g. mesh elements for a BarPlot) to the relevant indices in the parent BarPlot.