prototype

src/args.jl

@@ -1273,12 +1273,16 @@ function convertLegendValue(val::Symbol)
         :none
     elseif val in (:right, :left, :top, :bottom, :inside, :best, :legend, :topright, :topleft, :bottomleft, :bottomright, :outertopright, :outertopleft, :outertop, :outerright, :outerleft, :outerbottomright, :outerbottomleft, :outerbottom, :inline)
         val
+    elseif val == :horizontal
+        -1
     else
         error("Invalid symbol for legend: $val")
     end
 end
+convertLegendValue(val::Real) = val
 convertLegendValue(val::Bool) = val ? :best : :none
 convertLegendValue(val::Nothing) = :none
+convertLegendValue(v::Union{Tuple, NamedTuple}) = convertLegendValue.(v)
 convertLegendValue(v::Tuple{S,T}) where {S<:Real, T<:Real} = v
 convertLegendValue(v::Tuple{<:Real,Symbol}) = v
 convertLegendValue(v::Real) = v

src/backends/pgfplotsx.jl

@@ -140,6 +140,8 @@ function (pgfx_plot::PGFPlotsXPlot)(plt::Plot{PGFPlotsXBackend})
             axis_opt = PGFPlotsX.Options(
                 "point meta max" => get_clims(sp)[2],
                 "point meta min" => get_clims(sp)[1],
+                "legend cell align" => "left",
+                "legend columns" => pgfx_legend_col(sp[:legend]),
                 "title" => sp[:title],
                 "title style" => PGFPlotsX.Options(
                         pgfx_get_title_pos(title_loc)...,
@@ -918,6 +920,15 @@ function pgfx_linestyle(linewidth::Real, color, α = 1, linestyle = :solid)
     )
 end
 
+function pgfx_legend_col(s::Symbol)
+    if s == :horizontal
+        return -1
+    end
+    return 1
+end
+pgfx_legend_col(n) = n
+
+
 function pgfx_linestyle(plotattributes, i = 1)
     lw = pgfx_thickness_scaling(plotattributes) * get_linewidth(plotattributes, i)
     lc = single_color(get_linecolor(plotattributes, i))

src/components.jl

@@ -777,3 +777,15 @@ function extrema_plus_buffer(v, buffmult = 0.2)
     buffer = vdiff * buffmult
     vmin - buffer, vmax + buffer
 end
+
+### Legend
+
+@add_annotations subplot struct Legend
+    background_color
+    foreground_color
+    position
+    title
+    font::Font # TODO: check if macro is recursive enough
+    title_font
+    column
+end