add showtheme recipe

src/themes.jl

@@ -4,11 +4,16 @@
 Specify the colour theme for plots.
 """
 function theme(s::Symbol; kw...)
+    defaults = _get_defaults(s)
+    _theme(s, defaults; kw...)
+end
+
+function _get_defaults(s::Symbol)
     thm = PlotThemes._themes[s]
-    defaults = if :defaults in fieldnames(thm)
-        thm.defaults
+    if :defaults in fieldnames(thm)
+        return thm.defaults
     else # old PlotTheme type
-        defs = KW(
+        defaults = KW(
             :bg       => thm.bg_secondary,
             :bginside => thm.bg_primary,
             :fg       => thm.lines,
@@ -18,14 +23,12 @@ function theme(s::Symbol; kw...)
             :palette  => thm.palette,
         )
         if thm.gradient != nothing
-            push!(defs, :gradient => thm.gradient)
+            push!(defaults, :gradient => thm.gradient)
         end
-        defs
+        return defaults
     end
-    _theme(s, defaults; kw...)
 end
 
-
 function _theme(s::Symbol, defaults::KW; kw...)
     # Reset to defaults to overwrite active theme
     reset_defaults()
@@ -58,3 +61,109 @@ function _theme(s::Symbol, defaults::KW; kw...)
 end
 
 @deprecate set_theme(s) theme(s)
+
+@userplot ShowTheme
+
+_color_functions = KW(
+    :protanopic => protanopic,
+    :deuteranopic => deuteranopic,
+    :tritanopic => tritanopic,
+)
+_get_showtheme_args(thm::Symbol) = thm, identity
+_get_showtheme_args(thm::Symbol, func::Symbol) = thm, get(_color_functions, func, identity)
+
+@recipe function showtheme(st::ShowTheme)
+    thm, cfunc = _get_showtheme_args(st.args...)
+    defaults = _get_defaults(thm)
+
+    # get the gradient
+    gradient_colors = pop!(defaults, :gradient, cgrad(:inferno).colors)
+    gradient = cgrad(cfunc.(RGB.(gradient_colors)))
+
+    # get the palette
+    palette = pop!(defaults, :palette, get_color_palette(:auto, plot_color(:white), 17))
+    palette = cfunc.(RGB.(palette))
+
+    # apply the theme
+    for k in keys(defaults)
+        def = defaults[k]
+        arg = get(_keyAliases, k, k)
+        plotattributes[arg] = if typeof(def) <: Colorant
+            cfunc(RGB(def))
+        elseif eltype(def) <: Colorant
+            cfunc.(RGB.(def))
+        elseif contains(string(arg), "color")
+            cfunc.(RGB.(plot_color.(def)))
+        else
+            def
+        end
+    end
+
+    srand(1)
+
+    label := ""
+    colorbar := false
+    layout := (2, 3)
+
+    for j in 1:4
+        @series begin
+            subplot := 1
+            palette := palette
+            seriestype := :path
+            linewidth := 2
+            cumsum(randn(50))
+        end
+
+        @series begin
+            subplot := 2
+            seriestype := :scatter
+            palette := palette
+            markersize := 5
+            markerstrokewidth := 0
+            marker := (:circle, :diamond, :star5, :square)[j]
+            randn(10), randn(10)
+        end
+    end
+
+    @series begin
+        subplot := 3
+        seriestype := :histogram
+        palette := palette
+        randn(1000) .+ (0:2:4)'
+    end
+
+    f(r) = sin(r) / r
+    _norm(x, y) = norm([x, y])
+    x = y = linspace(-3π, 3π, 30)
+    z = f.(_norm.(x, y'))
+    wi = 2:3:30
+
+    @series begin
+        subplot := 4
+        seriestype := :heatmap
+        seriescolor := gradient
+        x, y, z
+    end
+
+    @series begin
+        subplot := 5
+        seriestype := :surface
+        seriescolor := gradient
+        x, y, z
+    end
+
+    n = 100
+    ts = linspace(0, 10π, n)
+    x = ts .* cos.(ts)
+    y = (0.1ts) .* sin.(ts)
+    z = 1:n
+
+    @series begin
+        subplot := 6
+        seriescolor := gradient
+        linewidth := 3
+        line_z := z
+        x, y, z
+    end
+
+end