fix creating empty plot with plot()

src/backends/immerse.jl

@@ -114,7 +114,7 @@ function buildSubplotObject!(::ImmersePackage, subplt::Subplot)
   end
 
   # destructor... clean up plots
-  Gtk.on_signal_destroy((x...) -> [Immerse.dropfig(_display,i) for i in figindices], win)
+  Gtk.on_signal_destroy((x...) -> [Immerse.dropfig(Immerse._display,i) for i in figindices], win)
 
   subplt.o = win
 end

src/colors.jl

@@ -88,7 +88,9 @@ function adjustAway(val, bgval, vmin=0., vmax=100.)
   end
 end
 
+# borrowed from http://stackoverflow.com/a/1855903:
 lightnessLevel(c::Colorant) = 0.299 * red(c) + 0.587 * green(c) + 0.114 * blue(c)
+
 isdark(c::Colorant) = lightnessLevel(c) < 0.5
 islight(c::Colorant) = !isdark(c)
 
@@ -128,8 +130,6 @@ end
 function getPaletteUsingColorDiffFromBackground(bgcolor::Colorant, numcolors::Int = _defaultNumColors)
   colordiffs = [colordiff(c, bgcolor) for c in _allColors]
   mindiff = colordiffs[reverse(sortperm(colordiffs))[numcolors]]
-  @show bgcolor numcolors mindiff colordiffs
-  # filter(c -> colordiff(c, bgcolor) > 0.5, _allColors)
   filter(c -> colordiff(c, bgcolor) >= mindiff, _allColors)
 end
 
@@ -143,11 +143,9 @@ function getBackgroundRGBColor(c, d::Dict)
   # d[:color_palette] = getPaletteUsingDistinguishableColors(bgcolor)
   # d[:color_palette] = getPaletteUsingFixedColorList(bgcolor)
   d[:color_palette] = getPaletteUsingColorDiffFromBackground(bgcolor)
-  @show d[:color_palette]
 
   # set the foreground color (text, ticks, gridlines) to be white or black depending
-  # on how dark the background is.  borrowed from http://stackoverflow.com/a/1855903
-  # a = 0.299 * red(bgcolor) + 0.587 * green(bgcolor) + 0.114 * blue(bgcolor)
+  # on how dark the background is.  
   if !haskey(d, :foreground_color) || d[:foreground_color] == :auto
     d[:foreground_color] = isdark(bgcolor) ? colorant"white" : colorant"black"
   end
@@ -165,7 +163,6 @@ function getSeriesRGBColor(c, d::Dict, n::Int)
   end
 
   # should be a RGB now... either it was passed in, generated automatically, or created from a string
-  # @assert isa(c, RGB)
   @assert isa(c, Colorant)
 
   # return the RGB

src/plot.jl

@@ -264,8 +264,11 @@ end
 function createKWargsList(plt::PlottingObject; kw...)
   d = Dict(kw)
   if !haskey(d, :y)
-    error("Called plot/subplot without args... must set y in the keyword args.  Example: plot(; y=rand(10))")
+    # assume we just want to create an empty plot object which can be added to later
+    return []
+    # error("Called plot/subplot without args... must set y in the keyword args.  Example: plot(; y=rand(10))")
   end
+  
   if haskey(d, :x)
     return createKWargsList(plt, d[:x], d[:y]; kw...)
   else