Concept implementation of apply theme transformations

NEWS.md

@@ -8,7 +8,7 @@ Each release typically has a number of minor bug fixes beyond what is listed her
  * Add dodged boxplots (#1246)
  * Add `Stat.dodge` (#1240) 
  * `Stat.smooth(method=:lm)` confidence bands (#1231)
- * Develop Rectangular Geometry. (#1263)
+ * Develop Rectangular Geometry, and add `apply_theme_transformations!()` hook. (#1263)
 
 # Version 0.9.0
  * conditionally depend on DataFrames (#1204)

src/Gadfly.jl

@@ -809,6 +809,18 @@ function render_prepared(plot::Plot,
     # IV. Geometries
     themes = Theme[layer.theme === nothing ? plot.theme : layer.theme
                    for layer in plot.layers]
+
+    for (layer, stats, aes, theme) in zip(plot.layers, layer_stats, layer_aess, themes)
+
+        if length(stats)> 1
+            @warn "stats" stats
+        end
+
+        for stat in stats
+            apply_theme_transformations!(layer.geom, stat, aes, theme)
+        end
+    end
+
     zips = trim_zip(plot.layers, layer_aess,
                                                    layer_subplot_aess,
                                                    layer_subplot_datas,
@@ -1102,6 +1114,17 @@ include("geometry.jl")
 include("guide.jl")
 include("statistics.jl")
 
+function apply_theme_transformations!(geom::GeometryElement, stat::StatisticElement, aes::Aesthetics, theme::Theme)
+#     @info "apply_theme_transformations!" geom stat aes theme
+end
+
+function apply_theme_transformations!(geom::Geom.RectangularGeometry, stat::Stat.RectbinStatistic, aes::Aesthetics, theme::Theme)
+
+    @info "apply_theme_transformations! specific to geom::Geom.RectangularGeometry, stat::Stat.RectbinStatistic combination."
+
+	 aes.xmax = aes.xmax .* cx .- theme.bar_spacing
+	 aes.ymax = aes.ymax .* cy .- theme.bar_spacing
+end
 
 # All aesthetics must have a scale. If none is given, we use a default.
 # The default depends on whether the input is discrete or continuous (i.e.,