Add polar legend position

src/args.jl

@@ -1262,6 +1262,8 @@ end
 convertLegendValue(val::Bool) = val ? :best : :none
 convertLegendValue(val::Nothing) = :none
 convertLegendValue(v::Tuple{S,T}) where {S<:Real, T<:Real} = v
+convertLegendValue(v::Tuple{<:Real,Symbol}) = v
+convertLegendValue(v::Real) = v
 convertLegendValue(v::AbstractArray) = map(convertLegendValue, v)
 
 # -----------------------------------------------------------------------------

src/backends/gr.jl

@@ -911,7 +911,7 @@ function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
     gr_update_viewport_ratio!(viewport_plotarea, sp)
     leg = gr_get_legend_geometry(viewport_plotarea, sp)
     gr_update_viewport_legend!(viewport_plotarea, sp, leg)
-    
+
     # fill in the plot area background
     gr_fill_plotarea(sp, viewport_plotarea)
 
@@ -1047,7 +1047,24 @@ end
 
 function gr_legend_pos(sp::Subplot, leg, viewport_plotarea)
     s = sp[:legend]
-    typeof(s) <: Symbol || return gr_legend_pos(s, viewport_plotarea)
+    s isa Real && return gr_legend_pos(s, leg, viewport_plotarea)
+    if s isa Tuple{<:Real,Symbol}
+        if s[2] !== :outer
+            return gr_legend_pos(s[1], leg, viewport_plotarea)
+        end
+
+        xaxis, yaxis = sp[:xaxis], sp[:yaxis]
+        xmirror = xaxis[:guide_position] == :top || (xaxis[:guide_position] == :auto && xaxis[:mirror] == true)
+        ymirror = yaxis[:guide_position] == :right || (yaxis[:guide_position] == :auto && yaxis[:mirror] == true)
+        axisclearance = [
+                         !ymirror*gr_axis_width(sp, sp[:yaxis]),
+                         ymirror*gr_axis_width(sp,sp[:yaxis]),
+                         !xmirror*gr_axis_height(sp,sp[:xaxis]),
+                         xmirror*gr_axis_height(sp,sp[:xaxis]),
+                        ]
+        return gr_legend_pos(s[1], leg, viewport_plotarea; axisclearance)
+    end
+    s isa Symbol || return gr_legend_pos(s, viewport_plotarea)
     str = string(s)
     if str == "best"
         str = "topright"
@@ -1098,6 +1115,55 @@ function gr_legend_pos(v::Tuple{S,T}, viewport_plotarea) where {S<:Real, T<:Real
     (xpos,ypos)
 end
 
+function gr_legend_pos(theta::Real, leg, viewport_plotarea; axisclearance=nothing)
+    xmean = +(viewport_plotarea[1:2]...)/2
+    ymean = +(viewport_plotarea[3:4]...)/2
+    (s,c) = sincosd(theta)
+
+    if isnothing(axisclearance)
+        # Inner
+        # rectangle relative to midpoint where the anchor can legally be
+        rect = viewport_plotarea .+ [
+                                     - xmean + leg.xoffset + leg.leftw,
+                                     - xmean - leg.xoffset - leg.rightw - leg.textw,
+                                     - ymean + leg.yoffset + leg.h,
+                                     - ymean - leg.yoffset - leg.dy,
+                                    ]
+        x = c < 0 ? rect[1]/c : rect[2]/c
+        y = s < 0 ? rect[3]/s : rect[4]/s
+        A = min(x,y) # Biggest A  that places (Acos(theta),Asin(theta)) inside rectangle
+    else
+        # Outer
+        # rectangle relative to midpoint where the anchor is forbidden
+        rect = viewport_plotarea .+ [
+                                     - xmean - leg.xoffset - leg.rightw - leg.textw - axisclearance[1],
+                                     - xmean + leg.xoffset + leg.leftw + axisclearance[2],
+                                     - ymean - leg.yoffset - leg.dy - axisclearance[3],
+                                     - ymean + leg.yoffset + leg.h + axisclearance[4],
+                                    ]
+        t = tand(theta)
+        if c  < 0
+            if t < rect[4]/rect[1]
+                A = rect[4]/s
+            elseif t < rect[3]/rect[1]
+                A = rect[1]/c
+            else
+                A = rect[3]/s
+            end
+        else
+            if t < rect[3]/rect[2]
+                A = rect[3]/s
+            elseif t <rect[4]/rect[2]
+                A = rect[2]/c
+            else
+                A = rect[4]/s
+            end
+        end
+    end
+
+    return xmean + A*c, ymean + A*s
+end
+
 function gr_get_legend_geometry(viewport_plotarea, sp)
     legendn = 0
     legendw = 0
@@ -1154,12 +1220,28 @@ end
 ## Viewport, window and scale
 
 function gr_update_viewport_legend!(viewport_plotarea, sp, leg)
-    leg_str = string(sp[:legend])
+    s = sp[:legend]
 
     xaxis, yaxis = sp[:xaxis], sp[:yaxis]
     xmirror = xaxis[:guide_position] == :top || (xaxis[:guide_position] == :auto && xaxis[:mirror] == true)
     ymirror = yaxis[:guide_position] == :right || (yaxis[:guide_position] == :auto && yaxis[:mirror] == true)
 
+    if s isa Tuple{<:Real,Symbol}
+        if s[2] === :outer
+            (x,y) = gr_legend_pos(sp, leg, viewport_plotarea) # Dry run, to figure out
+            if x < viewport_plotarea[1]
+                viewport_plotarea[1] += leg.leftw + leg.textw + leg.rightw + leg.xoffset + !ymirror * gr_axis_width(sp, sp[:yaxis])
+            elseif x > viewport_plotarea[2]
+                viewport_plotarea[2] -= leg.leftw + leg.textw + leg.rightw + leg.xoffset
+            end
+            if y < viewport_plotarea[3]
+                viewport_plotarea[3] += leg.h + leg.dy + leg.yoffset + !xmirror * gr_axis_height(sp, sp[:xaxis])
+            elseif y > viewport_plotarea[4]
+                viewport_plotarea[4] -= leg.h + leg.dy + leg.yoffset
+            end
+        end
+    end
+    leg_str = string(s)
     if occursin("outer", leg_str)
         if occursin("right", leg_str)
             viewport_plotarea[2] -= leg.leftw + leg.textw + leg.rightw + leg.xoffset
@@ -1171,7 +1253,7 @@ function gr_update_viewport_legend!(viewport_plotarea, sp, leg)
             viewport_plotarea[3] += leg.h + leg.dy + leg.yoffset + !xmirror * gr_axis_height(sp, sp[:xaxis])
         end
     end
-    if sp[:legend] == :inline
+    if s === :inline
         if sp[:yaxis][:mirror]
             viewport_plotarea[1] += leg.w
         else
@@ -1464,10 +1546,10 @@ function gr_label_axis_3d(sp, letter)
     if ax[:guide] != ""
         near_letter = letter in (:x, :z) ? :y : :x
         far_letter = letter in (:x, :y) ? :z : :x
-    
+
         nax = sp[Symbol(near_letter, :axis)]
         fax = sp[Symbol(far_letter, :axis)]
-    
+
         amin, amax = axis_limits(sp, letter)
         namin, namax = axis_limits(sp, near_letter)
         famin, famax = axis_limits(sp, far_letter)
@@ -1732,7 +1814,7 @@ function gr_draw_contour(series, x, y, z, clims)
 end
 
 function gr_draw_surface(series, x, y, z, clims)
-    
+
     if series[:seriestype] === :surface
         fillalpha = get_fillalpha(series)
         fillcolor = get_fillcolor(series)