arrow conveniences

src/args.jl

@@ -605,6 +605,24 @@ function preprocessArgs!(d::KW)
 
   # convert into strokes and brushes
 
+    if haskey(d, :arrow)
+        a = d[:arrow]
+        d[:arrow] = if a == true
+            arrow()
+        elseif a == false
+            nothing
+        elseif !(typeof(a) <: Arrow)
+            arrow(wraptuple(a)...)
+        else
+            a
+        end
+    end
+
+
+    if get(d, :arrow, false) == true
+        d[:arrow] = arrow()
+    end
+
     # legends
     if haskey(d, :legend)
         d[:legend] = convertLegendValue(d[:legend])

src/components.jl

@@ -410,13 +410,19 @@ end
 function arrow(args...)
     style = :simple
     headlength = 0.3
-    headwidth = 0.2
+    headwidth = 0.3
+    setlength = false
     for arg in args
         T = typeof(arg)
         if T == Symbol
             style = arg
         elseif T <: Number
-            headlength = headwidth = Float64(arg)
+            # first we apply to both, but if there's more, then only change width after the first number
+            headwidth = Float64(arg)
+            if !setlength
+                headlength = headwidth
+            end
+            setlength = true
         elseif T <: Tuple && length(arg) == 2
             headlength, headwidth = Float64(arg[1]), Float64(arg[2])
         else