Label on pie

lib/matplotex.ex

@@ -155,7 +155,7 @@ defmodule Matplotex do
 
     * Custom Elements: The materializer function's primary role is to generate a list of structs that implement the Matplotex.Element behavior. This enables the SVG generator to produce the appropriate tags for custom visualizations
 
-    ### Matplotex.Element behaviour
+    ## Matplotex.Element behaviour
 
     The Matplotex.Element behavior defines a callback function, assemble/1, which takes a struct as input and returns its corresponding SVG tag as a string. The assemble/1 function is responsible for interpolating the struct's values into the SVG element.
 

lib/matplotex/element/slice.ex

@@ -28,6 +28,7 @@ defmodule Matplotex.Element.Slice do
      A #{get_radius(slice)} #{get_radius(slice)} 0 0 1 #{get_x2(slice)} #{get_y2(slice)}
      L #{get_cx(slice)} #{get_cy(slice)}
      Z" fill="#{slice.color}" />
+     #{Element.assemble(slice.label)}
     """
   end
 

lib/matplotex/figure/radial.ex

@@ -30,7 +30,7 @@ defmodule Matplotex.Figure.Radial do
         %{axes | title: title, show_title: true}
       end
 
-      def materialized(figure) do
+      def materialized_by_region(figure) do
         figure
         |> Lead.set_regions_radial()
         |> Cast.cast_border()

lib/matplotex/figure/radial/pie.ex

@@ -1,5 +1,6 @@
 defmodule Matplotex.Figure.Radial.Pie do
   @moduledoc false
+  alias Matplotex.Element.Label
   alias Matplotex.Figure.RcParams
   alias Matplotex.Utils.Algebra
   alias Matplotex.Figure.Areal.Region
@@ -42,14 +43,13 @@ defmodule Matplotex.Figure.Radial.Pie do
   @impl Radial
   def materialize(figure) do
     figure
-    |> __MODULE__.materialized()
     |> materialize_slices()
   end
 
   defp materialize_slices(
          %Figure{
            figsize: {fwidth, fheight},
-           rc_params: %RcParams{legend_font: legend_font},
+           rc_params: %RcParams{legend_font: legend_font, slice_label_font: slice_label_font},
            axes:
              %__MODULE__{
                size: {_width, height},
@@ -88,7 +88,7 @@ defmodule Matplotex.Figure.Radial.Pie do
           }
         },
         fn raw, color, acc ->
-          roll_across(raw, color, acc, center, radius, total_size, legend_font)
+          roll_across(raw, color, acc, center, radius, total_size, legend_font, slice_label_font)
         end
       )
       |> then(fn %Accumulator{slices: slices, legends: legends} ->
@@ -123,7 +123,8 @@ defmodule Matplotex.Figure.Radial.Pie do
          %{x: cx, y: cy} = center,
          radius,
          total_size,
-         legend_font
+         legend_font,
+         slice_label_font
        ) do
     percentage = size / total_size
     angle_for_size = percentage * @full_circle + start_angle
@@ -140,7 +141,8 @@ defmodule Matplotex.Figure.Radial.Pie do
       percentage: percentage,
       color: color,
       cx: cx,
-      cy: cy
+      cy: cy,
+      label: with_label(x1, y1, x2, y2, cx, cy, label, slice_label_font)
     }
 
     {x_legend, y_legend} =
@@ -166,4 +168,17 @@ defmodule Matplotex.Figure.Radial.Pie do
       legend_acc: %LegendAcc{legend_acc | y: y_legend}
     }
   end
+
+  defp with_label(x1, y1, x2, y2, cx, cy, label, label_font) do
+    label_x = (x1 + x2 + cx) / 3
+    label_y = (y1 + y2 + cy) / 3
+
+    %Label{
+      type: "pie.slice",
+      text: label,
+      x: label_x,
+      y: label_y
+    }
+    |> Label.cast_label(label_font)
+  end
 end

lib/matplotex/figure/rc_params.ex

@@ -26,6 +26,7 @@ defmodule Matplotex.Figure.RcParams do
             y_label_font: @font,
             title_font: %Font{font_size: @default_title_font_size, dominant_baseline: "auto"},
             legend_font: %Font{text_anchor: "start"},
+            slice_label_font: @font,
             figure_size: @default_figsize,
             figure_dpi: @default_dpi,
             line_width: @line_width,

test/matplotex/figure/radial/pie_test.exs

@@ -28,7 +28,7 @@ defmodule Matplotex.Figure.Radial.PieTest do
       # Colors for the slices
       colors = ["lightblue", "lightgreen", "orange", "pink"]
       figure = Pie.create(%Figure{axes: %Pie{}}, sizes, labels: labels, colors: colors)
-      assert %Figure{axes: %{element: element}} = Pie.materialize(figure)
+      assert %Figure{axes: %{element: element}} = figure |> Figure.materialize()
 
       assert Enum.filter(element, fn elem -> String.contains?(elem.type, "border") end)
              |> length() == 4
@@ -42,7 +42,7 @@ defmodule Matplotex.Figure.Radial.PieTest do
       # Colors for the slices
       colors = ["lightblue", "lightgreen", "orange", "pink"]
       figure = Pie.create(%Figure{axes: %Pie{}}, sizes, labels: labels, colors: colors)
-      assert %Figure{axes: %{element: element}} = Pie.materialize(figure)
+      assert %Figure{axes: %{element: element}} = figure|> Figure.materialize()
 
       assert Enum.filter(element, fn elem -> elem.type == "pie.slice" end) |> length() ==
                length(sizes)