Add new config option for hiding all dots except major labeled ones

pygal/config.py

@@ -140,6 +140,10 @@ class Config(MetaConfig('ConfigBase', (object,), {})):
 
     show_dots = Key(True, bool, "Look", "Set to false to remove dots")
 
+    show_only_major_dots = Key(
+        False, bool, "Look",
+        "Set to true to show only major dots according to their majored label")
+
     dots_size = Key(2.5, float, "Look", "Radius of the dots")
 
     stroke = Key(

pygal/graph/line.py

@@ -67,10 +67,30 @@ class Line(Graph):
             points = serie.points
         view_values = list(map(self.view, points))
         if self.show_dots:
+            if self.show_only_major_dots:
+                major_dots_index = []
+                if self.x_labels:
+                    if self.x_labels_major:
+                        major_dots_index = []
+                        for major in self.x_labels_major:
+                            start = -1
+                            while True:
+                                try:
+                                    index = self.x_labels.index(
+                                        major, start + 1)
+                                except ValueError:
+                                    break
+                                else:
+                                    major_dots_index.append(index)
+                                    start = index
+                    elif self.x_labels_major_every:
+                        major_dots_index = range(
+                            0, len(self.x_labels), self.x_labels_major_every)
+
             for i, (x, y) in enumerate(view_values):
-                if None in (x, y):
+                if None in (x, y) or (self.show_only_major_dots
+                                      and i not in major_dots_index):
                     continue
-
                 metadata = serie.metadata.get(i)
                 classes = []
                 if x > self.view.width / 2: