Add `stack_from_top` option to reverse stack graph data order. Fix #141

CHANGELOG

@@ -1,3 +1,6 @@
+V 1.5.1 - UNRELEASED
+	Add `stack_from_top` option to reverse stack graph data order
+
 V 1.5.0
 	Add per serie configuration
 	Add half pie (thanks philt2001)

demo/moulinrouge/tests.py

@@ -338,6 +338,13 @@ def get_test_routes(app):
         stacked.add('2', [4, 5, 6])
         return stacked.render_response()
 
+    @app.route('/test/stacked/reverse')
+    def test_stacked_reverse():
+        stacked = StackedBar(stack_from_top=True)
+        stacked.add('1', [1, 2, 3])
+        stacked.add('2', [4, 5, 6])
+        return stacked.render_response()
+
     @app.route('/test/show_dots')
     def test_show_dots():
         line = Line(show_dots=False)

pygal/config.py

@@ -224,6 +224,13 @@ class Config(CommonConfig):
     legend_box_size = Key(
         12, int, "Look", "Size of legend boxes")
 
+    rounded_bars = Key(
+        None, int, "Look", "Set this to the desired radius in px")
+
+    stack_from_top = Key(
+        False, bool, "Look", "Stack from top to zero, this makes the stacked "
+                           "data match the legend order")
+
     spacing = Key(
         10, int, "Look",
         "Space between titles/legend/axes")

pygal/graph/stackedbar.py

@@ -128,3 +128,9 @@ class StackedBar(Bar):
             class_='rect reactive tooltip-trigger')
         transpose = swap if self.horizontal else ident
         return transpose((x + width / 2, y + height / 2))
+
+    def _plot(self):
+        for serie in self.series[::-1 if self.stack_from_top else 1]:
+            self.bar(serie)
+        for serie in self.secondary_series[::-1 if self.stack_from_top else 1]:
+            self.bar(serie, True)

pygal/graph/stackedline.py

@@ -54,3 +54,9 @@ class StackedLine(Line):
                     serie.interpolated = self._interpolate(x_pos, accumulation)
                 else:
                     serie.interpolated = []
+
+    def _plot(self):
+        for serie in self.series[::-1 if self.stack_from_top else 1]:
+            self.line(serie)
+        for serie in self.secondary_series[::-1 if self.stack_from_top else 1]:
+            self.line(serie, True)

pygal/test/test_stacked.py

@@ -28,6 +28,15 @@ def test_stacked_line():
         ('1', '2', '11', '14'))
 
 
+def test_stacked_line_reverse():
+    stacked = StackedLine(stack_from_top=True)
+    stacked.add('one_two', [1, 2])
+    stacked.add('ten_twelve', [10, 12])
+    q = stacked.render_pyquery()
+    assert set(q("desc.value").text().split(' ')) == set(
+        ('11', '14', '1', '2'))
+
+
 def test_stacked_line_log():
     stacked = StackedLine(logarithmic=True)
     stacked.add('one_two', [1, 2])