From c69b2ff20010e90754a3e66db53d7384bfc0aa2e Mon Sep 17 00:00:00 2001
From: Mathieu Virbel <mat@kivy.org>
Date: Wed, 19 Sep 2012 01:23:19 +0200
Subject: [PATCH] doc fixes

---
 kivy/graphics/instructions.pyx | 17 ++++++++++++++++-
 kivy/uix/widget.py             |  4 ++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/kivy/graphics/instructions.pyx b/kivy/graphics/instructions.pyx
index 090505ac7..10e8ca3ba 100644
--- a/kivy/graphics/instructions.pyx
+++ b/kivy/graphics/instructions.pyx
@@ -584,7 +584,22 @@ cdef class Canvas(CanvasBase):
             return self._after
 
     property opacity:
-        '''Property for getting the opacity value
+        '''Property for get/set the opacity value of the canvas.
+
+        .. versionadded:: 1.4.1
+
+        The opacity attribute controls the opacity of the canvas and its
+        children.  Be careful, it's a cumulative attribute: the value is
+        multiplied to the current global opacity, and the result is applied to
+        the current context color.
+
+        For example: if your parent have an opacity of 0.5, and one children have an
+        opacity of 0.2, the real opacity of the children will be 0.5 * 0.2 = 0.1.
+
+        Then, the opacity is applied on the shader as::
+
+            frag_color = color * vec4(1.0, 1.0, 1.0, opacity);
+
         '''
         def __get__(self):
             return self._opacity
diff --git a/kivy/uix/widget.py b/kivy/uix/widget.py
index 43755a65f..f06dd326f 100644
--- a/kivy/uix/widget.py
+++ b/kivy/uix/widget.py
@@ -537,8 +537,8 @@ class Widget(EventDispatcher):
 
     .. versionadded:: 1.4.1
 
-    The opacity attribute control the opacity of the widget and the children.
-    Take care, it's a cumulative attribute: the value is multiplied to the
+    The opacity attribute controls the opacity of the widget and its children.
+    Be careful, it's a cumulative attribute: the value is multiplied to the
     current global opacity, and the result is applied to the current context
     color.