Improve documentation of buttons (Bug#19628)

 doc/lispref/display.texi (Manipulating Buttons): Explain more about the
 'action' property.

2 files changed, 9 insertions, 4 deletions

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index c855bbec863..11a6f32718c 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,5 +1,8 @@
 2015-01-20  Eli Zaretskii  <eliz@gnu.org>
 
+        * display.texi (Manipulating Buttons): Explain more about the
+        'action' property.  (Bug#19628)
+
         * text.texi (Clickable Text): Improve indexing.  (Bug#19629)
 
 2015-01-15  Eli Zaretskii  <eliz@gnu.org>
diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 0128e469db2..9501e8145fa 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -5511,10 +5511,12 @@ Set @var{button}'s @var{prop} property to @var{val}.
 @end defun
 
 @defun button-activate button &optional use-mouse-action
-Call @var{button}'s @code{action} property (i.e., invoke it).  If
-@var{use-mouse-action} is non-@code{nil}, try to invoke the button's
-@code{mouse-action} property instead of @code{action}; if the button
-has no @code{mouse-action} property, use @code{action} as normal.
+Call @var{button}'s @code{action} property (i.e., invoke the function
+that is the value of that property, passing it the single argument
+@var{button}).  If @var{use-mouse-action} is non-@code{nil}, try to
+invoke the button's @code{mouse-action} property instead of
+@code{action}; if the button has no @code{mouse-action} property, use
+@code{action} as normal.
 @end defun
 
 @defun button-label button