Display of the current function can be disabled.

The new variable elpy-eldoc-show-current-function allows users to
disable the display of the function or class and method being edited
in the echo area in case Elpy can not find a calltip.

Fixes #377
Fixes #432

elpy.el

@@ -285,6 +285,15 @@ message again within this amount of seconds."
   :type 'integer
   :group 'elpy)
 
+(defcustom elpy-eldoc-show-current-function t
+  "If true, show the current function if no calltip is available.
+
+When Elpy can not find the calltip of the function call at point,
+it can show the name of the function or class and method being
+edited instead. Setting this variable to nil disables this feature."
+  :type 'boolean
+  :group 'elpy)
+
 (defcustom elpy-test-runner 'elpy-test-discover-runner
   "The test runner to use to run tests."
   :type '(choice (const :tag "Unittest Discover" elpy-test-discover-runner)
@@ -3055,9 +3064,10 @@ display the current class and method instead."
          (eldoc-message
           (cond
            ((not calltip)
-            (let ((current-defun (python-info-current-defun)))
-              (when current-defun
-                (format "In: %s()" current-defun))))
+            (when elpy-eldoc-show-current-function
+              (let ((current-defun (python-info-current-defun)))
+                (when current-defun
+                  (format "In: %s()" current-defun)))))
            ((stringp calltip)
             calltip)
            (t

test/elpy-eldoc-documentation-test.el

@@ -17,6 +17,18 @@
 
       (should (equal calltip "In: FooClass.method()")))))
 
+(ert-deftest elpy-eldoc-documentation-should-not-display-current-defun-if-no-calltip-and-show-defun-disabled ()
+  (elpy-testcase ()
+    (mletf* ((elpy-rpc-get-calltip (callback) (funcall callback nil))
+             (calltip nil)
+             (eldoc-message (tip) (setq calltip tip))
+             (python-info-current-defun () "FooClass.method")
+             (elpy-eldoc-show-current-function nil))
+
+      (elpy-eldoc-documentation)
+
+      (should (null calltip)))))
+
 (ert-deftest elpy-eldoc-documentation-should-return-nil-without-defun ()
   (elpy-testcase ()
     (mletf* ((elpy-rpc-get-calltip (callback) (funcall callback nil))