Issue #20338: Increase allowed tip width slightly and wrap long signagure lines.

Original patch by Serhiy Storchaka.

Lib/idlelib/CallTips.py

@@ -5,16 +5,16 @@ parameter and docstring information when you type an opening parenthesis, and
 which disappear when you type a closing parenthesis.
 
 """
+import __main__
+import inspect
 import re
 import sys
+import textwrap
 import types
-import inspect
 
 from idlelib import CallTipWindow
 from idlelib.HyperParser import HyperParser
 
-import __main__
-
 class CallTips:
 
     menudefs = [
@@ -117,8 +117,9 @@ def get_entity(expression):
             return None
 
 # The following are used in get_argspec and some in tests
-_MAX_COLS = 79
+_MAX_COLS = 85
 _MAX_LINES = 5  # enough for bytes
+_INDENT = ' '*4  # for wrapped signatures
 _first_param = re.compile('(?<=\()\w*\,?\s*')
 _default_callable_argspec = "See source or doc"
 
@@ -149,13 +150,15 @@ def get_argspec(ob):
                 isinstance(ob_call, types.MethodType)):
             argspec = _first_param.sub("", argspec)
 
+    lines = (textwrap.wrap(argspec, _MAX_COLS, subsequent_indent=_INDENT)
+            if len(argspec) > _MAX_COLS else [argspec] if argspec else [])
+
     if isinstance(ob_call, types.MethodType):
         doc = ob_call.__doc__
     else:
         doc = getattr(ob, "__doc__", "")
     if doc:
-        lines = [argspec] if argspec else []
-        for line in doc.split('\n', 5)[:_MAX_LINES]:
+        for line in doc.split('\n', _MAX_LINES)[:_MAX_LINES]:
             line = line.strip()
             if not line:
                 break

Lib/idlelib/idle_test/test_calltips.py

 import unittest
 import idlelib.CallTips as ct
+import textwrap
 import types
 
 default_tip = ct._default_callable_argspec
@@ -64,20 +65,35 @@ class Get_signatureTest(unittest.TestCase):
         gtest(types.MethodType, "method(function, instance)")
         gtest(SB(), default_tip)
 
+    def test_signature_wrap(self):
+        self.assertEqual(signature(textwrap.TextWrapper), '''\
+(width=70, initial_indent='', subsequent_indent='', expand_tabs=True,
+    replace_whitespace=True, fix_sentence_endings=False, break_long_words=True,
+    drop_whitespace=True, break_on_hyphens=True, tabsize=8)''')
+
+    def test_docline_truncation(self):
+        def f(): pass
+        f.__doc__ = 'a'*300
+        self.assertEqual(signature(f), '()\n' + 'a' * (ct._MAX_COLS-3) + '...')
+
     def test_multiline_docstring(self):
         # Test fewer lines than max.
         self.assertEqual(signature(list),
                 "list() -> new empty list\n"
                 "list(iterable) -> new list initialized from iterable's items")
 
-        # Test max lines and line (currently) too long.
-        self.assertEqual(signature(bytes),
-"bytes(iterable_of_ints) -> bytes\n"
-"bytes(string, encoding[, errors]) -> bytes\n"
-"bytes(bytes_or_buffer) -> immutable copy of bytes_or_buffer\n"
-#bytes(int) -> bytes object of size given by the parameter initialized with null bytes
-"bytes(int) -> bytes object of size given by the parameter initialized with n...\n"
-"bytes() -> empty bytes object")
+        # Test max lines
+        self.assertEqual(signature(bytes), '''\
+bytes(iterable_of_ints) -> bytes
+bytes(string, encoding[, errors]) -> bytes
+bytes(bytes_or_buffer) -> immutable copy of bytes_or_buffer
+bytes(int) -> bytes object of size given by the parameter initialized with null bytes
+bytes() -> empty bytes object''')
+
+        # Test more than max lines
+        def f(): pass
+        f.__doc__ = 'a\n' * 15
+        self.assertEqual(signature(f), '()' + '\na' * ct._MAX_LINES)
 
     def test_functions(self):
         def t1(): 'doc'