Tools/idle/CallTips.py

   1 # CallTips.py - An IDLE extension that provides "Call Tips" - ie, a floating window that
   2 # displays parameter information as you open parens.
   3
   4 import string
   5 import sys
   6 import types
   7
   8 class CallTips:
   9
  10     menudefs = [
  11     ]
  12
  13     keydefs = {
  14         '<<paren-open>>': ['<Key-parenleft>'],
  15         '<<paren-close>>': ['<Key-parenright>'],
  16         '<<check-calltip-cancel>>': ['<KeyRelease>'],
  17         '<<calltip-cancel>>': ['<ButtonPress>', '<Key-Escape>'],
  18     }
  19
  20     windows_keydefs = {
  21     }
  22
  23     unix_keydefs = {
  24     }
  25
  26     def __init__(self, editwin):
  27         self.editwin = editwin
  28         self.text = editwin.text
  29         self.calltip = None
  30         if hasattr(self.text, "make_calltip_window"):
  31             self._make_calltip_window = self.text.make_calltip_window
  32         else:
  33             self._make_calltip_window = self._make_tk_calltip_window
  34
  35     def close(self):
  36         self._make_calltip_window = None
  37
  38     # Makes a Tk based calltip window.  Used by IDLE, but not Pythonwin.
  39     # See __init__ above for how this is used.
  40     def _make_tk_calltip_window(self):
  41         import CallTipWindow
  42         return CallTipWindow.CallTip(self.text)
  43
  44     def _remove_calltip_window(self):
  45         if self.calltip:
  46             self.calltip.hidetip()
  47             self.calltip = None
  48
  49     def paren_open_event(self, event):
  50         self._remove_calltip_window()
  51         arg_text = get_arg_text(self.get_object_at_cursor())
  52         if arg_text:
  53             self.calltip_start = self.text.index("insert")
  54             self.calltip = self._make_calltip_window()
  55             self.calltip.showtip(arg_text)
  56         return "" #so the event is handled normally.
  57
  58     def paren_close_event(self, event):
  59         # Now just hides, but later we should check if other
  60         # paren'd expressions remain open.
  61         self._remove_calltip_window()
  62         return "" #so the event is handled normally.
  63
  64     def check_calltip_cancel_event(self, event):
  65         if self.calltip:
  66             # If we have moved before the start of the calltip,
  67             # or off the calltip line, then cancel the tip.
  68             # (Later need to be smarter about multi-line, etc)
  69             if self.text.compare("insert", "<=", self.calltip_start) or \
  70                self.text.compare("insert", ">", self.calltip_start + " lineend"):
  71                 self._remove_calltip_window()
  72         return "" #so the event is handled normally.
  73
  74     def calltip_cancel_event(self, event):
  75         self._remove_calltip_window()
  76         return "" #so the event is handled normally.
  77
  78     def get_object_at_cursor(self,
  79                              wordchars="._" + string.ascii_letters + string.digits):
  80         # Usage of ascii_letters is necessary to avoid UnicodeErrors
  81         # if chars contains non-ASCII.
  82
  83         # XXX - This needs to be moved to a better place
  84         # so the "." attribute lookup code can also use it.
  85         text = self.text
  86         chars = text.get("insert linestart", "insert")
  87         i = len(chars)
  88         while i and chars[i-1] in wordchars:
  89             i = i-1
  90         word = chars[i:]
  91         if word:
  92             # How is this for a hack!
  93             import sys, __main__
  94             namespace = sys.modules.copy()
  95             namespace.update(__main__.__dict__)
  96             try:
  97                 return eval(word, namespace)
  98             except:
  99                 pass
 100         return None # Can't find an object.
 101
 102 def _find_constructor(class_ob):
 103     # Given a class object, return a function object used for the
 104     # constructor (ie, __init__() ) or None if we can't find one.
 105     try:
 106         return class_ob.__init__.im_func
 107     except AttributeError:
 108         for base in class_ob.__bases__:
 109             rc = _find_constructor(base)
 110             if rc is not None: return rc
 111     return None
 112
 113 def get_arg_text(ob):
 114     # Get a string describing the arguments for the given object.
 115     argText = ""
 116     if ob is not None:
 117         argOffset = 0
 118         if type(ob)==types.ClassType:
 119             # Look for the highest __init__ in the class chain.
 120             fob = _find_constructor(ob)
 121             if fob is None:
 122                 fob = lambda: None
 123             else:
 124                 argOffset = 1
 125         elif type(ob)==types.MethodType:
 126             # bit of a hack for methods - turn it into a function
 127             # but we drop the "self" param.
 128             fob = ob.im_func
 129             argOffset = 1
 130         else:
 131             fob = ob
 132         # Try and build one for Python defined functions
 133         if type(fob) in [types.FunctionType, types.LambdaType]:
 134             try:
 135                 realArgs = fob.func_code.co_varnames[argOffset:fob.func_code.co_argcount]
 136                 defaults = fob.func_defaults or []
 137                 defaults = list(map(lambda name: "=%s" % name, defaults))
 138                 defaults = [""] * (len(realArgs)-len(defaults)) + defaults
 139                 items = map(lambda arg, dflt: arg+dflt, realArgs, defaults)
 140                 if fob.func_code.co_flags & 0x4:
 141                     items.append("...")
 142                 if fob.func_code.co_flags & 0x8:
 143                     items.append("***")
 144                 argText = string.join(items , ", ")
 145                 argText = "(%s)" % argText
 146             except:
 147                 pass
 148         # See if we can use the docstring
 149         doc = getattr(ob, "__doc__", "")
 150         if doc:
 151             while doc[:1] in " \t\n":
 152                 doc = doc[1:]
 153             pos = doc.find("\n")
 154             if pos < 0 or pos > 70:
 155                 pos = 70
 156             if argText:
 157                 argText += "\n"
 158             argText += doc[:pos]
 159
 160     return argText
 161
 162 #################################################
 163 #
 164 # Test code
 165 #
 166 if __name__=='__main__':
 167
 168     def t1(): "()"
 169     def t2(a, b=None): "(a, b=None)"
 170     def t3(a, *args): "(a, ...)"
 171     def t4(*args): "(...)"
 172     def t5(a, *args): "(a, ...)"
 173     def t6(a, b=None, *args, **kw): "(a, b=None, ..., ***)"
 174
 175     class TC:
 176         "(a=None, ...)"
 177         def __init__(self, a=None, *b): "(a=None, ...)"
 178         def t1(self): "()"
 179         def t2(self, a, b=None): "(a, b=None)"
 180         def t3(self, a, *args): "(a, ...)"
 181         def t4(self, *args): "(...)"
 182         def t5(self, a, *args): "(a, ...)"
 183         def t6(self, a, b=None, *args, **kw): "(a, b=None, ..., ***)"
 184
 185     def test( tests ):
 186         failed=[]
 187         for t in tests:
 188             expected = t.__doc__ + "\n" + t.__doc__
 189             if get_arg_text(t) != expected:
 190                 failed.append(t)
 191                 print "%s - expected %s, but got %s" % (t, `expected`, `get_arg_text(t)`)
 192         print "%d of %d tests failed" % (len(failed), len(tests))
 193
 194     tc = TC()
 195     tests = t1, t2, t3, t4, t5, t6, \
 196             TC, tc.t1, tc.t2, tc.t3, tc.t4, tc.t5, tc.t6
 197
 198     test(tests)