1"""Pop up a reminder of how to call a function. 2 3Call Tips are floating windows which display function, class, and method 4parameter and docstring information when you type an opening parenthesis, and 5which disappear when you type a closing parenthesis. 6""" 7import __main__ 8import inspect 9import re 10import sys 11import textwrap 12import types 13 14from idlelib import calltip_w 15from idlelib.hyperparser import HyperParser 16 17 18class Calltip: 19 20 def __init__(self, editwin=None): 21 if editwin is None: # subprocess and test 22 self.editwin = None 23 else: 24 self.editwin = editwin 25 self.text = editwin.text 26 self.active_calltip = None 27 self._calltip_window = self._make_tk_calltip_window 28 29 def close(self): 30 self._calltip_window = None 31 32 def _make_tk_calltip_window(self): 33 # See __init__ for usage 34 return calltip_w.CalltipWindow(self.text) 35 36 def remove_calltip_window(self, event=None): 37 if self.active_calltip: 38 self.active_calltip.hidetip() 39 self.active_calltip = None 40 41 def force_open_calltip_event(self, event): 42 "The user selected the menu entry or hotkey, open the tip." 43 self.open_calltip(True) 44 return "break" 45 46 def try_open_calltip_event(self, event): 47 """Happens when it would be nice to open a calltip, but not really 48 necessary, for example after an opening bracket, so function calls 49 won't be made. 50 """ 51 self.open_calltip(False) 52 53 def refresh_calltip_event(self, event): 54 if self.active_calltip and self.active_calltip.tipwindow: 55 self.open_calltip(False) 56 57 def open_calltip(self, evalfuncs): 58 self.remove_calltip_window() 59 60 hp = HyperParser(self.editwin, "insert") 61 sur_paren = hp.get_surrounding_brackets('(') 62 if not sur_paren: 63 return 64 hp.set_index(sur_paren[0]) 65 expression = hp.get_expression() 66 if not expression: 67 return 68 if not evalfuncs and (expression.find('(') != -1): 69 return 70 argspec = self.fetch_tip(expression) 71 if not argspec: 72 return 73 self.active_calltip = self._calltip_window() 74 self.active_calltip.showtip(argspec, sur_paren[0], sur_paren[1]) 75 76 def fetch_tip(self, expression): 77 """Return the argument list and docstring of a function or class. 78 79 If there is a Python subprocess, get the calltip there. Otherwise, 80 either this fetch_tip() is running in the subprocess or it was 81 called in an IDLE running without the subprocess. 82 83 The subprocess environment is that of the most recently run script. If 84 two unrelated modules are being edited some calltips in the current 85 module may be inoperative if the module was not the last to run. 86 87 To find methods, fetch_tip must be fed a fully qualified name. 88 89 """ 90 try: 91 rpcclt = self.editwin.flist.pyshell.interp.rpcclt 92 except AttributeError: 93 rpcclt = None 94 if rpcclt: 95 return rpcclt.remotecall("exec", "get_the_calltip", 96 (expression,), {}) 97 else: 98 return get_argspec(get_entity(expression)) 99 100 101def get_entity(expression): 102 """Return the object corresponding to expression evaluated 103 in a namespace spanning sys.modules and __main.dict__. 104 """ 105 if expression: 106 namespace = {**sys.modules, **__main__.__dict__} 107 try: 108 return eval(expression, namespace) # Only protect user code. 109 except BaseException: 110 # An uncaught exception closes idle, and eval can raise any 111 # exception, especially if user classes are involved. 112 return None 113 114# The following are used in get_argspec and some in tests 115_MAX_COLS = 85 116_MAX_LINES = 5 # enough for bytes 117_INDENT = ' '*4 # for wrapped signatures 118_first_param = re.compile(r'(?<=\()\w*\,?\s*') 119_default_callable_argspec = "See source or doc" 120_invalid_method = "invalid method signature" 121_argument_positional = " # '/' marks preceding args as positional-only." 122 123def get_argspec(ob): 124 '''Return a string describing the signature of a callable object, or ''. 125 126 For Python-coded functions and methods, the first line is introspected. 127 Delete 'self' parameter for classes (.__init__) and bound methods. 128 The next lines are the first lines of the doc string up to the first 129 empty line or _MAX_LINES. For builtins, this typically includes 130 the arguments in addition to the return value. 131 ''' 132 # Determine function object fob to inspect. 133 try: 134 ob_call = ob.__call__ 135 except BaseException: # Buggy user object could raise anything. 136 return '' # No popup for non-callables. 137 fob = ob_call if isinstance(ob_call, types.MethodType) else ob 138 139 # Initialize argspec and wrap it to get lines. 140 try: 141 argspec = str(inspect.signature(fob)) 142 except Exception as err: 143 msg = str(err) 144 if msg.startswith(_invalid_method): 145 return _invalid_method 146 else: 147 argspec = '' 148 149 if '/' in argspec and len(argspec) < _MAX_COLS - len(_argument_positional): 150 # Add explanation TODO remove after 3.7, before 3.9. 151 argspec += _argument_positional 152 if isinstance(fob, type) and argspec == '()': 153 # If fob has no argument, use default callable argspec. 154 argspec = _default_callable_argspec 155 156 lines = (textwrap.wrap(argspec, _MAX_COLS, subsequent_indent=_INDENT) 157 if len(argspec) > _MAX_COLS else [argspec] if argspec else []) 158 159 # Augment lines from docstring, if any, and join to get argspec. 160 if isinstance(ob_call, types.MethodType): 161 doc = ob_call.__doc__ 162 else: 163 doc = getattr(ob, "__doc__", "") 164 if doc: 165 for line in doc.split('\n', _MAX_LINES)[:_MAX_LINES]: 166 line = line.strip() 167 if not line: 168 break 169 if len(line) > _MAX_COLS: 170 line = line[: _MAX_COLS - 3] + '...' 171 lines.append(line) 172 argspec = '\n'.join(lines) 173 174 return argspec or _default_callable_argspec 175 176 177if __name__ == '__main__': 178 from unittest import main 179 main('idlelib.idle_test.test_calltip', verbosity=2) 180