diff options
Diffstat (limited to 'cmd2/rl_utils.py')
| -rw-r--r-- | cmd2/rl_utils.py | 76 |
1 files changed, 75 insertions, 1 deletions
diff --git a/cmd2/rl_utils.py b/cmd2/rl_utils.py index 7e49ea47..96a74b67 100644 --- a/cmd2/rl_utils.py +++ b/cmd2/rl_utils.py @@ -26,13 +26,54 @@ class RlType(Enum): # Check what implementation of readline we are using - rl_type = RlType.NONE +# Tells if the terminal we are running in supports vt100 control characters +vt100_support = False + # The order of this check matters since importing pyreadline will also show readline in the modules list if 'pyreadline' in sys.modules: rl_type = RlType.PYREADLINE + from ctypes import byref + from ctypes.wintypes import DWORD, HANDLE + import atexit + + # Check if we are running in a terminal + if sys.stdout.isatty(): + # noinspection PyPep8Naming + def enable_win_vt100(handle: HANDLE) -> bool: + """ + Enables VT100 character sequences in a Windows console + This only works on Windows 10 and up + :param handle: the handle on which to enable vt100 + :return: True if vt100 characters are enabled for the handle + """ + ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004 + + # Get the current mode for this handle in the console + cur_mode = DWORD(0) + readline.rl.console.GetConsoleMode(handle, byref(cur_mode)) + + retVal = False + + # Check if ENABLE_VIRTUAL_TERMINAL_PROCESSING is already enabled + if (cur_mode.value & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0: + retVal = True + + elif readline.rl.console.SetConsoleMode(handle, cur_mode.value | ENABLE_VIRTUAL_TERMINAL_PROCESSING): + # Restore the original mode when we exit + atexit.register(readline.rl.console.SetConsoleMode, handle, cur_mode) + retVal = True + + return retVal + + # Enable VT100 sequences for stdout and stderr + STD_OUT_HANDLE = -11 + STD_ERROR_HANDLE = -12 + vt100_support = enable_win_vt100(readline.rl.console.GetStdHandle(STD_OUT_HANDLE)) and \ + enable_win_vt100(readline.rl.console.GetStdHandle(STD_ERROR_HANDLE)) + ############################################################################################################ # pyreadline is incomplete in terms of the Python readline API. Add the missing functions we need. ############################################################################################################ @@ -74,6 +115,10 @@ elif 'gnureadline' in sys.modules or 'readline' in sys.modules: import ctypes readline_lib = ctypes.CDLL(readline.__file__) + # Check if we are running in a terminal + if sys.stdout.isatty(): + vt100_support = True + # noinspection PyProtectedMember def rl_force_redisplay() -> None: @@ -96,3 +141,32 @@ def rl_force_redisplay() -> None: # Call _print_prompt() first to set the new location of the prompt readline.rl.mode._print_prompt() readline.rl.mode._update_line() + + +# noinspection PyProtectedMember +def rl_get_point() -> int: + """ + Returns the offset of the current cursor position in rl_line_buffer + """ + if rl_type == RlType.GNU: # pragma: no cover + return ctypes.c_int.in_dll(readline_lib, "rl_point").value + + elif rl_type == RlType.PYREADLINE: # pragma: no cover + return readline.rl.mode.l_buffer.point + + else: # pragma: no cover + return 0 + + +# noinspection PyProtectedMember +def rl_set_prompt(prompt: str) -> None: + """ + Sets readline's prompt + :param prompt: the new prompt value + """ + if rl_type == RlType.GNU: # pragma: no cover + encoded_prompt = bytes(prompt, encoding='utf-8') + readline_lib.rl_set_prompt(encoded_prompt) + + elif rl_type == RlType.PYREADLINE: # pragma: no cover + readline.rl._set_prompt(prompt) |