Detect keyboard's focus and paste from clipboard, automatically using Python

Question

I am using Python and trying to paste an already copied text from the clipboard automatically to an active textbox or anything that has the keyboard's focus. In other words, the program should paste automatically the copied data from clipboard once I click for example on a browser's address bar or any text editor or any text box.

Is this possible in python? is there any function for this? I have searched on the website but did not find any good solution.

If possible, a small demo would be appreciated.

Thank You.

Answer 1

You can use SendInput to grab the focus of the current window and input characters. Here is an implementation that should work for your purposes. It takes the contents of the clipboard and types them out if the object in focus collects such keyboard input.

import time
import string
import ctypes
import ctypes.wintypes

# part one: clipboard text retrieval
CF_UNICODETEXT = 13  # unicode text format; terminates with a linefeed

OpenClipboard = ctypes.windll.user32.OpenClipboard
OpenClipboard.argtypes = ctypes.wintypes.HWND,
OpenClipboard.restype = ctypes.wintypes.BOOL

GetClipboardData = ctypes.windll.user32.GetClipboardData
GetClipboardData.argtypes = ctypes.wintypes.UINT,
GetClipboardData.restype = ctypes.wintypes.HANDLE

GlobalLock = ctypes.windll.kernel32.GlobalLock
GlobalLock.argtypes = ctypes.wintypes.HGLOBAL,
GlobalLock.restype = ctypes.wintypes.LPVOID

GlobalUnlock = ctypes.windll.kernel32.GlobalUnlock
GlobalUnlock.argtypes = ctypes.wintypes.HGLOBAL,
GlobalUnlock.restype = ctypes.wintypes.BOOL

CloseClipboard = ctypes.windll.user32.CloseClipboard
CloseClipboard.argtypes = None
CloseClipboard.restype = ctypes.wintypes.BOOL


def get_clipboard_text():
    text = ""
    if OpenClipboard(None):
        h_clip_mem = GetClipboardData(CF_UNICODETEXT)
        text = ctypes.wstring_at(GlobalLock(h_clip_mem))
        GlobalUnlock(h_clip_mem)
        CloseClipboard()
    return text


CB_TEXT = get_clipboard_text()

# part two: typing it into the focused element of a window

LONG = ctypes.c_long
DWORD = ctypes.c_ulong
ULONG_PTR = ctypes.POINTER(DWORD)
WORD = ctypes.c_ushort

VK_SHIFT = 0x10  # Shift key
# special keys
VK_OEM_1 = 0xBA
VK_OEM_PLUS = 0xBB
VK_OEM_COMMA = 0xBC
VK_OEM_MINUS = 0xBD
VK_OEM_PERIOD = 0xBE
VK_OEM_2 = 0xBF
VK_OEM_3 = 0xC0
VK_OEM_4 = 0xDB
VK_OEM_5 = 0xDC
VK_OEM_6 = 0xDD
VK_OEM_7 = 0xDE
KEYEVENTF_KEYUP = 0x0002  # Releases the key
INPUT_KEYBOARD = 1


UPPER = frozenset('~!@#$%^&*()_+QWERTYUIOP{}|ASDFGHJKL:"ZXCVBNM<>?')
LOWER = frozenset("`1234567890-=qwertyuiop[]\\asdfghjkl;'zxcvbnm,./")
ORDER = string.ascii_letters + string.digits + ' \b\r\t'
ALTER = dict(zip('!@#$%^&*()', '1234567890'))
OTHER = {
    '`': VK_OEM_3, '~': VK_OEM_3, '-': VK_OEM_MINUS, '_': VK_OEM_MINUS,
    '=': VK_OEM_PLUS, '+': VK_OEM_PLUS, '[': VK_OEM_4, '{': VK_OEM_4,
    ']': VK_OEM_6, '}': VK_OEM_6, '\\': VK_OEM_5, '|': VK_OEM_5,
    ';': VK_OEM_1, ':': VK_OEM_1, "'": VK_OEM_7, '"': VK_OEM_7,
    ',': VK_OEM_COMMA, '<': VK_OEM_COMMA, '.': VK_OEM_PERIOD,
    '>': VK_OEM_PERIOD, '/': VK_OEM_2, '?': VK_OEM_2
}


class KEYBDINPUT(ctypes.Structure):
    _fields_ = (
        ('wVk', WORD),
        ('wScan', WORD),
        ('dwFlags', DWORD),
        ('time', DWORD),
        ('dwExtraInfo', ULONG_PTR)
    )


class INPUT(ctypes.Structure):
    _fields_ = ('type', DWORD), ('ki', KEYBDINPUT), ('pad', ctypes.c_ubyte * 8)


def Input(structure):
    return INPUT(INPUT_KEYBOARD, structure)


def KeyboardInput(code, flags):
    return KEYBDINPUT(code, code, flags, 0, None)


def Keyboard(code, flags=0):
    return Input(KeyboardInput(code, flags))


def SendInput(*inputs):
    nInputs = len(inputs)
    LPINPUT = INPUT * nInputs
    pInputs = LPINPUT(*inputs)
    cbSize = ctypes.c_int(ctypes.sizeof(INPUT))
    return ctypes.windll.user32.SendInput(nInputs, pInputs, cbSize)


def stream(string):
    mode = False
    for character in string.replace('\r\n', '\r').replace('\n', '\r'):
        if mode and character in LOWER or not mode and character in UPPER:
            yield Keyboard(VK_SHIFT, mode and KEYEVENTF_KEYUP)
            mode = not mode
        character = ALTER.get(character, character)
        if character in ORDER:
            code = ord(character.upper())
        elif character in OTHER:
            code = OTHER[character]
        else:
            continue
            raise ValueError('Undecoded')
        yield Keyboard(code)
        yield Keyboard(code, KEYEVENTF_KEYUP)
    if mode:
        yield Keyboard(VK_SHIFT, KEYEVENTF_KEYUP)


def send_clipboard():
    for k in stream(CB_TEXT + '\r'):
        SendInput(k)


def demo(wait=3):
    time.sleep(wait)
    send_clipboard()


if __name__ == '__main__':
    demo()