keyboardext.py

# SPDX-FileCopyrightText: 2017 Dan Halbert for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
`adafruit_hid.keyboard.Keyboard`
====================================================

* Author(s): Scott Shawcroft, Dan Halbert
"""

import time
from micropython import const

from adafruit_hid.keycode import Keycode

from adafruit_hid import find_device

_MAX_KEYPRESSES = const(6)


class Keyboardext:
    """Send HID keyboard reports."""

    LED_NUM_LOCK = 0x01
    """LED Usage ID for Num Lock"""
    LED_CAPS_LOCK = 0x02
    """LED Usage ID for Caps Lock"""
    LED_SCROLL_LOCK = 0x04
    """LED Usage ID for Scroll Lock"""
    LED_COMPOSE = 0x08
    """LED Usage ID for Compose"""

    # No more than _MAX_KEYPRESSES regular keys may be pressed at once.

    def __init__(self, devices):
        """Create a Keyboard object that will send keyboard HID reports.

        Devices can be a list of devices that includes a keyboard device or a keyboard device
        itself. A device is any object that implements ``send_report()``, ``usage_page`` and
        ``usage``.
        """
        self._keyboard_device = find_device(devices, usage_page=0x1, usage=0x06)

        # Reuse this bytearray to send keyboard reports.
        self.report = bytearray(8)

        # report[0] modifiers
        # report[1] unused
        # report[2:8] regular key presses

        # View onto byte 0 in report.
        self.report_modifier = memoryview(self.report)[0:1]

        # List of regular keys currently pressed.
        # View onto bytes 2-7 in report.
        self.report_keys = memoryview(self.report)[2:]

        # Do a no-op to test if HID device is ready.
        # If not, wait a bit and try once more.
        try:
            self.release_all()
        except OSError:
            time.sleep(1)
            self.release_all()  

        self._layout = ""
        # Set default layout
        # self._layout = "en_us"
        # self._asciimap = __import__("keyboardext/" + self._layout)

    def set_layout(self, layout):
        """Sets the layout of the keyboard object. The string must match
           the name of the mapping file.
        """        
        self._asciimap = __import__("keyboardext/" + layout)
        self._layout = layout

    def get_layout(self):
        """Returns the selected layout as string
        """   
        return self._layout

    def write(self, string):
        """Type the string by pressing and releasing keys on my keyboard.

        :param string: A string of ASCII characters.

        Example::

            # Write abc to the keyboard
            keyboard.write('abc')
        """

        if self._layout == "":
            print("Error: No layout selected.")
            return

        if isinstance(self._asciimap.asciiToKeycode, list):
            isList = True
        elif isinstance(self._asciimap.asciiToKeycode, dict):
            isList = False

        for char in string:
            if isList:
                ascii_num = ord(str(char, "ascii"))            
                if (ascii_num > 255): continue  # in case the character is not part of latin-1 charset
                keycodes = self._asciimap.asciiToKeycode[ascii_num]
            else:
                keycodes = self._asciimap.asciiToKeycode[char]

            if isinstance(keycodes, list):  # list of tuples = DEADKEYS                 
                for item in keycodes:
                    if isinstance(item, tuple):
                        self.send(*item)
                    else:
                        self.send(item)
            elif isinstance(keycodes, tuple):        
                self.send(*keycodes)    # tuples needs to be unpacked by *
            else:
                self.send(keycodes)     # send a single keycode as int            

    def writeln(self, string):
        """Type the string by pressing and releasing keys on my keyboard.

        :param string: A string of ASCII characters.

        Example::

            # Write abc followed by RETURN to the keyboard
            keyboard.writeln('abc')
        """
        self.write(string)
        self.send(Keycode.ENTER)

    def press(self, *keycodes):
        """Send a report indicating that the given keys have been pressed.

        :param keycodes: Press these keycodes all at once.
        :raises ValueError: if more than six regular keys are pressed.

        Keycodes may be modifiers or regular keys.
        No more than six regular keys may be pressed simultaneously.

        Examples::

            from adafruit_hid.keycode import Keycode

            # Press ctrl-x.
            kbd.press(Keycode.LEFT_CONTROL, Keycode.X)

            # Or, more conveniently, use the CONTROL alias for LEFT_CONTROL:
            kbd.press(Keycode.CONTROL, Keycode.X)

            # Press a, b, c keys all at once.
            kbd.press(Keycode.A, Keycode.B, Keycode.C)
        """
        for keycode in keycodes:
            self._add_keycode_to_report(keycode)
        self._keyboard_device.send_report(self.report)

    def release(self, *keycodes):
        """Send a USB HID report indicating that the given keys have been released.

        :param keycodes: Release these keycodes all at once.

        If a keycode to be released was not pressed, it is ignored.

        Example::

            # release SHIFT key
            kbd.release(Keycode.SHIFT)
        """
        for keycode in keycodes:
            self._remove_keycode_from_report(keycode)
        self._keyboard_device.send_report(self.report)

    def release_all(self):
        """Release all pressed keys."""
        for i in range(8):
            self.report[i] = 0
        self._keyboard_device.send_report(self.report)

    def send(self, *keycodes):
        """Press the given keycodes and then release all pressed keys.

        :param keycodes: keycodes to send together
        """
        self.press(*keycodes)
        self.release_all()

    def _add_keycode_to_report(self, keycode):
        """Add a single keycode to the USB HID report."""
        modifier = Keycode.modifier_bit(keycode)
        if modifier:
            # Set bit for this modifier.
            self.report_modifier[0] |= modifier
        else:
            # Don't press twice.
            # (I'd like to use 'not in self.report_keys' here, but that's not implemented.)
            for i in range(_MAX_KEYPRESSES):
                if self.report_keys[i] == keycode:
                    # Already pressed.
                    return
            # Put keycode in first empty slot.
            for i in range(_MAX_KEYPRESSES):
                if self.report_keys[i] == 0:
                    self.report_keys[i] = keycode
                    return
            # All slots are filled.
            raise ValueError("Trying to press more than six keys at once.")

    def _remove_keycode_from_report(self, keycode):
        """Remove a single keycode from the report."""
        modifier = Keycode.modifier_bit(keycode)
        if modifier:
            # Turn off the bit for this modifier.
            self.report_modifier[0] &= ~modifier
        else:
            # Check all the slots, just in case there's a duplicate. (There should not be.)
            for i in range(_MAX_KEYPRESSES):
                if self.report_keys[i] == keycode:
                    self.report_keys[i] = 0

    @property
    def led_status(self):
        """Returns the last received report"""
        return self._keyboard_device.last_received_report

    def led_on(self, led_code):
        """Returns whether an LED is on based on the led code
        Examples::
            import usb_hid
            from adafruit_hid.keyboard import Keyboard
            from adafruit_hid.keycode import Keycode
            import time
            # Press and release CapsLock.
            kbd.press(Keycode.CAPS_LOCK)
            time.sleep(.09)
            kbd.release(Keycode.CAPS_LOCK)
            # Check status of the LED_CAPS_LOCK
            print(kbd.led_on(Keyboard.LED_CAPS_LOCK))
        """
        return bool(self.led_status[0] & led_code)