FlatCAM/FlatCAMCommon.py

# ##########################################################
# FlatCAM: 2D Post-processing for Manufacturing            #
# http://flatcam.org                                       #
# Author: Juan Pablo Caram (c)                             #
# Date: 2/5/2014                                           #
# MIT Licence                                              #
# ##########################################################

# ##########################################################
# File Modified (major mod): Marius Adrian Stanciu         #
# Date: 11/4/2019                                          #
# ##########################################################

import gettext
import FlatCAMTranslation as fcTranslate
import builtins

fcTranslate.apply_language('strings')
if '_' not in builtins.__dict__:
    _ = gettext.gettext


class GracefulException(Exception):
    # Graceful Exception raised when the user is requesting to cancel the current threaded task
    def __init__(self):
        super().__init__()

    def __str__(self):
        return '\n\n%s' % _("The user requested a graceful exit of the current task.")


class LoudDict(dict):
    """
    A Dictionary with a callback for item changes.
    """

    def __init__(self, *args, **kwargs):
        dict.__init__(self, *args, **kwargs)
        self.callback = lambda x: None

    def __setitem__(self, key, value):
        """
        Overridden __setitem__ method. Will emit 'changed(QString)' if the item was changed, with key as parameter.
        """
        if key in self and self.__getitem__(key) == value:
            return

        dict.__setitem__(self, key, value)
        self.callback(key)

    def update(self, *args, **kwargs):
        if len(args) > 1:
            raise TypeError("update expected at most 1 arguments, got %d" % len(args))
        other = dict(*args, **kwargs)
        for key in other:
            self[key] = other[key]

    def set_change_callback(self, callback):
        """
        Assigns a function as callback on item change. The callback
        will receive the key of the object that was changed.

        :param callback: Function to call on item change.
        :type callback: func
        :return: None
        """

        self.callback = callback


class FCSignal:
    """
    Taken from here: https://blog.abstractfactory.io/dynamic-signals-in-pyqt/
    """

    def __init__(self):
        self.__subscribers = []

    def emit(self, *args, **kwargs):
        for subs in self.__subscribers:
            subs(*args, **kwargs)

    def connect(self, func):
        self.__subscribers.append(func)

    def disconnect(self, func):
        try:
            self.__subscribers.remove(func)
        except ValueError:
            print('Warning: function %s not removed '
                  'from signal %s' % (func, self))


def color_variant(hex_color, bright_factor=1):
    """
    Takes a color in HEX format #FF00FF and produces a lighter or darker variant

    :param hex_color:           color to change
    :param bright_factor:   factor to change the color brightness [0 ... 1]
    :return:                    modified color
    """

    if len(hex_color) != 7:
        print("Color is %s, but needs to be in #FF00FF format. Returning original color." % hex_color)
        return hex_color

    if bright_factor > 1.0:
        bright_factor = 1.0
    if bright_factor < 0.0:
        bright_factor = 0.0

    rgb_hex = [hex_color[x:x + 2] for x in [1, 3, 5]]
    new_rgb = []
    for hex_value in rgb_hex:
        # adjust each color channel and turn it into a INT suitable as argument for hex()
        mod_color = round(int(hex_value, 16) * bright_factor)
        # make sure that each color channel has two digits without the 0x prefix
        mod_color_hex = str(hex(mod_color)[2:]).zfill(2)
        new_rgb.append(mod_color_hex)

    return "#" + "".join([i for i in new_rgb])