colorbutton.py

import sys

if "PySide6" in sys.modules:
    from PySide6 import QtGui, QtWidgets
    from PySide6.QtCore import Qt, Signal
elif "PyQt5" in sys.modules:
    from PyQt5 import QtGui, QtWidgets
    from PyQt5.QtCore import Qt
    from PyQt5.QtCore import pyqtSignal as Signal
else:
    from PySide2 import QtGui, QtWidgets
    from PySide2.QtCore import Qt, Signal


class ColorButton(QtWidgets.QPushButton):
    '''
    Custom Qt Widget to show a chosen color.

    Left-clicking the button shows the color-chooser, while
    right-clicking resets the color to the default color (None by default).
    '''

    colorChanged = Signal(object)

    def __init__(self, *args, color=None, **kwargs):
        super(ColorButton, self).__init__(*args, **kwargs)

        self._color = None
        self._default = color
        self.pressed.connect(self.onColorPicker)

        # Set the initial/default state.
        self.setColor(self._default)

    def setColor(self, color):
        if color != self._color:
            self._color = color
            self.colorChanged.emit(color)

        if self._color:
            self.setStyleSheet("background-color: %s;" % self._color)
        else:
            self.setStyleSheet("")

    def color(self):
        return self._color

    def onColorPicker(self):
        '''
        Show color-picker dialog to select color.

        Qt will use the native dialog by default.

        '''
        dlg = QtWidgets.QColorDialog(self)
        if self._color:
            dlg.setCurrentColor(QtGui.QColor(self._color))

        if dlg.exec_():
            self.setColor(dlg.currentColor().name())

    def mousePressEvent(self, e):
        if e.button() == Qt.RightButton:
            self.setColor(self._default)

        return super(ColorButton, self).mousePressEvent(e)