Mastering GUI Programming with Python

The editing form

Before we create the actual form, we're going to simplify our code slightly by creating some custom button classes: a ColorButton class for setting colors, a FontButton class for setting fonts, and an ImageFileButton class for selecting images.

The ColorButton class begins like this:

class ColorButton(qtw.QPushButton):   changed = qtc.pyqtSignal()    def __init__(self, default_color, changed=None):        super().__init__()        self.set_color(qtg.QColor(default_color))        self.clicked.connect(self.on_click)        if changed:            self.changed.connect(changed)

This button inherits QPushButton but makes a few changes. We've defined a changed signal to track when the value of the button changes and added a keyword option so that this signal can be connected ...