How can I change animation of button when using QShortcut?

Question

Before, I was used to using button.clicked.connect(function) to trigger a button and setting qss by setStyleSheet() (Eg: QPushButton:pressed{background:#EAEAEA;}). And the button will change background color when pressing button by clicking mouse and work as expected. However, Currently I'm using QShortcut to trigger the button (Eg: QtCore.Qt.Key_Return) but the button seems not to be affected by qss.

The code that I've used:

from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(400, 300)
        Form.setStyleSheet(""
                        "#Form {\n"
                        "background-color: rgb(255, 255, 255);\n"
                        "}\n"
                        "QPushButton:hover {\n"
                        "color: white;\n"
                        "background-color: rgb(255, 85, 127);\n"
                        "border-radius: 6px;\n"
                        "font-size:16px;\n"
                        "}\n"
                        "\n"
                        " QPushButton:pressed{\n"
                        "background:#EAEAEA;\n"
                        "color: black;\n"
                        "font-size:16px;\n"
                        "}")
        self.frame = QtWidgets.QFrame(Form)
        self.frame.setGeometry(QtCore.QRect(20, 20, 351, 241))
        self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame.setObjectName("frame")
        self.pushButton = QtWidgets.QPushButton(self.frame)
        self.pushButton.setGeometry(QtCore.QRect(130, 100, 93, 28))
        self.pushButton.setObjectName("pushButton")

        # old (be affected by qss (QPushButton:pressed) when clicking mouse)
        # self.pushButton.clicked.connect(self.send_message)

        # new (not to be affected by qss (QPushButton:pressed) when using Enter key)
        send_message_shortcut = QtWidgets.QShortcut(QtGui.QKeySequence(QtCore.Qt.Key_Return), Form)
        send_message_shortcut.activated.connect(self.send_message)

        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        _translate = QtCore.QCoreApplication.translate
        Form.setWindowTitle(_translate("Form", "Form"))
        self.pushButton.setText(_translate("Form", "PushButton"))

    def send_message(self):
        # do something here
        print("send message")


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Form = QtWidgets.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())

Answer 1

You are not seeing the "animation" because the button is not being pressed at all, but you can trigger it by using QAbstractButton.animateClick:

send_message_shortcut.activated.connect(self.pushButton.animateClick)

This sets the button pressed (as in setDown(True)), then restores it after a default 100ms interval and sends both released and clicked signals respectively. If you want a different time interval, use a lambda (or do it in your own method) and set the argument in ms.