PyQt5 – QAction

QAction : In PyQt5 applications many common commands can be invoked via menus, toolbar buttons, and keyboard shortcuts, since the user expects each command to be performed in the same way, regardless of the user interface used, QAction is useful to represent each command as an action. Actions can be added to menus and toolbars, and will automatically keep them in sync. For example, in a word processor, if the user presses a Bold toolbar button, the Bold menu item will automatically be checked. Below is how an action will look inside the tool bar

Syntax:

action = QAction(name)

This action can be added to toolbars or QMenus with the help of addAction and addActions method. Below are the some frequently used commands with the QAction

setCheckable : To make QAction Checkable

setIcon : To add icon to the QAction

setText : To set the display name of the QAction

text : To get the display name of the QAction

setPriority : To set the priority of the action

triggered.connect : To connect an method with it when triggered signal is emitted

Example : In this example we will create a main window having a tool bar, label and tool bar is consisting of QAction each having separate method connected to it, below is the implementation 

Python3

# importing libraries
from PyQt5.QtWidgets import * from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * from PyQt5.QtCore import * import sys


class Window(QMainWindow):

    def __init__(self):
        super().__init__()

        # setting title
        self.setWindowTitle("Python ")

        # setting geometry
        self.setGeometry(100, 100, 500, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()



    # method for components
    def UiComponents(self):

        # creating a tool bar
        toolbar = QToolBar(self)

        # setting geometry to the tool bar
        toolbar.setGeometry(50, 100, 300, 35)


        # creating QAction Instances
        action1 = QAction("First Action", self)
        action2 = QAction("Second Action", self)
        action3 = QAction("Third Action", self)

        # adding these actions to the tool bar
        toolbar.addAction(action1)
        toolbar.addAction(action2)
        toolbar.addAction(action3)

        # creating a label
        label = QLabel("GeeksforGeeks", self)

        # setting geometry to the label
        label.setGeometry(100, 150, 200, 50)

        # adding triggered action to the first action
        action1.triggered.connect(lambda: label.setText("First Action Triggered"))

        # adding triggered action to the second action
        action2.triggered.connect(lambda: label.setText("Second Action Triggered"))

        # adding triggered action to the third action
        action3.triggered.connect(lambda: label.setText("Third Action Triggered"))





# create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()

# start the app
sys.exit(App.exec())

Output :

Another example In this example we will create a commandlink button and add menu to it which is having QAction, below is the implementation 

Python3

# importing libraries
from PyQt5.QtWidgets import * from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import * from PyQt5.QtCore import * import sys


class Window(QMainWindow):

    def __init__(self):
        super().__init__()

        # setting title
        self.setWindowTitle("Python ")

        # setting geometry
        self.setGeometry(100, 100, 500, 400)

        # calling method
        self.UiComponents()

        # showing all the widgets
        self.show()

        # method for components

    def UiComponents(self):
        # creating a command link button
        cl_button = QCommandLinkButton("Press", self)

        # setting geometry
        cl_button.setGeometry(150, 100, 150, 60)

        # QActions
        action1 = QAction("Geeks", self)
        action2 = QAction("GfG", self)

        # making action2 checkable
        action2.setCheckable(True)



        # QMenu
        menu = QMenu()

        # adding actions to menu
        menu.addActions([action1, action2])

        # setting menu to the button
        cl_button.setMenu(menu)


        # creating label
        label = QLabel("GeeksforGeeks", self)

        # setting label geometry
        label.setGeometry(100, 200, 300, 80)

        # making label multiline
        label.setWordWrap(True)

        # adding method to the action
        action1.triggered.connect(lambda: label.setText("Action1 is triggered"))

        # adding method to the action2 when it get checked
        action2.toggled.connect(lambda: label.setText("Action2 is toggled"))



# create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()

# start the app
sys.exit(App.exec())

Output :