System tray applications (or menu bar applications) can be useful for making common functions or information available in a small number of clicks. For full desktop applications they're a useful shortcut to control apps without opening up the whole window.
Qt provides a simple interface for building cross-platform system tray (Windows) or menu bar (MacOS) apps.
Below is a minimal working example for showing an icon in the toolbar/system tray with a menu. The action in the menu isn't connected and so doesn't do anything yet.
from PyQt5.QtGui import * from PyQt5.QtWidgets import * app = QApplication() app.setQuitOnLastWindowClosed(False) # Create the icon icon = QIcon("icon.png") # Create the tray tray = QSystemTrayIcon() tray.setIcon(icon) tray.setVisible(True) # Create the menu menu = QMenu() action = QAction("A menu item") menu.addAction(action) # Add the menu to the tray tray.setContextMenu(menu) app.exec_()
You'll notice that there isn't a
QMainWindow, simply because we don't actually have any window to show. You can create a window as normal without affecting the behaviour of the system tray icon.
The default behaviour in Qt is to close an application once all the active windows have closed. This won't affect this toy example, but will be an issue in application where you do create windows and then close them. Setting
app.setQuitOnLastWindowClosed(False) stops this and will ensure your application keeps running.
The provided icon shows up in the toolbar (you can see it on the left).
Clicking on the icon shows the added menu.
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Create Simple GUI Applications with Python & Qt is my beginners guide to building cross-platform GUI applications with Python. In this book I take you step by step from displaying your first window, to fully functional software.
Below is a more complete working example using the built in
QColorDialog from Qt to give a toolbar accessible color picker. The menu lets you choose to get the picked color as HTML-format
from PyQt5.QtGui import * from PyQt5.QtWidgets import * app = QApplication() app.setQuitOnLastWindowClosed(False) # Create the icon icon = QIcon("color.png") clipboard = QApplication.clipboard() dialog = QColorDialog() def copy_color_hex(): if dialog.exec_(): color = dialog.currentColor() clipboard.setText(color.name()) def copy_color_rgb(): if dialog.exec_(): color = dialog.currentColor() clipboard.setText("rgb(%d, %d, %d)" % ( color.red(), color.green(), color.blue() )) def copy_color_hsv(): if dialog.exec_(): color = dialog.currentColor() clipboard.setText("hsv(%d, %d, %d)" % ( color.hue(), color.saturation(), color.value() )) # Create the tray tray = QSystemTrayIcon() tray.setIcon(icon) tray.setVisible(True) # Create the menu menu = QMenu() action1 = QAction("Hex") action1.triggered.connect(copy_color_hex) menu.addAction(action1) action2 = QAction("RGB") action2.triggered.connect(copy_color_rgb) menu.addAction(action2) action3 = QAction("HSV") action3.triggered.connect(copy_color_hsv) menu.addAction(action3) # Add the menu to the tray tray.setContextMenu(menu) app.exec_()
You'll need an icon to use to run this example — I recommend the fugue icon set.
As in the previous example there is no
QMainWindow for this example. The menu is created as before, but adding 3 actions for the different output formats. Each action is connected to a specific handler function for the format it represents. Each handler shows a dialog and, if a color is selected, copies that color to the clipboard in the given format.
As before, the icon appears in the toolbar.
Clicking the icon shows a menu, from which you can select the format of image you want to return.
Once you've chosen the format, you'll see the standard Qt color picker window.
Select the colour you want and click OK. The chosen colour will be copied to the clipboard in the requested format. The formats available will product the following output:
#a2b3cc # range 00-FF rgb(25, 28, 29) # range 0-255 hsv(14, 93, 199) # range 0-255