I have a taskbar menu that when clicked is connected to a slot that gets the trigger event. Now the problem is that I want to know which menu item was clicked, but I don't know how to send that information to the function connected to. Here is the used to connect the action to the function:
QtCore.QObject.connect(menuAction, 'triggered()', menuClickedFunc)
I know that some events return a value, but triggered() doesn't. So how do I make this happen? Do I have to make my own signal?
Use a lambda
Here's an example from the PyQt book:
self.connect(button3, SIGNAL("clicked()"),
lambda who="Three": self.anyButton(who))
By the way, you can also use functools.partial, but I find the lambda method simpler and clearer.
As already mentioned here you can use the lambda function to pass extra arguments to the method you want to execute.
In this example you can pass a string obj to the function AddControl() invoked when the button is pressed.
# Create the build button with its caption
self.build_button = QPushButton('&Build Greeting', self)
# Connect the button's clicked signal to AddControl
self.build_button.clicked.connect(lambda: self.AddControl('fooData'))
def AddControl(self, name):
print name
Source: snip2code - Using Lambda Function To Pass Extra Argument in PyQt4
use functools.partial
otherwise you will find you cannot pass arguments dynamically when script is running, if you use lambda.
In general, you should have each menu item connected to a different slot, and have each slot handle the functionality only for it's own menu item. For example, if you have menu items like "save", "close", "open", you ought to make a separate slot for each, not try to have a single slot with a case statement in it.
If you don't want to do it that way, you could use the QObject::sender() function to get a pointer to the sender (ie: the object that emitted the signal). I'd like to hear a bit more about what you're trying to accomplish, though.
I'd also like to add that you can use the sender method if you just need to find out what widget sent the signal. For example:
def menuClickedFunc(self):
# The sender object:
sender = self.sender()
# The sender object's name:
senderName = sender.objectName()
print senderName
