有没有办法通过 QStateMachine QState 转换传递信号参数？

Question

For example, let's say I have some QButtonBucket class containing some number N QPushButton s within it, and I want pushing any of those buttons to cause a transition from some state to another. This is simple enough:

for button in button_bucket.get_buttons():
    state_1.addTransition(button.clicked, state_2)

However, let's say I want to do something with the source QPushButton that causes the transition, such as changing its color if the transition is from state_1 to state_2 , or maybe disabling it if the transition is from state_3 back to state_1

I want to handle this within the tight bounds of the QStateMachine logic due to the asynchronous nature of QStateMachine s. I don't want to have to track what button was clicked, or any other stateful data for that matter, within QButtonBucket .

If there was a way to acquire arguments passed along with the signal identified in addTransition , and act on them after the new state is entered, that would be pretty much perfect. But I'm not seeing an easy solution to implement that.

Is there a known-good way of achieving what I'm trying to accomplish?

Answer 1

You can use QState.assignProperty (self, QObject object, str name, QVariant value) function which instructs a state to set a property of an object when the state is entered. So something like this could be done:

state_1.assignProperty(button, "enabled", false)