UserInterface.commandStarting Event

# Import fusion360utils folder, which includes event_utils.py.
from ...lib import fusion360utils as futil

# Global variable used to maintain a reference to all event handlers.
local_handlers = []

# "userInterface_var" is a variable referencing a UserInterface object.
# "userInterface_commandStarting" is the event handler function.
futil.add_handler(userInterface_var.commandStarting, userInterface_commandStarting, local_handlers=local_handlers)

# Event handler for the commandStarting event.
def userInterface_commandStarting(args: adsk.core.ApplicationCommandEventArgs):
    # Code to react to the event.
    app.log('In userInterface_commandStarting event handler.')

# Global variable used to maintain a reference to all event handlers.
handlers = []

# "userInterface_var" is a variable referencing a UserInterface object.
# "MyCommandStartingHandler" is the name of the class that handles the event.
onCommandStarting = MyCommandStartingHandler()
userInterface_var.commandStarting.add(onCommandStarting)
handlers.append(onCommandStarting)

# Event handler for the commandStarting event.
class MyCommandStartingHandler(adsk.core.ApplicationCommandEventHandler):
    def __init__(self):
        super().__init__()
    def notify(self, args: adsk.core.ApplicationCommandEventArgs):
        # Code to react to the event.
        app.log('In MyCommandStartingHandler event handler.')

#include <Core/UserInterface/UserInterface.h>
#include <Core/UserInterface/ApplicationCommandEvent.h>
#include <Core/UserInterface/ApplicationCommandEventHandler.h>
#include <Core/UserInterface/ApplicationCommandEventArgs.h>

// Event handler for the commandStarting event.
class MyCommandStartingEventHandler : public adsk::core::ApplicationCommandEventHandler
{
public:
    void notify(const Ptr<ApplicationCommandEventArgs>& eventArgs) override
    {
        // Code to react to the event.
        ui->messageBox("In MyCommandStartingEventHandler event handler.");
    }
} _commandStarting;

// "userInterface_var" is a variable referencing a UserInterface object.
// Connect the handler function to the event.
Ptr<ApplicationCommandEvent> commandStartingEvent = userInterface_var->commandStarting();
if (!commandStartingEvent)
    return;

bool isOk = commandStartingEvent->add(&_commandStarting);
if (!isOk)
    return;