UserInterface.workspacePreActivate 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_workspacePreActivate" is the event handler function.
futil.add_handler(userInterface_var.workspacePreActivate, userInterface_workspacePreActivate, local_handlers=local_handlers)

# Event handler for the workspacePreActivate event.
def userInterface_workspacePreActivate(args: adsk.core.WorkspaceEventArgs):

# Code to react to the event.
app.log('In userInterface_workspacePreActivate event handler.')

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

# Connect the handler to the event.
onWorkspacePreActivate = MyWorkspacePreActivateHandler()
userInterface_var.workspacePreActivate.add(onWorkspacePreActivate)
handlers.append(onWorkspacePreActivate)

# Event handler for the workspacePreActivate event.
class MyWorkspacePreActivateHandler(adsk.core.WorkspaceEventHandler):
    def __init__(self):
        super().__init__()
    def notify(self, args: adsk.core.WorkspaceEventArgs):
        # Code to react to the event.
        app.log('In MyWorkspacePreActivateHandler event handler.')

#include <Core/UserInterface/UserInterface.h>
#include <Core/UserInterface/WorkspaceEvent.h>
#include <Core/UserInterface/WorkspaceEventHandler.h>
#include <Core/UserInterface/WorkspaceEventArgs.h>

// Event handler for the workspacePreActivate event.
class MyWorkspacePreActivateEventHandler : public adsk::core::WorkspaceEventHandler {
public:
    void notify(const Ptr<WorkspaceEventArgs>& eventArgs) override {
        // Code to react to the event.
        ui->messageBox("In MyWorkspacePreActivateEventHandler event handler.");
    }
} _workspacePreActivate;

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

bool isOk = workspacePreActivateEvent->add(&_workspacePreActivate);
if (!isOk)
    return;

// Event handler for the workspacePreActivate event.
class MyWorkspacePreActivateHandler {
    notify(args: adsk.core.WorkspaceEventHandler): void {
        // Code to react to the event.
        app.log('In MyWorkspacePreActivateHandler event handler.')
    }
}

// Connect the handler to the event.
userInterface_var!.workspacePreActivate.add(new MyWorkspacePreActivateHandler());