I have created a very simple widget (and I plan to create a more complex one which should work sometimes in maximized mode.)
However, when adding the widget in a panel it does not come with maximize button as built-in widgets do.
In fact, it is quite confusing:
After I have added successfully built-in widgets with the regular OpDashboard, all having the maximize button, in Dev Mode I am not able to get those buttons neither on my custom Widgets, nor the regular ones!
Previewing the result in the browser also comes without that button on all widgets I have added in Dev Mode!
This looks like kind of a bug!!!