When I have to write a reference to a callable function I use the standard syntax of PHP defined as:
A PHP function is passed by its name as a string. Any built-in or user-defined function can be used [... omitted...].
A method of an instantiated object is passed as an array containing an object at index 0 and the method name (aka string) at index 1.
Static class methods can also be passed without instantiating an object of that class by passing the class name (still a string) instead of an object at index 0.
As of PHP 5.2.3, it is also possible to pass (the string) 'ClassName::methodName'.
Apart from common user-defined function, anonymous functions can also be passed to a callback parameter.
All of these ways are not "IDE friendly" for operations like function name refactor or find usage of.
In my answer I propose a solution, but there are other approaches that can be applied, even totally different, that allow to IDE to "find" the invocation of the methods?