ListenerList

ListenerList

Description

Holds and manages a collection of functions and target objects

Functions

• invoke
• new
• registerListener

invoke

Description

Calls the listeners with the given arguments.

Definition

invoke(any ..., )

Arguments

any	...	The collection of arguments to pass to the functions.
any	...

Code

function ListenerList:invoke(targetObject, .. .)

    -- Invoke each listener.
    if self.ignoreFirstArgument then
        for _, listener in ipairs( self.listeners) do
            listener:invoke( .. .)
        end
    else
            for _, listener in ipairs( self.listeners) do
                listener:invoke(targetObject, .. .)
            end
        end
    end

new

Description

Creates a new listener list.

Definition

new(boolean? ignoreFirstArgument)

Arguments

boolean?	ignoreFirstArgument	If this is true, the first argument is not passed along when invoking. Used to ignore the table instance when the listener list is a member of a table.

Return Values

boolean?	instance	The created instance.

Code

function ListenerList.new(ignoreFirstArgument)

    -- Create the instance.
    local self = setmetatable( { } , ListenerList _mt)

    -- The collection of listening functions.
    self.listeners = { }

    -- If this is true, the first argument is not passed to the invoked functions.This is useful to ignore the table instance when the listener list is a member of a table.
    self.ignoreFirstArgument = ignoreFirstArgument = = true

    -- Return the created instance.
    return self
end

registerListener

Description

Adds the given listener function and target object to the listeners list.

Definition

registerListener((function|TargetedFunction) listenerFunction, table? targetObject)

Arguments

(function	TargetedFunction)	listenerFunction	The function or TargetedFunction to add to the list.
table?	targetObject	The optional target object.

Code

function ListenerList:registerListener(listenerFunction, targetObject)

    -- Resolve the listener function.
        local listener = TargetedFunction.resolveListener(listenerFunction, targetObject)

        -- Add the listener function to the list.
            table.insert( self.listeners, listener)
        end