|
The ActionScript side of your extension calls C functions
you implement by calling the ExtensionContext instance’s
call()
method.
The
call()
method takes these parameters:
-
The name of the function. You provided this name in
an output parameter of your context initialization function. This
name is an arbitrary string agreed to between the ActionScript side
and the native side. Typically, it is the same name as the actual
name of the native C function. However, these names can be different
because the runtime associates the arbitrary name with the actual function.
-
A list of arguments for the native function. These arguments
can be any ActionScript objects: primitive types or ActionScript
class objects.
Define each of your native functions with the same function signature:
FREFunction()
. The runtime passes
the following parameters to each native function:
-
The FREContext value. The native function can use
this value to access and set the context-specific data. Also, the
native implementation uses the FREContext value to dispatch an asynchronous
event back to the ActionScript side.
-
A pointer to the data associated with the function. This
data is any native data. When the runtime calls the native function,
it passes the function this data pointer.
-
The number of function parameters.
-
The function parameters. Each function parameter has the
type FREObject. These parameters correspond to ActionScript class
objects or primitive data types.
A native function also has a return value with the type FREObject.
The runtime returns the corresponding ActionScript object as the
return value for the ExtensionContext
call()
method.
Note:
Do not set a native function’s visibility to hidden. Use the
default visibility.
The following sequence diagram shows an AIR application making
a function call that results in calling a native C function named
FREFunctionF()
.
In this example, the C function:
-
Gets the context-specific native data.
-
Gets the int32 value of an ActionScript object.
-
Starts an asynchronous thread which later dispatches an event.
Note:
The behavior of the C function
FREFunctionF()
is
only a sample behavior to illustrate a call sequence.
|
|
|
