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Package:
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com.adobe.fre
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Runtime version
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AIR 3
The FREFunction interface defines the interface used by the runtime
to invoke the Java functions defined in your native extension.
Methods
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Method
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Description
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FREObject call( FREContext ctx, FREObject[]
args )
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Called by the AIR runtime when this function
is invoked by the ActionScript side of the extension.
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Implement the FREFunction interface for each Java function in
the extension that can be invoked by the ActionScript portion of
the native extension library. Add the class to the Java Map object
returned by the
getFunctions()
method of the FREContext
instance that provides the function.
The runtime invokes the
call()
method when you
execute the ExtensionContext instance’s
call()
method
in the ActionScript portion.
When you add the FREFunction to the context’s function map, you
specify a string value as a key. Use the same value when invoking
the function from ActionScript.
Method details
call
FREObject call( FREContext ctx, FREObject[] args )
Called
by the runtime when this function is invoked from ActionScript. Implement
(or initiate) the functionality provided by an FREFunction instance
in the
call()
method.
Parameters:
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ctx
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The FREContext variable that represents this extension context.
Use
the
ctx
parameter to:
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Get and
set data you associate with the extension context.
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Dispatch an asynchronous event to the ExtensionContext instance
on the ActionScript side using the FREContext
dispatchStatusEventAsync()
method.
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args
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The arguments passed to the function as an array of FREObject
variables. The objects in the array are the arguments from the ActionScript
ExtensionContext
call()
method used to invoke the
Java function.
Returns:
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FREObject
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The result. All objects shared between the Java and the ActionScript
portions of the extension are encapsulated in an FREObject or one
of its subclasses.
Class Example
The following example illustrates a function that takes
a string argument and returns a new string with the characters reversed.
The
call()
function uses the
ctx
parameter
to get an identifier string from the context through which the function
is invoked.
package com.example;
import com.adobe.fre.FREContext;
import com.adobe.fre.FREFunction;
import com.adobe.fre.FREInvalidObjectException;
import com.adobe.fre.FREObject;
import com.adobe.fre.FRETypeMismatchException;
import com.adobe.fre.FREWrongThreadException;
import android.util.Log;
public class ReverseStringFunction implements FREFunction {
public static final String NAME = "reverseString";
private String tag;
public FREObject call(FREContext arg0, FREObject[] arg1) {
DataExchangeContext ctx = (DataExchangeContext) arg0;
tag = ctx.getIdentifier() + "." + NAME;
Log.i( tag, "Invoked " + NAME );
FREObject returnValue = null;
try {
String value = arg1[0].getAsString();
value = reverse( value );
returnValue = FREObject.newObject( value );//Invert the received value
} catch (IllegalStateException e) {
Log.d(tag, e.getMessage());
e.printStackTrace();
} catch (FRETypeMismatchException e) {
Log.d(tag, e.getMessage());
e.printStackTrace();
} catch (FREInvalidObjectException e) {
Log.d(tag, e.getMessage());
e.printStackTrace();
} catch (FREWrongThreadException e) {
Log.d(tag, e.getMessage());
e.printStackTrace();
}
return returnValue;
}
private String reverse( String source ) {
int i, len = source.length();
StringBuffer dest = new StringBuffer(len);
for (i = (len - 1); i >= 0; i--)
dest.append(source.charAt(i));
return dest.toString();
}
}
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