RequestFactory Class Reference

A default request factory. More...

Public Member Functions
Request	createRequest (Device arg0, int arg1)
synchronized void	delete ()
	RequestFactory ()
void	swigReleaseOwnership ()
void	swigTakeOwnership ()

Protected Member Functions
void	finalize ()
	RequestFactory (long cPtr, boolean cMemoryOwn)
void	swigDirectorDisconnect ()

Static Protected Member Functions
static long	swigRelease (RequestFactory obj)

Protected Attributes
transient boolean	swigCMemOwn

Detailed Description

A default request factory.

Applications need to derive from this class and must re-implement the function mvIMPACT.acquire.RequestFactory.createRequest to work with custom objects derived from mvIMPACT.acquire.Request.

Deriving from mvIMPACT.acquire.Request can be useful when a certain device driver or device offers a custom feature that is returned as part of the request object that can not be accessed using the mvIMPACT.acquire.Request class offered by this interface.

This shows how a request factory could be used to create custom request objects from within a mvIMPACT::acquire::FunctionInterface instance.

MyRequest.java:

import mvIMPACT.acquire.*;
 
//-----------------------------------------------------------------------------
// Example for a derived request object. It doesn't introduce new functionality
// but rebinds an existing property. Custom properties could bound in a similar
// way.
class MyRequest extends Request
//-----------------------------------------------------------------------------
{
  private PropertyI myRequestResult_ = new PropertyI();
 
  private void init()
  {
    DeviceComponentLocator locator = new DeviceComponentLocator( getComponentLocator().hObj() );
    locator.bindComponent( myRequestResult_, "Result" );
  }
 
  protected MyRequest( Device pDev, int requestNr )
  {
    super( pDev, requestNr );
    init();
  }
 
  // Without this constructor this whole 'RequestFactory' concept will not work
  // at the moment as in 'FunctionInterface.getRequest' the internal correctly
  // constructed 'MyRequest' generated via the director class and 'MyRequestFactory'
  // will be used to create a new 'Request' instance from it. We now use this to
  // re-create yet another 'MyRequest' instance from that which is kind of silly
  // but in Python we have a very similar effect(see corresponding snippet in the Python manual).
  //
  // Maybe there is a better way to do this! Suggestions welcome!
  public MyRequest( Request pRequest )
  {
    super( Request.getCPtr( pRequest ), false );
    init();
  }
 
  public PropertyI getMyRequestResult()
  {
    return myRequestResult_;
  }
}

MyRequestFactory.java:

import mvIMPACT.acquire.*;
 
//-----------------------------------------------------------------------------
// Example for a factory that creates 'MyRequest' instances
class MyRequestFactory extends RequestFactory
//-----------------------------------------------------------------------------
{
  @Override
  public Request createRequest( Device pDev, int requestNr )
  {
    return new MyRequest( pDev, requestNr );
  }
}

Now the request factory must be passed to the constructor of the function interface! This might happen in some other source file or class within the application.

//-----------------------------------------------------------------------------
void fn( Device pDev )
//-----------------------------------------------------------------------------
{
  // ... some code ...
  MyRequestFactory mrf = new MyRequestFactory();
  FunctionInterface fi = new FunctionInterface( pDev, mrf );
  // ... more additional code
  // assuming we got back a request from the driver at this point:
  Request pRequest = fi.getRequest( getRequestNrFromSomewhere() );
  if( pRequest->isOK() )
  {
    System.out.println( String.format( "%s: %s", ( ( MyRequest )pRequest ).getMyRequestResult().name(), ( ( MyRequest )pRequest ).getMyRequestResult().readS() );
    // do what you want to do with your derived request instance here!
  }
  // ... probably even more additional code
}

Since

1.12.56

Constructor & Destructor Documentation

RequestFactory() [1/2]

RequestFactory ( long cPtr, boolean cMemoryOwn )

protected

RequestFactory() [2/2]

RequestFactory

(

)

Member Function Documentation

createRequest()

Request createRequest	(	Device	arg0,
		int	arg1 )

delete()

synchronized void delete

(

)

finalize()

void finalize ( )

protected

swigDirectorDisconnect()

void swigDirectorDisconnect ( )

protected

swigRelease()

static long swigRelease ( RequestFactory obj )

staticprotected

swigReleaseOwnership()

void swigReleaseOwnership

(

)

swigTakeOwnership()

void swigTakeOwnership

(

)

Member Data Documentation

swigCMemOwn

transient boolean swigCMemOwn

protected