mswINS_DATA_MONITOR

NAME

PARENT CLASS

public mswINS_CONFIG_DATA

DESCRIPTION

  This class is part of the TCS-public msw library and provides
  access for TCS applications to instrument configuration data.
  On top of features to access the msw instrument database
  consiguration table, inherited from the base class
  mswINS_CONFIG_DATA,  it allows to install/define a callback
  to be called when the configuration of the currently
  selected instrument changes.
  This is implemented attaching an event on ANY WRITE on the database
  attribute containing the ID of the currently selected instrument.
  The class mswINS_CONFIG_TABLE(4) used by the msw module to handle
  the instrument data configuration takes care of updating this attribute
  whenever necessary.

PUBLIC METHODS

  mswINS_DATA_MONITOR(const dbSYMADDRESS dbPoint = dbEMPTY);
    The constructor provides a default value for the dbPoint
    parameter to behave like two distinct constructors: one with
    no parameters and one with a dbPoint parameter.
    The first one defines the online database support point calling
    the standard tcsDbRoot(4) function and appending the
    default relative path from the TCS database root point,
    assuming a complete default TCS database structure.
    This is what will be generally used.
    The second one receives as parameter the symbolic address of
    online database support point for the object, i.e. the point
    where the object can find configuration and run time values.
    This will be typically used for testing purposes.
    When the object is created, the event is immediately attached
    and the object is ready to handle events.

  virtual ~mswINS_DATA_MONITOR();
    The descructor cleans-up the object and detach the event

  ccsCOMPL_STAT         DbPoint(const dbSYMADDRESS point);
  virtual const char   *DbPoint() const;
    The methods of the base class to access the symbolic address of
    the base point have been overwritten to implement detach of the event
    on the old attribute and attach on the new one.

 virtual ccsCOMPL_STAT Action(evhCALLBACK &cb);
    This method is used to dynamically define a callback to be executed
    when the event for new instrument configuration data occurrs.
    The method can be used to change the callback on the fly.
    This technique of handling the events is typically used when an
    instance of the mswINS_DATA_MONITOR class is created as a data member
    of the object that has to handle the event.
    In this case the callback will be typically a method of the class
    containing the instance of mswINS_DATA_MONITOR.

PROTECTED METHODS

 virtual int  _ActionCB(msgMESSAGE &msg, void *udata);
    This method if the implementation of the real callback installed
    in the event handler for the new instrument configuration data
    event.
    In this default implementation it just calls the callback installed
    via the Action() method and performs some basic clean-up.
    This implementation can be changed in sub-classes overwriting the
    method.
    This technique of handling the events is typically used when an
    instance of a sub-class of the mswINS_DATA_MONITOR class is
    created  in order to directly handle the received event.
    In this case the implementation of the callback will handle directly
    all the operations necessary when instrument configuration changes.

PRIVATE DATA MEMBERS

  evtEVENT     evt;       // Database event handling object
  evhCALLBACK *actionCb;  // Storage for the handling callback structure

ON LINE DATABASE

  These members are used to store the values retrieved by
  InsId() and InsData() methods.
  They can change at the next call of the methods, so the user
  must copy them upon return.

  The class assumes that the database support point is a subclass
  of mswINS_CONFIG_DATA, with the following structure:
    CLASS BASE_CLASS  mswINS_CONFIG_DATA                                    \\
    BEGIN                                                                   \\
       ATTRIBUTE BYTES32        selectedIns  "NONE"                         \\
       ATTRIBUTE Table          data( mswNO_OF_INSTRUMENTS,                 \\
                                      BYTES32    insId,                     \\
                                           .....                            \\
                                         )                                  \\
    END                                                                     \\
  The detailed definition of the table record format is important only
  for the class mswINS_DATA_RECORD(4); look there for details.

SEE ALSO

eccsERROR_CLASS(4), mswINS_CONFIG_DATA(4)

Index

NAME

PARENT CLASS

DESCRIPTION

PUBLIC METHODS

PROTECTED METHODS

PRIVATE DATA MEMBERS

ON LINE DATABASE

SEE ALSO