org.dvb.user.UserPreferenceManager Maven / Gradle / Ivy
package org.dvb.user ;
import java.io.*;
import java.util.*;
/**
* The UserPreferenceManager class gives access to the user preference settings. This
* class provides a set of methods that allow an application to read or
* save user settings. It also provides a mechanism to notify applications when
* a preference has been modified. The value of a user setting, retrieved with
* the read method, is a copy of the value that is stored in the receiver. The
* write method, if authorized, overwrites the stored value.
* NOTE: MHP implementations are not required to validate the values in Preference objects,
* even those which are saved using the write method. Applications with write permissions
* need to be very careful that the values written are valid. Applications reading
* permissions need to be aware of the possibility that a previous application has set
* an invalid value.
*/
public class UserPreferenceManager {
private UserPreferenceManager() {}
/**
* Return an instance of the UserPreferenceManager for this application.
* Repeated calls to this method by the same application shall return the
* same instance.
* @return an instance of UserPreferenceManager
*/
public static UserPreferenceManager getInstance(){ return null; }
/**
* Allows an application to read a specified user preference.
* When end-user preferences are read into a Preference object from the MHP
* terminal, the ordering of these values shall be as determined by the end-user, from
* most preferred to least preferred to the extent that this is known.
*
* @param p an object representing the preference to read.
* @throws SecurityException if the calling application is denied access to this preference
*/
public void read (Preference p) {}
/**
* Allows an application to read a specified user preference taking
* into account the facility defined by the application.
* After this method returns, the values in the Preference object shall be the values
* of that user preference with any unsupported values from the Facility removed from
* that list. Note that the order of values returned here need not be the same as that
* returned by read(Preference).
* If the intersection
* between the two sets of values is empty then the preference will have
* no value. If there is a mis-match between the name of the preference used
* when constructing the facility and the name of the preference used in this
* method then the preference will have no value.
*
* @param p an object representing the preference to read.
* @param facility the preferred values of the application for the preference
* @throws SecurityException if the calling application is denied access to this preference
*/
public void read
(Preference p, Facility facility) {}
/**
* Saves the specified user preference. If this method succeeds then
* it will change the value of this preference for all future MHP
* applications.
*
* @param p the preference to save.
* @throws UnsupportedPreferenceException if the preference provided is not a standardized
* preference as defined for use with GeneralPreference.
* @throws java.lang.SecurityException if the application does not have permission to call this method
* @throws IOException if saving the preference fails for other I/O reasons
*/
public void write (Preference p) throws
UnsupportedPreferenceException, IOException {}
/**
* Adds a listener for changes in user preferences as held in the MHP terminal.
* Specifically this includes changes made by MHP applications succeeding in
* calling the write() method on this class. If the implementation of the MHP
* terminal allows the end user to change preferences then these changes also
* includes changes made to preferences by this mechanism. It does not include
* changes made to a Preference instance within the scope of a single MHP application. *
* @param l the listener to add.
*/
public void addUserPreferenceChangeListener
(UserPreferenceChangeListener l) {}
/**
* Removes a listener for changes in user preferences.
*
* @param l the listener to remove.
*/
public void removeUserPreferenceChangeListener
(UserPreferenceChangeListener l) {}
}