info.pppc.base.system.operation

Interface IMonitor

All Known Implementing Classes:

NullMonitor

public interface IMonitor

A monitor is passed to an operation to signal the current status to a user interface or to some other external observing entity. For operations that are not observed, the framework provides a default null monitor that simply observes an operation.

Author:

Marcus Handte

Field Summary

Fields

Modifier and Type	Field and Description
static int	EVENT_MONITOR_CANCEL This constant is used to represent an event that signals that the operation should be canceled.
static int	EVENT_MONITOR_DONE This constant is used to represent an event that signals that the operation monitored by this monitor has called the done method.
static int	EVENT_MONITOR_NAME This constant is used to represent an event that signals a call to the set name method.
static int	EVENT_MONITOR_START This constant is used to represent an event that signals a call to the start method.
static int	EVENT_MONITOR_STEP This constant is used to represent an event that signals a call to the stop method.
static int	STEP_UNKNOWN This constant should be used if the total number of steps performed by the operation is not known.

Method Summary

Methods

Modifier and Type	Method and Description
void	addMonitorListener(int types, IListener listener) Adds the specified listener to the set of listeners that need to be informed whenever the state of the monitor changes.
void	cancel() Sets the canceled state of the monitor to true.
void	done() Informs the monitor that the operation has finished.
boolean	isCanceled() Queries the monitor to determine whether the operation has been canceled.
boolean	isDone() Determines whether the progress monitor assumes that the operation is still running.
void	join() Waits until the monitor's state is set to done or an the thread is interrupted.
boolean	removeMonitorListener(int types, IListener listener) Removes the specified listener from the set of registered listeners for the specified types of events.
void	setName(java.lang.String operation) Sets the name of the current operation.
void	start(int total) Begins an operation that has the specified total number of steps to perform.
void	step(int steps) Informs the monitor that the specified number of steps has been performed.

Field Detail

EVENT_MONITOR_START

static final int EVENT_MONITOR_START

This constant is used to represent an event that signals a call to the start method. The source of the event will be the monitor, the data object will contain the integer that denotes the number of steps of the task.

See Also:

Constant Field Values

EVENT_MONITOR_STEP

static final int EVENT_MONITOR_STEP

This constant is used to represent an event that signals a call to the stop method. The source of the event will be the monitor, the data object will contain the integer that denotes the number of steps that has been performed.

See Also:

Constant Field Values

EVENT_MONITOR_NAME

static final int EVENT_MONITOR_NAME

This constant is used to represent an event that signals a call to the set name method. The source of the event will be the monitor, the data object will contain the string that denotes the new name of the operation.

See Also:

Constant Field Values

EVENT_MONITOR_DONE

static final int EVENT_MONITOR_DONE

This constant is used to represent an event that signals that the operation monitored by this monitor has called the done method. The source of the event will be the monitor, the data object will be null.

See Also:

Constant Field Values

EVENT_MONITOR_CANCEL

static final int EVENT_MONITOR_CANCEL

This constant is used to represent an event that signals that the operation should be canceled. The source of the event will be the monitor, the data object will be null.

See Also:

Constant Field Values

STEP_UNKNOWN

static final int STEP_UNKNOWN

This constant should be used if the total number of steps performed by the operation is not known.

See Also:

Constant Field Values

Method Detail

addMonitorListener

void addMonitorListener(int types,
                      IListener listener)

Adds the specified listener to the set of listeners that need to be informed whenever the state of the monitor changes. The monitor must at least support the event constants defined by this interface with the corresponding source and data objects.

Parameters:

types - The types of events to register for. The types supported depend on the monitor implementation. However, each monitor must implement at least the event constants defined by this interface.

listener - The listener that listens to changes.

removeMonitorListener

boolean removeMonitorListener(int types,
                            IListener listener)

Removes the specified listener from the set of registered listeners for the specified types of events.

Parameters:

types - The types of events to unregister.

listener - The listener to unregister.

Returns:

True if the listener has been unregistered, false otherwise.

setName

void setName(java.lang.String operation)

Sets the name of the current operation.

Parameters:

operation - The name of the current operation.

start

void start(int total)

Begins an operation that has the specified total number of steps to perform.

Parameters:

total - The total number of steps to perform.

step

void step(int steps)

Informs the monitor that the specified number of steps has been performed.

Parameters:

steps - The number of steps that has been performed.

done

void done()

Informs the monitor that the operation has finished.

isDone

boolean isDone()

Determines whether the progress monitor assumes that the operation is still running.

Returns:

True if the progress monitor assumes that the operation is still running, false otherwise.

cancel

void cancel()

Sets the canceled state of the monitor to true. After a call to this method returns, the monitor state must return true for canceled.

isCanceled

boolean isCanceled()

Queries the monitor to determine whether the operation has been canceled. Note that this operation is not the opposite of running. An operation might be canceled although it is still running.

Returns:

True if the operation has been canceled, false if the operation should be performed.

join

void join()
          throws java.lang.InterruptedException

Waits until the monitor's state is set to done or an the thread is interrupted.

Throws:

java.lang.InterruptedException - Thrown if the thread is interrupted.