Module imagingbook.common

Package imagingbook.common.util.progress

Class ProgressMonitor

java.lang.Object

java.lang.Thread

imagingbook.common.util.progress.ProgressMonitor

All Implemented Interfaces:

AutoCloseable, Runnable

Direct Known Subclasses:

ConsoleProgressMonitor, IjProgressBarMonitor

public abstract class ProgressMonitor
extends Thread
implements AutoCloseable

This class represents a "progress monitor". This is a simple Thread that queries the attached target task (implementing ProgressReporter) and calls its handleProgress(double, long) method at regular intervals. ProgressMonitor implements the AutoCloseable and thus can (and should) be used in a try-with-resources context, e.g.,

 ProgressReporter task = ....; // the activity to be monitored
 try (ProgressMonitor m = new ConsoleProgressMonitor(task)) {
     // run task ...
 }
 

Otherwise, if not used in a auto-start/close mode, the methods Thread.start() and close() should be used to "manually" start and terminate monitoring. See ProgressMonitorExample, GenericFilter, ConsoleProgressMonitor and IjProgressBarMonitor for examples.

Note that this mechanism cannot be used to monitor activities inside a constructor, since no reference to the monitored instance is available before the constructor is finished.

See Also:

• ProgressReporter
• ProgressMonitorExample
• ConsoleProgressMonitor

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DefaultWaitTime	The default wait time between successive progress queries.

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor	Description
ProgressMonitor(ProgressReporter target)	Constructor, starts monitoring immediately.
ProgressMonitor(ProgressReporter target, boolean autoStart)	Constructor, optionally starts monitoring immediately or waits for its Thread.start() method to be called (which starts the associated thread).

Method Summary

Modifier and Type	Method	Description
void	close()
double	getElapsedTime()	Returns the time elapsed since monitoring started (in seconds).
abstract void	handleProgress(double progress, long elapsedNanoTime)	Called periodically by the ProgressMonitor thread supplying the current progress value (degree of completion).
void	run()
void	setWaitTime(int waitTime)	The time interval between progress queries can be set with this method.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

DefaultWaitTime

public static final int DefaultWaitTime

The default wait time between successive progress queries.

See Also:

• Constant Field Values

Constructor Details

ProgressMonitor

public ProgressMonitor(ProgressReporter target)

Constructor, starts monitoring immediately. The target object's ProgressReporter.getProgress() method is called it regular intervals.

Parameters:

target - the object (task) to be monitored

ProgressMonitor

public ProgressMonitor(ProgressReporter target,
 boolean autoStart)

Constructor, optionally starts monitoring immediately or waits for its Thread.start() method to be called (which starts the associated thread). The target object's ProgressReporter.getProgress() method is called it regular intervals.

Parameters:

target - the object (task) to be monitored

autoStart - starts immediately if true

Method Details

setWaitTime

public void setWaitTime(int waitTime)

The time interval between progress queries can be set with this method. See also DefaultWaitTime.

Parameters:

waitTime - the time interval (in milliseconds)

handleProgress

public abstract void handleProgress(double progress,
 long elapsedNanoTime)

Called periodically by the ProgressMonitor thread supplying the current progress value (degree of completion). It is up to the implementation what action should be performed, e.g., display the current progress graphically (see e.g. IjProgressBarMonitor).

Parameters:

progress - the current progress value (degree of completion) in [0,1)

elapsedNanoTime - the time elapsed since this progress monitor was started (in nanoseconds)

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

close

public void close()

Specified by:

close in interface AutoCloseable

getElapsedTime

public double getElapsedTime()

Returns the time elapsed since monitoring started (in seconds).

Returns:

the elapsed time in seconds