public interface IProgressMonitor
IProgressMonitor
interface is implemented by objects that
monitor the progress of an activity; the methods in this interface are
invoked by code that performs the activity.
All activity is broken down into a linear sequence of tasks against which
progress is reported. When a task begins, a beginTask(String, int)
notification is reported, followed by any number and mixture of progress
reports (worked()
) and subtask notifications (subTask(String)
).
When the task is eventually completed, a done()
notification
is reported. After the done()
notification, the progress
monitor cannot be reused; i.e.,
beginTask(String, int)
cannot
be called again after the call to done()
.
A request to cancel an operation can be signaled using the
setCanceled
method. Operations taking a progress monitor are
expected to poll the monitor (using isCanceled
) periodically
and abort at their earliest convenience. Operation can however choose to
ignore cancelation requests.
Since notification is synchronous with the activity itself, the listener should provide a fast and robust implementation. If the handling of notifications would involve blocking operations, or operations which might throw uncaught exceptions, the notifications should be queued, and the actual processing deferred (or perhaps delegated to a separate thread).
Clients may implement this interface.
Modifier and Type | Field and Description |
---|---|
static int |
UNKNOWN
Constant indicating an unknown amount of work.
|
Modifier and Type | Method and Description |
---|---|
void |
beginTask(String name,
int totalWork)
Notifies that the main task is beginning.
|
void |
done()
Notifies that the work is done; that is, either the main task is
completed or the user canceled it.
|
void |
internalWorked(double work)
Internal method to handle scaling correctly.
|
boolean |
isCanceled()
Returns whether cancelation of current operation has been requested.
|
void |
setCanceled(boolean value)
Sets the cancel state to the given value.
|
void |
setTaskName(String name)
Sets the task name to the given value.
|
void |
subTask(String name)
Notifies that a subtask of the main task is beginning.
|
void |
worked(int work)
Notifies that a given number of work unit of the main task has been
completed.
|
static final int UNKNOWN
void beginTask(String name, int totalWork)
name
- the name (or description) of the main tasktotalWork
- the total number of work units into which the main task is
been subdivided. If the value is UNKNOWN
the
implementation is free to indicate progress in a way which
doesn't require the total number of work units in advance.void done()
void internalWorked(double work)
work
- the amount of work doneboolean isCanceled()
true
if cancellation has been requested, and
false
otherwisesetCanceled(boolean)
void setCanceled(boolean value)
value
- true
indicates that cancelation has been
requested (but not necessarily acknowledged);
false
clears this flagisCanceled()
void setTaskName(String name)
name
- the name (or description) of the main taskbeginTask(java.lang.String, int)
void subTask(String name)
name
- the name (or description) of the subtaskvoid worked(int work)
work
- the number of work units just completedCopyright © 2006–2016 Dirk Lemmermann Software & Consulting. All rights reserved.