Basic usage

There are 3 types of progress indication:

• 1. indefinite when it's not known how much time will be needed to complete
• 2. definite with time estimate for completion (UI shows time that remains)
• 3. definite without time estimate where the UI shows percentage completed.

The default location of the progress indication is the status bar which aggregates all tasks running in the IDE that show progress. However it's possible to exclude the task from the default location and show the progress in one's custom dialog component. In such a case the same task should not appear in the status line component as well.

It's possible to request cancelling the task from status line progress aggregator if the task allows cancelling.

Progress tasks that get started as a result of explicit user action takes precedence in the status line docked component over tasks that are triggered by the system. (say filesystem refresh for example)

The most common usecase of the API looks like this:

ProgressHandle handle = ProgressHandleFactory.creatHandle("My custom task");
...
// we have 100 workunits
// at this point the task appears in status bar.
handle.start(100);
...
handle.progress(10);
...
handle.progress("half way through", 50);
...
handle.progress(99);
// at this point the task is finished and removed from status bar
// it's not realy necessary to count all the way to the limit, finish can be called earlier.
// however it has to be called at the end of the processing.
handle.finish();

Advanced Usage

In case your usage of the API

• spans across multiple independent modules,
• requires adjusting of number of workunits or
• triggers additional action based on the current progress

then you should consider using the aggregating version of APIs which is similar to the simple APIs but has distinctive differences and additions that allow for more complex scenarios.

It allows to compose the progress bar from 1+ independent sources, all sharing proportional piece of the progress bar. Additionally you can monitor the task's overall progress from one central place and possibly add more contributing sources of the progress during processing.

        // let's have a factory for client code that performs some part of the job to be done..
        Lookup.Result res = Lookup.getDefault().lookup(new LookupTemplate(MyWorkerFactory.class));
        Iterator it = res.allInstances().iterator();
        ProgressContributor[] contribs = new ProgressContributor[res.allInstances().size()];
        int i = 0;
        while (it.hasNext()) {
            MyWorkerFactory prov = (MyWorkerFactory)it.next();
            contribs[i] = AggregateProgressFactory.createProgressContributor("Module X contribution");
            MyWorker worker = prov.createWorker(contribs[i]);
            //... snip ... do something with the worker..
            i = i + 1;
        }
        AggregateProgressHandle handle = AggregateProgressFactory.createHandle("My Task", contribs, null, null);
        // non-cancellable and with out output link.
        
        // calling start() at the time when the actual long running task starts processing
        handle.start("here we go");
        // ...snip...
        // now the individual MyWorker instances log their progress.
        // possibly in other threads too..
        // ... snip...
        // 
        if (myConditionThatSpawnsAnotherContributor()) {
            ProgressContributor cont = AggregateProgressFactory.createProgressContributor("Additional exceptional contribution");
            handle.addContributor(cont);
            // ... snip ...
        }
        
        // the task is finished when all the ProgressContributors finish..