Show, activate and stop indetermined progress indicator

Question

I'm having some issues with showing a progress indicator whenever a button is clicked, and then stop and hide the indicator when a NSTask is completed.

This should be the timeline: 1- Button clicked 2- shows progress indicator (from originally hidden state) 3- activates progress indicator 4- activate associated NSTask 5- Continue showing the indicator until the NSTask is completed 6- after the completion of the NSTask, hide the progress indicator.

I know how to get a progress indicator to animate etc. I just do not know how to combine these with the NSTask completing thing..

Thanks for the help in advance!

CRD · Accepted Answer · 2013-07-31T23:21:12.153

1

Use NSTask's terminationHandler property to set a block to execute when the task terminates. In that block stop/hide your progress indicator.

Addendum (see comments)

In rough outline:

NSTask *myTask = ...;
NSProgressIndicator *myIndicator = ...;

myTask.terminationHandler = ^(NSTask *theTask) { [myIndicator stopAnimation:nil]; };

Note that the handler is passed the NSTask in case it needs to access information from it. Also nil is passed as the sender to stopAnimation: - you usually pass self but that would cause a retain cycle and what object is actually invoking the method isn't important.

edited Jul 31 '13 at 23:21

answered Jul 31 '13 at 21:43

CRD

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Thanks! I have to give you accepted answer because you were first. – Rstew Jul 31 '13 at 21:50
Would you mind giving a tiny example of how to implement this? – Rstew Jul 31 '13 at 21:59

score 1 · Answer 2 · answered Jul 31 '13 at 21:46

1

You should be able to set a block to the NSTask's terminationHandler.

NSTask terminationHandler

answered Jul 31 '13 at 21:46

Matt J

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Show, activate and stop indetermined progress indicator

2 Answers2