Yes, but that will block the UI. The progress bar update (world rendering) is done by force using âself currentWorld displayWorldâ, which also means that if the #do:displayingProgress: is forked there will be more than one UI rendering at the same time. Open a window, evaluate the script below, drag and drop the window around. [ Smalltalk allClasses do:[:aClass| (Delay forMilliseconds: 1) wait] displayingProgress:[:aClass| 'Processing ', aClass name]. ] fork Best regards, Henrik Fra: Pharo-dev [mailto:pharo-dev-bounces@lists.pharo.org] PÃ¥ vegne av phil@highoctane.be Sendt: 05 February 2017 21:43 Til: Pharo Development List <pharo-dev@lists.pharo.org> Emne: Re: [Pharo-dev] How can I create a trivial "spinner" etc, to see if image is busy? In the base image Smalltalk allClasses do:[:aClass| (Delay forMilliseconds: 1) wait] displayingProgress:[:aClass| 'Processing ', aClass name]. Phil On Sun, Feb 5, 2017 at 7:16 PM, Henrik Nergaard <draagren@outlook.com<mailto:draagren@outlook.com>> wrote: http://smalltalkhub.com/#!/~Latsabben/GafletFremgangFremviser --------------------- | ston file| ston := (1 to: 30) flatCollect: [:ix |STON toStringPretty: Smalltalk allClasses]. file := (FileStream fileNamed: 'file.ston'). ston whileDisplayingProgress action: [ :stream | file nextPutAll: stream ] whenDone: [ file close ]; open; fillOwner --------------------- Best regards, Henrik -----Opprinnelig melding----- Fra: Pharo-dev [mailto:pharo-dev-bounces@lists.pharo.org<mailto:pharo-dev-bounces@lists.pharo.org>] PÃ¥ vegne av Yuriy Tymchuk Sendt: 05 February 2017 16:56 Til: Pharo Development List <pharo-dev@lists.pharo.org<mailto:pharo-dev@lists.pharo.org>> Emne: [Pharo-dev] How can I create a trivial "spinner" etc, to see if image is busy? Hi all, is there an easy was to do some thing that is constantly changing? so if my image freezes (to export a 1gb ston file for example) I can see when itâs done. Or maybe there is a way to send a mac notification from Pharo? Cheers. Uko