Golang : Qt update UI elements with core.QCoreApplication_ProcessEvents
Not a tutorial, but putting this here in case I need to refer back in future. While developing a Golang-Qt application recently, I found out that UI elements such as progress bar or progress dialog will not be updated without this line:
core.QCoreApplication_ProcessEvents(core.QEventLoop__AllEvents)
Why? Basically, a graphical user interface(GUI) Qt application needs to update/redraw itself....but doing so every second can be a resource hogging process.
From http://doc.qt.io/qt-5/qcoreapplication.html#processEvents:
In the event that you are running a local loop which calls this function continuously, without an event loop, the DeferredDelete events will not be processed. This can affect the behaviour of widgets, e.g. QToolTip, that rely on DeferredDelete events to function properly. An alternative would be to call sendPostedEvents() from within that local loop.
Calling this function processes events only for the calling thread.
Therefore, need to invoke the core.QCoreApplication_ProcessEvents(core.QEventLoop__AllEvents)
function to get Qt to update the UI elements such as a progress bar.
References:
http://doc.qt.io/qt-5/qcoreapplication.html#processEvents
https://www.socketloop.com/tutorials/golang-qt-progress-dialog-example
See also : Golang : Qt progress dialog example
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+4.2k Swift : Get substring with rangeOfString() function example
+5k Get Facebook friends working in same company
+11.8k Golang : Recombine chunked files example
+7.4k Golang : How to get garbage collection data?
+8.3k Golang : Setting variable value with ldflags
+10.3k Golang : Skip blank/empty lines in CSV file and trim whitespaces example
+14.3k Golang : Find file size(disk usage) with filepath.Walk
+14.4k Golang : How to make a file read only and set it to writable again?
+7.2k Golang : Random integer with rand.Seed() within a given range
+6.7k PHP : How to parse ElasticSearch JSON ?
+30.8k Golang : All update packages with go get command
+9.7k Swift : Convert (cast) Float to String