Thread and signals

mahd96

i have a singleton class that handles downloading files. and some other classes that have data of files to be downloaded and pathes and ... . this second classes have some SIGNAL-SLOT connections to Communicate with downloader class. for preformance reseaons i want this conecction to be Queued connections ( this to classes live in same thread). but my slots dont invoke when appropriate signal emits.

i tried to move my downloader class to another thread so automaticaly i would have a Queued connection but it down'nt work.

i contemplate connecting signals after changing thread.

jsulm

@mahd96 Without code it is hard to say why the slots are not called.
Are you sure signals are emitted? Do you see any warnings at runtime?

mahd96

signals are emiting but i got this :
QObject::connect: Cannot queue arguments of type XXXX

J.Hilk

@mahd96
what are the arguments of your signal? My guess is some custom object/class/struct

That will work fine, if it's used in direct connection, otherwise you'll have to register it to the MetaObjectSystem for Qt to know how to Queue (copy) them.

jsulm

@mahd96 said in Thread and signals:

QObject::connect: Cannot queue arguments of type XXXX

Take a look at this: http://doc.qt.io/qt-5/qtcore-threads-queuedcustomtype-example.html
You need to register your own custom types before using them as parameter for signals/slots.