I have a basic Qt question on the way it handles Signals and Slots. I am very new to the framework, so pardon me if it sounds stupid. I was wondering if I have certain signals connected to certain slots.
signal1() ---> slot1(){ cout <<"a"; }
signal2() ---> slot2(){ cout <<"b"; }
signal3() ---> slot3(){ cout <<"c"; }
And in my code I call
emit signal1();
emit signal2();
emit signal3();
Does Qt guarantee to print out "abc" to the screen, in other words process the slots sequentially? Or will it spawn a separate thread to execute each slot? Thanks!
By default:
1) If the signal is emitted in the thread which the receiving object has affinity then the slots connected to this signal are executed immediately, just like a normal function calls. Execution of the code following the emit statement will occur once all slots have returned.
2) Otherwise, the slot is invoked when control returns to the event loop of the receiver's thread. The code following the emit keyword will continue immediately, and the slots will be executed later in the receiver's thread.
More info about connection types here: http://qt-project.org/doc/qt-4.8/threads-qobject.html#signals-and-slots-across-threads