Qt/C++ - confused about caller/callee, object ownership
- by Isabel
I am creating a GUI to manipulate a robot arm. The location of the arm can be described by 6 floats (describing the positions of the various arm joints.
The interface consists of a QGraphicsView with a diagram of the arm (which can be clicked to change the arm position - adjusting the 6 floats). The interface also has 6 lineEdit boxes, to also adjust those values separately.
When the graphics view is clicked, and when the line edit boxes are changed, I'd like the line edit boxes / graphics view to stay in synchronisation.
This brings me to confusion about how to store the 6 floats, and trigger events when they're updated. My current idea is this:
The robot arm's location should be represented by a class, RobotArmLocation. Objects of this class then have methods such as obj.ShoulderRotation() and obj.SetShoulderRotation().
The MainWindow has a single instance of RobotArmLocation.
Next is the bit I'm more confused about, how to join everything up. I am thinking:
The MainWindow has a ArmLocationChanged slot. This is signalled whenever the location object is changed.
The diagram class will have a SetRobotArmLocation(RobotArmLocation &loc). When the diagram is changed, it's free to change the location object, and fire a signal to the ArmLocationChanged slot.
Likewise, changing any of the text boxes will fire a signal to that ArmLocationChanged slot. The slot then has code to synchronise all the elements.
This kind of seems like a mess to me, does anyone have any other suggestions? I've also thought of the following, does it have any merrit?
The RobotArmLocation class has a ValueChanged slot, the diagram and textboxes can use that directly, and bypass the MainWindow directly (seems cleaner?)
thanks for any wisdom!
