Game Programming using Qt 5 Beginner's Guide - Second Edition

Behaviors

In the previous chapter, we implemented a dashboard for a racing game where we had a number of clocks with needles. We could set values for each clock (for example, car speed) and a respective needle would immediately set itself to the given value. However, such an approach is unrealistic—in the real world, changes of a value happen over time. In our example, the car accelerates from 10 mph to 50 mph by going through 11 mph, 12 mph, and so on, until after some time it reaches the desired value. We call this the behavior of a value—it is essentially a model that tells how the parameter reaches its destined value. Defining such models is a perfect use case for declarative programming. Fortunately, QML exposes a Behavior element that ...