Make QStateMachine inherit QState

This removes the need for a "root state" in the machine; or rather,
the machine _is_ the root state.
User code can now pass in a QStateMachine directly to the QState
constructor, instead of machine->rootState().
This also means we could get rid of the "proxying" from the machine
to the root state for things like properties (initialState et al),
finished() signal and auto-reparenting of states (the ChildAdded
event hack).
A fun little side-effect of this change is that it's now possible
to embed state machines within state machines. We can't think of
a good use case yet where you would rather embed a stand-alone
state machine (with its own event processing etc.) rather than
having just a regular nested state, but it's neat and it works.

Reviewed-by: Eskil Abrahamsen Blomfeldt

1 files changed, 3 insertions, 3 deletions

diff --git a/examples/animation/stickman/lifecycle.cpp b/examples/animation/stickman/lifecycle.cpp
index 2a54c82..c761d87 100644
--- a/examples/animation/stickman/lifecycle.cpp
+++ b/examples/animation/stickman/lifecycle.cpp
@@ -108,11 +108,11 @@ LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
     m_machine->addDefaultAnimation(m_animationGroup);
 //! [3]
 
-    m_alive = new QState(m_machine->rootState());
+    m_alive = new QState(m_machine);
     m_alive->setObjectName("alive");
     
     // Make it blink when lightning strikes before entering dead animation
-    QState *lightningBlink = new QState(m_machine->rootState());    
+    QState *lightningBlink = new QState(m_machine);    
     lightningBlink->assignProperty(m_stickMan->scene(), "backgroundBrush", Qt::white);
     lightningBlink->assignProperty(m_stickMan, "penColor", Qt::black);
     lightningBlink->assignProperty(m_stickMan, "fillColor", Qt::white);
@@ -126,7 +126,7 @@ LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
     QObject::connect(lightningBlink, SIGNAL(exited()), timer, SLOT(stop()));
 //! [5]
   
-    m_dead = new QState(m_machine->rootState());
+    m_dead = new QState(m_machine);
     m_dead->assignProperty(m_stickMan->scene(), "backgroundBrush", Qt::black);
     m_dead->assignProperty(m_stickMan, "penColor", Qt::white);
     m_dead->assignProperty(m_stickMan, "fillColor", Qt::black);