Remove the connectByAnimation() function and add some documentation for the Stickman example

The connectByAnimation() function is no longer needed since we have default
animations. The docs are unfinished.

5 files changed, 137 insertions, 28 deletions

diff --git a/doc/src/examples/stickman.qdoc b/doc/src/examples/stickman.qdoc
new file mode 100644
index 0000000..0313c81
--- /dev/null
+++ b/doc/src/examples/stickman.qdoc
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \example animation/stickman
+    \title Stickman Example
+
+    The Stickman example shows how to animate transitions in a state machine to implement key frame 
+    animations.
+
+    \image stickman-example.png
+    
+    In this example, we will write a small application which animates the joints in a skeleton and
+    projects a stickman figure on top. The stickman can be either "alive" or "dead", and when in the
+    "alive" state, he can be performing different actions defined by key frame animations. 
+    
+    Animations are implemented as composite states. Each child state of the animation state 
+    represents a frame in the animation by setting the position of each joint in the stickman's 
+    skeleton to the positions defined for the particular frame. The frames are then bound together 
+    with animated transitions that trigger on the source state's polished() signal. Thus, the 
+    machine will enter the state representing the next state in the animation immediately after it
+    has finished animating into the previous frame.
+    
+    \image stickman-example1.png
+        
+    The states for an animation is constructed by reading a custom animation file format and 
+    creating states that assign values to the the "position" properties of each of the nodes in the 
+    skeleton graph. 
+    
+    \snippet examples/animation/stickman/lifecycle.cpp 1
+    
+    The states are then bound together with signal transitions that listen to the polished() signal.
+    
+    \snippet examples/animation/stickman/lifecycle.cpp 2
+    
+    The last frame state is given a transition to the first one, so that the animation will loop
+    until it is interrupted when a transition out from the animation state is taken. To get smooth 
+    animations between the different key frames, we set a default animation on the state machine. 
+    This is a parallel animation group which contain animations for all the "position" properties 
+    and will be selected by default when taking any transition that leads into a state that assigns 
+    values to these properties.
+    
+    \snippet examples/animation/stickman/lifecycle.cpp 3
+    
+    Several such animation states are constructed, and are placed together as children of a top 
+    level "alive" state which represents the stickman life cycle. Transitions go from the parent
+    state to the child state to ensure that each of the child states inherit them. 
+    
+    \image stickman-example2.png
+    
+    This saves us the effort of connect every state to every state with identical transitions. The 
+    state machine  makes sure that transitions between the key frame animations are also smooth by 
+    applying the default animation when interrupting one and starting another.
+        
+    Finally, there is a transition out from the "alive" state and into the "dead" state. This is 
+    a custom transition type called LightningStrikesTransition which samples every second and 
+    triggers at random (one out of fifty times on average.) 
+    
+    \snippet examples/animation/stickman/lifecycle.cpp 4
+    
+    When it triggers, the machine will first enter a "lightningStrike" state which uses a timer to 
+    pause for a brief period of time while the background color of the scene is white. This gives us 
+    a flash effect when the lightning strikes.
+    
+    \snippet examples/animation/stickman/lifecycle.cpp 5
+    
+    We start and stop a QTimer object when entering and exiting the state. Then we transition into
+    the "dead" state when the timer times out.
+    
+    \snippet examples/animation/stickman/lifecycle.cpp 0
+    
+    When the machine is in the "dead" state, it will be unresponsive. This is because the "dead" 
+    state has no transitions leading out.
+    
+    \image stickman-example3.png
+    
+*/
diff --git a/doc/src/images/stickman-example.png b/doc/src/images/stickman-example.png
new file mode 100644
index 0000000..a40f37b
--- /dev/null
+++ b/doc/src/images/stickman-example.png
diff --git a/doc/src/images/stickman-example1.png b/doc/src/images/stickman-example1.png
new file mode 100644
index 0000000..7b9a5b8
--- /dev/null
+++ b/doc/src/images/stickman-example1.png
diff --git a/examples/animation/stickman/lifecycle.cpp b/examples/animation/stickman/lifecycle.cpp
index 6b69a26..1feb31d 100644
--- a/examples/animation/stickman/lifecycle.cpp
+++ b/examples/animation/stickman/lifecycle.cpp
@@ -82,6 +82,7 @@ private:
     Qt::Key m_key;
 };
 
+//! [4]
 class LightningStrikesTransition: public QEventTransition
 {
 public:
@@ -97,6 +98,7 @@ public:
         return QEventTransition::eventTest(e) && ((qrand() % 50) == 0);
     }
 };
+//! [4]
 
 LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
     : m_stickMan(stickMan), m_keyReceiver(keyReceiver)
@@ -110,7 +112,10 @@ LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
     }
 
     // Set up intial state graph
+//! [3]
     m_machine = new QStateMachine();
+    m_machine->addDefaultAnimation(m_animationGroup);
+//! [3]
 
     m_alive = new QState(m_machine->rootState());
     m_alive->setObjectName("alive");
@@ -122,11 +127,13 @@ LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
     lightningBlink->assignProperty(m_stickMan, "fillColor", Qt::white);
     lightningBlink->assignProperty(m_stickMan, "isDead", true);
     
+//! [5]
     QTimer *timer = new QTimer(lightningBlink);
     timer->setSingleShot(true);
     timer->setInterval(100);
     QObject::connect(lightningBlink, SIGNAL(entered()), timer, SLOT(start()));
     QObject::connect(lightningBlink, SIGNAL(exited()), timer, SLOT(stop()));
+//! [5]
   
     m_dead = new QState(m_machine->rootState());
     m_dead->assignProperty(m_stickMan->scene(), "backgroundBrush", Qt::black);
@@ -141,9 +148,9 @@ LifeCycle::LifeCycle(StickMan *stickMan, GraphicsView *keyReceiver)
     m_alive->setInitialState(m_idle);
 
     // Lightning strikes at random
-//! [0]
     m_alive->addTransition(new LightningStrikesTransition(lightningBlink));
-    connectByAnimation(lightningBlink, m_dead, new QSignalTransition(timer, SIGNAL(timeout())));
+//! [0]
+    lightningBlink->addTransition(timer, SIGNAL(timeout()), m_dead);
 //! [0]
 
     m_machine->setInitialState(m_alive);
@@ -160,23 +167,10 @@ void LifeCycle::start()
     m_machine->start();
 }
 
-//! [1]
-void LifeCycle::connectByAnimation(QState *s1, QAbstractState *s2, QAbstractTransition *transition)
-{
-    if (transition == 0) {
-        transition = s1->addTransition(s2);
-    } else {
-        transition->setTargetState(s2);
-        s1->addTransition(transition);
-    }
-    transition->addAnimation(m_animationGroup);
-}
-//! [1]
-
 void LifeCycle::addActivity(const QString &fileName, Qt::Key key)
 {
     QState *state = makeState(m_alive, fileName);
-    connectByAnimation(m_alive, state, new KeyPressTransition(m_keyReceiver, key));
+    m_alive->addTransition(new KeyPressTransition(m_keyReceiver, key, state));
 }
 
 QState *LifeCycle::makeState(QState *parentState, const QString &animationFileName)
@@ -193,26 +187,28 @@ QState *LifeCycle::makeState(QState *parentState, const QString &animationFileNa
     const int frameCount = animation.totalFrames();
     QState *previousState = 0;
     for (int i=0; i<frameCount; ++i) {
-        QState *frameState = new QState(topLevel);
-        frameState->setObjectName(QString::fromLatin1("frame %0").arg(i));
-
         animation.setCurrentFrame(i);
+
+//! [1]
+        QState *frameState = new QState(topLevel);                       
         const int nodeCount = animation.nodeCount();
         for (int j=0; j<nodeCount; ++j)
             frameState->assignProperty(m_stickMan->node(j), "position", animation.nodePos(j));
+//! [1]
 
-        if (previousState == 0) {
+        frameState->setObjectName(QString::fromLatin1("frame %0").arg(i));
+        if (previousState == 0)
             topLevel->setInitialState(frameState);
-        } else {
-            connectByAnimation(previousState, frameState, 
-                new QSignalTransition(previousState, SIGNAL(polished())));
-        }
+        else
+//! [2]
+            previousState->addTransition(previousState, SIGNAL(polished()), frameState);
+//! [2]
+        
         previousState = frameState;
     }
 
     // Loop
-    connectByAnimation(previousState, topLevel->initialState(), 
-        new QSignalTransition(previousState, SIGNAL(polished())));
+    previousState->addTransition(previousState, SIGNAL(polished()), topLevel->initialState());
 
     return topLevel;
 
diff --git a/examples/animation/stickman/lifecycle.h b/examples/animation/stickman/lifecycle.h
index e520402..8fd0fb2 100644
--- a/examples/animation/stickman/lifecycle.h
+++ b/examples/animation/stickman/lifecycle.h
@@ -63,8 +63,6 @@ public:
     void start();
 
 private:
-    void connectByAnimation(QState *s1, QAbstractState *s2, 
-                            QAbstractTransition *transition = 0);
     QState *makeState(QState *parentState, const QString &animationFileName);
 
     StickMan *m_stickMan;