Merge branch 'kinetic-animations' into kinetic-statemachine

2 files changed, 153 insertions, 100 deletions

diff --git a/src/corelib/animation/qabstractanimation.cpp b/src/corelib/animation/qabstractanimation.cpp
index 71ef45c..440a37d 100644
--- a/src/corelib/animation/qabstractanimation.cpp
+++ b/src/corelib/animation/qabstractanimation.cpp
@@ -42,51 +42,58 @@
 /*!
     \class QAbstractAnimation
     \ingroup animation
-    \brief The QAbstractAnimation class provides an abstract base class for animations.
+    \brief The QAbstractAnimation class is the base of all animations.
     \since 4.5
     \preliminary
 
-    This class is part of \l{The Animation Framework}. It serves as a base class
-    for standard animations and groups, with functions for shared
-    functionality, and it also makes it easy for you to define custom
+    The class defines the functions for the functionality shared by
+    all animations. By inheriting this class, you can create custom
     animations that plug into the rest of the animation framework.
 
-    If you want to create an animation, you should look at the two subclasses,
-    QVariantAnimation and QAnimationGroup, instead.
-
-    QAbstractAnimation provides an interface for the current time and
-    duration, the loop count, and the state of an animation. These properties
-    define the base functionality common to all animations in Qt. The virtual
-    duration() function returns the local duration of the animation; i.e., for
-    how long the animation should update the current time before
-    looping. Subclasses can implement this function differently; for example,
-    QVariantAnimation returns the duration of a simple animated property, whereas
-    QAnimationGroup returns the duration of a set or sequence of
-    animations. You can also set a loop count by calling setLoopCount(); a
-    loop count of 2 will let the animation run twice (the default value is
-    1).
-
-    Like QTimeLine, QAbstractAnimation also provides an interface for starting
-    and stopping an animation, and for tracking its progress. You can call the
-    start() slot to start the animation. When the animation starts, the
-    stateChanged() signal is emitted, and state() returns Running. If you call the
-    stop() slot, the stateChanged() signal is emitted, and state() returns
-    Stopped. If you call the pause() slot, the stateChanged() signal is emitted
-    and state() returns Paused. If the animation reaches the end, the finished()
-    signal is emitted. You can check the current state by calling state().
-
-    QAbstractAnimation provides two functions that are pure virtual, and must
-    be reimplemented in a subclass: duration(), and updateCurrentTime(). The
-    duration() function lets you report a duration for the animation (a return
-    value of -1 signals that the animation runs forever until explicitly
-    stopped). The current time is delivered by the framework through calls to
-    updateCurrentTime(). By reimplementing this function, you can track the
-    animation progress and update your target objects accordingly. By
-    reimplementing updateState(), you can track the animation's state
-    changes, which is particularily useful for animations that are not driven
-    by time.
-
-    \sa QVariantAnimation, QAnimationGroup, {The Animation Framework}
+    The progress of an animation is given by its current time
+    (currentTime()), which is measured in milliseconds from the start
+    of the animation (0) to its end (duration()). The value is updated
+    automatically while the animation is running. It can also be set
+    directly with setCurrentTime().
+
+    At any point an animation is in one of three states:
+    \l{QAbstractAnimation::}{Running},
+    \l{QAbstractAnimation::}{Stopped}, or
+    \l{QAbstractAnimation::}{Paused}--as defined by the
+    \l{QAbstractAnimation::}{State} enum. The current state can be
+    changed by calling start(), stop(), pause(), or resume(). An
+    animation will always reset its \l{currentTime()}{current time}
+    when it is started. If paused, it will continue with the same
+    current time when resumed. When an animation is stopped, it cannot
+    be resumed, but will keep its current time (until started again).
+    QAbstractAnimation will emit stateChanged() whenever its state
+    changes.
+
+    An animation can loop any number of times by setting the loopCount
+    property. When an animation's current time reaches its duration(),
+    it will reset the current time and keep running. A loop count of 1
+    (the default value) means that the animation will run one time.
+    Note that a duration of -1 means that the animation will run until
+    stopped; the current time will increase indefinitely. When the
+    current time equals duration() and the animation is in its
+    final loop, the \l{QAbstractAnimation::}{Stopped} state is
+    entered, and the finished() signal is emitted.
+
+    QAbstractAnimation provides pure virtual functions used by
+    subclasses to track the progress of the animation: duration() and
+    updateCurrentTime(). The duration() function lets you report a
+    duration for the animation (as discussed above). The current time
+    is delivered by the animation framework through calls to
+    updateCurrentTime(). By reimplementing this function, you can
+    track the animation progress. Note that neither the interval
+    between calls nor the number of calls to this function are
+    defined; though, it will normally be 60 updates per second.
+
+    By reimplementing updateState(), you can track the animation's
+    state changes, which is particularly useful for animations that
+    are not driven by time.
+
+    \sa QVariantAnimation, QPropertyAnimation, QAnimationGroup, {The Animation Framework}
 */
 
 /*!
diff --git a/src/corelib/animation/qvariantanimation.cpp b/src/corelib/animation/qvariantanimation.cpp
index 9f8cbf0..73ed0df 100644
--- a/src/corelib/animation/qvariantanimation.cpp
+++ b/src/corelib/animation/qvariantanimation.cpp
@@ -59,26 +59,68 @@ QT_BEGIN_NAMESPACE
     \since 4.5
     \preliminary
 
-    This class is part of {The Animation Framework}. It serves as a base class
-    for property and item animations, with functions for shared functionality.
-
-    If you want to create an animation, you should look at QPropertyAnimation instead.
-
+    This class is part of \l{The Animation Framework}. It serves as a
+    base class for property and item animations, with functions for
+    shared functionality.
+
+    QVariantAnimation cannot be used directly as it is an abstract
+    class; it does not implement
+    \l{QAbstractAnimation::}{updateCurrentValue()} from
+    QAbstractAnimation. The class performs interpolation over
+    \l{QVariant}s, but leaves using the interpolated values to its
+    subclasses. Currently, Qt provides QPropertyAnimation, which
+    animates Qt \l{Qt's Property System}{properties}. See the
+    QPropertyAnimation class description if you wish to animate such
+    properties.
+    
     You can then set start and end values for the property by calling
     setStartValue() and setEndValue(), and finally call start() to
-    start the animation. When control goes back to the event loop, QVariantAnimation
-    will interpolate the property of the target object and emit the valueChanged
-    signal. To react to a change in the current value you have to reimplement the
-    updateCurrentValue virtual method.
-
-    There are two ways to affect how QVariantAnimation interpolates the values.
-    You can set an easing curve by calling setEasingCurve(), and configure the
-    duration by calling setDuration(). You can change how the QVariants are
-    interpolated by creating a subclass of QVariantAnimation, and reimplementing the
-    virtual interpolated() function.
-
-
-    \sa QPropertyAnimation, {The Animation Framework}
+    start the animation. QVariantAnimation will interpolate the
+    property of the target object and emit valueChanged(). To react to
+    a change in the current value you have to reimplement the
+    updateCurrentValue() virtual function.
+
+    It is also possible to set values at specified steps situated
+    between the start and end value. The interpolation will then
+    touch these points at the specified steps. Note that the start and
+    end values are defined as the key values at 0.0 and 1.0.
+
+    There are two ways to affect how QVariantAnimation interpolates
+    the values. You can set an easing curve by calling
+    setEasingCurve(), and configure the duration by calling
+    setDuration(). You can change how the QVariants are interpolated
+    by creating a subclass of QVariantAnimation, and reimplementing
+    the virtual interpolated() function.
+
+    Subclassing QVariantAnimation can be an alternative if you have
+    \l{QVariant}s that you do not wish to declare as Qt properties.
+    Note, however, that you in most cases will be better off declaring
+    your QVariant as a property.
+
+    Not all QVariant types are supported. Below is a list of currently
+    supported QVariant types:
+
+    \list
+        \o \l{QMetaType::}{Int}
+        \o \l{QMetaType::}{Double}
+        \o \l{QMetaType::}{Float}
+        \o \l{QMetaType::}{QLine}
+        \o \l{QMetaType::}{QLineF}
+        \o \l{QMetaType::}{QPoint}
+        \o \l{QMetaType::}{QSize}
+        \o \l{QMetaType::}{QSizeF}
+        \o \l{QMetaType::}{QRect}
+        \o \l{QMetaType::}{QRectF}
+    \endlist 
+
+    If you need to interpolate other variant types, including custom
+    types, you have to implement interpolation for these yourself.
+    You do this by reimplementing interpolated(), which returns
+    interpolation values for the value being interpolated. 
+
+    \omit We need some snippets around here. \endomit
+
+    \sa QPropertyAnimation, QAbstractAnimation, {The Animation Framework}
 */
 
 /*!
@@ -175,26 +217,16 @@ void QVariantAnimationPrivate::updateCurrentValue()
                 endProgress = currentInterval.end.first;
     const qreal localProgress = (progress - startProgress) / (endProgress - startProgress);
 
-    bool changed = false;
-    {
-      //we do that here in a limited scope so that ret is dereferenced and frees memory
-      //and the call to updateCurrentValue can recreate QVariant of the same type (for ex. in
-      //QGraphicsItem::setPos
-      QVariant ret = q->interpolated(currentInterval.start.second,
-                                    currentInterval.end.second,
-                                    localProgress);
-      if (currentValue != ret) {
-          changed = true;
-          qSwap(currentValue, ret);
-      }
-    }
-
-    if (changed) {
-        //the value has changed
-        q->updateCurrentValue(currentValue);
+    QVariant ret = q->interpolated(currentInterval.start.second,
+                                   currentInterval.end.second,
+                                   localProgress);
+    qSwap(currentValue, ret);
+    q->updateCurrentValue(currentValue);
 #ifndef QT_EXPERIMENTAL_SOLUTION
         if (connectedSignals & changedSignalMask)
 #endif
+    if (currentValue != ret) {
+        //the value has changed
             emit q->valueChanged(currentValue);
     }
 }
@@ -271,16 +303,16 @@ QVariantAnimation::~QVariantAnimation()
     \property QVariantAnimation::easingCurve
     \brief the easing curve of the animation
 
-    This property defines the easing curve of the animation. By default, a
-    linear easing curve is used, resulting in linear interpolation of the
-    end property. For many animations, it's useful to try different easing
-    curves, including QEasingCurve::InCirc, which provides a circular entry curve,
-    and QEasingCurve::InOutElastic, which provides an elastic effect on the values
-    of the interpolated property.
+    This property defines the easing curve of the animation. By
+    default, a linear easing curve is used, resulting in linear
+    interpolation. Other curves are provided, for instance,
+    QEasingCurve::InCirc, which provides a circular entry curve.
+    Another example is QEasingCurve::InOutElastic, which provides an
+    elastic effect on the values of the interpolated variant.
 
-    The easing curve is used with the interpolator, the interpolated() virtual
-    function, the animation's duration, and loopCount, to control how the
-    current value changes as the animation progresses.
+    The easing curve is used with the interpolator, the interpolated()
+    virtual function, the animation's duration, and iterationCount, to
+    control how the current value changes as the animation progresses.
 */
 QEasingCurve QVariantAnimation::easingCurve() const
 {
@@ -382,8 +414,8 @@ QVariantAnimation::Interpolator QVariantAnimationPrivate::getInterpolator(int in
     \property QVariantAnimation::duration
     \brief the duration of the animation
 
-    This property describes the duration of the animation. The default
-    duration is 250 milliseconds.
+    This property describes the duration in milliseconds of the
+    animation. The default duration is 250 milliseconds.
 
     \sa QAbstractAnimation::duration()
  */
@@ -519,17 +551,22 @@ void QVariantAnimation::setKeyValues(const KeyValues &keyValues)
 
 /*!
     \property QVariantAnimation::currentValue
-    \brief the current value of the animation
+    \brief the current value of the animation.
 
-    This property describes the current value; an interpolation between the
-    start value and the end value, using the current time for progress.
+    This property describes the current value; an interpolated value
+    between the \l{startValue}{start value} and the \l{endValue}{end
+    value}, using the current time for progress. The value itself is
+    obtained from interpolated(), which is called repeatedly as the
+    animation is running.
 
-    QVariantAnimation calls the virtual updateCurrentValue() function when the
-    current value changes. This is particularily useful for subclasses that
-    need to track updates.
+    QVariantAnimation calls the virtual updateCurrentValue() function
+    when the current value changes. This is particularly useful for
+    subclasses that need to track updates. For example,
+    QPropertyAnimation uses this function to animate Qt \l{Qt's
+    Property System}{properties}.
 
     \sa startValue, endValue
- */
+*/
 QVariant QVariantAnimation::currentValue() const
 {
     Q_D(const QVariantAnimation);
@@ -559,13 +596,22 @@ void QVariantAnimation::updateState(QAbstractAnimation::State oldState,
 }
 
 /*!
-    This virtual function returns the linear interpolation between variants \a
-    from and \a to, at \a progress, usually a value between 0 and 1. You can reimplement
-    this function in a subclass of QVariantAnimation to provide your own interpolation
-    algorithm. Note that in order for the interpolation to work with a QEasingCurve
-    that return a value smaller than 0 or larger than 1 (such as QEasingCurve::InBack)
-    you should make sure that it can extrapolate. If the semantic of the datatype
-    does not allow extrapolation this function should handle that gracefully.
+
+    This virtual function returns the linear interpolation between
+    variants \a from and \a to, at \a progress, usually a value
+    between 0 and 1. You can reimplement this function in a subclass
+    of QVariantAnimation to provide your own interpolation algorithm.
+
+    Note that in order for the interpolation to work with a
+    QEasingCurve that return a value smaller than 0 or larger than 1
+    (such as QEasingCurve::InBack) you should make sure that it can
+    extrapolate. If the semantic of the datatype does not allow
+    extrapolation this function should handle that gracefully.
+
+    You should call the QVariantAnimation implementation of this
+    function if you want your class to handle the types already
+    supported by Qt (see class QVariantAnimation description for a
+    list of supported types).
 
     \sa QEasingCurve
  */