diff options
| -rw-r--r-- | src/corelib/animation/qabstractanimation.cpp | 95 |
1 files changed, 49 insertions, 46 deletions
diff --git a/src/corelib/animation/qabstractanimation.cpp b/src/corelib/animation/qabstractanimation.cpp index 40fa8fa..440a37d 100644 --- a/src/corelib/animation/qabstractanimation.cpp +++ b/src/corelib/animation/qabstractanimation.cpp @@ -42,55 +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 - The class defines the functions for the functionality shared - between all animations. By inheriting this class, you can create - custom animations that plug into the rest of the animation - framework. - - - - 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. - - \omit - If you want to create an animation, you should look at the two subclasses, - QVariantAnimation and QAnimationGroup, instead. - \endomit - - \sa QVariantAnimation, QAnimationGroup, {The Animation Framework} + 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. + + 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} */ /*! |