com.trolltech.qt.core
Class QTimeLine

java.lang.Object
  extended by com.trolltech.qt.internal.QSignalEmitterInternal
      extended by com.trolltech.qt.QSignalEmitter
          extended by com.trolltech.qt.QtJambiObject
              extended by com.trolltech.qt.core.QObject
                  extended by com.trolltech.qt.core.QTimeLine
All Implemented Interfaces:
QtJambiInterface

public class QTimeLine
extends QObject

The QTimeLine class provides a timeline for controlling animations. It's most commonly used to animate a GUI control by calling a slot periodically. You can construct a timeline by passing its duration in milliseconds to QTimeLine's constructor. The timeline's duration describes for how long the animation will run. Then you set a suitable frame range by calling setFrameRange(). Finally connect the frameChanged() signal to a suitable slot in the widget you wish to animate (e.g., setValue() in QProgressBar). When you proceed to calling start(), QTimeLine will enter Running state, and start emitting frameChanged() at regular intervals, causing your widget's connected property's value to grow from the lower end to the upper and of your frame range, at a steady rate. You can specify the update interval by calling setUpdateInterval(). When done, QTimeLine enters NotRunning state, and emits finished() .

Example:

        // ...
        progressBar = new QProgressBar(this);
        progressBar.setRange(0, 100);

        // Construct a 1-second timeline with a frame range of 0 - 100
        QTimeLine timeLine = new QTimeLine(1000, this);
        timeLine.setFrameRange(0, 100);
        timeLine.frameChanged.connect(progressBar, "setValue(int)");

        // Clicking the push button will start the progress bar animation
        pushButton = new QPushButton(tr("Start animation"), this);
        pushButton.clicked.connect(timeLine, "start()");
        // ...
You can also use QTimeLine with the Graphics View framework for animations. The QGraphicsItemAnimation class implements animation of QGraphicsItems with a timeline.

By default the timeline runs once, from the beginning and towards the end, upon which you must call start() again to restart from the beginning. To make the timeline loop, you can call setLoopCount(), passing the number of times the timeline should run before finishing. The direction can also be changed, causing the timeline to run backward, by calling setDirection(). You can also pause and unpause the timeline while it's running by calling setPaused(). For interactive control, the setCurrentTime() function is provided, which sets the time position of the time line directly. Although most useful in NotRunning state, (e.g., connected to a valueChanged() signal in a QSlider,) this function can be called at any time.

The frame interface is useful for standard widgets, but QTimeLine can be used to control any type of animation. The heart of QTimeLine lies in the valueForTime() function, which generates a value between 0 and 1 for a given time. This value is typically used to describe the steps of an animation, where 0 is the first step of an animation, and 1 is the last step. When running, QTimeLine generates values between 0 and 1 by calling valueForTime() and emitting valueChanged() . By default, valueForTime() applies an interpolation algorithm to generate these value. You can choose from a set of predefined timeline algorithms by calling setCurveShape(). By default, QTimeLine uses the EaseInOut curve shape, which provides a value that grows slowly, then grows steadily, and finally grows slowly. For a custom timeline, you can reimplement valueForTime(), in which case QTimeLine's curveShape property is ignored.

See also:
QProgressBar, QProgressDialog, and QGraphicsItemAnimation.


Nested Class Summary
static class QTimeLine.CurveShape
          This enum describes the default shape of QTimeLine's value curve.
static class QTimeLine.Direction
          This enum describes the direction of the timeline when in Running state.
static class QTimeLine.State
          This enum describes the state of the timeline.
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.PrivateSignal0, QSignalEmitter.PrivateSignal1, QSignalEmitter.PrivateSignal2, QSignalEmitter.PrivateSignal3, QSignalEmitter.PrivateSignal4, QSignalEmitter.PrivateSignal5, QSignalEmitter.PrivateSignal6, QSignalEmitter.PrivateSignal7, QSignalEmitter.PrivateSignal8, QSignalEmitter.PrivateSignal9, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9
 
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal
 
Field Summary
 QSignalEmitter.Signal0 finished
          This signal is emitted when QTimeLine finishes (i.e., reaches the end of its time line), and does not loop.
 QSignalEmitter.Signal1 frameChanged
          This signal takes 1 generic argument(s).
 QSignalEmitter.Signal1 stateChanged
          This signal takes 1 generic argument(s).
 QSignalEmitter.Signal1 valueChanged
          This signal takes 1 generic argument(s).
 
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
currentSender
 
Constructor Summary
QTimeLine()
          Constructs a timeline with a duration of duration milliseconds.
QTimeLine(int duration)
          Constructs a timeline with a duration of duration milliseconds.
QTimeLine(int duration, QObject parent)
          Constructs a timeline with a duration of duration milliseconds.
 
Method Summary
 int currentFrame()
          Returns the frame corresponding to the current time.
 int currentTime()
          This property holds the current time of the time line.
 double currentValue()
          Returns the value corresponding to the current time.
 QTimeLine.CurveShape curveShape()
          This property holds the shape of the timeline curve.
 QTimeLine.Direction direction()
          This property holds the direction of the timeline when QTimeLine is in Running state..
 int duration()
          This property holds the total duration of the timeline in milliseconds.
 int endFrame()
          Returns the end frame, which is the frame corresponding to the end of the timeline (i.
 int frameForTime(int msec)
          Returns the frame corresponding to the time msec.
 int loopCount()
          This property holds the number of times the timeline should loop before it's finished.
 void resume()
          Resumes the timeline from the current time.
 void setCurrentTime(int msec)
          This property holds the current time of the time line.
 void setCurveShape(QTimeLine.CurveShape shape)
          This property holds the shape of the timeline curve.
 void setDirection(QTimeLine.Direction direction)
          This property holds the direction of the timeline when QTimeLine is in Running state..
 void setDuration(int duration)
          This property holds the total duration of the timeline in milliseconds.
 void setEndFrame(int frame)
          Sets the end frame, which is the frame corresponding to the end of the timeline (i.
 void setFrameRange(int startFrame, int endFrame)
          Sets the timeline's frame counter to start at startFrame, and end and endFrame.
 void setLoopCount(int count)
          This property holds the number of times the timeline should loop before it's finished.
 void setPaused(boolean paused)
          If paused is true, the timeline is paused, causing QTimeLine to enter Paused state.
 void setStartFrame(int frame)
          Sets the start frame, which is the frame corresponding to the start of the timeline (i.
 void setUpdateInterval(int interval)
          This property holds the time in milliseconds between each time QTimeLine updates its current time.
 void start()
          Starts the timeline.
 int startFrame()
          Returns the start frame, which is the frame corresponding to the start of the timeline (i.
 QTimeLine.State state()
          Returns the state of the timeline.
 void stop()
          Stops the timeline, causing QTimeLine to enter NotRunning state.
 void toggleDirection()
          Toggles the direction of the timeline.
 int updateInterval()
          This property holds the time in milliseconds between each time QTimeLine updates its current time.
 double valueForTime(int msec)
          Returns the timeline value for the time msec.
 
Methods inherited from class com.trolltech.qt.core.QObject
childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, startTimer, timerEvent, toString, userProperty
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
__qt_signalInitialization
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Field Detail

finished

public final QSignalEmitter.Signal0 finished
This signal is emitted when QTimeLine finishes (i.e., reaches the end of its time line), and does not loop.


frameChanged

public final QSignalEmitter.Signal1 frameChanged

This signal takes 1 generic argument(s). We list their type and the name they go by in the description of this signal. <java.lang.Integer(named: frame)>:

QTimeLine emits this signal at regular intervals when in Running state, but only if the current frame changes. frame is the current frame number.

See also:
QTimeLine::setFrameRange(), and QTimeLine::updateInterval.


stateChanged

public final QSignalEmitter.Signal1 stateChanged

This signal takes 1 generic argument(s). We list their type and the name they go by in the description of this signal. <com.trolltech.qt.core.QTimeLine$State(named: newState)>:

This signal is emitted whenever QTimeLine's state changes. The new state is newState.


valueChanged

public final QSignalEmitter.Signal1 valueChanged

This signal takes 1 generic argument(s). We list their type and the name they go by in the description of this signal. <java.lang.Double(named: value)>:

QTimeLine emits this signal at regular intervals when in Running state, but only if the current value changes. value is the current value. value is a number between 0.0 and 1.0

See also:
QTimeLine::setDuration(), QTimeLine::valueForTime(), and QTimeLine::updateInterval.

Constructor Detail

QTimeLine

public QTimeLine(int duration)
Constructs a timeline with a duration of duration milliseconds. parent is passed to QObject's constructor. The default duration is 1000 milliseconds.


QTimeLine

public QTimeLine()
Constructs a timeline with a duration of duration milliseconds. parent is passed to QObject's constructor. The default duration is 1000 milliseconds.


QTimeLine

public QTimeLine(int duration,
                 QObject parent)
Constructs a timeline with a duration of duration milliseconds. parent is passed to QObject's constructor. The default duration is 1000 milliseconds.

Method Detail

currentFrame

public final int currentFrame()
Returns the frame corresponding to the current time.

See also:
currentTime(), frameForTime(), and setFrameRange().


currentTime

public final int currentTime()
This property holds the current time of the time line. When QTimeLine is in Running state, this value is updated continuously as a function of the duration and direction of the timeline. Otherwise, it is value that was current when stop() was called last, or the value set by setCurrentTime().

By default, this property contains a value of 0.


currentValue

public final double currentValue()
Returns the value corresponding to the current time.

See also:
valueForTime(), and currentFrame().


curveShape

public final QTimeLine.CurveShape curveShape()
This property holds the shape of the timeline curve. The curve shape describes the relation between the time and value for the base implementation of valueForTime().

If you have reimplemented valueForTime(), this value is ignored.

By default, this property is set to EaseInOutCurve .

See also:
valueForTime().


direction

public final QTimeLine.Direction direction()
This property holds the direction of the timeline when QTimeLine is in Running state.. This direction indicates whether the time moves from 0 towards the timeline duration, or from the value of the duration and towards 0 after start() has been called.

By default, this property is set to Forward .


duration

public final int duration()
This property holds the total duration of the timeline in milliseconds. By default, this value is 1000 (i.e., 1 second), but you can change this by either passing a duration to QTimeLine's constructor, or by calling setDuration(). The duration must be larger than 0.


endFrame

public final int endFrame()
Returns the end frame, which is the frame corresponding to the end of the timeline (i. ., the frame for which the current value is 1).

See also:
setEndFrame(), and setFrameRange().


frameForTime

public final int frameForTime(int msec)
Returns the frame corresponding to the time msec. This value is calculated using a linear interpolation of the start and end frame, based on the value returned by valueForTime().

See also:
valueForTime(), and setFrameRange().


loopCount

public final int loopCount()
This property holds the number of times the timeline should loop before it's finished. A loop count of of 0 means that the timeline will loop forever.

By default, this property contains a value of 1.


resume

public final void resume()
Resumes the timeline from the current time. QTimeLine will reenter Running state, and once it enters the event loop, it will update its current time, frame and value at regular intervals.

In contrast to start(), this function does not restart the timeline before is resumes.

See also:
start(), updateInterval(), frameChanged() , and valueChanged() .


setCurrentTime

public final void setCurrentTime(int msec)
This property holds the current time of the time line. When QTimeLine is in Running state, this value is updated continuously as a function of the duration and direction of the timeline. Otherwise, it is value that was current when stop() was called last, or the value set by setCurrentTime().

By default, this property contains a value of 0.


setCurveShape

public final void setCurveShape(QTimeLine.CurveShape shape)
This property holds the shape of the timeline curve. The curve shape describes the relation between the time and value for the base implementation of valueForTime().

If you have reimplemented valueForTime(), this value is ignored.

By default, this property is set to EaseInOutCurve .

See also:
valueForTime().


setDirection

public final void setDirection(QTimeLine.Direction direction)
This property holds the direction of the timeline when QTimeLine is in Running state.. This direction indicates whether the time moves from 0 towards the timeline duration, or from the value of the duration and towards 0 after start() has been called.

By default, this property is set to Forward .


setDuration

public final void setDuration(int duration)
This property holds the total duration of the timeline in milliseconds. By default, this value is 1000 (i.e., 1 second), but you can change this by either passing a duration to QTimeLine's constructor, or by calling setDuration(). The duration must be larger than 0.


setEndFrame

public final void setEndFrame(int frame)
Sets the end frame, which is the frame corresponding to the end of the timeline (i. ., the frame for which the current value is 1), to frame.

See also:
endFrame(), startFrame(), and setFrameRange().


setFrameRange

public final void setFrameRange(int startFrame,
                                int endFrame)
Sets the timeline's frame counter to start at startFrame, and end and endFrame. For each time value, QTimeLine will find the corresponding frame when you call currentFrame() or frameForTime() by interpolating, using the return value of valueForTime().

When in Running state, QTimeLine also emits the frameChanged() signal when the frame changes.

See also:
startFrame(), endFrame(), start(), and currentFrame().


setLoopCount

public final void setLoopCount(int count)
This property holds the number of times the timeline should loop before it's finished. A loop count of of 0 means that the timeline will loop forever.

By default, this property contains a value of 1.


setPaused

public final void setPaused(boolean paused)
If paused is true, the timeline is paused, causing QTimeLine to enter Paused state. No updates will be signaled until either start() or setPaused(false) is called. If paused is false, the timeline is resumed and continues where it left.

See also:
state(), and start().


setStartFrame

public final void setStartFrame(int frame)
Sets the start frame, which is the frame corresponding to the start of the timeline (i. ., the frame for which the current value is 0), to frame.

See also:
startFrame(), endFrame(), and setFrameRange().


setUpdateInterval

public final void setUpdateInterval(int interval)
This property holds the time in milliseconds between each time QTimeLine updates its current time. When updating the current time, QTimeLine will emit valueChanged() if the current value changed, and frameChanged() if the frame changed.

By default, the interval is 40 ms, which corresponds to a rate of 25 updates per second.


start

public final void start()
Starts the timeline. QTimeLine will enter Running state, and once it enters the event loop, it will update its current time, frame and value at regular intervals. The default interval is 40 ms (i.e., 25 times per second). You can change the update interval by calling setUpdateInterval().

If you want to resume a stopped timeline without restarting, you can call resume() instead.

See also:
resume(), updateInterval(), frameChanged() , and valueChanged() .


startFrame

public final int startFrame()
Returns the start frame, which is the frame corresponding to the start of the timeline (i. ., the frame for which the current value is 0).

See also:
setStartFrame(), and setFrameRange().


state

public final QTimeLine.State state()
Returns the state of the timeline.

See also:
start(), setPaused(), and stop().


stop

public final void stop()
Stops the timeline, causing QTimeLine to enter NotRunning state.

See also:
start().


toggleDirection

public final void toggleDirection()
Toggles the direction of the timeline. If the direction was Forward, it becomes Backward, and vice verca.

See also:
setDirection().


updateInterval

public final int updateInterval()
This property holds the time in milliseconds between each time QTimeLine updates its current time. When updating the current time, QTimeLine will emit valueChanged() if the current value changed, and frameChanged() if the frame changed.

By default, the interval is 40 ms, which corresponds to a rate of 25 updates per second.


valueForTime

public double valueForTime(int msec)
Returns the timeline value for the time msec. The returned value, which varies depending on the curve shape, is always between 0 and 1. If msec is 0, the default implementation always returns 0.

Reimplement this function to provide a custom curve shape for your timeline.

See also:
CurveShape , and frameForTime().