Qt Jambi Home

com.trolltech.qt.core
Class QTimeLine

java.lang.Object
  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);
    connect(timeLine, SIGNAL(frameChanged(int)), progressBar, SLOT(setValue(int)));

    // Clicking the push button will start the progress bar animation
    pushButton = new QPushButton(tr("Start animation"), this);
    connect(pushButton, SIGNAL(clicked()), timeLine, SLOT(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, 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.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I>
 
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<java.lang.Integer> frameChanged
          QTimeLine emits this signal at regular intervals when in Running state, but only if the current frame changes.
 QSignalEmitter.Signal1<QTimeLine.State> stateChanged
          This signal is emitted whenever QTimeLine's state changes.
 QSignalEmitter.Signal1<java.lang.Double> valueChanged
          QTimeLine emits this signal at regular intervals when in Running state, but only if the current value changes.
 
Constructor Summary
QTimeLine()
          Equivalent to QTimeLine(1000, 0).
QTimeLine(int duration)
          Equivalent to QTimeLine(duration, 0).
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()
          Returns the current time of the time line..
 double currentValue()
          Returns the value corresponding to the current time.
 QTimeLine.CurveShape curveShape()
          Returns the shape of the timeline curve..
 QTimeLine.Direction direction()
          Returns the direction of the timeline when QTimeLine is in Running state..
 int duration()
          Returns 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.e., the frame for which the current value is 1).
 int frameForTime(int msec)
          Returns the frame corresponding to the time msec.
static QTimeLine fromNativePointer(QNativePointer nativePointer)
          This function returns the QTimeLine instance pointed to by nativePointer
 int loopCount()
          Returns 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)
          Sets the current time of the time line.
 void setCurveShape(QTimeLine.CurveShape shape)
          Sets the shape of the timeline curve.
 void setDirection(QTimeLine.Direction direction)
          Sets the direction of the timeline when QTimeLine is in Running state.
 void setDuration(int duration)
          Sets 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.e., the frame for which the current value is 1), to frame.
 void setFrameRange(int startFrame, int endFrame)
          Sets the timeline's frame counter to start at startFrame, and end and endFrame.
 void setLoopCount(int count)
          Sets 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.e., the frame for which the current value is 0), to frame.
 void setUpdateInterval(int interval)
          Sets the time in milliseconds between each time QTimeLine updates its current time.
 void start()
          Starts or restarts the timeline.
 int startFrame()
          Returns the start frame, which is the frame corresponding to the start of the timeline (i.e., the frame for which the current value is 0).
 QTimeLine.State state()
          Returns the state of the timeline.
 void stop()
          Stops the timeline, causing QTimeLine to enter NotRunning state.
protected  void timerEvent(QTimerEvent event)
          

This event handler can be reimplemented in a subclass to receive timer events for the object.

 void toggleDirection()
          Toggles the direction of the timeline.
 int updateInterval()
          Returns 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
blockSignals, childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, property, removeEventFilter, setObjectName, setParent, setProperty, signalsBlocked, startTimer, thread
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
disconnect, disconnect, signalSender
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, 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.

Compatible Slot Signature:
void mySlot()


frameChanged

public final QSignalEmitter.Signal1<java.lang.Integer> frameChanged

QTimeLine emits this signal at regular intervals when in Running state, but only if the current frame changes. arg__1 is the current frame number.

Compatible Slot Signatures:
void mySlot(int arg__1)
void mySlot()
See Also:
QTimeLine::setFrameRange, QTimeLine::updateInterval


stateChanged

public final QSignalEmitter.Signal1<QTimeLine.State> stateChanged

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

Compatible Slot Signatures:
void mySlot(com.trolltech.qt.core.QTimeLine.State newState)
void mySlot()


valueChanged

public final QSignalEmitter.Signal1<java.lang.Double> valueChanged

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

Compatible Slot Signatures:
void mySlot(double x)
void mySlot()
See Also:
QTimeLine::setDuration, QTimeLine::valueForTime, QTimeLine::updateInterval

Constructor Detail

QTimeLine

public QTimeLine(int duration)

Equivalent to QTimeLine(duration, 0).


QTimeLine

public QTimeLine()

Equivalent to QTimeLine(1000, 0).


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, setFrameRange

currentTime

public final int currentTime()

Returns 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.

See Also:
setCurrentTime

currentValue

public final double currentValue()

Returns the value corresponding to the current time.

See Also:
valueForTime, currentFrame

curveShape

public final QTimeLine.CurveShape curveShape()

Returns 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.

See Also:
setCurveShape, valueForTime

direction

public final QTimeLine.Direction direction()

Returns 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.

See Also:
setDirection

duration

public final int duration()

Returns 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.

See Also:
setDuration

endFrame

public final int endFrame()

Returns the end frame, which is the frame corresponding to the end of the timeline (i.e., the frame for which the current value is 1).

See Also:
setEndFrame, 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, setFrameRange

loopCount

public final int loopCount()

Returns 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.

See Also:
setLoopCount

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, valueChanged

setCurrentTime

public final void setCurrentTime(int msec)

Sets the current time of the time line. to msec.

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.

See Also:
currentTime

setCurveShape

public final void setCurveShape(QTimeLine.CurveShape shape)

Sets the shape of the timeline curve. to shape.

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.

See Also:
curveShape, valueForTime

setDirection

public final void setDirection(QTimeLine.Direction direction)

Sets the direction of the timeline when QTimeLine is in Running state. to direction.

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.

See Also:
direction

setDuration

public final void setDuration(int duration)

Sets the total duration of the timeline in milliseconds. to duration.

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.

See Also:
duration

setEndFrame

public final void setEndFrame(int frame)

Sets the end frame, which is the frame corresponding to the end of the timeline (i.e., the frame for which the current value is 1), to frame.

See Also:
endFrame, startFrame, 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, currentFrame

setLoopCount

public final void setLoopCount(int count)

Sets the number of times the timeline should loop before it's finished. to count.

A loop count of of 0 means that the timeline will loop forever.

See Also:
loopCount

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, start

setStartFrame

public final void setStartFrame(int frame)

Sets the start frame, which is the frame corresponding to the start of the timeline (i.e., the frame for which the current value is 0), to frame.

See Also:
startFrame, endFrame, setFrameRange

setUpdateInterval

public final void setUpdateInterval(int interval)

Sets the time in milliseconds between each time QTimeLine updates its current time. to interval.

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.

See Also:
updateInterval

start

public final void start()

Starts or restarts 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, valueChanged

startFrame

public final int startFrame()

Returns the start frame, which is the frame corresponding to the start of the timeline (i.e., the frame for which the current value is 0).

See Also:
setStartFrame, setFrameRange

state

public final QTimeLine.State state()

Returns the state of the timeline.

See Also:
start, setPaused, 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()

Returns 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.

See Also:
setUpdateInterval

timerEvent

protected void timerEvent(QTimerEvent event)

This event handler can be reimplemented in a subclass to receive timer events for the object.

QTimer provides a higher-level interface to the timer functionality, and also more general information about timers. The timer event is passed in the arg__1 parameter.

Overrides:
timerEvent in class QObject
See Also:
startTimer, killTimer, event

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, frameForTime

fromNativePointer

public static QTimeLine fromNativePointer(QNativePointer nativePointer)
This function returns the QTimeLine instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.

Qt Jambi Home