The QEasingCurve class provides easing curves for controlling animation. More...

Public Typedefs
using	EasingFunction = qreal (*)(qreal progress)

Public Types
enum	Type

Public Methods
	QEasingCurve (const QEasingCurve &other)

	QEasingCurve (QEasingCurve &&other)

	QEasingCurve (Type type=Type::Linear)

	~QEasingCurve ()

qreal	amplitude () const

EasingFunction	customType () const

bool	operator!= (const QEasingCurve &other) const

QEasingCurve &	operator= (const QEasingCurve &other)

QEasingCurve &	operator= (QEasingCurve &&other)

bool	operator== (const QEasingCurve &other) const

qreal	overshoot () const

qreal	period () const

void	setAmplitude (qreal amplitude)

void	setCustomType (EasingFunction func)

void	setOvershoot (qreal overshoot)

void	setPeriod (qreal period)

void	setType (Type type)

void	swap (QEasingCurve &other)

Type	type () const

qreal	valueForProgress (qreal progress) const

Friends
QDataStream &	operator<< (QDataStream &stream, const QEasingCurve &easing)

Related Functions
These are not member functions
QDataStream &	operator>> (QDataStream &stream, const QEasingCurve &easing)

Detailed Description

The QEasingCurve class provides easing curves for controlling animation.

An easing curve is a function which controls the position of an object in an animation. The purpose is to make the transitions smoother so the motion looks more realistic. This class is normally used in combination with QVariantAnimation and QPropertyAnimation.

Methods

The primary method in this class is valueForProgress() which calculates the position of an object being animated. A floating point number between the values of 0 and 1 must be passed to this method. This value represents a point in time. This method should be called repeatedly with the passed value incrementing.

QEasingCurve easing(QEasingCurve::InOutQuad);
 
for (double value = 0.0; value < 1.0; value += 0.1) {
   qWarning() << "Current input: " << value << "  Position is: " << easing.valueForProgress(value);
}

The following example shows how to use a QPropertyAnimation with a QEasingCurve to control the progress of the animation.

QPropertyAnimation animation;
 
animation.setStartValue(0);
animation.setEndValue(1000);
animation.setDuration(1000);
 
animation.setEasingCurve(QEasingCurve::InOutQuad);

The ability to set an amplitude, overshoot, or period depends on the QEasingCurve type. Amplitude access is available to curves which behave as springs such as elastic and bounce curves. Changing the amplitude changes the height of the curve. Period access is only available to elastic curves and setting a higher period slows the rate of bounce. Only curves that have "boomerang" behaviors such as the InBack, OutBack, InOutBack, and OutInBack have overshoot settings. These curves will extend beyond the end points and return to the end point, acting similar to a boomerang.

See also: setAmplitude()

Member Typedef Documentation

QEasingCurve::EasingFunction

Typedef for a pointer to a function with the following signature.

qreal myEasingFunction(qreal progress);

Member Enumeration Documentation

enum QEasingCurve::Type

The type of easing curve.

Constant	Value	Description
`QEasingCurve::Linear`	`0`	Easing curve for a linear (t) function: velocity is constant.
`QEasingCurve::InQuad`	`1`	Easing curve for a quadratic (t^2) function: accelerating from zero velocity.
`QEasingCurve::OutQuad`	`2`	Easing curve for a quadratic (t^2) function: decelerating to zero velocity.
`QEasingCurve::InOutQuad`	`3`	Easing curve for a quadratic (t^2) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInQuad`	`4`	Easing curve for a quadratic (t^2) function: deceleration until halfway, then acceleration.
`QEasingCurve::InCubic`	`5`	Easing curve for a cubic (t^3) function: accelerating from zero velocity.
`QEasingCurve::OutCubic`	`6`	Easing curve for a cubic (t^3) function: decelerating to zero velocity.
`QEasingCurve::InOutCubic`	`7`	Easing curve for a cubic (t^3) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInCubic`	`8`	Easing curve for a cubic (t^3) function: deceleration until halfway, then acceleration.
`QEasingCurve::InQuart`	`9`	Easing curve for a quartic (t^4) function: accelerating from zero velocity.
`QEasingCurve::OutQuart`	`10`	Easing curve for a quartic (t^4) function: decelerating to zero velocity.
`QEasingCurve::InOutQuart`	`11`	Easing curve for a quartic (t^4) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInQuart`	`12`	Easing curve for a quartic (t^4) function: deceleration until halfway, then acceleration.
`QEasingCurve::InQuint`	`13`	Easing curve for a quintic (t^5) easing in: accelerating from zero velocity.
`QEasingCurve::OutQuint`	`14`	Easing curve for a quintic (t^5) function: decelerating to zero velocity.
`QEasingCurve::InOutQuint`	`15`	Easing curve for a quintic (t^5) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInQuint`	`16`	Easing curve for a quintic (t^5) function: deceleration until halfway, then acceleration.
`QEasingCurve::InSine`	`17`	Easing curve for a sinusoidal (sin(t)) function: accelerating from zero velocity.
`QEasingCurve::OutSine`	`18`	Easing curve for a sinusoidal (sin(t)) function: decelerating from zero velocity.
`QEasingCurve::InOutSine`	`19`	Easing curve for a sinusoidal (sin(t)) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInSine`	`20`	Easing curve for a sinusoidal (sin(t)) function: deceleration until halfway, then acceleration.
`QEasingCurve::InExpo`	`21`	Easing curve for an exponential (2^t) function: accelerating from zero velocity.
`QEasingCurve::OutExpo`	`22`	Easing curve for an exponential (2^t) function: decelerating from zero velocity.
`QEasingCurve::InOutExpo`	`23`	Easing curve for an exponential (2^t) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInExpo`	`24`	Easing curve for an exponential (2^t) function: deceleration until halfway, then acceleration.
`QEasingCurve::InCirc`	`25`	Easing curve for a circular (sqrt(1-t^2)) function: accelerating from zero velocity.
`QEasingCurve::OutCirc`	`26`	Easing curve for a circular (sqrt(1-t^2)) function: decelerating from zero velocity.
`QEasingCurve::InOutCirc`	`27`	Easing curve for a circular (sqrt(1-t^2)) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInCirc`	`28`	Easing curve for a circular (sqrt(1-t^2)) function: deceleration until halfway, then acceleration.
`QEasingCurve::InElastic`	`29`	Easing curve for an elastic (exponentially decaying sine wave) function: accelerating from zero velocity. The peak amplitude can be set with the amplitude parameter, and the period of decay by the period parameter.
`QEasingCurve::OutElastic`	`30`	Easing curve for an elastic (exponentially decaying sine wave) function: decelerating from zero velocity. The peak amplitude can be set with the amplitude parameter, and the period of decay by the period parameter.
`QEasingCurve::InOutElastic`	`31`	Easing curve for an elastic (exponentially decaying sine wave) function: acceleration until halfway, then deceleration.
`QEasingCurve::OutInElastic`	`32`	Easing curve for an elastic (exponentially decaying sine wave) function: deceleration until halfway, then acceleration.
`QEasingCurve::InBack`	`33`	Easing curve for a back (overshooting cubic function: (s+1)t^3 - st^2) easing in: accelerating from zero velocity.
`QEasingCurve::OutBack`	`34`	Easing curve for a back (overshooting cubic function: (s+1)t^3 - st^2) easing out: decelerating to zero velocity.
`QEasingCurve::InOutBack`	`35`	Easing curve for a back (overshooting cubic function: (s+1)t^3 - st^2) easing in/out: acceleration until halfway, then deceleration.
`QEasingCurve::OutInBack`	`36`	Easing curve for a back (overshooting cubic easing: (s+1)t^3 - st^2) easing out/in: deceleration until halfway, then acceleration.
`QEasingCurve::InBounce`	`37`	Easing curve for a bounce (exponentially decaying parabolic bounce) function: accelerating from zero velocity.
`QEasingCurve::OutBounce`	`38`	Easing curve for a bounce (exponentially decaying parabolic bounce) function: decelerating from zero velocity.
`QEasingCurve::InOutBounce`	`39`	Easing curve for a bounce (exponentially decaying parabolic bounce) function easing in/out: acceleration until halfway, then deceleration.
`QEasingCurve::OutInBounce`	`40`	Easing curve for a bounce (exponentially decaying parabolic bounce) function easing out/in: deceleration until halfway, then acceleration.
`QEasingCurve::Custom`	`45`	This is returned if the user specified a custom curve type with setCustomType(). You can not call setType() with this value, but type() can return it.

Constructor & Destructor Documentation

QEasingCurve::QEasingCurve ( Type type = Type::Linear )

Constructs a new QEasingCurve using the given type.

QEasingCurve::QEasingCurve ( const QEasingCurve & other )

Copy constructs a new QEasingCurve from other.

QEasingCurve::QEasingCurve ( QEasingCurve && other )

inline

Move constructs a new QEasingCurve from other.

QEasingCurve::~QEasingCurve ( )

Destroys the current QEasingCurve.

Method Documentation

qreal QEasingCurve::amplitude ( ) const

Returns the amplitude of the current QEasingCurve. This does not apply to all values in QEasingCurve::Type, only to bounce and elastic curves types.

See also: setAmplitude()

EasingFunction QEasingCurve::customType ( ) const

Returns a function pointer to the custom easing curve. If type() does not return QEasingCurve::Custom, this method will return a nullptr.

See also: setCustomType()

bool QEasingCurve::operator!= ( const QEasingCurve & other ) const

inline

Compares this QEasingCurve with other and returns true if they are not equal.

See also: operator==()

QEasingCurve & QEasingCurve::operator= ( const QEasingCurve & other )

inline

Copy assigns from other and returns a reference to this QEasingCurve.

QEasingCurve & QEasingCurve::operator= ( QEasingCurve && other )

inline

Move assigns from other and returns a reference to this QEasingCurve.

bool QEasingCurve::operator== ( const QEasingCurve & other ) const

Compares the current QEasingCurve with other and returns true if they are equal. I

qreal QEasingCurve::overshoot ( ) const

Returns the overshoot value. This is the how far past the end point the position can travel. This does not apply to all curve types, only when the type() is QEasingCurve::InBack, QEasingCurve::OutBack, QEasingCurve::InOutBack, or QEasingCurve::OutInBack.

See also: setOvershoot()

qreal QEasingCurve::period ( ) const

Returns the period. This does not apply to all curve types, only when the type() is QEasingCurve::InElastic, QEasingCurve::OutElastic, QEasingCurve::InOutElastic or QEasingCurve::OutInElastic.

See also: setPeriod()

void QEasingCurve::setAmplitude ( qreal amplitude )

Sets the amplitude to amplitude. This will set the amplitude of the bounce or the amplitude of the elastic "spring" effect. The higher the number the higher the amplitude.

See also: amplitude()

void QEasingCurve::setCustomType ( EasingFunction func )

Sets a custom easing curve which is defined by the function func. The signature of the custom function must match the signature shown below. The range for progress and the return value is normalized between 0 and 1. The value for func can not be a nullptr.

qreal myEasingFunction(qreal progress)

See also: customType(), valueForProgress()

void QEasingCurve::setOvershoot ( qreal overshoot )

Sets the overshoot to overshoot. A value of 0 produces no overshoot. If you do not call this method, the overshoot value will be 1.70158 which will produce an overshoot of 10 percent.

See also: overshoot()

void QEasingCurve::setPeriod ( qreal period )

Sets the period to period. Setting a small period value will give a high frequency of the curve. A large period will give it a small frequency.

See also: period()

void QEasingCurve::setType ( Type type )

Sets the type of the easing curve to type.

See also: type()

void QEasingCurve::swap ( QEasingCurve & other )

inline

Swaps other with this QEasingCurve. This operation is very fast and never fails.

Type QEasingCurve::type ( ) const

Returns the QEasingCurve::Type for this QEasingCurve.

See also: setType()

qreal QEasingCurve::valueForProgress ( qreal progress ) const

Return the progress for this QEasingCurve at progress. While progress must be between 0 and 1, the returned progress can be outside those bounds. For instance, if the QEasingCurve::Type is QEasingCurve::InBack then progress will return negative values at the beginning of the curve.

Friends And Related Function Documentation

QDataStream & operator<<	(	QDataStream &	stream,
		const QEasingCurve &	easing
	)

friend

Writes the given easing to the stream. Returns a reference to the stream.

Refer to Serializing Data Types for additional information.

QDataStream & operator>>	(	QDataStream &	stream,
		const QEasingCurve &	easing
	)

Refer to Serializing Data Types for additional information.

Public Typedefs

Public Types

Public Methods

Friends

Related Functions

Detailed Description

Methods

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation

Friends And Related Function Documentation