QEasingCurve#
The QEasingCurve
class provides easing curves for controlling animation. More…
New in version 4.6.
Synopsis#
Functions#
def
addCubicBezierSegment
(c1, c2, endPoint)def
addTCBSegment
(nextPoint, t, c, b)def
amplitude
()def
customType
()def
__ne__
(other)def
__eq__
(other)def
overshoot
()def
period
()def
setAmplitude
(amplitude)def
setCustomType
(arg__1)def
setOvershoot
(overshoot)def
setPeriod
(period)def
setType
(type)def
swap
(other)def
toCubicSpline
()def
type
()def
valueForProgress
(progress)
Note
This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE
Detailed Description#
Warning
This section contains snippets that were automatically translated from C++ to Python and may contain errors.
Easing curves describe a function that controls how the speed of the interpolation between 0 and 1 should be. Easing curves allow transitions from one value to another to appear more natural than a simple constant speed would allow. The QEasingCurve
class is usually used in conjunction with the QVariantAnimation
and QPropertyAnimation
classes but can be used on its own. It is usually used to accelerate the interpolation from zero velocity (ease in) or decelerate to zero velocity (ease out). Ease in and ease out can also be combined in the same easing curve.
To calculate the speed of the interpolation, the easing curve provides the function valueForProgress()
, where the progress
argument specifies the progress of the interpolation: 0 is the start value of the interpolation, 1 is the end value of the interpolation. The returned value is the effective progress of the interpolation. If the returned value is the same as the input value for all input values the easing curve is a linear curve. This is the default behaviour.
For example,
easing = QEasingCurve(QEasingCurve.InOutQuad) for t in range(0.0, 1.0): qWarning() << "Effective progress" << t << "is" << easing.valueForProgress(t)
will print the effective progress of the interpolation between 0 and 1.
When using a QPropertyAnimation
, the associated easing curve will be used to control the progress of the interpolation between startValue and endValue:
animation = QPropertyAnimation() 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 that 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 interpolate beyond the end points and return to the end point, acting similar to a boomerang.
The Easing Curves Example contains samples of QEasingCurve
types and lets you change the curve settings.
- class PySide6.QtCore.QEasingCurve([type=QEasingCurve.Type.Linear])#
PySide6.QtCore.QEasingCurve(other)
- Parameters:
other –
PySide6.QtCore.QEasingCurve
type –
Type
Constructs an easing curve of the given type
.
Construct a copy of other
.
- PySide6.QtCore.QEasingCurve.Type#
The type of easing curve.
Constant
Description
QEasingCurve.Linear
Easing curve for a linear (t) function: velocity is constant.
Constant
Description
QEasingCurve.InQuad
Easing curve for a quadratic (t^2) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutQuad
Easing curve for a quadratic (t^2) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutQuad
Easing curve for a quadratic (t^2) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInQuad
Easing curve for a quadratic (t^2) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InCubic
Easing curve for a cubic (t^3) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutCubic
Easing curve for a cubic (t^3) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutCubic
Easing curve for a cubic (t^3) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInCubic
Easing curve for a cubic (t^3) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InQuart
Easing curve for a quartic (t^4) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutQuart
Easing curve for a quartic (t^4) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutQuart
Easing curve for a quartic (t^4) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInQuart
Easing curve for a quartic (t^4) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InQuint
Easing curve for a quintic (t^5) easing in: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutQuint
Easing curve for a quintic (t^5) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutQuint
Easing curve for a quintic (t^5) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInQuint
Easing curve for a quintic (t^5) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InSine
Easing curve for a sinusoidal (sin(t)) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutSine
Easing curve for a sinusoidal (sin(t)) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutSine
Easing curve for a sinusoidal (sin(t)) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInSine
Easing curve for a sinusoidal (sin(t)) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InExpo
Easing curve for an exponential (2^t) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutExpo
Easing curve for an exponential (2^t) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutExpo
Easing curve for an exponential (2^t) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInExpo
Easing curve for an exponential (2^t) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InCirc
Easing curve for a circular (sqrt(1-t^2)) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutCirc
Easing curve for a circular (sqrt(1-t^2)) function: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutCirc
Easing curve for a circular (sqrt(1-t^2)) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInCirc
Easing curve for a circular (sqrt(1-t^2)) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InElastic
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.
Constant
Description
QEasingCurve.OutElastic
Easing curve for an elastic (exponentially decaying sine wave) function: decelerating to zero velocity. The peak amplitude can be set with the amplitude parameter, and the period of decay by the period parameter.
Constant
Description
QEasingCurve.InOutElastic
Easing curve for an elastic (exponentially decaying sine wave) function: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInElastic
Easing curve for an elastic (exponentially decaying sine wave) function: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InBack
Easing curve for a back (overshooting cubic function: (s+1)*t^3 - s*t^2) easing in: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutBack
Easing curve for a back (overshooting cubic function: (s+1)*t^3 - s*t^2) easing out: decelerating to zero velocity.
Constant
Description
QEasingCurve.InOutBack
Easing curve for a back (overshooting cubic function: (s+1)*t^3 - s*t^2) easing in/out: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInBack
Easing curve for a back (overshooting cubic easing: (s+1)*t^3 - s*t^2) easing out/in: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.InBounce
Easing curve for a bounce (exponentially decaying parabolic bounce) function: accelerating from zero velocity.
Constant
Description
QEasingCurve.OutBounce
Easing curve for a bounce (exponentially decaying parabolic bounce) function: decelerating from zero velocity.
Constant
Description
QEasingCurve.InOutBounce
Easing curve for a bounce (exponentially decaying parabolic bounce) function easing in/out: acceleration until halfway, then deceleration.
Constant
Description
QEasingCurve.OutInBounce
Easing curve for a bounce (exponentially decaying parabolic bounce) function easing out/in: deceleration until halfway, then acceleration.
Constant
Description
QEasingCurve.BezierSpline
Allows defining a custom easing curve using a cubic bezier spline
QEasingCurve.TCBSpline
Allows defining a custom easing curve using a TCB spline
QEasingCurve.Custom
This is returned if the user specified a custom curve type with
setCustomType()
. Note that you cannot callsetType()
with this value, buttype()
can return it.See also
- PySide6.QtCore.QEasingCurve.addCubicBezierSegment(c1, c2, endPoint)#
- Parameters:
endPoint –
PySide6.QtCore.QPointF
Adds a segment of a cubic bezier spline to define a custom easing curve. It is only applicable if type()
is BezierSpline
. Note that the spline implicitly starts at (0.0, 0.0) and has to end at (1.0, 1.0) to be a valid easing curve. c1
and c2
are the control points used for drawing the curve. endPoint
is the endpoint of the curve.
- PySide6.QtCore.QEasingCurve.addTCBSegment(nextPoint, t, c, b)#
- Parameters:
nextPoint –
PySide6.QtCore.QPointF
t – float
c – float
b – float
Adds a segment of a TCB bezier spline to define a custom easing curve. It is only applicable if type()
is TCBSpline
. The spline has to start explicitly at (0.0, 0.0) and has to end at (1.0, 1.0) to be a valid easing curve. The tension t
changes the length of the tangent vector. The continuity c
changes the sharpness in change between the tangents. The bias b
changes the direction of the tangent vector. nextPoint
is the sample position. All three parameters are valid between -1 and 1 and define the tangent of the control point. If all three parameters are 0 the resulting spline is a Catmull-Rom spline. The begin and endpoint always have a bias of -1 and 1, since the outer tangent is not defined.
- PySide6.QtCore.QEasingCurve.amplitude()#
- Return type:
float
Returns the amplitude. This is not applicable for all curve types. It is only applicable for bounce and elastic curves (curves of type()
InBounce
, OutBounce
, InOutBounce
, OutInBounce
, InElastic
, OutElastic
, InOutElastic
or OutInElastic
).
See also
- PySide6.QtCore.QEasingCurve.customType()#
- Return type:
object
- PySide6.QtCore.QEasingCurve.__ne__(other)#
- Parameters:
other –
PySide6.QtCore.QEasingCurve
- Return type:
bool
Compare this easing curve with other
and returns true
if they are not equal. It will also compare the properties of a curve.
See also
operator==()
- PySide6.QtCore.QEasingCurve.__eq__(other)#
- Parameters:
other –
PySide6.QtCore.QEasingCurve
- Return type:
bool
Compare this easing curve with other
and returns true
if they are equal. It will also compare the properties of a curve.
- PySide6.QtCore.QEasingCurve.overshoot()#
- Return type:
float
Returns the overshoot. This is not applicable for all curve types. It is only applicable if type()
is InBack
, OutBack
, InOutBack
or OutInBack
.
See also
- PySide6.QtCore.QEasingCurve.period()#
- Return type:
float
Returns the period. This is not applicable for all curve types. It is only applicable if type()
is InElastic
, OutElastic
, InOutElastic
or OutInElastic
.
See also
- PySide6.QtCore.QEasingCurve.setAmplitude(amplitude)#
- Parameters:
amplitude – float
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
- PySide6.QtCore.QEasingCurve.setCustomType(arg__1)#
- Parameters:
arg__1 – object
- PySide6.QtCore.QEasingCurve.setOvershoot(overshoot)#
- Parameters:
overshoot – float
Sets the overshoot to overshoot
.
0 produces no overshoot, and the default value of 1.70158 produces an overshoot of 10 percent.
See also
- PySide6.QtCore.QEasingCurve.setPeriod(period)#
- Parameters:
period – float
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
Sets the type of the easing curve to type
.
See also
- PySide6.QtCore.QEasingCurve.swap(other)#
- Parameters:
other –
PySide6.QtCore.QEasingCurve
Swaps curve other
with this curve. This operation is very fast and never fails.
Returns the cubicBezierSpline that defines a custom easing curve. If the easing curve does not have a custom bezier easing curve the list is empty.
Returns the type of the easing curve.
See also
- PySide6.QtCore.QEasingCurve.valueForProgress(progress)#
- Parameters:
progress – float
- Return type:
float
Return the effective progress for the easing curve at progress
. Whereas progress
must be between 0 and 1, the returned effective progress can be outside those bounds. For example, InBack
will return negative values in the beginning of the function.