class QScrollerProperties

The QScrollerProperties class stores the settings for a QScroller . More

Synopsis

Methods

Static functions

Note

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Detailed Description

The QScrollerProperties class stores the parameters used by QScroller .

The default settings are platform dependent so that Qt emulates the platform behaviour for kinetic scrolling.

As a convention the QScrollerProperties are in physical units (meter, seconds) and are converted by QScroller using the current DPI.

See also

QScroller

class OvershootPolicy

This enum describes the various modes of overshooting.

Constant

Description

QScrollerProperties.OvershootWhenScrollable

Overshooting is possible when the content is scrollable. This is the default.

QScrollerProperties.OvershootAlwaysOff

Overshooting is never enabled, even when the content is scrollable.

QScrollerProperties.OvershootAlwaysOn

Overshooting is always enabled, even when the content is not scrollable.

class FrameRates

This enum describes the available frame rates used while dragging or scrolling.

Constant

Description

QScrollerProperties.Fps60

60 frames per second

QScrollerProperties.Fps30

30 frames per second

QScrollerProperties.Fps20

20 frames per second

QScrollerProperties.Standard

the default value is 60 frames per second (which corresponds to QAbstractAnimation).

class ScrollMetric

This enum contains the different scroll metric types. When not indicated otherwise the setScrollMetric function expects a QVariant of type qreal.

See the QScroller documentation for further details of the concepts behind the different values.

Constant

Description

QScrollerProperties.MousePressEventDelay

This is the time a mouse press event is delayed when starting a flick gesture in [s]. If the gesture is triggered within that time, no mouse press or release is sent to the scrolled object. If it triggers after that delay the delayed mouse press plus a faked release event at global position QPoint(-QWIDGETSIZE_MAX, -QWIDGETSIZE_MAX) is sent. If the gesture is canceled, then both the delayed mouse press plus the real release event are delivered.

QScrollerProperties.DragStartDistance

This is the minimum distance the touch or mouse point needs to be moved before the flick gesture is triggered in m.

QScrollerProperties.DragVelocitySmoothingFactor

A value that describes to which extent new drag velocities are included in the final scrolling velocity. This value should be in the range between 0 and 1. The lower the value, the more smoothing is applied to the dragging velocity.

QScrollerProperties.AxisLockThreshold

Restricts the movement to one axis if the movement is inside an angle around the axis. The threshold must be in the range 0 to 1.

QScrollerProperties.ScrollingCurve

The QEasingCurve used when decelerating the scrolling velocity after an user initiated flick. Please note that this is the easing curve for the positions, not the velocity: the default is QEasingCurve::OutQuad, which results in a linear decrease in velocity (1st derivative) and a constant deceleration (2nd derivative).

QScrollerProperties.DecelerationFactor

This factor influences how long it takes the scroller to decelerate to 0 velocity. The actual value depends on the chosen ScrollingCurve. For most types the value should be in the range from 0.1 to 2.0

QScrollerProperties.MinimumVelocity

The minimum velocity that is needed after ending the touch or releasing the mouse to start scrolling in m/s.

QScrollerProperties.MaximumVelocity

This is the maximum velocity that can be reached in m/s.

QScrollerProperties.MaximumClickThroughVelocity

This is the maximum allowed scroll speed for a click-through in m/s. This means that a click on a currently (slowly) scrolling object will not only stop the scrolling but the click event will also be delivered to the UI control. This is useful when using exponential-type scrolling curves.

QScrollerProperties.AcceleratingFlickMaximumTime

This is the maximum time in seconds that a flick gesture can take to be recognized as an accelerating flick. If set to zero no such gesture is detected. An “accelerating flick” is a flick gesture executed on an already scrolling object. In such cases the scrolling speed is multiplied by AcceleratingFlickSpeedupFactor in order to accelerate it.

QScrollerProperties.AcceleratingFlickSpeedupFactor

The current speed is multiplied by this number if an accelerating flick is detected. Should be >= 1.

QScrollerProperties.SnapPositionRatio

This is the distance that the user must drag the area between two snap points in order to snap it to the next position. 0.33 means that the scroll must only reach one third of the distance between two snap points to snap to the next one. The ratio must be between 0 and 1.

QScrollerProperties.SnapTime

This is the time factor for the scrolling curve. A lower value means that the scrolling will take longer. The scrolling distance is independent of this value.

QScrollerProperties.OvershootDragResistanceFactor

This value is the factor between the mouse dragging and the actual scroll area movement (during overshoot). The factor must be between 0 and 1.

QScrollerProperties.OvershootDragDistanceFactor

This is the maximum distance for overshoot movements while dragging. The actual overshoot distance is calculated by multiplying this value with the viewport size of the scrolled object. The factor must be between 0 and 1.

QScrollerProperties.OvershootScrollDistanceFactor

This is the maximum distance for overshoot movements while scrolling. The actual overshoot distance is calculated by multiplying this value with the viewport size of the scrolled object. The factor must be between 0 and 1.

QScrollerProperties.OvershootScrollTime

This is the time in seconds that is used to play the complete overshoot animation.

QScrollerProperties.HorizontalOvershootPolicy

This is the horizontal overshooting policy (see OvershootPolicy ).

QScrollerProperties.VerticalOvershootPolicy

This is the horizontal overshooting policy (see OvershootPolicy ).

QScrollerProperties.FrameRate

This is the frame rate which should be used while dragging or scrolling. QScroller uses a QAbstractAnimation timer internally to sync all scrolling operations to other animations that might be active at the same time. If the standard value of 60 frames per second is too fast, it can be lowered with this setting, while still being in-sync with QAbstractAnimation. Please note that only the values of the FrameRates enum are allowed here.

QScrollerProperties.ScrollMetricCount

This is always the last entry.

__init__()

Constructs new scroller properties.

__init__(sp)
Parameters:

spQScrollerProperties

Constructs a copy of sp.

__ne__(sp)
Parameters:

spQScrollerProperties

Return type:

bool

Returns true if these scroller properties are different from sp; otherwise returns false.

__eq__(sp)
Parameters:

spQScrollerProperties

Return type:

bool

Returns true if these scroller properties are equal to sp; otherwise returns false.

scrollMetric(metric)
Parameters:

metricScrollMetric

Return type:

object

Query the metric value of the scroller properties.

static setDefaultScrollerProperties(sp)
Parameters:

spQScrollerProperties

Sets the scroller properties for all new QScrollerProperties objects to sp.

Use this function to override the platform default properties returned by the default constructor. If you only want to change the scroller properties of a single scroller, use setScrollerProperties()

Note

Calling this function will not change the content of already existing QScrollerProperties objects.

setScrollMetric(metric, value)
Parameters:

Set a specific value of the metric ScrollerMetric to value.

static unsetDefaultScrollerProperties()

Sets the scroller properties returned by the default constructor back to the platform default properties.