Class QAccelPlot::DataTransition¶

ClassList > QAccelPlot > DataTransition

Abstract base class for animated data transitions on plot elements. More...

#include <DataTransition.hpp>

Inherits the following classes: QObject

Inherited by the following classes: QAccelPlot::DrawTransition, QAccelPlot::MorphTransition

Inheritance diagram¶

flowchart TB
  classQAccelPlot_1_1DataTransition["QAccelPlot::DataTransition"]

  external_base_classQAccelPlot_1_1DataTransition_1["QObject"]
  external_base_classQAccelPlot_1_1DataTransition_1 --> classQAccelPlot_1_1DataTransition

  classQAccelPlot_1_1DrawTransition["QAccelPlot::DrawTransition"]
  classQAccelPlot_1_1DataTransition --> classQAccelPlot_1_1DrawTransition
  click classQAccelPlot_1_1DrawTransition "../classQAccelPlot_1_1DrawTransition/" "Open QAccelPlot::DrawTransition"

  classQAccelPlot_1_1MorphTransition["QAccelPlot::MorphTransition"]
  classQAccelPlot_1_1DataTransition --> classQAccelPlot_1_1MorphTransition
  click classQAccelPlot_1_1MorphTransition "../classQAccelPlot_1_1MorphTransition/" "Open QAccelPlot::MorphTransition"

Classes¶

Type	Name
struct	Dataset Data a transition animates: `count` items of`stride` values each, e.g. XY points with a stride of 2.
class	Run One animation of a transition on one host element.

Public Properties¶

Type	Name
property QML_ANONYMOUSint	duration Duration of the transition in milliseconds. Default: 300.
property QEasingCurve	easing Easing curve applied to the animation progress. Default: `QEasingCurve::Linear` .
property bool	enabled Whether the transition is active. When `false` , data updates are applied instantly.
property bool	running Read-only: `true` while the transition is playing on at least one element.

Public Signals¶

Type	Name
signal void	durationChanged Emitted when the duration property changes.
signal void	easingChanged Emitted when the easing property changes.
signal void	enabledChanged Emitted when the enabled property changes.
signal void	runningChanged Emitted when the running property changes.

Public Functions¶

Type	Name
	DataTransition (QObject * parent=nullptr) Constructs an DataTransition with the given__parent .
bool	advance (Run & run, std::vector< double > & outData, int & outPointCount) Advances run by one frame, writing the interpolated data into__outData .
void	cancel () Ends every active run immediately.
int	duration () const Returns the animation duration in milliseconds.
QEasingCurve	easing () const Returns the easing curve.
bool	enabled () const Returns `true` if the transition is enabled.
bool	running () const Returns `true` while at least one run is active.
void	setDuration (int duration) Sets the animation duration to duration milliseconds.
void	setEasing (const QEasingCurve & easing) Sets the easing curve to easing .
void	setEnabled (bool enabled) Sets the enabled state to enabled .
void	start (Run & run, const std::vector< double > & currentData, int currentPointCount, std::vector< double > && newData, int newPointCount, int stride=2) Starts run from__currentData to__newData , restarting it if it is already active.
	~DataTransition () override Destroys the transition. Its runs stay pending, so their hosts can still show the target data.

Protected Functions¶

Type	Name
virtual void	interpolate (double easedProgress, const Dataset & from, const Dataset & to, Dataset & out) = 0 Subclass entry point — writes the dataset between from and__to at__easedProgress into__out .

Detailed Description¶

Subclasses implement interpolate() to define how the element animates between an old dataset and a new one. The transition is driven frame-by-frame by advance(), which the host element calls on the GUI thread before each scene graph synchronization, so runningChanged is always emitted on the GUI thread.

Time comes from Qt's animation timer on the transition's thread, the clock of QML animations. An installed QAnimationDriver therefore steps transitions too, for example to record frames offscreen at a fixed time step.

One transition can be assigned to several elements. Each element keeps its own Run with the data it animates between, so the elements animate independently.

Public Properties Documentation¶

property duration¶

Duration of the transition in milliseconds. Default: 300.

QML_ANONYMOUSint QAccelPlot::DataTransition::duration;

With 0 or less, a run shows the target data at its next frame.

property easing¶

Easing curve applied to the animation progress. Default: QEasingCurve::Linear .

QEasingCurve QAccelPlot::DataTransition::easing;

property enabled¶

Whether the transition is active. When false , data updates are applied instantly.

bool QAccelPlot::DataTransition::enabled;

property running¶

Read-only: true while the transition is playing on at least one element.

bool QAccelPlot::DataTransition::running;

Public Signals Documentation¶

signal durationChanged¶

Emitted when the duration property changes.

void QAccelPlot::DataTransition::durationChanged;

signal easingChanged¶

Emitted when the easing property changes.

void QAccelPlot::DataTransition::easingChanged;

signal enabledChanged¶

Emitted when the enabled property changes.

void QAccelPlot::DataTransition::enabledChanged;

signal runningChanged¶

Emitted when the running property changes.

void QAccelPlot::DataTransition::runningChanged;

Public Functions Documentation¶

function DataTransition¶

Constructs an DataTransition with the given__parent .

explicit QAccelPlot::DataTransition::DataTransition (
    QObject * parent=nullptr
)

function advance¶

Advances run by one frame, writing the interpolated data into__outData .

bool QAccelPlot::DataTransition::advance (
    Run & run,
    std::vector< double > & outData,
    int & outPointCount
)

When the duration has elapsed, writes the target data and finishes the run.

Returns:

true if run is still active after this call.

function cancel¶

Ends every active run immediately.

void QAccelPlot::DataTransition::cancel ()

The runs stay pending; hosts show the target data after running turns false.

function duration¶

Returns the animation duration in milliseconds.

int QAccelPlot::DataTransition::duration () const

function easing¶

Returns the easing curve.

QEasingCurve QAccelPlot::DataTransition::easing () const

function enabled¶

Returns true if the transition is enabled.

bool QAccelPlot::DataTransition::enabled () const

function running¶

Returns true while at least one run is active.

bool QAccelPlot::DataTransition::running () const

function setDuration¶

Sets the animation duration to duration milliseconds.

void QAccelPlot::DataTransition::setDuration (
    int duration
)

function setEasing¶

Sets the easing curve to easing .

void QAccelPlot::DataTransition::setEasing (
    const QEasingCurve & easing
)

function setEnabled¶

Sets the enabled state to enabled .

void QAccelPlot::DataTransition::setEnabled (
    bool enabled
)

function start¶

Starts run from__currentData to__newData , restarting it if it is already active.

void QAccelPlot::DataTransition::start (
    Run & run,
    const std::vector< double > & currentData,
    int currentPointCount,
    std::vector< double > && newData,
    int newPointCount,
    int stride=2
)

Parameters:

run Run of the host element; ended first if another transition advances it.
currentData Current double buffer (copied as the from state).
currentPointCount Number of points in currentData.
newData Target double buffer (moved as the to state).
newPointCount Number of points in newData.
stride Number of values per point in both buffers. Default: 2, XY points.

function ~DataTransition¶

Destroys the transition. Its runs stay pending, so their hosts can still show the target data.

QAccelPlot::DataTransition::~DataTransition () override

Protected Functions Documentation¶

function interpolate¶

Subclass entry point — writes the dataset between from and__to at__easedProgress into__out .

virtual void QAccelPlot::DataTransition::interpolate (
    double easedProgress,
    const Dataset & from,
    const Dataset & to,
    Dataset & out
) = 0

easedProgress runs from 0 to 1 and leaves that range with an overshooting easing curve. from and to share one stride, which out already has; set its values and count.

The documentation for this class was generated from the following file QAccelPlot/src/QAccelPlot/transitions/DataTransition.hpp