QDeclarativePath Class Reference

#include <qdeclarativepath_p.h>

Inheritance diagram for QDeclarativePath:

Classes
struct	AttributePoint

Signals
void	changed ()
void	startXChanged ()
void	startYChanged ()
Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...

Public Functions
qreal	attributeAt (const QString &, qreal) const
QStringList	attributes () const
bool	isClosed () const
QPainterPath	path () const
QDeclarativeListProperty< QDeclarativePathElement >	pathElements ()
QPointF	pointAt (qreal) const
	QDeclarativePath (QObject *parent=0)
void	setStartX (qreal x)
void	setStartY (qreal y)
qreal	startX () const
qreal	startY () const
	~QDeclarativePath ()
Public Functions inherited from QObject
bool	blockSignals (bool b)
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More...
const QObjectList &	children () const
	Returns a list of child objects. More...
bool	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0)
bool	disconnect (const QObject *receiver, const char *member=0)
void	dumpObjectInfo ()
	Dumps information about signal connections, etc. More...
void	dumpObjectTree ()
	Dumps a tree of children to the debug output. More...
QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...
virtual bool	event (QEvent *)
	This virtual function receives events to an object and should return true if the event e was recognized and processed. More...
virtual bool	eventFilter (QObject *, QEvent *)
	Filters events if this object has been installed as an event filter for the watched object. More...
template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...
template<typename T >
QList< T >	findChildren (const QString &aName=QString()) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More...
template<typename T >
QList< T >	findChildren (const QRegExp &re) const
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More...
void	installEventFilter (QObject *)
	Installs an event filter filterObj on this object. More...
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false. More...
void	killTimer (int id)
	Kills the timer with timer identifier, id. More...
virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...
QString	objectName () const
QObject *	parent () const
	Returns a pointer to the parent object. More...
QVariant	property (const char *name) const
	Returns the value of the object's name property. More...
Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...
void	removeEventFilter (QObject *)
	Removes an event filter object obj from this object. More...
void	setObjectName (const QString &name)
void	setParent (QObject *)
	Makes the object a child of parent. More...
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value. More...
void	setUserData (uint id, QObjectUserData *data)
bool	signalsBlocked () const
	Returns true if signals are blocked; otherwise returns false. More...
int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...
QThread *	thread () const
	Returns the thread in which the object lives. More...
QObjectUserData *	userData (uint id) const
virtual	~QObject ()
	Destroys the object, deleting all its child objects. More...
Public Functions inherited from QDeclarativeParserStatus
	QDeclarativeParserStatus ()
virtual	~QDeclarativeParserStatus ()

Protected Functions
virtual void	classBegin ()
	Invoked after class creation, but before any properties have been set. More...
virtual void	componentComplete ()
	Invoked after the root component that caused this instantiation has completed construction. More...
Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...
virtual void	connectNotify (const char *signal)
	This virtual function is called when something has been connected to signal in this object. More...
virtual void	customEvent (QEvent *)
	This event handler can be reimplemented in a subclass to receive custom events. More...
virtual void	disconnectNotify (const char *signal)
	This virtual function is called when something has been disconnected from signal in this object. More...
	QObject (QObjectPrivate &dd, QObject *parent=0)
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal. More...
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More...
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *)
	This event handler can be reimplemented in a subclass to receive timer events for the object. More...

Private Slots
void	processPath ()

Private Functions
void	createPointCache () const
void	endpoint (const QString &name)
void	interpolate (int idx, const QString &name, qreal value)

Properties
bool	closed
QDeclarativeListProperty< QDeclarativePathElement >	pathElements
qreal	startX
qreal	startY

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...
Static Public Functions inherited from QObject
static bool	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...
static bool	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	Disconnects signal in object sender from method in object receiver. More...
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static uint	registerUserData ()
static QString	tr (const char *sourceText, const char *comment=0, int n=-1)
static QString	trUtf8 (const char *sourceText, const char *comment=0, int n=-1)
Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...
Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject
Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()
T *	qobject_cast (QObject *object)
	QObjectList
void *	qt_find_obj_child (QObject *parent, const char *type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

Definition at line 208 of file qdeclarativepath_p.h.

Constructors and Destructors

QDeclarativePath()

QDeclarativePath::QDeclarativePath

(

QObject *

parent = 0

)

Definition at line 89 of file qdeclarativepath.cpp.

 : QObject(*(new QDeclarativePathPrivate), parent)
{
}

~QDeclarativePath()

QDeclarativePath::~QDeclarativePath

(

)

Definition at line 94 of file qdeclarativepath.cpp.

{
}

Functions

attributeAt()

qreal QDeclarativePath::attributeAt	(	const QString &	name,
		qreal	percent
	)		const

Definition at line 451 of file qdeclarativepath.cpp.

{
    Q_D(const QDeclarativePath);
    if (percent < 0 || percent > 1)
        return 0;

    for (int ii = 0; ii < d->_attributePoints.count(); ++ii) {
        const AttributePoint &point = d->_attributePoints.at(ii);

        if (point.percent == percent) {
            return point.values.value(name);
        } else if (point.percent > percent) {
            qreal lastValue =
                ii?(d->_attributePoints.at(ii - 1).values.value(name)):0;
            qreal lastPercent =
                ii?(d->_attributePoints.at(ii - 1).percent):0;
            qreal curValue = point.values.value(name);
            qreal curPercent = point.percent;

            return lastValue + (curValue - lastValue) * (percent - lastPercent) / (curPercent - lastPercent);
        }
    }

    return 0;
}

attributes()

QStringList QDeclarativePath::attributes

(

)

const

Definition at line 329 of file qdeclarativepath.cpp.

{
    Q_D(const QDeclarativePath);
    if (!d->componentComplete) {
        QSet<QString> attrs;

        // First gather up all the attributes
        foreach (QDeclarativePathElement *pathElement, d->_pathElements) {
            if (QDeclarativePathAttribute *attribute =
                qobject_cast<QDeclarativePathAttribute *>(pathElement))
                attrs.insert(attribute->name());
        }
        return attrs.toList();
    }
    return d->_attributes;
}

changed

void QDeclarativePath::changed ( )

signal

Referenced by componentComplete(), processPath(), QDeclarativePathCubic::setControl1X(), QDeclarativePathCubic::setControl1Y(), QDeclarativePathCubic::setControl2X(), QDeclarativePathCubic::setControl2Y(), QDeclarativePathQuad::setControlX(), QDeclarativePathQuad::setControlY(), QDeclarativePathAttribute::setValue(), QDeclarativePathPercent::setValue(), QDeclarativeCurve::setX(), and QDeclarativeCurve::setY().

classBegin()

void QDeclarativePath::classBegin ( )

protectedvirtual

Invoked after class creation, but before any properties have been set.

Implements QDeclarativeParserStatus.

Definition at line 297 of file qdeclarativepath.cpp.

{
    Q_D(QDeclarativePath);
    d->componentComplete = false;
}

componentComplete()

void QDeclarativePath::componentComplete ( )

protectedvirtual

Invoked after the root component that caused this instantiation has completed construction.

At this point all static values and binding values have been assigned to the class.

Implements QDeclarativeParserStatus.

Definition at line 303 of file qdeclarativepath.cpp.

{
    Q_D(QDeclarativePath);
    QSet<QString> attrs;
    d->componentComplete = true;

    // First gather up all the attributes
    foreach (QDeclarativePathElement *pathElement, d->_pathElements) {
        if (QDeclarativePathAttribute *attribute =
            qobject_cast<QDeclarativePathAttribute *>(pathElement))
            attrs.insert(attribute->name());
    }
    d->_attributes = attrs.toList();

    processPath();

    foreach (QDeclarativePathElement *pathElement, d->_pathElements)
        connect(pathElement, SIGNAL(changed()), this, SLOT(processPath()));
}

createPointCache()

void QDeclarativePath::createPointCache ( ) const

private

Definition at line 383 of file qdeclarativepath.cpp.

Referenced by pointAt().

{
    Q_D(const QDeclarativePath);
    qreal pathLength = d->_path.length();
    if (pathLength <= 0 || qIsNaN(pathLength))
        return;
    // more points means less jitter between items as they move along the
    // path, but takes longer to generate
    const int points = qCeil(pathLength*5);
    const int lastElement = d->_path.elementCount() - 1;
    d->_pointCache.resize(points+1);

    int currElement = 0;
    qreal bezLength = 0;
    QBezier currBez = nextBezier(d->_path, &currElement, &bezLength);
    qreal currLength = bezLength;
    qreal epc = currLength / pathLength;

    for (int i = 0; i < d->_pointCache.size(); i++) {
        //find which set we are in
        qreal prevPercent = 0;
        qreal prevOrigPercent = 0;
        for (int ii = 0; ii < d->_attributePoints.count(); ++ii) {
            qreal percent = qreal(i)/points;
            const AttributePoint &point = d->_attributePoints.at(ii);
            if (percent < point.percent || ii == d->_attributePoints.count() - 1) { //### || is special case for very last item
                qreal elementPercent = (percent - prevPercent);

                qreal spc = prevOrigPercent + elementPercent * point.scale;

                while (spc > epc) {
                    if (currElement > lastElement)
                        break;
                    currBez = nextBezier(d->_path, &currElement, &bezLength);
                    if (bezLength == 0.0) {
                        currLength = pathLength;
                        epc = 1.0;
                        break;
                    }
                    currLength += bezLength;
                    epc = currLength / pathLength;
                }
                qreal realT = (pathLength * spc - (currLength - bezLength)) / bezLength;
                d->_pointCache[i] = currBez.pointAt(qBound(qreal(0), realT, qreal(1)));
                break;
            }
            prevOrigPercent = point.origpercent;
            prevPercent = point.percent;
        }
    }
}

endpoint()

void QDeclarativePath::endpoint ( const QString &  name )

private

Definition at line 209 of file qdeclarativepath.cpp.

Referenced by processPath().

{
    Q_D(QDeclarativePath);
    const AttributePoint &first = d->_attributePoints.first();
    qreal val = first.values.value(name);
    for (int ii = d->_attributePoints.count() - 1; ii >= 0; ii--) {
        const AttributePoint &point = d->_attributePoints.at(ii);
        if (point.values.contains(name)) {
            for (int jj = ii + 1; jj < d->_attributePoints.count(); ++jj) {
                AttributePoint &setPoint = d->_attributePoints[jj];
                setPoint.values.insert(name, val);
            }
            return;
        }
    }
}

interpolate()

void QDeclarativePath::interpolate ( int  idx, const QString &  name, qreal  value  )

private

Definition at line 178 of file qdeclarativepath.cpp.

Referenced by processPath().

{
    Q_D(QDeclarativePath);
    if (!idx)
        return;

    qreal lastValue = 0;
    qreal lastPercent = 0;
    int search = idx - 1;
    while(search >= 0) {
        const AttributePoint &point = d->_attributePoints.at(search);
        if (point.values.contains(name)) {
            lastValue = point.values.value(name);
            lastPercent = point.origpercent;
            break;
        }
        --search;
    }

    ++search;

    const AttributePoint &curPoint = d->_attributePoints.at(idx);

    for (int ii = search; ii < idx; ++ii) {
        AttributePoint &point = d->_attributePoints[ii];

        qreal val = lastValue + (value - lastValue) * (point.origpercent - lastPercent) / (curPoint.origpercent - lastPercent);
        point.values.insert(name, val);
    }
}

isClosed()

bool QDeclarativePath::isClosed

(

)

const

Definition at line 145 of file qdeclarativepath.cpp.

{
    Q_D(const QDeclarativePath);
    return d->closed;
}

path()

QPainterPath QDeclarativePath::path

(

)

const

Definition at line 323 of file qdeclarativepath.cpp.

{
    Q_D(const QDeclarativePath);
    return d->_path;
}

pathElements()

QDeclarativeListProperty<QDeclarativePathElement> QDeclarativePath::pathElements

(

)

Referenced by isClosed().

pointAt()

QPointF QDeclarativePath::pointAt

(

qreal

p

)

const

Definition at line 435 of file qdeclarativepath.cpp.

Referenced by QDeclarativePathViewPrivate::pointNear().

{
    Q_D(const QDeclarativePath);
    if (d->_pointCache.isEmpty()) {
        createPointCache();
        if (d->_pointCache.isEmpty())
            return QPointF();
    }
    int idx = qRound(p*d->_pointCache.size());
    if (idx >= d->_pointCache.size())
        idx = d->_pointCache.size() - 1;
    else if (idx < 0)
        idx = 0;
    return d->_pointCache.at(idx);
}

processPath

void QDeclarativePath::processPath ( )

privateslot

Definition at line 226 of file qdeclarativepath.cpp.

Referenced by componentComplete(), setStartX(), and setStartY().

{
    Q_D(QDeclarativePath);

    if (!d->componentComplete)
        return;

    d->_pointCache.clear();
    d->_attributePoints.clear();
    d->_path = QPainterPath();

    AttributePoint first;
    for (int ii = 0; ii < d->_attributes.count(); ++ii)
        first.values[d->_attributes.at(ii)] = 0;
    d->_attributePoints << first;

    d->_path.moveTo(d->startX, d->startY);

    QDeclarativeCurve *lastCurve = 0;
    foreach (QDeclarativePathElement *pathElement, d->_pathElements) {
        if (QDeclarativeCurve *curve = qobject_cast<QDeclarativeCurve *>(pathElement)) {
            curve->addToPath(d->_path);
            AttributePoint p;
            p.origpercent = d->_path.length();
            d->_attributePoints << p;
            lastCurve = curve;
        } else if (QDeclarativePathAttribute *attribute = qobject_cast<QDeclarativePathAttribute *>(pathElement)) {
            AttributePoint &point = d->_attributePoints.last();
            point.values[attribute->name()] = attribute->value();
            interpolate(d->_attributePoints.count() - 1, attribute->name(), attribute->value());
        } else if (QDeclarativePathPercent *percent = qobject_cast<QDeclarativePathPercent *>(pathElement)) {
            AttributePoint &point = d->_attributePoints.last();
            point.values[QLatin1String("_qfx_percent")] = percent->value();
            interpolate(d->_attributePoints.count() - 1, QLatin1String("_qfx_percent"), percent->value());
        }
    }

    // Fixup end points
    const AttributePoint &last = d->_attributePoints.last();
    for (int ii = 0; ii < d->_attributes.count(); ++ii) {
        if (!last.values.contains(d->_attributes.at(ii)))
            endpoint(d->_attributes.at(ii));
    }

    // Adjust percent
    qreal length = d->_path.length();
    qreal prevpercent = 0;
    qreal prevorigpercent = 0;
    for (int ii = 0; ii < d->_attributePoints.count(); ++ii) {
        const AttributePoint &point = d->_attributePoints.at(ii);
        if (point.values.contains(QLatin1String("_qfx_percent"))) { //special string for QDeclarativePathPercent
            if ( ii > 0) {
                qreal scale = (d->_attributePoints[ii].origpercent/length - prevorigpercent) /
                            (point.values.value(QLatin1String("_qfx_percent"))-prevpercent);
                d->_attributePoints[ii].scale = scale;
            }
            d->_attributePoints[ii].origpercent /= length;
            d->_attributePoints[ii].percent = point.values.value(QLatin1String("_qfx_percent"));
            prevorigpercent = d->_attributePoints[ii].origpercent;
            prevpercent = d->_attributePoints[ii].percent;
        } else {
            d->_attributePoints[ii].origpercent /= length;
            d->_attributePoints[ii].percent = d->_attributePoints[ii].origpercent;
        }
    }

    d->closed = lastCurve && d->startX == lastCurve->x() && d->startY == lastCurve->y();

    emit changed();
}

setStartX()

void QDeclarativePath::setStartX

(

qreal

x

)

Definition at line 112 of file qdeclarativepath.cpp.

{
    Q_D(QDeclarativePath);
    if (qFuzzyCompare(x, d->startX))
        return;
    d->startX = x;
    emit startXChanged();
    processPath();
}

setStartY()

void QDeclarativePath::setStartY

(

qreal

y

)

Definition at line 128 of file qdeclarativepath.cpp.

{
    Q_D(QDeclarativePath);
    if (qFuzzyCompare(y, d->startY))
        return;
    d->startY = y;
    emit startYChanged();
    processPath();
}

startX()

qreal QDeclarativePath::startX

(

)

const

Referenced by ~QDeclarativePath().

startXChanged

void QDeclarativePath::startXChanged ( )

signal

Referenced by setStartX().

startY()

qreal QDeclarativePath::startY

(

)

const

Referenced by setStartX().

startYChanged

void QDeclarativePath::startYChanged ( )

signal

Referenced by setStartY().

Properties

closed

bool QDeclarativePath::closed

private

Definition at line 216 of file qdeclarativepath_p.h.

pathElements

QDeclarativeListProperty< QDeclarativePathElement > QDeclarativePath::pathElements

private

Definition at line 213 of file qdeclarativepath_p.h.

startX

qreal QDeclarativePath::startX

private

Definition at line 214 of file qdeclarativepath_p.h.

startY

qreal QDeclarativePath::startY

private

Definition at line 215 of file qdeclarativepath_p.h.

---

The documentation for this class was generated from the following files:

• /src/declarative/graphicsitems/qdeclarativepath_p.h
• /src/declarative/graphicsitems/qdeclarativepath.cpp