plasma-framework/graphicsview/private/kineticscroll.cpp

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/*
Copyright (C) 2009 Igor Trindade Oliveira <igor.oliveira@indt.org.br>
Copyright (C) 2009 Adenilson Cavalcanti <adenilson.silva@idnt.org.br>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "kineticscroll_p.h"
#include <QtCore/qglobal.h>
#include <QtCore/qmetatype.h>
#include <QGraphicsScene>
#include <QGraphicsSceneMouseEvent>
#include <QGraphicsSceneWheelEvent>
#include <QTime>
#include <QGraphicsWidget>
#include <QPoint>
#include <QPropertyAnimation>
#include <QCursor>
#include <kdebug.h>
/* TODO:
* - clean up the code(remove duplicated code, constify)
* - port to Plasma::Animator
*/
namespace Plasma
{
class KineticScrollingPrivate
{
public:
enum Direction {
None,
Up,
Down,
Left,
Right
};
enum Gesture {
GestureNone = 0,
GestureUndefined,
GestureScroll,
GestureZoom
};
KineticScrollingPrivate()
: overshoot(20),
hasOvershoot(true),
parent(0),
forwardingEvent(false),
multitouchGesture(GestureNone)
{
}
void count()
{
t = QTime::currentTime();
}
void syncViewportRect()
{
contentsSize = parent->property("contentsSize").toSizeF();
viewportGeometry = parent->property("viewportGeometry").toRectF();
}
bool canScroll(Direction direction, bool hasOvershoot = false) const
{
QPointF scrollPosition = -parent->property("scrollPosition").value<QPointF>();
int offset = (hasOvershoot?overshoot*2:0);
switch (direction) {
case Up:
return (scrollPosition.y() < offset);
case Down:
return (scrollPosition.y() + contentsSize.height() + offset >= viewportGeometry.bottom());
case Left:
return (scrollPosition.x() < offset);
case Right:
return (scrollPosition.x() + contentsSize.width() + offset >= viewportGeometry.right());
default:
return true;
}
}
QPointF kinMovement;
enum BounceStatus {
Running,
Finished
};
BounceStatus bounceStatus;
QPropertyAnimation *scrollAnimation;
int overshoot;
QPointF cposition;
bool hasOvershoot;
QGraphicsWidget *parent;
QRectF viewportGeometry;
QSizeF contentsSize;
QPointF maximum, minimum;
bool forwardingEvent;
Gesture multitouchGesture;
unsigned int timeDelta;
QTime t;
};
KineticScrolling::KineticScrolling(QGraphicsWidget *parent)
: d(new KineticScrollingPrivate)
{
setWidget(parent);
}
KineticScrolling::~KineticScrolling()
{
delete d;
}
void KineticScrolling::duration( )
{
d->timeDelta = d->t.msecsTo(QTime::currentTime());
}
void KineticScrolling::overshoot()
{
QPointF scrollPosition = -d->parent->property("scrollPosition").value<QPointF>();
if (!d->canScroll(KineticScrollingPrivate::Down) &&
!d->canScroll(KineticScrollingPrivate::Up)) {
return;
}
if (d->bounceStatus != KineticScrollingPrivate::Running) {
if ((d->cposition.y() > 0 ) || (d->cposition.y() <= d->minimum.y() + d->overshoot)) {
QPointF finalPosition;
d->scrollAnimation->setEasingCurve( QEasingCurve::OutBounce );
if (d->cposition.y() > 0) {
finalPosition = QPointF(scrollPosition.x(), 0);
} else {
finalPosition = QPointF(d->cposition.x(),
-d->contentsSize.height( ) + d->parent->size().height());
}
resetAnimation(-finalPosition, 900);
d->bounceStatus = KineticScrollingPrivate::Running;
}
} else {
d->bounceStatus = KineticScrollingPrivate::Finished;
d->scrollAnimation->setEasingCurve(QEasingCurve::OutCirc);
}
}
void KineticScrolling::setScrollValue(QPointF value)
{
const QPointF pos = thresholdPosition(value);
QPointF posf(-pos);
d->parent->setProperty("scrollPosition", posf);
if ((pos.y() == d->overshoot) || (pos.y() == d->minimum.y())) {
overshoot();
}
}
QPointF KineticScrolling::thresholdPosition(QPointF value) const
{
d->minimum.setX(-d->contentsSize.width() + d->viewportGeometry.width());
d->minimum.setY(-d->contentsSize.height() + d->viewportGeometry.height()
-d->overshoot);
d->minimum.setY(qMin((qreal)d->overshoot, d->minimum.y()));
d->maximum = value;
if(d->minimum.x() >= 0) {
d->cposition.setX(value.x());
} else {
d->cposition.setX(qBound(d->minimum.x(), d->maximum.x(), qreal(0)));
}
if((-d->contentsSize.height() + d->viewportGeometry.height() - d->overshoot) >= 0) {
d->cposition.setY(value.y());
} else {
d->cposition.setY(qBound(d->minimum.y(), d->maximum.y(), qreal(d->overshoot)));
}
return d->cposition;
}
void KineticScrolling::resetAnimation(QPointF finalPosition, int duration)
{
if (d->scrollAnimation->state() != QAbstractAnimation::Stopped) {
d->scrollAnimation->stop();
}
d->cposition = -finalPosition;
QPointF tmpPosition = d->parent->property("scrollPosition").value<QPointF>();
d->scrollAnimation->setStartValue(tmpPosition);
tmpPosition = finalPosition;
d->scrollAnimation->setEndValue(tmpPosition);
d->scrollAnimation->setDuration(duration);
d->scrollAnimation->start();
}
void KineticScrolling::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
Q_UNUSED(event);
if (d->scrollAnimation->state() != QAbstractAnimation::Stopped) {
d->scrollAnimation->stop();
}
d->syncViewportRect();
d->cposition = -d->parent->property("scrollPosition").value<QPointF>();
d->count();
d->kinMovement = QPointF(0,0);
d->scrollAnimation->setEasingCurve(QEasingCurve::OutCirc);
}
void KineticScrolling::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
QPointF movement = event->lastPos().toPoint() - event->pos().toPoint();
const QPointF scrollPosition = -d->parent->property("scrollPosition").value<QPointF>();
if (!movement.isNull()) {
if ((d->contentsSize.width() < d->viewportGeometry.width()) &&
(d->contentsSize.height() < d->viewportGeometry.height())) {
d->kinMovement = QPointF(0, 0);
movement = QPointF(0, 0);
} else if (d->contentsSize.height() < d->viewportGeometry.height()) {
d->kinMovement += QPointF(movement.x(), 0);
movement.setY(0);
} else if (d->contentsSize.width() < d->viewportGeometry.width()) {
d->kinMovement = QPointF(0, movement.y());
movement.setX(0);
} else {
d->kinMovement += movement;
}
setScrollValue(scrollPosition - movement);
}
}
void KineticScrolling::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
Q_UNUSED(event);
if (d->scrollAnimation->state() != QAbstractAnimation::Running) {
duration();
if (d->kinMovement != QPointF(0, 0)) {
const QPointF scrollPosition = -d->parent->property("scrollPosition").toPointF();
d->kinMovement = QPointF(d->kinMovement.x()*3, d->kinMovement.y()*3);
const QPointF finalPos = thresholdPosition(scrollPosition - d->kinMovement);
resetAnimation( -finalPos, d->timeDelta*8 );
}
}
}
void KineticScrolling::wheelReleaseEvent(QGraphicsSceneWheelEvent *event)
{
Q_UNUSED(event);
d->syncViewportRect();
d->kinMovement = QPointF(0,0);
if((event->orientation() == Qt::Vertical) &&
(((event->delta() < 0) && d->canScroll(KineticScrollingPrivate::Down)) ||
((event->delta() > 0) && d->canScroll(KineticScrollingPrivate::Up)))) {
d->kinMovement.setY(d->kinMovement.y() - event->delta());
} else if ((event->orientation() == Qt::Vertical) ||
(!d->canScroll(KineticScrollingPrivate::Down) &&
!d->canScroll(KineticScrollingPrivate::Up))) {
if (((event->delta() < 0) &&
d->canScroll(KineticScrollingPrivate::Right)) ||
(event->delta() > 0 && d->canScroll(KineticScrollingPrivate::Left))) {
d->kinMovement.setX(d->kinMovement.x() - event->delta());
} else {
event->ignore( );
}
} else {
event->ignore( );
return;
}
const QPointF scrollPosition = -d->parent->property("scrollPosition").value<QPointF>();
const QPointF pos = scrollPosition - d->kinMovement*2;
const QPointF finalPos = thresholdPosition(pos);
d->scrollAnimation->setEasingCurve(QEasingCurve::OutCirc);
resetAnimation(-finalPos, 900);
}
void KineticScrolling::keyPressEvent(QKeyEvent *event)
{
const int movement = 30;
const int duration = 900;
QPointF scrollPosition = -d->parent->property("scrollPosition").value<QPointF>();
QPointF finalPos;
switch (event->key()) {
case Qt::Key_Left:
scrollPosition.setX(scrollPosition.x() + movement);
finalPos = thresholdPosition(scrollPosition);
resetAnimation(-finalPos, duration);
break;
case Qt::Key_Right:
scrollPosition.setX(scrollPosition.x() - movement);
finalPos = thresholdPosition(scrollPosition);
resetAnimation(-finalPos, duration);
break;
case Qt::Key_Up:
scrollPosition.setY(scrollPosition.y() + movement);
finalPos = thresholdPosition(scrollPosition);
resetAnimation(-finalPos, duration);
break;
case Qt::Key_Down:
scrollPosition.setY(scrollPosition.y() - movement);
finalPos = thresholdPosition(scrollPosition);
resetAnimation(-finalPos, duration);
break;
default:
break;
}
}
void KineticScrolling::setWidget(QGraphicsWidget *parent)
{
if (d->parent) {
d->parent->removeEventFilter(this);
disconnect(d->scrollAnimation, SIGNAL(finished()), this, SLOT(overshoot()));
disconnect(d->scrollAnimation,
SIGNAL(stateChanged(QAbstractAnimation::State,QAbstractAnimation::State)), this,
SIGNAL(stateChanged(QAbstractAnimation::State,QAbstractAnimation::State)));
delete d->scrollAnimation;
}
setParent(parent);
d->parent = parent;
d->scrollAnimation = new QPropertyAnimation(parent, "scrollPosition", parent);
connect(d->scrollAnimation, SIGNAL(finished()), this, SLOT(overshoot()));
connect(d->scrollAnimation,
SIGNAL(stateChanged(QAbstractAnimation::State,QAbstractAnimation::State)), this,
SIGNAL(stateChanged(QAbstractAnimation::State,QAbstractAnimation::State)));
d->scrollAnimation->setEasingCurve(QEasingCurve::OutCirc);
if (parent) {
d->parent->installEventFilter(this);
}
/* TODO: add a new property in plasma::ScrollWidget 'hasOvershoot' */
}
void KineticScrolling::stop()
{
d->scrollAnimation->stop();
}
bool KineticScrolling::eventFilter(QObject *watched, QEvent *event)
{
Q_UNUSED(watched);
Q_UNUSED(event);
if (d->forwardingEvent) {
return false;
}
bool notBlocked = true;
if (d->multitouchGesture == KineticScrollingPrivate::GestureNone &&
d->parent && d->parent->scene()) {
d->forwardingEvent = true;
notBlocked = d->parent->scene()->sendEvent(d->parent, event);
d->forwardingEvent = false;
}
if (event->type() != QEvent::TouchBegin &&
event->type() != QEvent::TouchUpdate &&
event->type() != QEvent::TouchEnd &&
(!notBlocked ||
((event->type() != QEvent::GraphicsSceneMousePress && event->isAccepted()) &&
(event->type() != QEvent::GraphicsSceneWheel && event->isAccepted())))) {
return true;
}
QGraphicsSceneMouseEvent *me = static_cast<QGraphicsSceneMouseEvent *>(event);
QGraphicsSceneWheelEvent *we = static_cast<QGraphicsSceneWheelEvent *>(event);
switch (event->type()) {
case QEvent::GraphicsSceneMousePress:
mousePressEvent(me);
break;
case QEvent::GraphicsSceneMouseRelease:
mouseReleaseEvent(me);
break;
case QEvent::GraphicsSceneMouseMove:
mouseMoveEvent(me);
break;
case QEvent::TouchBegin:
mousePressEvent(0);
break;
case QEvent::TouchUpdate: {
QList<QTouchEvent::TouchPoint> touchPoints = static_cast<QTouchEvent *>(event)->touchPoints();
if (touchPoints.count() == 2) {
const QTouchEvent::TouchPoint &touchPoint0 = touchPoints.first();
const QTouchEvent::TouchPoint &touchPoint1 = touchPoints.last();
const QLineF line0(touchPoint0.lastPos(), touchPoint1.lastPos());
const QLineF line1(touchPoint0.pos(), touchPoint1.pos());
const QLineF startLine(touchPoint0.startPos(), touchPoint1.startPos());
const QPointF point = line1.pointAt(0.5);
const QPointF lastPoint = line0.pointAt(0.5);
if (d->multitouchGesture == KineticScrollingPrivate::GestureNone) {
d->multitouchGesture = KineticScrollingPrivate::GestureUndefined;
}
if (d->multitouchGesture == KineticScrollingPrivate::GestureUndefined) {
const int zoomDistance = qAbs(line1.length() - startLine.length());
const int dragDistance = (startLine.pointAt(0.5) - point).manhattanLength();
if (zoomDistance - dragDistance > 30) {
d->multitouchGesture = KineticScrollingPrivate::GestureZoom;
} else if (dragDistance - zoomDistance > 30) {
d->multitouchGesture = KineticScrollingPrivate::GestureScroll;
}
}
if (d->multitouchGesture == KineticScrollingPrivate::GestureScroll) {
QGraphicsSceneMouseEvent fakeEvent;
fakeEvent.setPos(point);
fakeEvent.setLastPos(lastPoint);
mouseMoveEvent(&fakeEvent);
} else if (d->multitouchGesture == KineticScrollingPrivate::GestureZoom) {
qreal scaleFactor = 1;
if (line0.length() > 0) {
scaleFactor = line1.length() / line0.length();
}
qreal zoom = d->parent->property("zoomFactor").toReal();
d->parent->setProperty("zoomFactor", zoom * scaleFactor);
}
}
break;
}
case QEvent::TouchEnd:
mouseReleaseEvent(0);
d->multitouchGesture = KineticScrollingPrivate::GestureNone;
break;
case QEvent::GraphicsSceneWheel:
wheelReleaseEvent(we);
break;
case QEvent::KeyPress: {
QKeyEvent *ke = static_cast<QKeyEvent *>(event);
keyPressEvent(ke);
break;
}
default:
break;
}
return true;
}
} // namespace Plasma