///////////////////////////////////////////////////////////////////////// // kineticscroll.cpp // // // // Copyright(C) 2009 Igor Trindade Oliveira // // Copyright(C) 2009 Adenilson Cavalcanti // // // // 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, write to the Free Software // // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA // // 02110-1301 USA // ///////////////////////////////////////////////////////////////////////// #include #include #include #include #include #include #include #include "kineticscroll_p.h" /* TODO: * - write a factory to animation/state object * - move timer based code to an implementation of the factory * - write another implementation using QPropertyAnimation Qt 4.6 * - generalize code concerning viewport and other parameters * - swap the 'magic numbers' for consts * - consider if direct access to control state/velocity variables should * be done directly or using functions */ namespace Plasma { class KineticScrollingPrivate { public: KineticScrollingPrivate(): mScrollVelocity(0), timerID(0), overshoot(40), bounceFlag(0) { } void count() { t = QTime::currentTime(); t.start(); } unsigned int elapsed() { return t.restart(); } void verticalScroll(int value) { widget->setPos(QPoint(0, -value*10)); } void horizontalScroll(int value) { widget->setPos(QPoint(-value*10, 0)); } unsigned int timeDelta; qreal scrollVelocity; QPoint movement; QPoint kinMovement; qreal mScrollVelocity; enum { None, Up, Down }; int timerID, overshoot, direction; QPoint cposition, minimalPos, maximumPos; char bounceFlag; QGraphicsWidget *widget; QGraphicsWidget *scrollingWidget; protected: QTime t; }; KineticScrolling::KineticScrolling(): d(0) { d = new KineticScrollingPrivate; } KineticScrolling::~KineticScrolling() { delete d; } QPoint KineticScrolling::movement() { return d->movement; } QPoint KineticScrolling::kinMovement() { return d->kinMovement; } qreal KineticScrolling::duration() { return d->timeDelta; } void KineticScrolling::mousePressEvent(QGraphicsSceneMouseEvent *event) { doneOvershoot(); Q_UNUSED(event); d->count(); d->scrollVelocity = 0; d->movement = QPoint(0, 0); d->kinMovement = QPoint(0, 0); } void KineticScrolling::mouseMoveEvent(QGraphicsSceneMouseEvent *event) { QPoint temp = event->lastPos().toPoint() - event->pos().toPoint(); if (!temp.isNull()) { d->movement = temp; d->kinMovement += temp; } /* After */ setKineticScrollValue(movement()); } void KineticScrolling::mouseReleaseEvent(QGraphicsSceneMouseEvent *event) { d->timeDelta = d->elapsed(); QPoint temp = event->lastPos().toPoint() - event->pos().toPoint(); if (!temp.isNull()) d->kinMovement += temp; if (d->timeDelta > 600) { if (d->kinMovement.y() > 0) d->kinMovement.setY(3); else d->kinMovement.setY(-3); } /* The after */ if (d->cposition.y() > 0) { d->direction = KineticScrollingPrivate::Up; } else if (abs(d->cposition.y()) > abs(d->scrollingWidget->size().height() - d->widget->size().height())) { d->direction = KineticScrollingPrivate::Down; } else { d->direction = KineticScrollingPrivate::None; d->mScrollVelocity = (d->kinMovement.x() + d->kinMovement.y())>>2; startAnimationTimer(30); return; } d->mScrollVelocity = 5; killTimer(d->timerID); startAnimationTimer(50); } void KineticScrolling::wheelReleaseEvent(QGraphicsSceneWheelEvent *event) { mousePressEvent(0); /* Core */ d->timeDelta = d->elapsed(); int temp = event->delta(); temp *= -0.5; d->kinMovement.setY(kinMovement().y() + temp); /* After */ d->mScrollVelocity = kinMovement().y(); startAnimationTimer(30); } void KineticScrolling::startAnimationTimer(int interval) { if (d->timerID) { killTimer(d->timerID); d->timerID = 0; } d->timerID = QObject::startTimer(interval); } void KineticScrolling::timerEvent(QTimerEvent *event) { Q_UNUSED(event); if (d->direction == KineticScrollingPrivate::None) { d->mScrollVelocity *= 0.9; if (qAbs(d->mScrollVelocity) < 5.0) { if (d->timerID) killTimer(d->timerID); } setKineticScrollValue( QPoint(d->mScrollVelocity, d->mScrollVelocity)); } else { if ((d->timerID != 0) && (d->direction != KineticScrollingPrivate::None)) { bounceTimer(); } } } void KineticScrolling::setKineticScrollValue(QPoint value) { d->minimalPos.setY((-(d->widget->size().height())) + d->scrollingWidget->size().height() -(d->overshoot)); d->minimalPos.setX((-(d->widget->size().width())) + d->scrollingWidget->size().width()); d->minimalPos.setY(qMin(d->overshoot, d->minimalPos.y())); d->minimalPos.setX(qMin( 0, d->minimalPos.x())); d->maximumPos = d->widget->pos().toPoint() - value; d->cposition.setY(qBound(d->minimalPos.y(), d->maximumPos.y(), d->overshoot)); d->cposition.setX( qBound(d->minimalPos.x(), d->maximumPos.x(), 0)); d->widget->setPos(d->cposition); if (d->cposition.y() == d->overshoot) { d->direction = KineticScrollingPrivate::Up; killTimer(d->timerID); d->mScrollVelocity = 5; startAnimationTimer(30); } else if (d->cposition.y() == d->minimalPos.y()) { d->direction = KineticScrollingPrivate::Down; killTimer(d->timerID); d->mScrollVelocity = 5; startAnimationTimer(30); } else d->direction = KineticScrollingPrivate::None; } void KineticScrolling::bounceTimer() { int delta = 5; if ((d->direction == KineticScrollingPrivate::Up) && (d->bounceFlag == 0)) delta = -5; else if ((d->direction == KineticScrollingPrivate::Up) && (d->bounceFlag == 1)) delta = -2; else if ((d->direction == KineticScrollingPrivate::Down) && (d->bounceFlag == 0)) delta = 5; else if ((d->direction == KineticScrollingPrivate::Down) && (d->bounceFlag == 1)) delta = 2; d->cposition.setY(d->cposition.y() + delta); d->widget->setPos(d->cposition); if ((d->direction == KineticScrollingPrivate::Up) && (d->cposition.y() < 0)) { if (!d->bounceFlag) { d->cposition.setY(d->overshoot/4); d->bounceFlag = 1; d->widget->setPos(d->cposition); return; } else { d->bounceFlag = 0; d->cposition = QPoint(d->cposition.x(), 0); doneOvershoot() ; } } else if ((d->direction == KineticScrollingPrivate::Down) && ((d->cposition.y() - d->overshoot) > d->minimalPos.y())) { if (!d->bounceFlag) { d->cposition.setY(d->minimalPos.y() + d->overshoot/4); d->bounceFlag = 1; d->widget->setPos(d->cposition); return; } else { d->bounceFlag = 0; d->cposition.setY(d->minimalPos.y() + d->overshoot); doneOvershoot(); } } } void KineticScrolling::doneOvershoot(void) { d->direction = KineticScrollingPrivate::None; d->mScrollVelocity = 0; killTimer(d->timerID); d->timerID = 0; } void KineticScrolling::setWidgets(QGraphicsWidget *widget, QGraphicsWidget *scrolling) { d->widget = widget; d->scrollingWidget = scrolling; } } // namespace Plasma