scroller.cpp
225 lines
| 5.7 KiB
| text/x-c
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CppLexer
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r0 | /**************************************************************************** | ||
** | ||||
** Copyright (C) 2016 The Qt Company Ltd. | ||||
** Contact: https://www.qt.io/licensing/ | ||||
** | ||||
** This file is part of the Qt Charts module of the Qt Toolkit. | ||||
** | ||||
** $QT_BEGIN_LICENSE:GPL$ | ||||
** Commercial License Usage | ||||
** Licensees holding valid commercial Qt licenses may use this file in | ||||
** accordance with the commercial license agreement provided with the | ||||
** Software or, alternatively, in accordance with the terms contained in | ||||
** a written agreement between you and The Qt Company. For licensing terms | ||||
** and conditions see https://www.qt.io/terms-conditions. For further | ||||
** information use the contact form at https://www.qt.io/contact-us. | ||||
** | ||||
** GNU General Public License Usage | ||||
** Alternatively, this file may be used under the terms of the GNU | ||||
** General Public License version 3 or (at your option) any later version | ||||
** approved by the KDE Free Qt Foundation. The licenses are as published by | ||||
** the Free Software Foundation and appearing in the file LICENSE.GPL3 | ||||
** included in the packaging of this file. Please review the following | ||||
** information to ensure the GNU General Public License requirements will | ||||
** be met: https://www.gnu.org/licenses/gpl-3.0.html. | ||||
** | ||||
** $QT_END_LICENSE$ | ||||
** | ||||
****************************************************************************/ | ||||
#include <private/scroller_p.h> | ||||
#include <QtCharts/QLegend> | ||||
#include <QtWidgets/QGraphicsSceneMouseEvent> | ||||
#include <QtCore/QDebug> | ||||
QT_CHARTS_BEGIN_NAMESPACE | ||||
Scroller::Scroller() | ||||
: m_ticker(this), | ||||
m_timeTresholdMin(50), | ||||
m_timeTresholdMax(300), | ||||
m_state(Idle), | ||||
m_treshold(10) | ||||
{ | ||||
} | ||||
Scroller::~Scroller() | ||||
{ | ||||
} | ||||
void Scroller::move(const QPointF &delta) | ||||
{ | ||||
switch (m_state) { | ||||
case Pressed: | ||||
m_timeStamp = QTime::currentTime(); | ||||
break; | ||||
case Scroll: | ||||
stopTicker(); | ||||
m_timeStamp = QTime::currentTime(); | ||||
break; | ||||
default: | ||||
break; | ||||
} | ||||
setOffset(offset() - delta); | ||||
} | ||||
void Scroller::scrollTo(const QPointF &delta) | ||||
{ | ||||
// Starts scrolling, if at least m_timeTresholdMin msecs has gone since timestamp | ||||
// current time is no more than m_timeTresholdMax from timestamp | ||||
if ((m_timeStamp.elapsed() > m_timeTresholdMin) && (m_timeStamp.msecsTo(QTime::currentTime()) < m_timeTresholdMax)) { | ||||
// Release was quick enough. Start scrolling. | ||||
qreal interval = 25; | ||||
qreal time = m_timeStamp.msecsTo(QTime::currentTime()); | ||||
if (qFuzzyCompare(time, 0)) { | ||||
m_speed = delta / 5; | ||||
} else { | ||||
m_speed = delta * interval / time; | ||||
} | ||||
qreal fraction = qMax(qAbs(m_speed.x()), qAbs(m_speed.y())); | ||||
if (!qFuzzyCompare(fraction, 0)) { | ||||
m_fraction.setX(qAbs(m_speed.x() / fraction)); | ||||
m_fraction.setY(qAbs(m_speed.y() / fraction)); | ||||
} else { | ||||
m_fraction.setX(1); | ||||
m_fraction.setY(1); | ||||
} | ||||
startTicker(interval); | ||||
} else { | ||||
stopTicker(); // Stop ticker, if one is running. | ||||
} | ||||
} | ||||
void Scroller::handleMousePressEvent(QGraphicsSceneMouseEvent *event) | ||||
{ | ||||
stopTicker(); | ||||
m_pressPos = event->screenPos(); | ||||
m_lastPos = m_pressPos; | ||||
m_state = Pressed; | ||||
event->accept(); | ||||
} | ||||
void Scroller::handleMouseMoveEvent(QGraphicsSceneMouseEvent *event) | ||||
{ | ||||
QPointF delta = event->screenPos() - m_lastPos; | ||||
switch (m_state) { | ||||
case Pressed: { | ||||
// calculate treshold. If enough, change to move state and send out move deltas. | ||||
if (qAbs(delta.x()) > m_treshold || qAbs(delta.y()) > m_treshold) { | ||||
m_lastPos = event->screenPos(); | ||||
move(delta); | ||||
m_state = Move; | ||||
} | ||||
event->accept(); | ||||
break; | ||||
} | ||||
case Move: { | ||||
m_lastPos = event->screenPos(); | ||||
move(delta); | ||||
event->accept(); | ||||
break; | ||||
} | ||||
case Idle: | ||||
default: { | ||||
event->ignore(); | ||||
break; | ||||
} | ||||
} | ||||
} | ||||
void Scroller::handleMouseReleaseEvent(QGraphicsSceneMouseEvent *event) | ||||
{ | ||||
switch (m_state) { | ||||
case Move: | ||||
{ | ||||
scrollTo(m_lastPos - m_pressPos); | ||||
event->accept(); | ||||
break; | ||||
} | ||||
default: | ||||
{ | ||||
m_state = Idle; | ||||
event->ignore(); | ||||
break; | ||||
} | ||||
} | ||||
} | ||||
void Scroller::startTicker(int interval) | ||||
{ | ||||
m_state = Scroll; | ||||
m_ticker.start(interval); | ||||
} | ||||
void Scroller::stopTicker() | ||||
{ | ||||
m_state = Idle; | ||||
m_ticker.stop(); | ||||
} | ||||
void Scroller::scrollTick() | ||||
{ | ||||
switch (m_state) { | ||||
case Scroll: | ||||
lowerSpeed(m_speed); | ||||
setOffset(offset() - m_speed); | ||||
if (m_speed == QPointF(0, 0)) { | ||||
m_state = Idle; | ||||
m_ticker.stop(); | ||||
} | ||||
break; | ||||
default: | ||||
qWarning() << __FUNCTION__ << "Scroller unexpected state" << m_state; | ||||
m_ticker.stop(); | ||||
m_state = Idle; | ||||
break; | ||||
} | ||||
} | ||||
void Scroller::lowerSpeed(QPointF &speed, qreal maxSpeed) | ||||
{ | ||||
qreal x = qBound(-maxSpeed, speed.x(), maxSpeed); | ||||
qreal y = qBound(-maxSpeed, speed.y(), maxSpeed); | ||||
x = (x == 0) ? x : | ||||
(x > 0) ? qMax(qreal(0), x - m_fraction.x()) : qMin(qreal(0), x + m_fraction.x()); | ||||
y = (y == 0) ? y : | ||||
(y > 0) ? qMax(qreal(0), y - m_fraction.y()) : qMin(qreal(0), y + m_fraction.y()); | ||||
speed.setX(x); | ||||
speed.setY(y); | ||||
} | ||||
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// | ||||
ScrollTicker::ScrollTicker(Scroller *scroller, QObject *parent) | ||||
: QObject(parent), | ||||
m_scroller(scroller) | ||||
{ | ||||
} | ||||
void ScrollTicker::start(int interval) | ||||
{ | ||||
if (!m_timer.isActive()) | ||||
m_timer.start(interval, this); | ||||
} | ||||
void ScrollTicker::stop() | ||||
{ | ||||
m_timer.stop(); | ||||
} | ||||
void ScrollTicker::timerEvent(QTimerEvent *event) | ||||
{ | ||||
Q_UNUSED(event); | ||||
m_scroller->scrollTick(); | ||||
} | ||||
#include "moc_scroller_p.cpp" | ||||
QT_CHARTS_END_NAMESPACE | ||||