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Diffstat (limited to 'src/declarative/util/qdeclarativesmoothedfollow.cpp')
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diff --git a/src/declarative/util/qdeclarativesmoothedfollow.cpp b/src/declarative/util/qdeclarativesmoothedfollow.cpp new file mode 100644 index 0000000..63c9618 --- /dev/null +++ b/src/declarative/util/qdeclarativesmoothedfollow.cpp @@ -0,0 +1,299 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtDeclarative module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qdeclarativesmoothedfollow_p.h" +#include "qdeclarativesmoothedanimation_p_p.h" + +#include <private/qobject_p.h> +#include <QtCore/qnumeric.h> + +#include "qdeclarativeglobal_p.h" + + +QT_BEGIN_NAMESPACE + +class QDeclarativeSmoothedFollowPrivate : public QObjectPrivate +{ + Q_DECLARE_PUBLIC(QDeclarativeSmoothedFollow) +public: + QDeclarativeSmoothedFollowPrivate(); + + bool enabled; + QSmoothedAnimation *anim; +}; + +/*! + \qmlclass SmoothedFollow QDeclarativeSmoothedFollow + \since 4.7 + \inherits NumberAnimation + \brief The SmoothedFollow element allows a property to smoothly track a value. + + The SmoothedFollow animates a property's value to a set target value + using an ease in/out quad easing curve. If the animation is restarted + with a different target value, the easing curves used to animate to the old + and the new target values are smoothly spliced together to avoid any obvious + visual glitches by maintaining the current velocity. + + The property animation is configured by setting the velocity at which the + animation should occur, or the duration that the animation should take. + If both a velocity and a duration are specified, the one that results in + the quickest animation is chosen for each change in the target value. + + For example, animating from 0 to 800 will take 4 seconds if a velocity + of 200 is set, will take 8 seconds with a duration of 8000 set, and will + take 4 seconds with both a velocity of 200 and a duration of 8000 set. + Animating from 0 to 20000 will take 10 seconds if a velocity of 200 is set, + will take 8 seconds with a duration of 8000 set, and will take 8 seconds + with both a velocity of 200 and a duration of 8000 set. + + The follow example shows one rectangle tracking the position of another. +\code +import Qt 4.6 + +Rectangle { + width: 800; height: 600; color: "blue" + + Rectangle { + color: "green" + width: 60; height: 60; + SmoothedFollow on x { to: rect1.x - 5; velocity: 200 } + SmoothedFollow on y { to: rect1.y - 5; velocity: 200 } + } + + Rectangle { + id: rect1 + color: "red" + width: 50; height: 50; + } + + focus: true + Keys.onRightPressed: rect1.x = rect1.x + 100 + Keys.onLeftPressed: rect1.x = rect1.x - 100 + Keys.onUpPressed: rect1.y = rect1.y - 100 + Keys.onDownPressed: rect1.y = rect1.y + 100 +} +\endcode + + The default velocity of SmoothedFollow is 200 units/second. Note that if the range of the + value being animated is small, then the velocity will need to be adjusted + appropriately. For example, the opacity of an item ranges from 0 - 1.0. + To enable a smooth animation in this range the velocity will need to be + set to a value such as 0.5 units/second. Animating from 0 to 1.0 with a velocity + of 0.5 will take 2000 ms to complete. + + \sa SpringFollow +*/ + +QDeclarativeSmoothedFollow::QDeclarativeSmoothedFollow(QObject *parent) + : QObject(*(new QDeclarativeSmoothedFollowPrivate), parent) +{ +} + +QDeclarativeSmoothedFollow::~QDeclarativeSmoothedFollow() +{ +} + +QDeclarativeSmoothedFollowPrivate::QDeclarativeSmoothedFollowPrivate() + : enabled(true), anim(new QSmoothedAnimation) +{ + Q_Q(QDeclarativeSmoothedFollow); + QDeclarative_setParent_noEvent(anim, q); +} + +/*! + \qmlproperty enumeration SmoothedFollow::reversingMode + + Sets how the SmoothedFollow behaves if an animation direction is reversed. + + If reversing mode is \c Eased, the animation will smoothly decelerate, and + then reverse direction. If the reversing mode is \c Immediate, the + animation will immediately begin accelerating in the reverse direction, + begining with a velocity of 0. If the reversing mode is \c Sync, the + property is immediately set to the target value. +*/ +QDeclarativeSmoothedFollow::ReversingMode QDeclarativeSmoothedFollow::reversingMode() const +{ + Q_D(const QDeclarativeSmoothedFollow); + return (ReversingMode) d->anim->reversingMode; +} + +void QDeclarativeSmoothedFollow::setReversingMode(ReversingMode m) +{ + Q_D(QDeclarativeSmoothedFollow); + if (d->anim->reversingMode == (QDeclarativeSmoothedAnimation::ReversingMode) m) + return; + + d->anim->reversingMode = (QDeclarativeSmoothedAnimation::ReversingMode) m; + emit reversingModeChanged(); +} + +/*! + \qmlproperty int SmoothedFollow::duration + + This property holds the animation duration, in msecs, used when tracking the source. + + Setting this to -1 (the default) disables the duration value. +*/ +int QDeclarativeSmoothedFollow::duration() const +{ + Q_D(const QDeclarativeSmoothedFollow); + return d->anim->userDuration; +} + +void QDeclarativeSmoothedFollow::setDuration(int duration) +{ + Q_D(QDeclarativeSmoothedFollow); + if (duration == d->anim->duration()) + return; + + d->anim->userDuration = duration; + emit durationChanged(); +} + +qreal QDeclarativeSmoothedFollow::velocity() const +{ + Q_D(const QDeclarativeSmoothedFollow); + return d->anim->velocity; +} + +/*! + \qmlproperty qreal SmoothedFollow::velocity + + This property holds the average velocity allowed when tracking the 'to' value. + + The default velocity of SmoothedFollow is 200 units/second. + + Setting this to -1 disables the velocity value. +*/ +void QDeclarativeSmoothedFollow::setVelocity(qreal v) +{ + Q_D(QDeclarativeSmoothedFollow); + if (d->anim->velocity == v) + return; + + d->anim->velocity = v; + emit velocityChanged(); +} + +/*! + \qmlproperty qreal SmoothedFollow::maximumEasingTime + + This property specifies the maximum time, in msecs, an "eases" during the follow should take. + Setting this property causes the velocity to "level out" after at a time. Setting + a negative value reverts to the normal mode of easing over the entire animation + duration. + + The default value is -1. +*/ +int QDeclarativeSmoothedFollow::maximumEasingTime() const +{ + Q_D(const QDeclarativeSmoothedFollow); + return d->anim->maximumEasingTime; +} + +void QDeclarativeSmoothedFollow::setMaximumEasingTime(int v) +{ + Q_D(QDeclarativeSmoothedFollow); + d->anim->maximumEasingTime = v; + emit maximumEasingTimeChanged(); +} + +/*! + \qmlproperty real SmoothedFollow::to + This property holds the ending value. + If not set, then the value defined in the end state of the transition or Behavior. +*/ +qreal QDeclarativeSmoothedFollow::to() const +{ + Q_D(const QDeclarativeSmoothedFollow); + return d->anim->to; +} + +void QDeclarativeSmoothedFollow::setTo(qreal t) +{ + Q_D(QDeclarativeSmoothedFollow); + + if (qIsNaN(t)) + return; + + if (d->anim->to == t) + return; + + d->anim->to = t; + + if (d->enabled) + d->anim->restart(); +} + +/*! + \qmlproperty bool SmoothedFollow::enabled + This property whether this animation should automatically restart when + the 'to' property is upated. + + The default value of this property is 'true'. +*/ +bool QDeclarativeSmoothedFollow::enabled() const +{ + Q_D(const QDeclarativeSmoothedFollow); + return d->enabled; +} + +void QDeclarativeSmoothedFollow::setEnabled(bool e) +{ + Q_D(QDeclarativeSmoothedFollow); + if (d->enabled == e) + return; + d->enabled = e; + + if (d->enabled) + d->anim->restart(); + else + d->anim->stop(); + emit enabledChanged(); +} + +void QDeclarativeSmoothedFollow::setTarget(const QDeclarativeProperty &t) +{ + Q_D(QDeclarativeSmoothedFollow); + d->anim->target = t; +} + +QT_END_NAMESPACE |