/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

#include <QGraphicsOpacityEffect>

#include <QPropertyAnimation>

#include <hbcolorscheme.h>

#include "hsapp_defs.h"

#include "hssnapline.h"

/*!

    Constructor.

    \a parent Owner.

*/

HsSnapLine::HsSnapLine(QGraphicsItem *parent)

  : QGraphicsLineItem(parent),

    mFadeInAnimation(0),

    mFadeOutAnimation(0),

    mOpacity(0.0),

    mFadeInAnimationDuration(0),

    mFadeOutAnimationDuration(0)

{

    QGraphicsOpacityEffect *effect = new QGraphicsOpacityEffect(this);

    effect->setOpacity(0.0);

    effect->setEnabled(false);

    setGraphicsEffect(effect);

    mFadeInAnimation = new QPropertyAnimation(graphicsEffect(), "opacity", this);

    connect(mFadeInAnimation, SIGNAL(finished()), SLOT(fadeInAnimationFinished()));

    mFadeOutAnimation = new QPropertyAnimation(graphicsEffect(), "opacity", this);

    connect(mFadeOutAnimation, SIGNAL(finished()), SLOT(fadeOutAnimationFinished()));

}

/*!

    Destructor.

*/

HsSnapLine::~HsSnapLine()

{

}

/*!

    Sets the configuration for the showing the snap line, it includes fade-in / fade-out timeout.

*/

void HsSnapLine::setConfiguration(const QVariantHash &configuration)

{

    bool canConvert = false;

    //The following values should be in int, so the status received in canConvert is ignored

    mFadeInAnimationDuration = configuration[Hs::snapLineFadeinDuration].toInt(&canConvert);

    mFadeOutAnimationDuration = configuration[Hs::snapLineFadeoutDuration].toInt(&canConvert);

}

/*!

    Show the snap line. fade-in animation is started on the line if the line is positioned at a different place.

    Before starting the fade-in animation, the fade-out animation is stoped if it is running.

*/

void HsSnapLine::showLine(const QLineF &snapLine)

{

    QLineF displayLine = snapLine;

    qreal angle = displayLine.angle();

    if (qAbs(angle) == 0.0 || qAbs(angle) == 180.0) { //this is a horizontal line

        //adding 1 is required below, as the line is 3 pixels wide and is translated by 1 point before displaying

        if (displayLine.y1() != (line().y1()+1.0) ) { //this horizontal line is at new position horizontally

            if (isFadeOutAnimationRunning()) { //if fade-out animation is running, stop it, animation is running at old position

                stopFadeOutAnimation();

            }

            //start fade-in animation at new position.

            startFadeInAnimation();

        }

        else { //this horizontal line is at the old position horizontally

            if (isFadeOutAnimationRunning()) { //if fade-out animation is running, stop it, animation is running at old position

                stopFadeOutAnimation();

                //start fade-in animation at the old position

                startFadeInAnimation();

            }

        }

        displayLine.translate(0.0, -1.0);

    }

    if (qAbs(angle) == 90.0 || qAbs(angle) == 270.0) { //this is a vertical line

        if (displayLine.x1() != (line().x1()+1)) { //this Vertical line is at different position vertically

            if (isFadeOutAnimationRunning()) {

                stopFadeOutAnimation();

            }

            startFadeInAnimation();

        }

        else {

            if (isFadeOutAnimationRunning()) {

                stopFadeOutAnimation();

                startFadeInAnimation();

            }

        }

        displayLine.translate(-1.0, 0.0);

    }

    QLinearGradient gradient(displayLine.p1(), displayLine.p2());

    gradient.setColorAt(0.0, Qt::white);

    QColor snapLineColor = HbColorScheme::color("qtc_hs_snapguide");

    if (!snapLineColor.isValid()) {

        //if valid color is not loaded from the theme, the darkCyan color is used as a backup.color

        snapLineColor = Qt::darkCyan;

    }

    gradient.setColorAt(0.4, snapLineColor);

    gradient.setColorAt(0.6, snapLineColor);

    gradient.setColorAt(1.0, Qt::white);

    QBrush brush(gradient);

    QPen pen;

    pen.setWidth(3);

    pen.setCapStyle(Qt::RoundCap);

    pen.setBrush(brush);

    setPen(pen);

    setLine(displayLine);

    show();

}

/*!

    Hide the snap line. Fade-out animation is started on the line to be hidden.

    If fade-in animation is running, it is stoped before starting the fade-out animation.

*/

void HsSnapLine::hideLine()

{

    if (isFadeInAnimationRunning()) {

        stopFadeInAnimation();

    }

    startFadeOutAnimation();

}

/*!

    Start fade-in animation.

*/

void HsSnapLine::startFadeInAnimation()

{

    mFadeInAnimation->setStartValue(mOpacity);

    mFadeInAnimation->setEndValue(1.0);

    mFadeInAnimation->setDuration(getFadeInDuration());

    graphicsEffect()->setEnabled(true);

    mFadeInAnimation->start();

}

/*!

    Check if fade-in animation is running.

*/

bool HsSnapLine::isFadeInAnimationRunning() const

{

    return mFadeInAnimation->state() == QAbstractAnimation::Running;

}

/*!

    Stop the fade-in animation.

*/

void HsSnapLine::stopFadeInAnimation()

{

    mFadeInAnimation->stop();

    actionOnFadeInAnimationStop();

}

/*!

    SLOT called when fade-in animation is finished / reaches it's end.

*/

void HsSnapLine::fadeInAnimationFinished()

{

    actionOnFadeInAnimationStop();

}

/*!

    Action when fade-in animation stops running.

*/

void HsSnapLine::actionOnFadeInAnimationStop()

{

    mOpacity = mFadeInAnimation->currentValue().toDouble();

    graphicsEffect()->setEnabled(false);

}

/*!

    Start fade-out animation.

*/

void HsSnapLine::startFadeOutAnimation()

{

    mFadeOutAnimation->setStartValue(mOpacity);

    mFadeOutAnimation->setEndValue(0.0);

    mFadeOutAnimation->setDuration(getFadeOutDuration());

    graphicsEffect()->setEnabled(true);

    mFadeOutAnimation->start();

}

/*!

    Check if fade-out animation is running.

*/

bool HsSnapLine::isFadeOutAnimationRunning() const

{

    return mFadeOutAnimation->state() == QAbstractAnimation::Running;

}

/*!

    Stop the fade-out animation.

*/

void HsSnapLine::stopFadeOutAnimation()

{

    mFadeOutAnimation->stop();

    actionOnFadeOutAnimationStop();

}

/*!

    SLOT called when fade-out animation is finished / reaches it's end.

*/

void HsSnapLine::fadeOutAnimationFinished()

{

    actionOnFadeOutAnimationStop();

}

/*!

    Action when fade-out animation stops running.

*/

void HsSnapLine::actionOnFadeOutAnimationStop()

{

    mOpacity = mFadeOutAnimation->currentValue().toDouble();

    graphicsEffect()->setEnabled(false);

    hide();

    setLine(QLineF());

}