/*
 Embedded Widgets Demo
 Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).*
 Contact:  Qt Software Information (qt-info@nokia.com)**
 This file may be used under the terms of the Embedded Widgets Demo License
 Agreement.
*/

#include "qtscrolldial.h"
#include "scrolldialpopup.h"

#include <QDesktopWidget>
#include <QtCore/QDebug>
#include <QPainter>
#include <QSvgRenderer>

#include <QtBasicDialGauge>
#include <QLabel>
#include <QVBoxLayout>

/*!
    \class QtScrollDial qtscrolldial.h

    \brief The QtScrollDial provides a scroll widget with SVG graphics.

    QtScrollDial is a custom widget and behaves like a slider. If clicked a
    popup window appears where the user can change the value.

    \section1 Example
    \code
    QtScrollDial * scroll = new QtScrollDial(parent);
    scroll->setSkin("Beryl");
    scroll->setRange(0, 100);
    scroll->setValue(50);
    \endcode

    The function \a minimum() and \a maximum() are used from the QAbstractSlider.

    It is important to call the function \a setSkin() to load a skin. If \a setSkin() is not called
    the QtScrollDial will not have any visible content.
    The parameter \p skin has the skin name. The skins are in the resource file defined in the project file.
    The name scheme in the resource file is "Skin Name"/"unique picture name.svg".

    The \a setSkin() function loads the diffrent skins over the "Skin name".
    The needed realised graphics for this control are "normal.svg", "hovered.svg" and "pressed.svg".
    If you want to add new skins, they have to follow the name scheme to work.

    The actual skin can be read over the \a skin() function.

    \sa skin(), setSkin()
*/

/*!
    Constructor of the QAbstractSlider with \p parent as
    Parent.
*/
QtScrollDial::QtScrollDial(QWidget* parent)
    : QAbstractSlider(parent)
{
    init();
}

/*!
    Destructor
*/
QtScrollDial::~QtScrollDial()
{

}

/*!
    \internal
    Internal initialisation function.
*/
void QtScrollDial::init()
{
    // set hover attribute so a repaint event is triggered on hover
    setAttribute(Qt::WA_Hover, true);

    // create the gui elements for the scroll dial: gauge + label
    QVBoxLayout* vLayout = new QVBoxLayout(this);
    vLayout->setSpacing(0);
    m_dialGauge = new QtBasicDialGauge(this);
    m_dialGauge->setRange(minimum(), maximum());
    m_dialGauge->setValue(value());
    m_label = new QLabel("0", this);
    m_label->setAlignment(Qt::AlignHCenter);
    m_label->setMinimumWidth(35);
    m_label->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed);
    vLayout->addWidget(m_dialGauge, 0, Qt::AlignHCenter);
    vLayout->addWidget(m_label, 0, Qt::AlignHCenter);

    // make sure this slider and the gauge are in sync
    connect(this, SIGNAL(valueChanged(int)), m_dialGauge, SLOT(setValue(int)));
    connect(this, SIGNAL(rangeChanged(int, int)), m_dialGauge, SLOT(setRange(int, int)));

    // make sure the label shows the correct value
    connect(this, SIGNAL(valueChanged(int)), this, SLOT(updateLabelValue()));

    // create the popup
    m_popup = new ScrollDialPopup(this);
    m_popup->setWindowFlags(windowFlags() | Qt::Popup);
}

/*!
    With this function you can set the skin that will be displayed in the widget.

    \code
        QtScrollDial * scroll = new QtScrollDial(this);
        scroll->setSkin("Beryl");
    \endcode

    This function has to be called before using the QtScrollDial.

    \sa skin()

*/
void QtScrollDial::setSkin(const QString& skin)
{
    m_skin = skin;
    const QString base = ":/scrolldial/" + skin + '/';

    m_popup->setSkin(skin);
    m_label->setStyleSheet("color: white; border-width: 2px;"
                           "border-image: url(" + base + "label.svg);");

    // set to null pictures
    m_background = QPicture();
    m_hoverBackground = QPicture();

    QSvgRenderer renderer;
    QPainter painter;

    if (renderer.load(base + "background.svg")) {
        painter.begin(&m_background);
        renderer.render(&painter, QRectF(0.0, 0.0, 1.0, 1.0));
        painter.end();
    }

    if (renderer.load(base + "background_hover.svg")) {
        painter.begin(&m_hoverBackground);
        renderer.render(&painter, QRectF(0.0, 0.0, 1.0, 1.0));
        painter.end();
    }

    // update geometry for new sizeHint and repaint
    updateGeometry();
    update();
}

/*!

    This function returns the actual skin name. If no skin has been set the return value is "".

    \code
        QtScrollDial * scroll = new QtScrollDial(this);
        scroll->setSkin("Beryl");
        qDebug() << scroll->skin();
    \endcode

    \sa setSkin()

*/
QString QtScrollDial::skin() const
{
    return m_skin;
}

/*!
    \overload
    \internal
    Show the QtScrollDial on mouse press.
    Event \a ev not used.
*/
void QtScrollDial::mousePressEvent(QMouseEvent* ev)
{
    Q_UNUSED(ev);
    m_popup->move(popupPosition());
    m_popup->setRange(minimum(), maximum());
    m_popup->setValue(value());
    m_popup->show();
}

/*!
    \overload
    \internal
    Draws the background.
    Event \a ev not used.
*/
void QtScrollDial::paintEvent(QPaintEvent* ev)
{
    Q_UNUSED(ev);
    QPainter p(this);
    p.save();
    p.scale(width(), height());
    if (underMouse() || m_popup->isVisible()) {
        m_hoverBackground.play(&p);
    } else {
        m_background.play(&p);
    }
    p.restore();
}

/*!
    \overload
    \internal
    Calculates the position at which the ScrollDial will
    be shown.
*/
QPoint QtScrollDial::popupPosition()
{
    // Get information about the users screen size
    QDesktopWidget desktop;
    QRect desktopRect = (desktop.rect());

    const int w = m_popup->sizeHint().width();
    const int h = m_popup->sizeHint().height();

    // 15 pixel is the popup's m_closeButton.height() / 2
    QPoint popupPosition(rect().right(), -15);

    QPoint globalPos = mapToGlobal(popupPosition);

    // if it does not fit on the right, move to the left
    if (globalPos.x() + w > desktopRect.right()) {
        globalPos.setX(globalPos.x() - width() - w);
    }

    if (globalPos.x() + w > desktopRect.right()) {
        globalPos.setX(desktopRect.right() - w);
    }
    if (globalPos.x() < desktopRect.left()) {
        globalPos.setX(desktopRect.left());
    }
    if (globalPos.y() < desktopRect.top()) {
        globalPos.setY(desktopRect.top());
    }
    if (globalPos.y() + h > desktopRect.bottom()) {
        globalPos.setY(desktopRect.bottom() - h);
    }

    return globalPos;
}
/**
    \internal
    Updates the label content.
**/
void QtScrollDial::updateLabelValue()
{
    m_label->setText(QString::number(value()));
}