/****************************************************************************
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** Public License version 3.0 as published by the Free Software Foundation
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****************************************************************************/

#include "qquickscreen_p.h"

#include "qquickitem.h"
#include "qquickitem_p.h"
#include "qquickcanvas.h"

#include <QScreen>

QT_BEGIN_NAMESPACE

/*!
    \qmlclass Screen QQuickScreenAttached
    \inqmlmodule QtQuick.Window 2
    \brief The Screen attached object provides information about the Screen an Item is displayed on.

    The Screen attached object is only valid inside Item or Item derived elements. Inside these elements
    it refers to the screen that the element is currently being displayed on.
*/

/*!
    \qmlattachedproperty int QtQuickWindow2::Screen::width
    \readonly

    This contains the width of the screen in pixels.
*/
/*!
    \qmlattachedproperty int QtQuickWindow2::Screen::height
    \readonly

    This contains the height of the screen in pixels.
*/
/*!
    \qmlattachedproperty Qt::ScreenOrientation QtQuickWindow2::Screen::primaryOrientation
    \readonly

    This contains the primary orientation of the screen.
*/
/*!
    \qmlattachedproperty Qt::ScreenOrientation QtQuickWindow2::Screen::orientation
    \readonly

    This contains the current orientation of the screen.
*/
/*!
    \qmlattachedmethod int QtQuickWindow2::Screen::angleBetween(Qt::ScreenOrientation a, Qt::ScreenOrientation b)

    Returns the rotation angle, in degrees, between the two specified angles.
*/

QQuickScreenAttached::QQuickScreenAttached(QObject* attachee)
    : QObject(attachee)
    , m_screen(0)
{
    m_attachee = qobject_cast<QQuickItem*>(attachee);

    if (m_attachee) {
        QQuickItemPrivate::get(m_attachee)->extra.value().screenAttached = this;

        if (m_attachee->canvas()) //It might not be assigned to a canvas yet
            canvasChanged(m_attachee->canvas());
    }
}

int QQuickScreenAttached::width() const
{
    if (!m_screen)
        return 0;
    return m_screen->size().width();
}

int QQuickScreenAttached::height() const
{
    if (!m_screen)
        return 0;
    return m_screen->size().height();
}

Qt::ScreenOrientation QQuickScreenAttached::primaryOrientation() const
{
    if (!m_screen)
        return Qt::PrimaryOrientation;
    return m_screen->primaryOrientation();
}

Qt::ScreenOrientation QQuickScreenAttached::orientation() const
{
    if (!m_screen)
        return Qt::PrimaryOrientation;
    return m_screen->orientation();
}

int QQuickScreenAttached::angleBetween(int a, int b)
{
    if (!m_screen)
        return Qt::PrimaryOrientation;
    return m_screen->angleBetween((Qt::ScreenOrientation)a,(Qt::ScreenOrientation)b);
}

void QQuickScreenAttached::canvasChanged(QQuickCanvas* c)//Called by QQuickItemPrivate::initCanvas
{
    QScreen* screen = c ? c->screen() : 0;
    if (screen != m_screen) {
        QScreen* oldScreen = m_screen;
        m_screen = screen;

        if (oldScreen) {
            disconnect(oldScreen, SIGNAL(sizeChanged(QSize)),
                    this, SIGNAL(widthChanged()));
            disconnect(oldScreen, SIGNAL(sizeChanged(QSize)),
                    this, SIGNAL(heightChanged()));
            disconnect(oldScreen, SIGNAL(orientationChanged(Qt::ScreenOrientation)),
                    this, SIGNAL(orientationChanged()));
            disconnect(oldScreen, SIGNAL(primaryOrientationChanged(Qt::ScreenOrientation)),
                    this, SIGNAL(primaryOrientationChanged()));
        }

        if (!screen)
            return; //Don't bother emitting signals, because the new values are garbage anyways

        if (!oldScreen || screen->size() != oldScreen->size()) {
            emit widthChanged();
            emit heightChanged();
        }

        if (!oldScreen || screen->orientation() != oldScreen->orientation())
            emit orientationChanged();
        if (!oldScreen || screen->primaryOrientation() != oldScreen->primaryOrientation())
            emit primaryOrientationChanged();


        connect(screen, SIGNAL(sizeChanged(QSize)),
                this, SIGNAL(widthChanged()));
        connect(screen, SIGNAL(sizeChanged(QSize)),
                this, SIGNAL(heightChanged()));
        connect(screen, SIGNAL(orientationChanged(Qt::ScreenOrientation)),
                this, SIGNAL(orientationChanged()));
        connect(screen, SIGNAL(primaryOrientationChanged(Qt::ScreenOrientation)),
                this, SIGNAL(primaryOrientationChanged()));
    }
}

QT_END_NAMESPACE