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#include "qhtml5screen.h"
#include "qhtml5window.h"
#include "qhtml5compositor.h"

#include <QtEglSupport/private/qeglconvenience_p.h>
#ifndef QT_NO_OPENGL
# include <QtEglSupport/private/qeglplatformcontext_p.h>
#endif
#include <qpa/qwindowsysteminterface.h>
#include <QtCore/QCoreApplication>
#include <QDebug>
#include <QGuiApplication>
#include <private/qhighdpiscaling_p.h>


QT_BEGIN_NAMESPACE

QHtml5Screen::QHtml5Screen(QHtml5Compositor *compositor)
    : mCompositor(compositor)
    , m_depth(32)
    , m_format(QImage::Format_RGB32)
{
    mCompositor->setScreen(this);
}

QHtml5Screen::~QHtml5Screen()
{

}

QRect QHtml5Screen::geometry() const
{
    return m_geometry;
}

int QHtml5Screen::depth() const
{
    return m_depth;
}

QImage::Format QHtml5Screen::format() const
{
    return m_format;
}

qreal QHtml5Screen::devicePixelRatio() const
{
    // FIXME: The effective device pixel ratio may be different from the
    // HTML window dpr if the OpenGL driver/GPU allocates a less than
    // full resolution surface. Use emscripten_webgl_get_drawing_buffer_size()
    // and compute the dpr instead.
    double htmlWindowDpr = EM_ASM_DOUBLE({
        return window.devicePixelRatio;
    });
    return qreal(htmlWindowDpr);
}

QPlatformCursor *QHtml5Screen::cursor() const
{
    return const_cast<QHtml5Cursor *>(&m_cursor);
}

void QHtml5Screen::resizeMaximizedWindows()
{
    QList<QWindow*> windows = QGuiApplication::allWindows();
    // 'screen()' still has the old geometry info while 'this' has the new geometry info
    const QRect oldGeometry = screen()->geometry();
    const QRect oldAvailableGeometry = screen()->availableGeometry();

    const QRect newGeometry = deviceIndependentGeometry();
    const QRect newAvailableGeometry = QHighDpi::fromNative(availableGeometry(), QHighDpiScaling::factor(this), newGeometry.topLeft());

    // make sure maximized and fullscreen windows are updated
    for (int i = 0; i < windows.size(); ++i) {
        QWindow *w = windows.at(i);

        // Skip non-platform windows, e.g., offscreen windows.
        if (!w->handle())
            continue;

        if (platformScreenForWindow(w) != this)
            continue;

        if (w->windowState() & Qt::WindowMaximized || w->geometry() == oldAvailableGeometry)
            w->setGeometry(newAvailableGeometry);

        else if (w->windowState() & Qt::WindowFullScreen || w->geometry() == oldGeometry)
            w->setGeometry(newGeometry);
    }
}

QWindow *QHtml5Screen::topWindow() const
{
    return mCompositor->keyWindow();
}

QWindow *QHtml5Screen::topLevelAt(const QPoint & p) const
{
    return mCompositor->windowAt(p);
}

void QHtml5Screen::invalidateSize()
{
    m_geometry = QRect();
}

void QHtml5Screen::setGeometry(const QRect &rect)
{
    m_geometry = rect;
    QWindowSystemInterface::handleScreenGeometryChange(QPlatformScreen::screen(), geometry(), availableGeometry());
    resizeMaximizedWindows();
}

QT_END_NAMESPACE