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** This file is part of the QtDeclarative module of the Qt Toolkit.

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****************************************************************************/

#include "private/qdeclarativepainteditem_p.h"

#include "private/qdeclarativepainteditem_p_p.h"

#include <QDebug>

#include <QPen>

#include <QFile>

#include <QEvent>

#include <QApplication>

#include <QGraphicsSceneMouseEvent>

#include <QPainter>

#include <QPaintEngine>

#include <qmath.h>

QT_BEGIN_NAMESPACE

/*!

    \class QDeclarativePaintedItem

    \brief The QDeclarativePaintedItem class is an abstract base class for QDeclarativeView items that want cached painting.

    \internal

    This is a convenience class for implementing items that cache their painting.

    The contents of the item are cached behind the scenes.

    The dirtyCache() function should be called if the contents change to

    ensure the cache is refreshed the next time painting occurs.

    To subclass QDeclarativePaintedItem, you must reimplement drawContents() to draw

    the contents of the item.

*/

/*!

    \fn void QDeclarativePaintedItem::drawContents(QPainter *painter, const QRect &rect)

    This function is called when the cache needs to be refreshed. When

    sub-classing QDeclarativePaintedItem this function should be implemented so as to

    paint the contents of the item using the given \a painter for the

    area of the contents specified by \a rect.

*/

/*!

    \property QDeclarativePaintedItem::contentsSize

    \brief The size of the contents

    The contents size is the size of the item in regards to how it is painted

    using the drawContents() function.  This is distinct from the size of the

    item in regards to height() and width().

*/

// XXX bug in WebKit - can call repaintRequested and other cache-changing functions from within render!

static int inpaint=0;

static int inpaint_clearcache=0;

extern Q_GUI_EXPORT bool qt_applefontsmoothing_enabled;

/*!

    Marks areas of the cache that intersect with the given \a rect as dirty and

    in need of being refreshed.

    \sa clearCache()

*/

void QDeclarativePaintedItem::dirtyCache(const QRect& rect)

{

    Q_D(QDeclarativePaintedItem);

    QRect srect(qCeil(rect.x()*d->contentsScale),

            qCeil(rect.y()*d->contentsScale),

            qCeil(rect.width()*d->contentsScale),

            qCeil(rect.height()*d->contentsScale));

    for (int i=0; i < d->imagecache.count(); ) {

        QDeclarativePaintedItemPrivate::ImageCacheItem *c = d->imagecache[i];

        QRect isect = (c->area & srect) | c->dirty;

        if (isect == c->area && !inpaint) {

            delete d->imagecache.takeAt(i);

        } else {

            c->dirty = isect;

            ++i;

        }

    }

}

/*!

    Marks the entirety of the contents cache as dirty.

    \sa dirtyCache()

*/

void QDeclarativePaintedItem::clearCache()

{

    if (inpaint) {

        inpaint_clearcache=1;

        return;

    }

    Q_D(QDeclarativePaintedItem);

    qDeleteAll(d->imagecache);

    d->imagecache.clear();

}

/*!

    Returns the size of the contents.

    \sa setContentsSize()

*/

QSize QDeclarativePaintedItem::contentsSize() const

{

    Q_D(const QDeclarativePaintedItem);

    return d->contentsSize;

}

/*!

    Sets the size of the contents to the given \a size.

    \sa contentsSize()

*/

void QDeclarativePaintedItem::setContentsSize(const QSize &size)

{

    Q_D(QDeclarativePaintedItem);

    if (d->contentsSize == size) return;

    prepareGeometryChange();

    d->contentsSize = size;

    clearCache();

    update();

    emit contentsSizeChanged();

}

qreal QDeclarativePaintedItem::contentsScale() const

{

    Q_D(const QDeclarativePaintedItem);

    return d->contentsScale;

}

void QDeclarativePaintedItem::setContentsScale(qreal scale)

{

    Q_D(QDeclarativePaintedItem);

    if (d->contentsScale == scale) return;

    d->contentsScale = scale;

    clearCache();

    update();

    emit contentsScaleChanged();

}

/*!

    Constructs a new QDeclarativePaintedItem with the given \a parent.

*/

QDeclarativePaintedItem::QDeclarativePaintedItem(QDeclarativeItem *parent)

  : QDeclarativeItem(*(new QDeclarativePaintedItemPrivate), parent)

{

}

/*!

    \internal

    Constructs a new QDeclarativePaintedItem with the given \a parent and

    initialized private data member \a dd.

*/

QDeclarativePaintedItem::QDeclarativePaintedItem(QDeclarativePaintedItemPrivate &dd, QDeclarativeItem *parent)

  : QDeclarativeItem(dd, parent)

{

}

/*!

    Destroys the image item.

*/

QDeclarativePaintedItem::~QDeclarativePaintedItem()

{

    clearCache();

}

void QDeclarativePaintedItem::geometryChanged(const QRectF &newGeometry,

                                              const QRectF &oldGeometry)

{

    if (newGeometry.width() != oldGeometry.width() ||

        newGeometry.height() != oldGeometry.height())

        clearCache();

    QDeclarativeItem::geometryChanged(newGeometry, oldGeometry);

}

QVariant QDeclarativePaintedItem::itemChange(GraphicsItemChange change,

                                             const QVariant &value)

{

    if (change == ItemVisibleHasChanged)

        clearCache();

    return QDeclarativeItem::itemChange(change, value);

}

void QDeclarativePaintedItem::setCacheFrozen(bool frozen)

{

    Q_D(QDeclarativePaintedItem);

    if (d->cachefrozen == frozen)

        return;

    d->cachefrozen = frozen;

    // XXX clear cache?

}

QRectF QDeclarativePaintedItem::boundingRect() const

{

    Q_D(const QDeclarativePaintedItem);

    qreal w = d->mWidth;

    QSizeF sz = d->contentsSize * d->contentsScale;

    if (w < sz.width())

        w = sz.width();

    qreal h = d->mHeight;

    if (h < sz.height())

        h = sz.height();

    return QRectF(0.0,0.0,w,h);

}

/*!

    \internal

*/

void QDeclarativePaintedItem::paint(QPainter *p, const QStyleOptionGraphicsItem *, QWidget *)

{

    Q_D(QDeclarativePaintedItem);

    const QRect content = boundingRect().toRect();

    if (content.width() <= 0 || content.height() <= 0)

        return;

    ++inpaint;

    const QTransform &x = p->deviceTransform();

    QTransform xinv = x.inverted();

    QRegion effectiveClip;

    QRegion sysClip = p->paintEngine()->systemClip();

    if (xinv.type() <= QTransform::TxScale && sysClip.numRects() < 5) {

        // simple transform, region gets no more complicated...

        effectiveClip = xinv.map(sysClip);

    } else {

        // do not make complicated regions...

        effectiveClip = xinv.mapRect(sysClip.boundingRect());

    }

    QRegion topaint = p->clipRegion();

    if (topaint.isEmpty()) {

        if (effectiveClip.isEmpty())

            topaint = QRect(0,0,p->device()->width(),p->device()->height());

        else

            topaint = effectiveClip;

    } else if (!effectiveClip.isEmpty()) {

        topaint &= effectiveClip;

    }

    topaint &= content;

    QRegion uncached(content);

    p->setRenderHints(QPainter::SmoothPixmapTransform, d->smooth);

    int cachesize=0;

    for (int i=0; i<d->imagecache.count(); ++i) {

        QRect area = d->imagecache[i]->area;

        if (topaint.contains(area)) {

            QRectF target(area.x(), area.y(), area.width(), area.height());

            if (!d->cachefrozen) {

                if (!d->imagecache[i]->dirty.isNull() && topaint.contains(d->imagecache[i]->dirty)) {

#ifdef Q_WS_MAC

                    bool oldSmooth = qt_applefontsmoothing_enabled;

                    qt_applefontsmoothing_enabled = false;

#endif

                    QPainter qp(&d->imagecache[i]->image);

#ifdef Q_WS_MAC

                    qt_applefontsmoothing_enabled = oldSmooth;

#endif

                    qp.setRenderHints(QPainter::HighQualityAntialiasing | QPainter::TextAntialiasing | QPainter::SmoothPixmapTransform, d->smoothCache);

                    qp.translate(-area.x(), -area.y());

                    qp.scale(d->contentsScale,d->contentsScale);

                    QRect clip = d->imagecache[i]->dirty;

                    QRect sclip(qFloor(clip.x()/d->contentsScale),

                            qFloor(clip.y()/d->contentsScale),

                            qCeil(clip.width()/d->contentsScale+clip.x()/d->contentsScale-qFloor(clip.x()/d->contentsScale)),

                            qCeil(clip.height()/d->contentsScale+clip.y()/d->contentsScale-qFloor(clip.y()/d->contentsScale)));

                    qp.setClipRect(sclip);

                    if (d->fillColor.isValid()){

                        if(d->fillColor.alpha() < 255){

                            // ### Might not work outside of raster paintengine

                            QPainter::CompositionMode prev = qp.compositionMode();

                            qp.setCompositionMode(QPainter::CompositionMode_Source);

                            qp.fillRect(sclip,d->fillColor);

                            qp.setCompositionMode(prev);

                        }else{

                            qp.fillRect(sclip,d->fillColor);

                        }

                    }

                    drawContents(&qp, sclip);

                    d->imagecache[i]->dirty = QRect();

                }

            }

            p->drawPixmap(target.toRect(), d->imagecache[i]->image);

            topaint -= area;

            d->imagecache[i]->age=0;

        } else {

            d->imagecache[i]->age++;

        }

        cachesize += area.width()*area.height();

        uncached -= area;

    }

    if (!topaint.isEmpty()) {

        if (!d->cachefrozen) {

            // Find a sensible larger area, otherwise will paint lots of tiny images.

            QRect biggerrect = topaint.boundingRect().adjusted(-64,-64,128,128);

            cachesize += biggerrect.width() * biggerrect.height();

            while (d->imagecache.count() && cachesize > d->max_imagecache_size) {

                int oldest=-1;

                int age=-1;

                for (int i=0; i<d->imagecache.count(); ++i) {

                    int a = d->imagecache[i]->age;

                    if (a > age) {

                        oldest = i;

                        age = a;

                    }

                }

                cachesize -= d->imagecache[oldest]->area.width()*d->imagecache[oldest]->area.height();

                uncached += d->imagecache[oldest]->area;

                delete d->imagecache.takeAt(oldest);

            }

            const QRegion bigger = QRegion(biggerrect) & uncached;

            const QVector<QRect> rects = bigger.rects();

            for (int i = 0; i < rects.count(); ++i) {

                const QRect &r = rects.at(i);

                QPixmap img(r.size());

                if (d->fillColor.isValid())

                    img.fill(d->fillColor);

                {

#ifdef Q_WS_MAC

                    bool oldSmooth = qt_applefontsmoothing_enabled;

                    qt_applefontsmoothing_enabled = false;

#endif

                    QPainter qp(&img);

#ifdef Q_WS_MAC

                    qt_applefontsmoothing_enabled = oldSmooth;

#endif

                    qp.setRenderHints(QPainter::HighQualityAntialiasing | QPainter::TextAntialiasing | QPainter::SmoothPixmapTransform, d->smoothCache);

                    qp.translate(-r.x(),-r.y());

                    qp.scale(d->contentsScale,d->contentsScale);

                    QRect sclip(qFloor(r.x()/d->contentsScale),

                            qFloor(r.y()/d->contentsScale),

                            qCeil(r.width()/d->contentsScale+r.x()/d->contentsScale-qFloor(r.x()/d->contentsScale)),

                            qCeil(r.height()/d->contentsScale+r.y()/d->contentsScale-qFloor(r.y()/d->contentsScale)));

                    drawContents(&qp, sclip);

                }

                QDeclarativePaintedItemPrivate::ImageCacheItem *newitem = new QDeclarativePaintedItemPrivate::ImageCacheItem;

                newitem->area = r;

                newitem->image = img;

                d->imagecache.append(newitem);

                p->drawPixmap(r, newitem->image);

            }

        } else {

            const QVector<QRect> rects = uncached.rects();

            for (int i = 0; i < rects.count(); ++i)

                p->fillRect(rects.at(i), Qt::lightGray);

        }

    }

    if (inpaint_clearcache) {

        clearCache();

        inpaint_clearcache = 0;

    }

    --inpaint;

}

/*!

  \qmlproperty int PaintedItem::pixelCacheSize

  This property holds the maximum number of pixels of image cache to

  allow. The default is 0.1 megapixels. The cache will not be larger

  than the (unscaled) size of the WebView.

*/

/*!

  \property QDeclarativePaintedItem::pixelCacheSize

  The maximum number of pixels of image cache to allow. The default

  is 0.1 megapixels. The cache will not be larger than the (unscaled)

  size of the QDeclarativePaintedItem.

*/

int QDeclarativePaintedItem::pixelCacheSize() const

{

    Q_D(const QDeclarativePaintedItem);

    return d->max_imagecache_size;

}

void QDeclarativePaintedItem::setPixelCacheSize(int pixels)

{

    Q_D(QDeclarativePaintedItem);

    if (pixels < d->max_imagecache_size) {

        int cachesize=0;

        for (int i=0; i<d->imagecache.count(); ++i) {

            QRect area = d->imagecache[i]->area;

            cachesize += area.width()*area.height();

        }

        while (d->imagecache.count() && cachesize > pixels) {

            int oldest=-1;

            int age=-1;

            for (int i=0; i<d->imagecache.count(); ++i) {

                int a = d->imagecache[i]->age;

                if (a > age) {

                    oldest = i;

                    age = a;

                }

            }

            cachesize -= d->imagecache[oldest]->area.width()*d->imagecache[oldest]->area.height();

            delete d->imagecache.takeAt(oldest);

        }

    }

    d->max_imagecache_size = pixels;

}

/*!

    \property QDeclarativePaintedItem::fillColor

    The color to be used to fill the item prior to calling drawContents().

    By default, this is Qt::transparent.

    Performance improvements can be achieved if subclasses call this with either an

    invalid color (QColor()), or an appropriate solid color.

*/

void QDeclarativePaintedItem::setFillColor(const QColor& c)

{

    Q_D(QDeclarativePaintedItem);

    if (d->fillColor == c)

        return;

    d->fillColor = c;

    emit fillColorChanged();

    update();

}

QColor QDeclarativePaintedItem::fillColor() const

{

    Q_D(const QDeclarativePaintedItem);

    return d->fillColor;

}

/*!

    \qmlproperty bool PaintedItem::smoothCache

    Controls whether the cached tiles of which the item is composed are

    rendered smoothly when they are generated.

    This is in addition toe Item::smooth, which controls the smooth painting of

    the already-painted cached tiles under transformation.

*/

bool QDeclarativePaintedItem::smoothCache() const

{

    Q_D(const QDeclarativePaintedItem);

    return d->smoothCache;

}

void QDeclarativePaintedItem::setSmoothCache(bool on)

{

    Q_D(QDeclarativePaintedItem);

    if (d->smoothCache != on) {

        d->smoothCache = on;

        clearCache();

    }

}

QT_END_NAMESPACE