/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
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** This file is part of the QtDeclarative module of the Qt Toolkit.
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** $QT_BEGIN_LICENSE:LGPL$
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** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
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** file. Please review the following information to ensure the GNU General
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****************************************************************************/

#include "QtQuick1/private/qdeclarativepainteditem_p.h"
#include "QtQuick1/private/qdeclarativepainteditem_p_p.h"

#include <QDebug>
#include <QPen>
#include <QEvent>
#include <QApplication>
#include <QGraphicsSceneMouseEvent>
#include <QPainter>
#include <QPaintEngine>
#include <qmath.h>

QT_BEGIN_NAMESPACE



/*!
    \class QDeclarative1PaintedItem
    \brief The QDeclarative1PaintedItem class is an abstract base class for QDeclarative1View 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 QDeclarative1PaintedItem, you must reimplement drawContents() to draw
    the contents of the item.
*/

/*!
    \fn void QDeclarative1PaintedItem::drawContents(QPainter *painter, const QRect &rect)

    This function is called when the cache needs to be refreshed. When
    sub-classing QDeclarative1PaintedItem 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 QDeclarative1PaintedItem::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 QDeclarative1PaintedItem::dirtyCache(const QRect& rect)
{
    Q_D(QDeclarative1PaintedItem);
    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(); ) {
        QDeclarative1PaintedItemPrivate::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 QDeclarative1PaintedItem::clearCache()
{
    if (inpaint) {
        inpaint_clearcache=1;
        return;
    }
    Q_D(QDeclarative1PaintedItem);
    qDeleteAll(d->imagecache);
    d->imagecache.clear();
}

/*!
    Returns the size of the contents.

    \sa setContentsSize()
*/
QSize QDeclarative1PaintedItem::contentsSize() const
{
    Q_D(const QDeclarative1PaintedItem);
    return d->contentsSize;
}

/*!
    Sets the size of the contents to the given \a size.

    \sa contentsSize()
*/
void QDeclarative1PaintedItem::setContentsSize(const QSize &size)
{
    Q_D(QDeclarative1PaintedItem);
    if (d->contentsSize == size) return;
    prepareGeometryChange();
    d->contentsSize = size;
    clearCache();
    update();
    emit contentsSizeChanged();
}

qreal QDeclarative1PaintedItem::contentsScale() const
{
    Q_D(const QDeclarative1PaintedItem);
    return d->contentsScale;
}

void QDeclarative1PaintedItem::setContentsScale(qreal scale)
{
    Q_D(QDeclarative1PaintedItem);
    if (d->contentsScale == scale) return;
    d->contentsScale = scale;
    clearCache();
    update();
    emit contentsScaleChanged();
}


/*!
    Constructs a new QDeclarative1PaintedItem with the given \a parent.
*/
QDeclarative1PaintedItem::QDeclarative1PaintedItem(QDeclarativeItem *parent)
  : QDeclarativeItem(*(new QDeclarative1PaintedItemPrivate), parent)
{
}

/*!
    \internal
    Constructs a new QDeclarative1PaintedItem with the given \a parent and
    initialized private data member \a dd.
*/
QDeclarative1PaintedItem::QDeclarative1PaintedItem(QDeclarative1PaintedItemPrivate &dd, QDeclarativeItem *parent)
  : QDeclarativeItem(dd, parent)
{
}

/*!
    Destroys the image item.
*/
QDeclarative1PaintedItem::~QDeclarative1PaintedItem()
{
    clearCache();
}

void QDeclarative1PaintedItem::geometryChanged(const QRectF &newGeometry,
                                              const QRectF &oldGeometry)
{
    if (newGeometry.width() != oldGeometry.width() ||
        newGeometry.height() != oldGeometry.height())
        clearCache();

    QDeclarativeItem::geometryChanged(newGeometry, oldGeometry);
}

QVariant QDeclarative1PaintedItem::itemChange(GraphicsItemChange change,
                                             const QVariant &value)
{
    if (change == ItemVisibleHasChanged)
        clearCache();

    return QDeclarativeItem::itemChange(change, value);
}

void QDeclarative1PaintedItem::setCacheFrozen(bool frozen)
{
    Q_D(QDeclarative1PaintedItem);
    if (d->cachefrozen == frozen)
        return;
    d->cachefrozen = frozen;
    // XXX clear cache?
}

QRectF QDeclarative1PaintedItem::boundingRect() const
{
    Q_D(const QDeclarative1PaintedItem);
    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 QDeclarative1PaintedItem::paint(QPainter *p, const QStyleOptionGraphicsItem *, QWidget *)
{
    Q_D(QDeclarative1PaintedItem);
    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.rectCount() < 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);
                }
                QDeclarative1PaintedItemPrivate::ImageCacheItem *newitem = new QDeclarative1PaintedItemPrivate::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 QtQuick1::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 QDeclarative1PaintedItem::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 QDeclarative1PaintedItem.
*/
int QDeclarative1PaintedItem::pixelCacheSize() const
{
    Q_D(const QDeclarative1PaintedItem);
    return d->max_imagecache_size;
}

void QDeclarative1PaintedItem::setPixelCacheSize(int pixels)
{
    Q_D(QDeclarative1PaintedItem);
    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 QDeclarative1PaintedItem::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 QDeclarative1PaintedItem::setFillColor(const QColor& c)
{
    Q_D(QDeclarative1PaintedItem);
    if (d->fillColor == c)
        return;
    d->fillColor = c;
    emit fillColorChanged();
    update();
}

QColor QDeclarative1PaintedItem::fillColor() const
{
    Q_D(const QDeclarative1PaintedItem);
    return d->fillColor;
}

/*!
    \qmlproperty bool QtQuick1::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 QDeclarative1PaintedItem::smoothCache() const
{
    Q_D(const QDeclarative1PaintedItem);
    return d->smoothCache;
}

void QDeclarative1PaintedItem::setSmoothCache(bool on)
{
    Q_D(QDeclarative1PaintedItem);
    if (d->smoothCache != on) {
        d->smoothCache = on;
        clearCache();
    }
}




QT_END_NAMESPACE