qdeclarativepainteditem.cpp

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

QT_BEGIN_NAMESPACE

// 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;

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;
        }
    }
}

void QDeclarativePaintedItem::clearCache()
{
    if (inpaint) {
        inpaint_clearcache=1;
        return;
    }
    Q_D(QDeclarativePaintedItem);
    qDeleteAll(d->imagecache);
    d->imagecache.clear();
}

QSize QDeclarativePaintedItem::contentsSize() const
{
    Q_D(const QDeclarativePaintedItem);
    return d->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();
}


QDeclarativePaintedItem::QDeclarativePaintedItem(QDeclarativeItem *parent)
  : QDeclarativeItem(*(new QDeclarativePaintedItemPrivate), parent)
{
}

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

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);
}

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;
}

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;
}



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;
}

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