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

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

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

#include "hbvgmaskeffect_p.h"

#include "hbvgmaskeffect_p_p.h"

#include <QPainter>

#include <QPaintEngine>

#include <QPaintDevice>

/*!

 * \class HbVgMaskEffect

 *

 * \brief OpenVG-based mask effect.

 *

 * The mask effect can be used to make a rectangular area or an area

 * defined by a pixmap's alpha channel transparent. The opacity effect

 * parameter is ignored.

 *

 * With certain OpenVG implementations masking with vgMask() may be

 * problematic.  In such cases enable the pure QPainter implementation

 * with setForceSwMode().

 *

 * Currently the sw version only support masks set by setMask() or

 * provided via the callback.  Mask rectangles are not supported.

 *

 * \internal

 */

HbVgMaskEffectPrivate::HbVgMaskEffectPrivate()

    : maskRectIsInDeviceCoords(false),

      maskCallback(0),

      maskCallbackParam(0),

      lastMainWindowRotationAngle(-1),

      includeSourceItemOnly(false)

{

}

HbVgMaskEffect::HbVgMaskEffect(QObject *parent)

    : HbVgFrameEffect(*new HbVgMaskEffectPrivate, parent)

{

}

HbVgMaskEffect::HbVgMaskEffect(HbVgMaskEffectPrivate &dd, QObject *parent)

    : HbVgFrameEffect(dd, parent)

{

}

HbVgMaskEffect::~HbVgMaskEffect()

{

}

/*!

 * Turns off masking. Any previously set mask pixmap or rectangle will not be

 * effective anymore.

 */

void HbVgMaskEffect::clear()

{

    Q_D(HbVgMaskEffect);

    d->mask = d->scaledMask = d->callbackResult = QPixmap();

    d->maskRect = QRectF();

    d->maskRectIsInDeviceCoords = false;

    d->maskCallback = 0;

    d->maskCallbackParam = 0;

}

/*!

 * Returns the mask pixmap set by the previous setMask() call.

 */

QPixmap HbVgMaskEffect::mask() const

{

    Q_D(const HbVgMaskEffect);

    return d->mask;

}

/*!

 * Returns the scaled version of the mask that was used during the previous

 * paint. Will return a null pixmap if no painting took place since the last

 * setMask() call. Any other automatic transformation (e.g. rotation) of the

 * mask is not included in the returned pixmap.

 */

QPixmap HbVgMaskEffect::scaledMask() const

{

    Q_D(const HbVgMaskEffect);

    return d->scaledMask;

}

/*!

 * Sets the mask pixmap. Only the alpha channel is relevant. Pixels where alpha

 * is 0 will be set transparent. The pixmap is subject to scaling and therefore

 * distortion may occur. If this is not acceptable then use the callback

 * version. Any previously set mask pixmap or rectangle will not be effective

 * anymore. If the graphics view is rotated (due to a transformed screen

 * orientation) then the mask will be rotated automatically too.

 */

void HbVgMaskEffect::setMask(const QPixmap &mask)

{

    Q_D(HbVgMaskEffect);

    clear();

    d->mask = mask;

    updateEffect();

    emit maskChanged(mask);

}

/*!

 * Returns the currently set mask callback pointer.

 */

HbVgMaskEffect::MaskCallback HbVgMaskEffect::maskCallback() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskCallback;

}

/*!

 * Returns the currently set custom parameter that will be passed to the

 * callback.

 */

void *HbVgMaskEffect::maskCallbackParam() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskCallbackParam;

}

/*!

 * If the user of the API is able to generate a mask pixmap for a given size,

 * use this function instead of setMask(). The callback will be invoked during

 * painting to get the mask pixmap. It should return a pixmap that has a size

 * that is same as the size that has been passed to the callback. The effect

 * tries to reduce the number of calls by calling only when a new callback is

 * set or when the size of the source item is different than before. Any

 * previously set mask pixmap or rectangle will not be effective anymore.

 */

void HbVgMaskEffect::setMaskCallback(MaskCallback callback, void *param)

{

    Q_D(HbVgMaskEffect);

    if (d->maskCallback == callback) {

        return;

    }

    clear();

    d->maskCallback = callback;

    d->maskCallbackParam = param;

    updateEffect();

    emit maskCallbackChanged(callback);

}

/*!

 * Returns the mask rectangle set by the previous setMaskRect() call.

 */

QRectF HbVgMaskEffect::maskRect() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskRectIsInDeviceCoords ? QRectF() : d->maskRect;

}

/*!

 * Returns the mask rectangle set by the previous setMaskDeviceRect() call.

 */

QRectF HbVgMaskEffect::maskDeviceRect() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskRectIsInDeviceCoords ? d->maskRect : QRectF();

}

/*!

 * Sets the mask rectangle. The area defined by the rectangle will be made

 * transparent inside the source item. Any previously set mask pixmap or

 * rectangle will not be effective anymore.

 */

void HbVgMaskEffect::setMaskRect(const QRectF &rect)

{

    Q_D(HbVgMaskEffect);

    if (rect == d->maskRect && !d->maskRectIsInDeviceCoords) {

        return;

    }

    clear();

    d->maskRect = rect;

    d->maskRectIsInDeviceCoords = false;

    updateEffect();

    emit maskRectChanged(rect);

}

/*!

 * Similar to setMask() but the rectangle is assumed to be in device coordinates

 * (i.e. relative to the entire screen instead of the source item), meaning that

 * the source item will be clipped where it intersects with \a rect.

 *

 * Even when the graphics view is transformed (e.g. when being in "landscape

 * orientation") the rectangle passed here is treated as being in device

 * coordinates, ignoring the rotation of the graphics view.

 */

void HbVgMaskEffect::setMaskDeviceRect(const QRectF &rect)

{

    Q_D(HbVgMaskEffect);

    if (rect == d->maskRect && d->maskRectIsInDeviceCoords) {

        return;

    }

    clear();

    d->maskRect = rect;

    d->maskRectIsInDeviceCoords = true;

    updateEffect();

    emit maskRectChanged(rect);

}

/*!

 * Returns the current setting for masking only the source graphics item. By

 * default this is disabled.

 */

bool HbVgMaskEffect::includeSourceItemOnly() const

{

    Q_D(const HbVgMaskEffect);

    return d->includeSourceItemOnly;

}

/*!

 * When enabled, only the source item (excluding its children) is masked.  This

 * is needed when shaping e.g. a pop-up or other widget that has a scroll area

 * in it. The real size, together with all the children, is usually much bigger

 * then the size of the widget itself (and it depends on the position in the

 * scroll area etc.).  To solve this issue, enable this setting when shaping

 * such widgets.

 */

void HbVgMaskEffect::setIncludeSourceItemOnly(bool b)

{

    Q_D(HbVgMaskEffect);

    clear();

    d->includeSourceItemOnly = b;

    updateEffect();

    emit includeSourceItemOnlyChanged(b);

}

/*!

 * \reimp

 */

QRectF HbVgMaskEffect::boundingRectFor(const QRectF &rect) const

{

    return rect;

}

/*!

 * Returns the OpenVG Y coordinate for a rectangle with the given Qt Y

 * coordinate and height.

 *

 * \internal

 */

inline int toVgYH(int y, int h, QPaintDevice *pdev)

{

    return pdev->height() - 1 - y - h;

}

/*!

 * \internal

 */

QRectF HbVgMaskEffectPrivate::mapRect(const QRectF &rect, const QSize &srcSize) const

{

    qreal rotationAngle = mainWindowRotation();

    qreal x1 = 0;

    qreal y1 = 0;

    QPointF mp = mapOffset(QPointF(rect.x(), rect.y()));

    QSizeF sz = mapSize(rect.size());

    if (rotationAngle == -90 || rotationAngle == 270) {

        x1 = mp.x();

        y1 = mp.y() + srcSize.height() - sz.height();

    } else if (rotationAngle == 90 || rotationAngle == -270) {

        x1 = mp.x() + srcSize.width() - sz.width();

        y1 = mp.y();

    } else {

        x1 = mp.x();

        y1 = mp.y();

    }

    return QRectF(x1, y1, sz.width(), sz.height());

}

/*!

 * \reimp

 *

 * OpenVG-based implementation. Supports all masking options.

 */

void HbVgMaskEffect::performEffect(QPainter *painter,

                                   const QPointF &offset,

                                   const QVariant &vgImage,

                                   const QSize &vgImageSize)

{

#ifdef HB_EFFECTS_OPENVG

    Q_UNUSED(vgImage);

    Q_D(HbVgMaskEffect);

    if (!painter->paintEngine()) {

        return;

    }

    // Find out the target size and position.

    QPaintDevice *pdev = painter->paintEngine()->paintDevice();

    QRectF srcDevRect(d->deviceRectForSource(HbVgFrameEffectPrivate::ExcludeChildren, pdev));

    QSize targetSize = d->includeSourceItemOnly ? srcDevRect.size().toSize() : vgImageSize;

    int posX = (int) offset.x();

    int posY = (int) offset.y();

    if (d->includeSourceItemOnly) {

        posX = (int) srcDevRect.x();

        posY = (int) srcDevRect.y();

    }

    // Initialize scaledMask if the mask has changed or the size of the source

    // is different than before.

    if (!d->mask.isNull()) {

        if (d->scaledMask.isNull()) {

            d->scaledMask = d->mask;

        }

        // Scale only when really needed, i.e. when the size is different than

        // before (or there is a new mask).

        if (d->scaledMask.size() != targetSize) {

            d->scaledMask = d->mask.scaled(targetSize);

            d->rotatedPixmap = QPixmap();

        }

    }

    vgSeti(VG_MASKING, VG_TRUE);

    // Set the mask for the entire surface to 1 (i.e. nothing is transparent).

    vgMask(VG_INVALID_HANDLE, VG_FILL_MASK,

           0, 0, pdev->width(), pdev->height());

    // If there is a pixmap then use that, otherwise use the rectangle. If none

    // of these is set then try the callback, if that is not set either then

    // just draw the source normally.

    QPixmap *maskPtr = 0;

    if (d->scaledMask.isNull() && !d->maskRect.isNull()) {

        QRectF mappedRect = d->maskRect;

        if (!d->maskRectIsInDeviceCoords) {

            mappedRect = d->mapRect(d->maskRect, targetSize);

            mappedRect.adjust(posX, posY, posX, posY);

        }

        int x1 = (int) mappedRect.x();

        int y1 = (int) mappedRect.y();

        int w = (int) mappedRect.width();

        int h = (int) mappedRect.height();

        // Make the area defined by the rectangle transparent. Passing

        // VG_CLEAR_MASK results in writing 0 to the mask which results in

        // transparent pixels at that position.

        vgMask(VG_INVALID_HANDLE, VG_CLEAR_MASK,

               x1, toVgYH(y1, h, pdev),

               w, h);

    } else if (!d->scaledMask.isNull()) {

        maskPtr = &d->scaledMask;

    } else if (d->maskCallback) {

        // Invoke the callback but only if it has just been set or the size of

        // the source is different than before.

        if (d->callbackResult.isNull() || d->callbackResult.size() != targetSize) {

            d->callbackResult = d->maskCallback(targetSize, d->maskCallbackParam);

            d->rotatedPixmap = QPixmap();

        }

        maskPtr = &d->callbackResult;

    }

    if (maskPtr) {

        int w = targetSize.width();

        int h = targetSize.height();

        QPixmap pm;

        qreal rotationAngle = d->mainWindowRotation();

        if (rotationAngle != 0) {

            if (d->rotatedPixmap.isNull() || rotationAngle != d->lastMainWindowRotationAngle) {

                d->rotatedPixmap = maskPtr->transformed(d->rotationTransform()).scaled(targetSize);

                d->lastMainWindowRotationAngle = rotationAngle;

            }

            pm = d->rotatedPixmap;

        }

        QPixmap *finalMaskPtr = pm.isNull() ? maskPtr : ±

        // Will use the alpha channel from the image, alpha=0 => 0 in the mask

        // => transparent pixel, alpha=255 => 1 in the mask => opaque pixel.

        vgMask(qPixmapToVGImage(*finalMaskPtr), VG_SET_MASK,

               posX, toVgYH(posY, h, pdev),

               w, h);

    }

    // Draw the source item with masking enabled.

    painter->drawPixmap(offset, d->srcPixmap);

    vgSeti(VG_MASKING, VG_FALSE);

#else

    Q_UNUSED(painter);

    Q_UNUSED(offset);

    Q_UNUSED(vgImage);

    Q_UNUSED(vgImageSize);

#endif

}

/*!

 * \reimp

 *

 * QPainter-based implementation. Currently only supports masking via pixmaps.

 *

 * The behavior for partially visible items (clipped by the device rect) is

 * somewhat wrong, the mask is never clipped, it is just scaled down to match

 * the visible part of the item.

 */

void HbVgMaskEffect::performEffectSw(QPainter *painter)

{

    Q_D(HbVgMaskEffect);

    QPoint offset;

    QPixmap srcPixmap = sourcePixmap(Qt::DeviceCoordinates, &offset); // needs the original world transform

    if (srcPixmap.isNull()) {

        return;

    }

    QPaintDevice *pdev = painter->paintEngine()->paintDevice();

    d->worldTransform = painter->worldTransform(); // deviceRectForSource needs this

    // The full source rect (without child items) would be

    // d->worldTransform.mapRect(sourceItemForRoot()->boundingRect()).toRect()

    // but we only care about the visible part here so clipping must be applied.

    QRect srcDevRect(d->deviceRectForSource(HbVgFrameEffectPrivate::ExcludeChildren, pdev).toRect());

    QPoint pos = d->includeSourceItemOnly ? srcDevRect.topLeft() : offset;

    QSize size = d->includeSourceItemOnly ? srcDevRect.size() : srcPixmap.size();

    if (size.width() <= 0 || size.height() <= 0) {

        return;

    }

    QPixmap maskPixmap;

    if (d->maskCallback) {

        if (d->callbackResult.isNull() || d->callbackResult.size() != size) {

            d->callbackResult = d->maskCallback(size, d->maskCallbackParam);

            d->rotatedPixmap = QPixmap();

        }

        maskPixmap = d->callbackResult;

    } else if (!d->mask.isNull()) {

        if (d->scaledMask.isNull()) {

            d->scaledMask = d->mask;

        }

        if (d->scaledMask.size() != size) {

            d->scaledMask = d->mask.scaled(size);

            d->rotatedPixmap = QPixmap();

        }

        maskPixmap = d->scaledMask;

    } else {

        // Masking via rectangles is not supported here.

        drawSource(painter);

        return;

    }

    qreal rotationAngle = d->mainWindowRotation();

    if (rotationAngle != 0) {

        if (d->rotatedPixmap.isNull() || rotationAngle != d->lastMainWindowRotationAngle) {

            d->rotatedPixmap = maskPixmap.transformed(d->rotationTransform()).scaled(size);

            d->lastMainWindowRotationAngle = rotationAngle;

        }

        maskPixmap = d->rotatedPixmap;

    }

    if (d->includeSourceItemOnly) {

        // Take only the source item itself, excluding its children.

        srcPixmap = srcPixmap.copy(srcDevRect.adjusted(-offset.x(), -offset.y(), -offset.x(), -offset.y()));

    }

    painter->setWorldTransform(QTransform());

    QImage image(size, QImage::Format_ARGB32_Premultiplied);

    QPainter p(&image);

    p.setCompositionMode(QPainter::CompositionMode_Source);

    p.fillRect(image.rect(), Qt::transparent);

    p.setCompositionMode(QPainter::CompositionMode_SourceOver);

    p.drawPixmap(0, 0, srcPixmap);

    p.setCompositionMode(QPainter::CompositionMode_DestinationIn);

    p.drawPixmap(0, 0, maskPixmap);

    p.end();

    painter->drawImage(pos, image);

    painter->setWorldTransform(d->worldTransform);

}