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

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the Qt Designer of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, 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

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** $QT_END_LICENSE$

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

#include "qdesigner_dnditem_p.h"

#include "formwindowbase_p.h"

#include "ui4_p.h"

#include <QtGui/QPainter>

#include <QtGui/QBitmap>

#include <QtGui/QPixmap>

#include <QtGui/QImage>

#include <QtGui/QLabel>

#include <QtGui/QDrag>

#include <QtGui/QCursor>

#include <QtGui/QDropEvent>

#include <QtGui/QRgb>

#include <QtCore/QMultiMap>

QT_BEGIN_NAMESPACE

namespace qdesigner_internal {

QDesignerDnDItem::QDesignerDnDItem(DropType type, QWidget *source) :

    m_source(source),

    m_type(type),

    m_dom_ui(0),

    m_widget(0),

    m_decoration(0)

{

}

void QDesignerDnDItem::init(DomUI *ui, QWidget *widget, QWidget *decoration,

                                    const QPoint &global_mouse_pos)

{

    Q_ASSERT(widget != 0 || ui != 0);

    Q_ASSERT(decoration != 0);

    m_dom_ui = ui;

    m_widget = widget;

    m_decoration = decoration;

    const QRect geometry = m_decoration->geometry();

    m_hot_spot = global_mouse_pos - m_decoration->geometry().topLeft();

}

QDesignerDnDItem::~QDesignerDnDItem()

{

    if (m_decoration != 0)

        m_decoration->deleteLater();

    delete m_dom_ui;

}

DomUI *QDesignerDnDItem::domUi() const

{

    return m_dom_ui;

}

QWidget *QDesignerDnDItem::decoration() const

{

    return m_decoration;

}

QPoint QDesignerDnDItem::hotSpot() const

{

    return m_hot_spot;

}

QWidget *QDesignerDnDItem::widget() const

{

    return m_widget;

}

QDesignerDnDItem::DropType QDesignerDnDItem::type() const

{

    return m_type;

}

QWidget *QDesignerDnDItem::source() const

{

    return m_source;

}

void QDesignerDnDItem::setDomUi(DomUI *dom_ui)

{

    delete m_dom_ui;

    m_dom_ui = dom_ui;

}

// ---------- QDesignerMimeData

// Make pixmap transparent on Windows only. Mac is transparent by default, Unix usually does not work.

#ifdef Q_WS_WIN

#  define TRANSPARENT_DRAG_PIXMAP

#endif

QDesignerMimeData::QDesignerMimeData(const QDesignerDnDItems &items, QDrag *drag) :

    m_items(items)

{

    enum { Alpha = 200 };

    QPoint decorationTopLeft;

    switch (m_items.size()) {

    case 0:

        break;

    case 1: {

        QWidget *deco = m_items.first()->decoration();

        decorationTopLeft = deco->pos();

        const QPixmap widgetPixmap = QPixmap::grabWidget(deco);

#ifdef TRANSPARENT_DRAG_PIXMAP

        QImage image(widgetPixmap.size(), QImage::Format_ARGB32);

        image.fill(QColor(Qt::transparent).rgba());

        QPainter painter(&image);

        painter.drawPixmap(QPoint(0, 0), widgetPixmap);

        painter.end();

        setImageTransparency(image, Alpha);

        drag->setPixmap(QPixmap::fromImage(image));

#else

        drag->setPixmap(widgetPixmap);

#endif

    }

        break;

    default: {

        // determine size of drag decoration by uniting all geometries

        const QDesignerDnDItems::const_iterator cend = m_items.constEnd();

        QDesignerDnDItems::const_iterator it =m_items.constBegin();

        QRect unitedGeometry = (*it)->decoration()->geometry();

        for (++it; it != cend; ++it )

            unitedGeometry  = unitedGeometry .united((*it)->decoration()->geometry());

        // paint with offset. At the same time, create a mask bitmap, containing widget rectangles.

        QImage image(unitedGeometry.size(), QImage::Format_ARGB32);

        image.fill(QColor(Qt::transparent).rgba());

        QBitmap mask(unitedGeometry.size());

        mask.clear();

        // paint with offset, determine action

        QPainter painter(&image);

        QPainter maskPainter(&mask);

        decorationTopLeft = unitedGeometry.topLeft();

        for (it = m_items.constBegin() ; it != cend; ++it ) {

            QWidget *w = (*it)->decoration();

            const QPixmap wp = QPixmap::grabWidget(w);

            const QPoint pos = w->pos() - decorationTopLeft;

            painter.drawPixmap(pos, wp);

            maskPainter.fillRect(QRect(pos, wp.size()), Qt::color1);

        }

        painter.end();

        maskPainter.end();

#ifdef TRANSPARENT_DRAG_PIXMAP

        setImageTransparency(image, Alpha);

#endif

        QPixmap pixmap = QPixmap::fromImage(image);

        pixmap.setMask(mask);

        drag->setPixmap(pixmap);

    }

        break;

    }

    // determine hot spot and reconstruct the exact starting position as form window

    // introduces some offset when detecting DnD

    m_globalStartPos =  m_items.first()->decoration()->pos() +  m_items.first()->hotSpot();

    m_hotSpot = m_globalStartPos - decorationTopLeft;

    drag->setHotSpot(m_hotSpot);

    drag->setMimeData(this);

}

QDesignerMimeData::~QDesignerMimeData()

{

    const QDesignerDnDItems::const_iterator cend = m_items.constEnd();

    for (QDesignerDnDItems::const_iterator it = m_items.constBegin(); it != cend; ++it )

        delete *it;

}

Qt::DropAction QDesignerMimeData::proposedDropAction() const

{

   return m_items.first()->type() == QDesignerDnDItemInterface::CopyDrop ? Qt::CopyAction : Qt::MoveAction;

}

Qt::DropAction QDesignerMimeData::execDrag(const QDesignerDnDItems &items, QWidget * dragSource)

{

    if (items.empty())

        return Qt::IgnoreAction;

    QDrag *drag = new QDrag(dragSource);

    QDesignerMimeData *mimeData = new QDesignerMimeData(items, drag);

    // Store pointers to widgets that are to be re-shown if a move operation is canceled

    QWidgetList reshowWidgets;

    const QDesignerDnDItems::const_iterator cend = items.constEnd();

    for (QDesignerDnDItems::const_iterator it = items.constBegin(); it != cend; ++it )

        if (QWidget *w = (*it)->widget())

            if ((*it)->type() ==  QDesignerDnDItemInterface::MoveDrop)

                reshowWidgets.push_back(w);

    const Qt::DropAction executedAction = drag->exec(Qt::CopyAction|Qt::MoveAction, mimeData->proposedDropAction());

    if (executedAction == Qt::IgnoreAction && !reshowWidgets.empty())

        foreach (QWidget *w, reshowWidgets)

            w->show();

    return executedAction;

}

void QDesignerMimeData::moveDecoration(const QPoint &globalPos) const

{

    const QPoint relativeDistance = globalPos - m_globalStartPos;

    const QDesignerDnDItems::const_iterator cend = m_items.constEnd();

    for (QDesignerDnDItems::const_iterator it =m_items.constBegin(); it != cend; ++it ) {

        QWidget *w = (*it)->decoration();

        w->move(w->pos() + relativeDistance);

    }

}

void QDesignerMimeData::removeMovedWidgetsFromSourceForm(const QDesignerDnDItems &items)

{

    typedef QMultiMap<FormWindowBase *, QWidget *> FormWidgetMap;

    FormWidgetMap formWidgetMap;

    // Find moved widgets per form

    const QDesignerDnDItems::const_iterator cend = items.constEnd();

    for (QDesignerDnDItems::const_iterator it = items.constBegin(); it != cend; ++it )

        if ((*it)->type() ==  QDesignerDnDItemInterface::MoveDrop)

            if (QWidget *w = (*it)->widget())

                if (FormWindowBase *fb = qobject_cast<FormWindowBase *>((*it)->source()))

                    formWidgetMap.insert(fb, w);

    if (formWidgetMap.empty())

        return;

    foreach (FormWindowBase * fb, formWidgetMap.keys())

        fb->deleteWidgetList(formWidgetMap.values(fb));

}

void QDesignerMimeData::acceptEventWithAction(Qt::DropAction desiredAction, QDropEvent *e)

{

    if (e->proposedAction() == desiredAction) {

        e->acceptProposedAction();

    } else {

        e->setDropAction(desiredAction);

        e->accept();

    }

}

void QDesignerMimeData::acceptEvent(QDropEvent *e) const

{

    acceptEventWithAction(proposedDropAction(), e);

}

void QDesignerMimeData::setImageTransparency(QImage &image, int alpha)

{

    const int height = image.height();

    for (int l = 0; l < height; l++) {

        QRgb *line = reinterpret_cast<QRgb *>(image.scanLine(l));

        QRgb *lineEnd = line + image.width();

        for ( ; line < lineEnd; line++) {

            const QRgb rgba = *line;

            *line = qRgba(qRed(rgba), qGreen(rgba), qBlue(rgba), alpha);

        }

    }

}

} // namespace qdesigner_internal

QT_END_NAMESPACE