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

**

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

** All rights reserved.

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

**

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

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** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

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

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** 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

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**

** 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.

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

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** $QT_END_LICENSE$

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

#include "zoomwidget_p.h"

#include <QtGui/QGraphicsScene>

#include <QtGui/QGraphicsProxyWidget>

#include <QtGui/QMenu>

#include <QtGui/QAction>

#include <QtGui/QActionGroup>

#include <QtGui/QContextMenuEvent>

#include <QtGui/QScrollBar>

#include <QtCore/QTextStream>

#include <QtCore/qmath.h>

#include <QtCore/QDebug>

#include <QtCore/QList>

QT_BEGIN_NAMESPACE

typedef QList<QAction*> ActionList;

typedef QList<QGraphicsItem *> GraphicsItemList;

enum { debugZoomWidget = 0 };

static const int menuZoomList[] = { 100, 25, 50, 75, 125, 150 , 175, 200 };

static inline QSize qCeiling(const QSizeF &s)

{

    return QSize(qCeil(s.width()), qCeil(s.height()));

}

namespace qdesigner_internal {

// ---------- ZoomMenu

ZoomMenu::ZoomMenu(QObject *parent) :

   QObject(parent),

   m_menuActions(new QActionGroup(this))

{

    connect(m_menuActions, SIGNAL(triggered(QAction*)), this, SLOT(slotZoomMenu(QAction*)));

    const int nz = sizeof(menuZoomList)/sizeof(int);

    for (int i = 0; i < nz; i++) {

        const int zoom = menuZoomList[i];

        //: Zoom factor

        QAction *a = m_menuActions->addAction(tr("%1 %").arg(zoom));

        a->setCheckable(true);

        a->setData(QVariant(zoom));

        if (zoom == 100)

            a->setChecked(true);

        m_menuActions->addAction(a);

    }

}

int ZoomMenu::zoomOf(const QAction *a)

{

    return a->data().toInt();

}

void ZoomMenu::addActions(QMenu *m)

{

    const ActionList za = m_menuActions->actions();

    const ActionList::const_iterator cend = za.constEnd();

    for (ActionList::const_iterator it =  za.constBegin(); it != cend; ++it) {

        m->addAction(*it);

        if (zoomOf(*it)  == 100)

            m->addSeparator();

    }

}

int ZoomMenu::zoom() const

{

    return m_menuActions->checkedAction()->data().toInt();

}

void ZoomMenu::setZoom(int percent)

{

    const ActionList za = m_menuActions->actions();

    const ActionList::const_iterator cend = za.constEnd();

    for (ActionList::const_iterator it =  za.constBegin(); it != cend; ++it)

        if (zoomOf(*it) == percent) {

            (*it)->setChecked(true);

            return;

        }

}

void ZoomMenu::slotZoomMenu(QAction *a)

{

    emit zoomChanged(zoomOf(a));

}

QList<int> ZoomMenu::zoomValues()

{

    QList<int> rc;

    const int nz = sizeof(menuZoomList)/sizeof(int);

    for (int i = 0; i < nz; i++)

        rc.push_back(menuZoomList[i]);

    return rc;

}

// --------- ZoomView

ZoomView::ZoomView(QWidget *parent) :

    QGraphicsView(parent),

    m_scene(new QGraphicsScene(this)),

    m_zoom(100),

    m_zoomFactor(1.0),

    m_zoomContextMenuEnabled(false),

    m_zoomMenu(0)

{

    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    setFrameShape(QFrame::NoFrame);

    setScene(m_scene);

    if (debugZoomWidget)

        qDebug() << "scene" << m_scene->sceneRect();

}

int ZoomView::zoom() const

{

    return m_zoom;

}

void ZoomView::scrollToOrigin()

{

    const QPoint origin(0 ,0);

    const QPoint current = scrollPosition();

    if (current != origin) {

        if (debugZoomWidget)

            qDebug() << "ZoomView::scrollToOrigin from " << current;

        setScrollPosition(origin);

    }

}

void ZoomView::setZoom(int percent)

{

    if (debugZoomWidget)

        qDebug() << "ZoomView::setZoom" << percent;

    if (m_zoom == percent)

        return;

    m_zoom = percent;

    const qreal hundred = 100.0;

    m_zoomFactor = static_cast<qreal>(m_zoom) / hundred;

    applyZoom();

    if (m_zoomMenu) // Do not force them into existence

        m_zoomMenu->setZoom(m_zoom);

    resetTransform();

    scale(m_zoomFactor, m_zoomFactor);

}

void ZoomView::applyZoom()

{

}

qreal ZoomView::zoomFactor() const

{

    return m_zoomFactor;

}

bool ZoomView::isZoomContextMenuEnabled() const

{

    return m_zoomContextMenuEnabled;

}

void ZoomView::setZoomContextMenuEnabled(bool e)

{

    m_zoomContextMenuEnabled = e;

}

ZoomMenu *ZoomView::zoomMenu()

{

    if (!m_zoomMenu) {

        m_zoomMenu = new ZoomMenu(this);

        m_zoomMenu->setZoom(m_zoom);

        connect(m_zoomMenu, SIGNAL(zoomChanged(int)), this, SLOT(setZoom(int)));

    }

    return m_zoomMenu;

}

void ZoomView::contextMenuEvent(QContextMenuEvent *event)

{

    if (debugZoomWidget > 1)

        qDebug() << "ZoomView::contextMenuEvent" << event->pos() << event->globalPos() << zoom() << '%';

    if (m_zoomContextMenuEnabled) {

        showContextMenu(event->globalPos());

    } else {

        QGraphicsView::contextMenuEvent(event);

    }

}

void ZoomView::showContextMenu(const QPoint &globalPos)

{

    QMenu menu;

    zoomMenu()->addActions(&menu);

    if (debugZoomWidget) {

        menu.addSeparator();

        QAction *da = menu.addAction(QLatin1String("Dump"));

        connect(da, SIGNAL(triggered()), this, SLOT(dump()));

    }

    menu.exec(globalPos);

}

QPoint ZoomView::scrollPosition() const

{

    return QPoint(horizontalScrollBar()->value(), verticalScrollBar()->value());

}

void ZoomView::setScrollPosition(const QPoint& pos)

{

    horizontalScrollBar()->setValue(pos.x());

    verticalScrollBar()->setValue(pos.y());

}

// -------------- ZoomProxyWidget

ZoomProxyWidget::ZoomProxyWidget(QGraphicsItem *parent, Qt::WindowFlags wFlags) :

    QGraphicsProxyWidget(parent, wFlags)

{

}

QVariant ZoomProxyWidget::itemChange(GraphicsItemChange change, const QVariant &value)

{

    switch (change) {

    case ItemPositionChange: {

        const QPointF newPos = value.toPointF();

        const QPointF desiredPos = QPointF(0, 0);

        if (newPos != desiredPos && debugZoomWidget)

            qDebug() << "ZoomProxyWidget::itemChange: refusing " << newPos;

        return desiredPos;

    }

    default:

        break;

    }

    return QGraphicsProxyWidget::itemChange(change, value);

}

/* ZoomedEventFilterRedirector: Event filter for the zoomed widget.

 * It redirects the events to another handler of ZoomWidget as its

 * base class QScrollArea also implements eventFilter() for its viewport. */

static const char *zoomedEventFilterRedirectorNameC = "__qt_ZoomedEventFilterRedirector";

class ZoomedEventFilterRedirector : public QObject {

    Q_DISABLE_COPY(ZoomedEventFilterRedirector)

public:

    explicit ZoomedEventFilterRedirector(ZoomWidget *zw, QObject *parent);

    virtual bool eventFilter(QObject *watched, QEvent *event);

private:

    ZoomWidget *m_zw;

};

ZoomedEventFilterRedirector::ZoomedEventFilterRedirector(ZoomWidget *zw, QObject *parent) :

    QObject(parent),

    m_zw(zw)

{

    setObjectName(QLatin1String(zoomedEventFilterRedirectorNameC));

}

bool ZoomedEventFilterRedirector::eventFilter(QObject *watched, QEvent *event)

{

    return m_zw->zoomedEventFilter(watched, event);

}

// --------- ZoomWidget

ZoomWidget::ZoomWidget(QWidget *parent) :

    ZoomView(parent),

    m_proxy(0),

    m_viewResizeBlocked(false),

    m_widgetResizeBlocked(false),

    m_widgetZoomContextMenuEnabled(false)

{

    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

}

void ZoomWidget::setWidget(QWidget *w, Qt::WindowFlags wFlags)

{

    if (debugZoomWidget)

        qDebug() << "ZoomWidget::setWidget" << w << bin << wFlags;

    if (m_proxy) {

        scene().removeItem(m_proxy);

        if (QWidget *w = m_proxy->widget()) {

            // remove the event filter

            if (QObject *evf =  qFindChild<QObject*>(w, QLatin1String(zoomedEventFilterRedirectorNameC)))

                w->removeEventFilter(evf);

        }

        m_proxy->deleteLater();

    }

    // Set window flags on the outer proxy for them to take effect

    m_proxy = createProxyWidget(0, Qt::Window);

    m_proxy->setWidget(w);

    m_proxy->setWindowFlags(wFlags);

    scene().addItem(m_proxy);

    w->installEventFilter(new ZoomedEventFilterRedirector(this, w));

    resizeToWidgetSize(); // Do manually for new widget

    m_proxy->show();

}

bool ZoomWidget::isWidgetZoomContextMenuEnabled() const

{

    return m_widgetZoomContextMenuEnabled;

}

void ZoomWidget::setWidgetZoomContextMenuEnabled(bool e)

{

    m_widgetZoomContextMenuEnabled = e;

}

QSize ZoomWidget::viewPortMargin() const

{

    return QSize(0, 0);

}

QSizeF ZoomWidget::widgetDecorationSizeF() const

{

    qreal left, top, right, bottom;

    m_proxy->getWindowFrameMargins (&left, &top, &right, &bottom);

    const QSizeF rc = QSizeF(left + right, top + bottom);

    return rc;

}

QSize ZoomWidget::widgetSize() const

{

    if (m_proxy)

        return m_proxy->widget()->size();

    return QSize(0, 0);

}

/* Convert widget size to QGraphicsView size.

 * Watch out for limits (0, QWIDGETSIZE_MAX); just pass them on */

QSize ZoomWidget::widgetSizeToViewSize(const QSize &s, bool *ptrToValid) const

{

    const QSize vpMargin = viewPortMargin();

    const QSizeF deco = widgetDecorationSizeF();

    const int width = s.width();

    QSize rc = s;

    bool valid = false;

    if (width != 0 && width != QWIDGETSIZE_MAX) {

        valid = true;

        rc.setWidth(vpMargin.width() + qCeil(deco.width() + zoomFactor() * static_cast<qreal>(width)));

    }

    const int height = s.height();

    if (height != 0 && height != QWIDGETSIZE_MAX) {

        valid = true;

        rc.setHeight(vpMargin.height() + qCeil(deco.height() + zoomFactor() * static_cast<qreal>(height)));

    }

    if (ptrToValid)

        *ptrToValid = valid;

    return rc;

}

// On changing zoom: Make QGraphicsView big enough to hold the widget

void ZoomWidget::resizeToWidgetSize()

{

    if (!m_proxy)

        return;

    m_viewResizeBlocked = true;

    // Convert size, apply transformed min/max size if applicable

    const QSize wsize = widgetSize();

    const QSize viewSize = widgetSizeToViewSize(wsize);

    bool hasMinimumSize = false;

    const QSize minimumSize = m_proxy->widget()->minimumSize();

    const QSize viewMinimumSize = widgetSizeToViewSize(minimumSize, &hasMinimumSize);

    bool hasMaximumSize = false;

    const QSize maximumSize = m_proxy->widget()->maximumSize();

    const QSize viewMaximumSize = widgetSizeToViewSize(maximumSize, &hasMaximumSize);

  if (debugZoomWidget) {

        qDebug()

            << "ZoomWidget::resizeToWidgetSize()\n"

            << "Widget: " <<  wsize << "(scaled)"  << (wsize * zoomFactor()) << " Min/Max" << minimumSize  <<  maximumSize << '\n'

            << "  View: " << viewSize <<  hasMinimumSize << viewMinimumSize << hasMaximumSize << viewMaximumSize;

    }

    // Apply

    if (hasMinimumSize)

        setMinimumSize(viewMinimumSize);

    if (hasMaximumSize)

        setMaximumSize(viewMaximumSize);

    // now resize

    doResize(viewSize);

    if (debugZoomWidget)

        qDebug() << "ZoomWidget::resizeToWidgetSize(): resulting view size" << size();

    m_viewResizeBlocked = false;

}

void ZoomWidget::applyZoom()

{

    resizeToWidgetSize();

}

/* virtual */ void  ZoomWidget::doResize(const QSize &s)

{

    if (debugZoomWidget > 1)

        qDebug() << ">ZoomWidget::doResize() " << s;

    resize(s);

}

void ZoomWidget::resizeEvent(QResizeEvent *event)

{

    /* QGraphicsView Resized from outside: Adapt widget. For some reason,

     * the size passed in the event is not to be trusted. This might be due

     * to some QScrollArea event fiddling. Have QScrollArea resize first

     * and the use the size ZoomView::resizeEvent(event); */

    if (m_proxy && !m_viewResizeBlocked) {

        if (debugZoomWidget > 1)

            qDebug() << '>' << Q_FUNC_INFO << size() << ")::resizeEvent from " << event->oldSize() << " to " << event->size();

        const QSizeF newViewPortSize = size() - viewPortMargin();

        const QSizeF widgetSizeF = newViewPortSize / zoomFactor() - widgetDecorationSizeF();

        m_widgetResizeBlocked = true;

        m_proxy->widget()->resize(widgetSizeF.toSize());

        setSceneRect(QRectF(QPointF(0, 0), widgetSizeF));

        scrollToOrigin();

        m_widgetResizeBlocked = false;

        if (debugZoomWidget > 1)

            qDebug() << '<' << Q_FUNC_INFO << widgetSizeF << m_proxy->widget()->size() << m_proxy->size();

    }

}

QSize ZoomWidget::minimumSizeHint() const

{

    if (!m_proxy)

        return QGraphicsView::minimumSizeHint();

    const QSizeF wmsh = m_proxy->widget()->minimumSizeHint();

    const QSize rc = viewPortMargin() + (wmsh * zoomFactor()).toSize();

    if (debugZoomWidget > 1)

        qDebug() << "minimumSizeHint()" << rc;

    return rc;

}

QSize ZoomWidget::sizeHint() const

{

    if (!m_proxy)

        return QGraphicsView::sizeHint();

    const QSizeF wsh = m_proxy->widget()->sizeHint();

    const QSize rc = viewPortMargin() + (wsh * zoomFactor()).toSize();

    if (debugZoomWidget > 1)

        qDebug() << "sizeHint()" << rc;

    return rc;

}

bool ZoomWidget::zoomedEventFilter(QObject * /*watched*/, QEvent *event)

{

    switch (event->type()) {

    case QEvent::KeyPress:

        if (debugZoomWidget) { // Debug helper: Press 'D' on the zoomed widget

            const QKeyEvent *kevent = static_cast<QKeyEvent*>(event);

            if (kevent->key() == Qt::Key_D)

                dump();

        }

        break;

    case QEvent::Resize:

        if (debugZoomWidget > 1) {

            const QResizeEvent *re = static_cast<const QResizeEvent *>(event);

            qDebug() << "ZoomWidget::zoomedEventFilter" << re->oldSize() << re->size() << " at " << m_proxy->widget()->geometry();

        }

        if (!m_widgetResizeBlocked)

            resizeToWidgetSize();

        break;

    case QEvent::ContextMenu:

        if (m_widgetZoomContextMenuEnabled) {

            // Calculate global position from scaled

            QContextMenuEvent *ce = static_cast<QContextMenuEvent*>(event);

            const QPointF origin = mapToGlobal(QPoint(0, 0)) - scrollPosition();

            const QPointF pos = QPointF(origin + (QPointF(ce->pos()) * zoomFactor()));

            showContextMenu(pos.toPoint());

            ce->accept();

            return true;

        }

        break;

    default: