/****************************************************************************
**
** Copyright (C) 2005-2006 Trolltech AS. All rights reserved.
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "hoverpoints.h"

#define printf

HoverPoints::HoverPoints(QWidget *widget, PointShape shape)
    : QObject(widget)
{
    m_widget = widget;
    widget->installEventFilter(this);

    m_connectionType = CurveConnection;
    m_sortType = NoSort;
    m_shape = shape;
    m_pointPen = QPen(QColor(255, 255, 255, 191), 1);
    m_connectionPen = QPen(QColor(255, 255, 255, 127), 2);
    m_pointBrush = QBrush(QColor(191, 191, 191, 127));
    m_pointSize = QSize(11, 11);
    m_currentIndex = -1;
    m_editable = true;
    m_enabled = true;

    connect(this, SIGNAL(pointsChanged(const QPolygonF &)),
            m_widget, SLOT(update()));
}


void HoverPoints::setEnabled(bool enabled)
{
    if (m_enabled != enabled) {
        m_enabled = enabled;
        m_widget->update();
    }
}


bool HoverPoints::eventFilter(QObject *object, QEvent *event)
{
    if (object == m_widget && m_enabled) {
        switch (event->type()) {

        case QEvent::MouseButtonPress:
            {
                QMouseEvent *me = (QMouseEvent *) event;

                QPointF clickPos = me->pos();
                int index = -1;
                for (int i=0; i<m_points.size(); ++i) {
                    QPainterPath path;
                    if (m_shape == CircleShape)
                        path.addEllipse(pointBoundingRect(i));
                    else
                        path.addRect(pointBoundingRect(i));

                    if (path.contains(clickPos)) {
                        index = i;
                        break;
                    }
                }

                if (me->button() == Qt::LeftButton) {
                    if (index == -1) {
                        if (!m_editable)
                            return false;
                        int pos = 0;
                        // Insert sort for x or y
                        if (m_sortType == XSort) {
                            for (int i=0; i<m_points.size(); ++i)
                                if (m_points.at(i).x() > clickPos.x()) {
                                    pos = i;
                                    break;
                                }
                        } else if (m_sortType == YSort) {
                            for (int i=0; i<m_points.size(); ++i)
                                if (m_points.at(i).y() > clickPos.y()) {
                                    pos = i;
                                    break;
                                }
                        }

                        m_points.insert(pos, clickPos);
                        m_locks.insert(pos, 0);
                        m_currentIndex = pos;
                        firePointChange();
                    } else {
                        m_currentIndex = index;
                    }
                    return true;

                } else if (me->button() == Qt::RightButton) {
                    if (index >= 0 && m_editable) {
                        if (m_locks[index] == 0) {
                            m_locks.remove(index);
                            m_points.remove(index);
                        }
                        firePointChange();
                        return true;
                    }
                }

            }
            break;

        case QEvent::MouseButtonRelease:
            m_currentIndex = -1;
            break;

        case QEvent::MouseMove:
            if (m_currentIndex >= 0)
                movePoint(m_currentIndex, ((QMouseEvent *)event)->pos());
            break;

        case QEvent::Resize:
            {
                QResizeEvent *e = (QResizeEvent *) event;
                double stretch_x = e->size().width() / double(e->oldSize().width());
                double stretch_y = e->size().height() / double(e->oldSize().height());
                for (int i=0; i<m_points.size(); ++i) {
                    QPointF p = m_points[i];
                    movePoint(i, QPointF(p.x() * stretch_x, p.y() * stretch_y), false);
                }

                firePointChange();
                break;
            }

        case QEvent::Paint:
            {
                QWidget *that_widget = m_widget;
                m_widget = 0;
                QApplication::sendEvent(object, event);
                m_widget = that_widget;
                paintPoints();
                return true;
            }
        default:
            break;
        }
    }

    return false;
}


void HoverPoints::paintPoints()
{
    QPainter p(m_widget);

    p.setRenderHint(QPainter::Antialiasing);

    if (m_connectionPen.style() != Qt::NoPen && m_connectionType != NoConnection) {
        p.setPen(m_connectionPen);

        if (m_connectionType == CurveConnection) {
            QPainterPath path;
            path.moveTo(m_points.at(0));
            for (int i=1; i<m_points.size(); ++i) {
                QPointF p1 = m_points.at(i-1);
                QPointF p2 = m_points.at(i);
                double distance = p2.x() - p1.x();

                path.cubicTo(p1.x() + distance / 2, p1.y(),
                             p1.x() + distance / 2, p2.y(),
                             p2.x(), p2.y());
            }
            p.drawPath(path);
        } else {
            p.drawPolyline(m_points);
        }
    }

    p.setPen(m_pointPen);
    p.setBrush(m_pointBrush);

    for (int i=0; i<m_points.size(); ++i) {
        QRectF bounds = pointBoundingRect(i);
        if (m_shape == CircleShape)
            p.drawEllipse(bounds);
        else
            p.drawRect(bounds);
    }
}

static QPointF bound_point(const QPointF &point, const QRectF &bounds, int lock)
{
    QPointF p = point;

    double left = bounds.left();
    double right = bounds.right();
    double top = bounds.top();
    double bottom = bounds.bottom();

    if (p.x() < left || (lock & HoverPoints::LockToLeft)) p.setX(left);
    else if (p.x() > right || (lock & HoverPoints::LockToRight)) p.setX(right);

    if (p.y() < top || (lock & HoverPoints::LockToTop)) p.setY(top);
    else if (p.y() > bottom || (lock & HoverPoints::LockToBottom)) p.setY(bottom);

    return p;
}

void HoverPoints::setPoints(const QPolygonF &points)
{
    m_points.clear();
    for (int i=0; i<points.size(); ++i)
        m_points << bound_point(points.at(i), boundingRect(), 0);

    m_locks.clear();
    if (m_points.size() > 0) {
        m_locks.resize(m_points.size());

        m_locks.fill(0);
    }
}


void HoverPoints::movePoint(int index, const QPointF &point, bool emitUpdate)
{
    m_points[index] = bound_point(point, boundingRect(), m_locks.at(index));
    if (emitUpdate)
        firePointChange();
}


inline static bool x_less_than(const QPointF &p1, const QPointF &p2)
{
    return p1.x() < p2.x();
}


inline static bool y_less_than(const QPointF &p1, const QPointF &p2)
{
    return p1.y() < p2.y();
}

void HoverPoints::firePointChange()
{
//    printf("HoverPoints::firePointChange(), current=%d\n", m_currentIndex);

    if (m_sortType != NoSort) {

        QPointF oldCurrent;
        if (m_currentIndex != -1) {
            oldCurrent = m_points[m_currentIndex];
        }

        if (m_sortType == XSort)
            qSort(m_points.begin(), m_points.end(), x_less_than);
        else if (m_sortType == YSort)
            qSort(m_points.begin(), m_points.end(), y_less_than);

        // Compensate for changed order...
        if (m_currentIndex != -1) {
            for (int i=0; i<m_points.size(); ++i) {
                if (m_points[i] == oldCurrent) {
                    m_currentIndex = i;
                    break;
                }
            }
        }

//         printf(" - firePointChange(), current=%d\n", m_currentIndex);

    }

//     for (int i=0; i<m_points.size(); ++i) {
//         printf(" - point(%2d)=[%.2f, %.2f], lock=%d\n",
//                i, m_points.at(i).x(), m_points.at(i).y(), m_locks.at(i));
//     }

    emit pointsChanged(m_points);
}
