tools/drawMapTest/drawmapscene.cpp
author Mitchell Kember <mk12360@gmail.com>
Fri, 30 Nov 2012 20:00:53 -0500
changeset 8149 237802cf4610
parent 4471 220d44cb8659
permissions -rw-r--r--
Google Code-in: Center help text field Modifies the grid layout slightly so that the help text which appears when hovering over certain elements is centered with respect to the window, even when there are more buttons on one side. https://google-melange.appspot.com/gci/task/view/google/gci2012/7968226

#include <QDebug>
#include <QGraphicsSceneMouseEvent>
#include <QGraphicsPathItem>
#include <QtEndian>

#include "drawmapscene.h"

template <class T> T sqr(const T & x)
{
    return x*x;
}

DrawMapScene::DrawMapScene(QObject *parent) :
    QGraphicsScene(parent),
    m_pen(Qt::yellow),
    m_brush(Qt::yellow)
{
    setSceneRect(0, 0, 4096, 2048);

    QLinearGradient gradient(0, 0, 0, 2048);
    gradient.setColorAt(0, QColor(60, 60, 155));
    gradient.setColorAt(1, QColor(155, 155, 60));
    setBackgroundBrush(QBrush(gradient));

    m_pen.setWidth(67);
    m_pen.setJoinStyle(Qt::RoundJoin);
    m_pen.setCapStyle(Qt::RoundCap);
    m_currPath = 0;
}

void DrawMapScene::mouseMoveEvent(QGraphicsSceneMouseEvent * mouseEvent)
{

    qDebug() << "move" << mouseEvent->scenePos();

    if(m_currPath && (mouseEvent->buttons() & Qt::LeftButton))
    {
        QPainterPath path = m_currPath->path();
        path.lineTo(mouseEvent->scenePos());
        paths.first().append(mouseEvent->scenePos().toPoint());
        m_currPath->setPath(path);

        emit pathChanged();
    }
}

void DrawMapScene::mousePressEvent(QGraphicsSceneMouseEvent * mouseEvent)
{
    qDebug() << "press" << mouseEvent->scenePos();

    m_currPath = addPath(QPainterPath(), m_pen);

    QPainterPath path = m_currPath->path();
    QPointF p = mouseEvent->scenePos();
    p += QPointF(0.01, 0.01);
    path.moveTo(p);
    path.lineTo(mouseEvent->scenePos());
    paths.prepend(QList<QPoint>() << mouseEvent->scenePos().toPoint());
    m_currPath->setPath(path);

    emit pathChanged();
}

void DrawMapScene::mouseReleaseEvent(QGraphicsSceneMouseEvent * mouseEvent)
{
    qDebug() << "release" << mouseEvent->scenePos();

    simplifyLast();

    m_currPath = 0;
}

void DrawMapScene::undo()
{
    if(items().size())
    {
        removeItem(items().first());
        paths.removeFirst();

        emit pathChanged();
    }
}

QByteArray DrawMapScene::encode()
{
    QByteArray b;

    foreach(QList<QPoint> points, paths)
    {
        int cnt = 0;
        foreach(QPoint point, points)
        {
            qint16 px = qToBigEndian((qint16)point.x());
            qint16 py = qToBigEndian((qint16)point.y());
            quint8 flags = 2;
            if(!cnt) flags |= 0x80;
            b.append((const char *)&px, 2);
            b.append((const char *)&py, 2);
            b.append((const char *)&flags, 1);

            ++cnt;
        }

    }

    return b;
}

void DrawMapScene::decode(QByteArray data)
{
    clear();
    paths.clear();

    QList<QPoint> points;

    while(data.size() >= 5)
    {
        qint16 px = qFromBigEndian(*(qint16 *)data.data());
        data.remove(0, 2);
        qint16 py = qFromBigEndian(*(qint16 *)data.data());
        data.remove(0, 2);
        quint8 flags = *(quint8 *)data.data();
        data.remove(0, 1);

        //last chunk or first point
        if((data.size() < 5) || (flags & 0x80))
        {
            if(points.size())
            {
                qDebug() << points;
                addPath(pointsToPath(points), m_pen);
                paths.prepend(points);

                points.clear();
            }
        }

        points.append(QPoint(px, py));
    }
}

void DrawMapScene::simplifyLast()
{
    QList<QPoint> points = paths[0];

    QPoint prevPoint = points.first();
    int i = 1;
    while(i < points.size())
    {
        if( (i != points.size() - 1)
            && (sqr(prevPoint.x() - points[i].x()) + sqr(prevPoint.y() - points[i].y()) < 1000)
          )
            points.removeAt(i);
        else
        {
            prevPoint = points[i];
            ++i;
        }
    }

    paths[0] = points;


    // redraw path
    {
        QGraphicsPathItem * pathItem = static_cast<QGraphicsPathItem *>(items()[0]);
        pathItem->setPath(pointsToPath(paths[0]));
    }

    emit pathChanged();
}

QPainterPath DrawMapScene::pointsToPath(const QList<QPoint> points)
{
    QPainterPath path;

    if(points.size())
    {
        QPointF p = points[0] + QPointF(0.01, 0.01);
        path.moveTo(p);

        foreach(QPoint p, points)
            path.lineTo(p);
    }

    return path;
}