RotationHandle.cpp

#include "RotationHandle.h"
#include "QPainter"
#include "QGraphicsSceneMouseEvent"
#include "QCursor"
#include "QtMath"
#include "QGraphicsScene"
#include "qdebug.h"

RotationHandle::RotationHandle(QPoint                      origin,
                               QAbstractGraphicsShapeItem* parent)
: QAbstractGraphicsShapeItem(parent)
, _origin(origin)
{
    setFlag(ItemIsMovable);
    setPen(QPen(Qt::black));
    setBrush(QBrush(Qt::red));
    // setFlag(QGraphicsItem::ItemIsSelectable);
    // setFlag(ItemIgnoresTransformations);
}

RotationHandle::~RotationHandle()
{
}

QRectF RotationHandle::boundingRect() const
{
    return QRectF(-5, -5, 10, 10);
}

void RotationHandle::paint(QPainter*                       painter,
                           const QStyleOptionGraphicsItem* option,
                           QWidget*                        widget)
{
    if (m_antialiasing) {
        painter->setRenderHint(QPainter::Antialiasing);
    }
    painter->setPen(this->pen());
    painter->setBrush(this->brush());

    painter->drawEllipse(QRect(-5, -5, 10, 10));

    // painter->drawRect(boundingRect());
}

void RotationHandle::mousePressEvent(QGraphicsSceneMouseEvent* event)
{
    if (event->button() == Qt::LeftButton) {
        // handle left mouse button here

        // unselect all selected items so this can be moved
        QList<QGraphicsItem*> allSelectedItems = scene()->selectedItems();
        QGraphicsItem*        item;
        foreach (item, allSelectedItems) {
            item->setSelected(false);
        }

        setCursor(Qt::ClosedHandCursor);
        update();
    }

    // pass on
    QGraphicsItem::mousePressEvent(event);
}

void RotationHandle::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
{
    if (event->button() == Qt::LeftButton) {
        // handle left mouse button here
        setCursor(Qt::ArrowCursor);

        double angleRad = atan2(this->y() - _origin.y(),
                                this->x() - _origin.x());
        double angleDeg = qRadiansToDegrees(angleRad);

        Q_EMIT emitShapeRotation(angleDeg, true);

        update();
    }
    // pass on
    QGraphicsItem::mouseReleaseEvent(event);
}

void RotationHandle::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
{
    double angleRad = atan2(this->y() - _origin.y(), this->x() - _origin.x());
    double angleDeg = qRadiansToDegrees(angleRad);

    Q_EMIT emitShapeRotation(angleDeg);

    update();

    // pass on
    QGraphicsItem::mouseMoveEvent(event);
}

void RotationHandle::setAntialiasing(bool toggle)
{
    m_antialiasing = toggle;
    update();
}