videosurface.cpp

#include "videosurface.h"

#include <QDebug>
#include <QImage>
#include <QPainter>
#include <QPaintEvent>
#include <QSize>

VideoSurface::VideoSurface(QWidget *parent, Qt::WindowFlags f) :
    QWidget( parent, f ),
    m_ScaleFactor(1)
{
    setMouseTracking(true);
}

QSize VideoSurface::sizeHint() const
{
    return m_ScaledSize;
}

void VideoSurface::present( const QImage& frame )
{
    m_Image = frame;
    m_ScaledSize = m_Image.size() * m_ScaleFactor;
    this->setMinimumSize(m_ScaledSize);
    this->update();
}

void VideoSurface::resize(int times)
{
    if (times != m_ScaleFactor) {
        m_ScaleFactor = times;
        present(m_Image);
        emit scaleFactorChanged(m_ScaleFactor);
    }
}

void VideoSurface::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
    const int w = m_Image.width();
    const int h = m_Image.height();
    const int stride = m_Image.bytesPerLine();
    const QVector<QRgb> palette = m_Image.colorTable();
    const uchar *img = m_Image.constBits();
    for (int y = 0; y < h; ++y) {
        for (int x = 0; x < w; ++x) {
            int idx = img[y*stride + x];
            if (m_ScaleFactor == 1) {
                painter.setPen(palette[idx]);
            }
            else {
                painter.setBrush(QBrush(palette[idx]));
            }
            painter.drawRect(x * m_ScaleFactor, y * m_ScaleFactor, m_ScaleFactor, m_ScaleFactor);
        }
    }
    if (m_MousePos.x() < m_ScaledSize.width() && m_MousePos.y() < m_ScaledSize.height()) {
        int x = (m_MousePos.x() / m_ScaleFactor) * m_ScaleFactor;
        int y = (m_MousePos.y() / m_ScaleFactor) * m_ScaleFactor;
        painter.setPen(Qt::red);
        painter.setBrush(QBrush());
        painter.drawRect(x, y, m_ScaleFactor, m_ScaleFactor);
    }
}

void VideoSurface::mouseMoveEvent(QMouseEvent *event)
{
    if (m_Image.isNull()) {
        return;
    }

    m_MousePos = event->pos();
    this->update();
    emit mouseMoved(m_MousePos.x() / m_ScaleFactor, m_MousePos.y() / m_ScaleFactor);
    event->accept();
}