#include "CustomHistogramBars.h"

CustomHistogramBars::CustomHistogramBars(QCPAxis *keyAxis, QCPAxis *valueAxis)
    : QCPBars(keyAxis, valueAxis),
      m_textAlignment(Qt::AlignCenter),
      m_spacing(5),
      m_font(QFont(QLatin1String("sans serif"), 12))
{
}

void CustomHistogramBars::setTextAlignment(Qt::Alignment alignment)
{
    m_textAlignment = alignment;
}

void CustomHistogramBars::setSpacing(double spacing)
{
    m_spacing = spacing;
}

void CustomHistogramBars::setFont(const QFont &font)
{
    m_font = font;
}

void CustomHistogramBars::draw(QCPPainter *painter)
{
    if (!mKeyAxis || !mValueAxis) {
        qDebug() << Q_FUNC_INFO << "invalid key or value axis";
        return;
    }
    if (mDataContainer->isEmpty())
        return;

    QCPBarsDataContainer::const_iterator visibleBegin, visibleEnd;
    getVisibleDataBounds(visibleBegin, visibleEnd);

    // loop over and draw segments of unselected/selected data:
    QList<QCPDataRange> selectedSegments, unselectedSegments, allSegments;
    getDataSegments(selectedSegments, unselectedSegments);
    allSegments << unselectedSegments << selectedSegments;
    for (int i = 0; i < allSegments.size(); ++i) {
        bool isSelectedSegment                     = i >= unselectedSegments.size();
        QCPBarsDataContainer::const_iterator begin = visibleBegin;
        QCPBarsDataContainer::const_iterator end   = visibleEnd;
        mDataContainer->limitIteratorsToDataRange(begin, end, allSegments.at(i));
        if (begin == end)
            continue;

        for (QCPBarsDataContainer::const_iterator it = begin; it != end; ++it) {
            // check data validity if flag set:
#ifdef QCUSTOMPLOT_CHECK_DATA
            if (QCP::isInvalidData(it->key, it->value))
                qDebug() << Q_FUNC_INFO << "Data point at" << it->key << "of drawn range invalid."
                         << "Plottable name:" << name();
#endif
            // draw bar:
            if (isSelectedSegment && mSelectionDecorator) {
                mSelectionDecorator->applyBrush(painter);
                mSelectionDecorator->applyPen(painter);
            } else {
                painter->setBrush(mBrush);
                painter->setPen(mPen);
            }
            applyDefaultAntialiasingHint(painter);

            // 修改一下
            QRectF barRect = getBarRect(it->key, it->value);
            painter->drawPolygon(barRect);

            // 计算文字的位置
            painter->setFont(m_font);                           // 设置字体
            QString text = QString::number(it->value, 'g', 2);  // 取得当前value轴的值，保留两位精度

            QRectF textRect = painter->fontMetrics().boundingRect(0, 0, 0, 0, Qt::TextDontClip | m_textAlignment,
                                                                  text);  // 计算文字所占用的大小

            if (mKeyAxis.data()->orientation() == Qt::Horizontal) {  // 当key轴为水平轴的时候
                if (mKeyAxis.data()->axisType() == QCPAxis::atTop)   // 上轴，移动文字到柱状图下面
                    textRect.moveTopLeft(barRect.bottomLeft() + QPointF(0, m_spacing));
                else  // 下轴，移动文字到柱状图上面
                    textRect.moveBottomLeft(barRect.topLeft() - QPointF(0, m_spacing));
                textRect.setWidth(barRect.width());
                painter->drawText(textRect, Qt::TextDontClip | m_textAlignment, text);
            } else {                                                 // 当key轴为竖直轴的时候
                if (mKeyAxis.data()->axisType() == QCPAxis::atLeft)  // 左轴，移动文字到柱状图右边
                    textRect.moveTopLeft(barRect.topRight() + QPointF(m_spacing, 0));
                else  // 右轴，移动文字到柱状图左边
                    textRect.moveTopRight(barRect.topLeft() - QPointF(m_spacing, 0));
                textRect.setHeight(barRect.height());
                painter->drawText(textRect, Qt::TextDontClip | m_textAlignment, text);
            }
        }
    }

    // draw other selection decoration that isn't just line/scatter pens and brushes:
    if (mSelectionDecorator)
        mSelectionDecorator->drawDecoration(painter, selection());
}