#include "multiLineHeaderView.h"
#include <QPainter>

MultiLineHeaderView::MultiLineHeaderView(Qt::Orientation orientation, QWidget* parent)
    : QHeaderView(orientation, parent)
{
    m_linSpacing = 2;
    m_bgColor = QColor(Qt::white);
    m_borderColor = QColor(Qt::lightGray);
    setSectionResizeMode(QHeaderView::ResizeToContents);//根据内容自动调整大小
}

void MultiLineHeaderView::setLineSpacing(int spacing)
{
    m_linSpacing = spacing;
}

void MultiLineHeaderView::setBackgroundColor(QColor& color)
{
    m_bgColor = color;
}

void MultiLineHeaderView::setBorderColor(QColor& color)
{
    m_borderColor = color;
}

void MultiLineHeaderView::paintSection(QPainter* painter, const QRect& rect, int logicalIndex) const
{
    if(!painter->isActive())
        return;

    //绘制背景
    painter->fillRect(rect, m_bgColor);
    //获取文本
    QString text = model()->headerData(logicalIndex, orientation()).toString();
    QStringList lines = text.split('\n');
    //获取当前列的样式
    QMap<int, HeaderLineStyle> styles = m_sectionStyles.value(logicalIndex);
    //计算总高度并垂直居中
    int totalHeight = 0;
    QVector<int> lineHeights;
    for(int i = 0; i < lines.size(); i++)
    {
        HeaderLineStyle style = styles.value(i, m_defaultStyle);
        QFontMetrics fm(style.font);
        lineHeights.append(fm.height());
        totalHeight += fm.height() + (i < lines.size() - 1 ? m_linSpacing : 0);
    }
    int y = rect.y() + (rect.height() - totalHeight) * 0.5;
    //逐行绘制文本
    for(int i = 0; i < lines.size(); i++)
    {
        const QString& line = lines.at(i);
        HeaderLineStyle style = styles.value(i, m_defaultStyle);
        QFontMetrics fm(style.font);
        //水平位置
        int padding = 10;
        int x = rect.x() + padding; //左对齐
        if(style.alignment & Qt::AlignRight) //右对齐
            x = rect.right() - fm.horizontalAdvance(line) - 4;//'horizontalAdvance'计算文本的横向距离
        else if(style.alignment & Qt::AlignHCenter) //水平居中
            x = rect.x() + (rect.width() - fm.horizontalAdvance(line)) * 0.5;
        //设置字体和颜色
        painter->setFont(style.font);
        painter->setPen(style.color);
        //绘制文本
        painter->drawText(x, y + fm.ascent(), line); //绘制文本的基线X轴离文本上方的距离为ascent，下方距离为descent
        y = y + lineHeights[i] + m_linSpacing;
    }

    //绘制边框
    QPen pen(m_borderColor, 1);
    painter->setPen(pen);
    QRect adjustRect = rect.adjusted(0, 0, 1, 0);
    //painter->drawLine(adjustRect.topLeft(), adjustRect.topRight());
    painter->drawLine(adjustRect.bottomLeft(), adjustRect.bottomRight());
    painter->drawLine(adjustRect.topRight(), adjustRect.bottomRight());
}
//自动调整行高
QSize MultiLineHeaderView::sectionSizeFromContents(int logicalIndex) const
{
    //获取文本
    QString text = model()->headerData(logicalIndex, orientation()).toString();
    //获取当前列的样式
    QMap<int, HeaderLineStyle> styles = m_sectionStyles.value(logicalIndex);
    QStringList lines = text.split('\n');
    int maxWidth = 0;
    int totalHeight = 0;
    for(int i = 0; i < lines.size(); i++)
    {
        HeaderLineStyle style = styles.value(i, m_defaultStyle);
        QFontMetrics fm(style.font);
        maxWidth = qMax(maxWidth, fm.horizontalAdvance(lines[i]));
        totalHeight += fm.height() + (i < lines.size() - 1 ? m_linSpacing : 0);
    }
    //qDebug() << maxWidth << "," << totalHeight;
    return QSize(maxWidth + 20, totalHeight + 4);
}

void MultiLineHeaderView::setSectionLineStyle(int section, int line, const HeaderLineStyle& style)
{
    m_sectionStyles[section][line] = style;
    updateSection(section);
}