//customtabbar.cpp

#include "customtabbar.h"
#include <QDebug>
#include <QDrag>
#include <QMimeData>
#include <QMouseEvent>
#include <QApplication>
#include <QCursor>
#include <QMainWindow>
#include <QFrame>
#include "customtabwidget.h"

CustomTabBar::CustomTabBar(QWidget *parent)
    : QTabBar(parent)
{
    setAcceptDrops(true);
    m_pInsertMarkerLine = new QFrame(this);
    m_pInsertMarkerLine->setObjectName("InsertMarkerLine");
    m_pInsertMarkerLine->setStyleSheet("QFrame{background-color: #ff0000;\
        max-width: 2px;}");
    m_pInsertMarkerLine->hide();
    setElideMode(Qt::ElideMiddle);

    //
    setStyleSheet("QTabBar{qproperty-tabsClosable:true;}");

    //关闭tab时，信号槽触发的函数
    //connect(this, SIGNAL(tabCloseRequested(int)),this,SLOT(slot_tabClose(int)));
}

CustomTabBar::~CustomTabBar()
{
}

////关闭
//void CustomTabBar::slot_tabClose(int index)
//{
//    auto parent = dynamic_cast<CustomTabWidget*>(parentWidget());
//    if (parent)
//    {
//        auto child = parent->currentWidget();
//        auto strTab = parent->tabText(index);
//        if (!child)
//        {
//            return;
//        }

//        qDebug()<<"slot_tabClose Name= " << strTab;
//        child->deleteLater();
//        parent->removeTab(index);
//    }
//}

void CustomTabBar::mousePressEvent(QMouseEvent *event)
{
    QTabBar::mousePressEvent(event);
    if (event->button() == Qt::LeftButton)
        m_dragStartPos = event->pos();
}

void CustomTabBar::mouseMoveEvent(QMouseEvent *event)
{
    QTabBar::mouseMoveEvent(event);
    if (!(event->buttons() & Qt::LeftButton))
        return;
    if ((event->pos() - m_dragStartPos).manhattanLength()
        < QApplication::startDragDistance())
        return;
    auto parent = dynamic_cast<CustomTabWidget*>(parentWidget());
    if (parent)
    {
        auto child = parent->currentWidget();
        auto strTab = parent->tabText(parent->currentIndex());
        if (!child)
        {
            return;
        }
        QPixmap pixmap = QPixmap::grabWidget(child,
            0, 0, child->width(), child->height());
        QByteArray itemData;
        QDataStream dataStream(&itemData, QIODevice::WriteOnly);
        dataStream << (long long)parent << parent->tabText(parent->currentIndex()) << (long long)child << parent->currentIndex();
        QMimeData *mimeData = new QMimeData;
        mimeData->setData("application/itemdata", itemData);
        QDrag *drag = new QDrag(this);
        drag->setMimeData(mimeData);
        drag->setPixmap(pixmap);
        parent->removeTab(parent->currentIndex());
        if (drag->exec(Qt::MoveAction, Qt::MoveAction) != Qt::MoveAction)
        {
            auto newTabWidget = new CustomTabWidget;
            newTabWidget->setAutoDelete(true);
            newTabWidget->addTab(child, strTab);
            newTabWidget->show();
            newTabWidget->move(QCursor::pos());
            newTabWidget->setCurrentIndex(0);
            m_pInsertMarkerLine->hide();
        }
    }
}

void CustomTabBar::mouseReleaseEvent(QMouseEvent *event)
{
    QTabBar::mouseReleaseEvent(event);
}

void CustomTabBar::dragMoveEvent(QDragMoveEvent *event)
{
    //显示效果可以在此添加
    m_pInsertMarkerLine->show();
    int index = tabAt(event->pos());
    auto rectTmp = tabRect(index);
    rectTmp.setWidth(rectTmp.width() / 2);
    if (rectTmp.contains(event->pos()))
    {
        m_pInsertMarkerLine->move(tabRect(index).topLeft());
    }
    else
    {
        m_pInsertMarkerLine->move(tabRect(index).topRight());
    }
}

void CustomTabBar::dragLeaveEvent(QDragLeaveEvent *event)
{
    m_pInsertMarkerLine->hide();
}

void CustomTabBar::dragEnterEvent(QDragEnterEvent *event)
{
    m_pInsertMarkerLine->show();
    event->acceptProposedAction();
}

void CustomTabBar::dropEvent(QDropEvent *event)
{
    if (event->mimeData()->hasFormat("application/itemdata"))
    {
        QByteArray itemData = event->mimeData()->data("application/itemdata");
        QDataStream dataStream(&itemData, QIODevice::ReadOnly);
        long long llPtrParent;
        QString strTab;
        long long llPtrChild;
        int nTabIndex;
        dataStream >> llPtrParent >> strTab >> llPtrChild >> nTabIndex;
        QWidget *child = (QWidget *)llPtrChild;
        auto parent = dynamic_cast<CustomTabWidget*>(parentWidget());
        if (parent && child)
        {
            int index = tabAt(event->pos());
            auto rectTmp = tabRect(index);
            rectTmp.setWidth(rectTmp.width() / 2);
            if (!rectTmp.contains(event->pos()))
            {
                index++;
            }
            parent->insertTab(index, child, strTab);
            setCurrentIndex(index);
            event->acceptProposedAction();
            m_pInsertMarkerLine->hide();
        }
    }
    else
    {
        event->ignore();
    }
}