#include "maskManager.h"
#include <QEvent>

MaskManager* MaskManager::m_instance = nullptr;

void MaskManager::initialize(QWidget* mainWindow)
{
    if(!m_instance)
        m_instance = new MaskManager(mainWindow);
}

MaskManager* MaskManager::instance()
{
    Q_ASSERT(m_instance);
    return m_instance;
}

MaskManager::MaskManager(QWidget* mainWindow)
    : QObject(mainWindow)
    , m_mainWindow(mainWindow)
{
    m_maskLayer = new QWidget(m_mainWindow);
    //m_maskLayer->setAttribute(Qt::WA_TransparentForMouseEvents, true);
    m_maskLayer->setStyleSheet("background:rgba(112,128,144,180);");
    m_maskLayer->hide();

    m_mainWindow->installEventFilter(this); //在Qt中，时间过滤会按照install的顺序反向执行，过程中，对于同一类型事件，任何一个过滤器返回true，表示事件被处理，后续过滤器和事件函数不会再被调用
}

bool MaskManager::eventFilter(QObject* obj, QEvent* event)
{
    if(obj == m_mainWindow && event->type() == QEvent::Resize)
    {
        if(m_maskLayer && m_maskLayer->isVisible())
            m_maskLayer->setGeometry(m_mainWindow->rect());
    }
    return QObject::eventFilter(obj, event);
}

void MaskManager::showMask(QWidget* requester)
{
    if(m_activeRequests.isEmpty())
    {
        m_maskLayer->setGeometry(m_mainWindow->rect());
        //m_maskLayer->raise(); //显示在最上层，后续打开的同级子窗口依然在其之上
        m_maskLayer->show();
    }
    m_activeRequests.insert(requester);
}

void MaskManager::hideMask(QWidget* requester)
{
    m_activeRequests.remove(requester);
    if(m_activeRequests.isEmpty())
        m_maskLayer->hide();
}