#include "MouseEventSpy.h"

#include <QEvent>
#include <QGuiApplication>
#include <QDebug>

MouseEventSpy::MouseEventSpy(QObject *parent) : QObject(parent)
{
    qDebug() << "created Instance";
}

/**
 * Implements the SINGLETON PATTERN
 */
MouseEventSpy* MouseEventSpy::instance()
{
    static MouseEventSpy* inst;
    if (inst == nullptr)
    {
        // If no instance has been created yet, create a new and install it as event filter.
        // Uppon first use of the instance, it will automatically
        // install itself in the QGuiApplication
        inst = new MouseEventSpy();
        QGuiApplication* app = qGuiApp;
        app->installEventFilter(inst);
    }
    return inst;
}

/**
 * This is the method is necessary for 'installEventFilter'
 */
bool MouseEventSpy::eventFilter(QObject* watched, QEvent* event)
{
    QEvent::Type t = event->type();
    if ((t == QEvent::MouseButtonDblClick
         || t == QEvent::MouseButtonPress
         || t == QEvent::MouseButtonRelease
         || t == QEvent::MouseMove)
            && event->spontaneous() // Take only mouse events from outside of Qt
            )
        emit mouseEventDetected();
        qDebug("MouseEvent detected.");
    return QObject::eventFilter(watched, event);
}