//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) 2011-2013 Ceetron AS
//
//   This library may be used under the terms of either the GNU General Public License or
//   the GNU Lesser General Public License as follows:
//
//   GNU General Public License Usage
//   This library is free software: you can redistribute it and/or modify
//   it under the terms of the GNU General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or
//   FITNESS FOR A PARTICULAR PURPOSE.
//
//   See the GNU General Public License at <<http://www.gnu.org/licenses/gpl.html>>
//   for more details.
//
//   GNU Lesser General Public License Usage
//   This library is free software; you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation; either version 2.1 of the License, or
//   (at your option) any later version.
//
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or
//   FITNESS FOR A PARTICULAR PURPOSE.
//
//   See the GNU Lesser General Public License at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
//   for more details.
//
//##################################################################################################

#include "cafMouseState.h"
#include "cvfBase.h"
#include "cvfMath.h"

#include <QGraphicsSceneMouseEvent>
#include <QMouseEvent>

#include <cmath>

namespace caf
{
//==================================================================================================
///
/// \class cvfqt::QtMouseState
/// \ingroup GuiQt
///
/// Helper class for storing mouse positions and button states.
/// Should be reset whenever widget looses focus.
///
//==================================================================================================

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QtMouseState::QtMouseState()
{
    m_cleanButtonClickTolerance = 3;

    reset();
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void QtMouseState::updateFromMouseEvent( QMouseEvent* event )
{
    // Always update with current state
    m_mouseButtonState      = event->buttons();
    m_keyboardModifierFlags = event->modifiers();

    // Now do the events themselves

    // Mouse press events
    if ( event->type() == QEvent::MouseButtonPress )
    {
        // Start by clearing them
        m_cleanButtonPressButton = Qt::NoButton;
        m_cleanButtonClickButton = Qt::NoButton;
        ;
        m_cleanButtonPressPosX = cvf::UNDEFINED_INT;
        m_cleanButtonPressPosY = cvf::UNDEFINED_INT;

        Qt::MouseButton buttonPressed = event->button();

        if ( numMouseButtonsInState( m_mouseButtonState ) == 1 )
        {
            m_cleanButtonPressButton = buttonPressed;
            m_cleanButtonPressPosX   = event->x();
            m_cleanButtonPressPosY   = event->y();
        }
    }

    // Mouse button release events
    else if ( event->type() == QEvent::MouseButtonRelease )
    {
        // Clear it now, might set it later
        m_cleanButtonClickButton = Qt::NoButton;

        Qt::MouseButton buttonReleased = event->button();

        // Check if we have a clean press/release sequence
        if ( m_cleanButtonPressButton == buttonReleased && m_cleanButtonPressPosX != cvf::UNDEFINED_INT &&
             m_cleanButtonPressPosY != cvf::UNDEFINED_INT )
        {
            // We have a candidate, check if movement is within tolerance
            if ( cvf::Math::abs( double( ( m_cleanButtonPressPosX - event->x() ) ) ) <= m_cleanButtonClickTolerance &&
                 cvf::Math::abs( double( ( m_cleanButtonPressPosY - event->y() ) ) ) <= m_cleanButtonClickTolerance )
            {
                m_cleanButtonClickButton = buttonReleased;
            }

            m_cleanButtonPressButton = Qt::NoButton;
            ;
            m_cleanButtonPressPosX = cvf::UNDEFINED_INT;
            m_cleanButtonPressPosY = cvf::UNDEFINED_INT;
        }
    }

    else if ( event->type() == QEvent::MouseMove )
    {
        // For now nothing to do
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void QtMouseState::updateFromMouseEvent( QGraphicsSceneMouseEvent* event )
{
    // Always update with current state
    m_mouseButtonState      = event->buttons();
    m_keyboardModifierFlags = event->modifiers();

    // Now do the events themselves
    if ( event->type() == QEvent::GraphicsSceneMousePress )
    {
        // Start by clearing them
        m_cleanButtonPressButton = Qt::NoButton;
        m_cleanButtonClickButton = Qt::NoButton;
        ;
        m_cleanButtonPressPosX = cvf::UNDEFINED_INT;
        m_cleanButtonPressPosY = cvf::UNDEFINED_INT;

        Qt::MouseButton buttonPressed = event->button();

        if ( numMouseButtonsInState( m_mouseButtonState ) == 1 )
        {
            m_cleanButtonPressButton = buttonPressed;
            m_cleanButtonPressPosX   = (int)event->scenePos().x();
            m_cleanButtonPressPosY   = (int)event->scenePos().y();
        }
    }

    // Mouse button release events
    else if ( event->type() == QEvent::GraphicsSceneMouseRelease )
    {
        // Clear it now, might set it later
        m_cleanButtonClickButton = Qt::NoButton;

        Qt::MouseButton buttonReleased = event->button();

        // Check if we have a clean press/release sequence
        if ( m_cleanButtonPressButton == buttonReleased && m_cleanButtonPressPosX != cvf::UNDEFINED_INT &&
             m_cleanButtonPressPosY != cvf::UNDEFINED_INT )
        {
            // We have a candidate, check if movement is within tolerance
            if ( cvf::Math::abs( double( ( m_cleanButtonPressPosX - event->scenePos().x() ) ) ) <=
                     m_cleanButtonClickTolerance &&
                 cvf::Math::abs( double( ( m_cleanButtonPressPosY - event->scenePos().y() ) ) ) <=
                     m_cleanButtonClickTolerance )
            {
                m_cleanButtonClickButton = buttonReleased;
            }

            m_cleanButtonPressButton = Qt::NoButton;
            ;
            m_cleanButtonPressPosX = cvf::UNDEFINED_INT;
            m_cleanButtonPressPosY = cvf::UNDEFINED_INT;
        }
    }

    else if ( event->type() == QEvent::GraphicsSceneMouseMove )
    {
        // For now nothing to do
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void QtMouseState::reset()
{
    m_mouseButtonState = Qt::NoButton;

    m_cleanButtonPressButton = Qt::NoButton;
    m_cleanButtonPressPosX   = cvf::UNDEFINED_INT;
    m_cleanButtonPressPosY   = cvf::UNDEFINED_INT;
    m_cleanButtonClickButton = Qt::NoButton;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
Qt::MouseButtons QtMouseState::mouseButtonState() const
{
    return m_mouseButtonState;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
Qt::KeyboardModifiers QtMouseState::keyboardModifierFlags() const
{
    return m_keyboardModifierFlags;
}

//--------------------------------------------------------------------------------------------------
/// Get button that was cleanly clicked if any
//--------------------------------------------------------------------------------------------------
Qt::MouseButton QtMouseState::cleanButtonClickButton() const
{
    return m_cleanButtonClickButton;
}

//--------------------------------------------------------------------------------------------------
/// Static helper function to determine the number of mouse buttons pressed
//--------------------------------------------------------------------------------------------------
int QtMouseState::numMouseButtonsInState( Qt::MouseButtons buttonState )
{
    int iNum = 0;

    if ( buttonState & Qt::LeftButton ) iNum++;
    if ( buttonState & Qt::RightButton ) iNum++;
    if ( buttonState & Qt::MiddleButton ) iNum++;

    return iNum;
}

} // namespace caf