//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) Ceetron Solutions 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 "cafPdmUiCheckBoxDelegate.h"

#include <QApplication>
#include <QMouseEvent>


namespace caf
{


//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
PdmUiCheckBoxDelegate::PdmUiCheckBoxDelegate(QObject* pParent)
    : QStyledItemDelegate(pParent)
{
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
PdmUiCheckBoxDelegate::~PdmUiCheckBoxDelegate()
{
}


//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void PdmUiCheckBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    QStyleOptionViewItemV4 viewItemOption(option);

    const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
    QRect newRect = QStyle::alignedRect(option.direction, Qt::AlignCenter,
        QSize(option.decorationSize.width() + 5,option.decorationSize.height()),
        QRect(option.rect.x() + textMargin, option.rect.y(),
        option.rect.width() - (2 * textMargin), option.rect.height()));
    viewItemOption.rect = newRect;

    QStyledItemDelegate::paint(painter, viewItemOption, index);
}


//--------------------------------------------------------------------------------------------------
/// Returns true to avoid other factories to produce editors for a check box
//--------------------------------------------------------------------------------------------------
bool PdmUiCheckBoxDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    Q_ASSERT(event);
    Q_ASSERT(model);

    // make sure that the item is checkable
    Qt::ItemFlags flags = model->flags(index);
    if (!(flags & Qt::ItemIsUserCheckable) || !(flags & Qt::ItemIsEnabled))
        return false;

    // make sure that we have a check state
    QVariant value = index.data(Qt::CheckStateRole);
    if (!value.isValid())
        return false;

    // make sure that we have the right event type
    if (event->type() == QEvent::MouseButtonRelease)
    {
        const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
        QRect checkRect = QStyle::alignedRect(option.direction, Qt::AlignCenter,
            option.decorationSize,
            QRect(option.rect.x() + (2 * textMargin), option.rect.y(),
            option.rect.width() - (2 * textMargin),
            option.rect.height()));
    
        if (!checkRect.contains(static_cast<QMouseEvent*>(event)->pos()))
            return true;
    }
    else if (event->type() == QEvent::KeyPress)
    {
        if (static_cast<QKeyEvent*>(event)->key() != Qt::Key_Space && static_cast<QKeyEvent*>(event)->key() != Qt::Key_Select)
            return true;
    }
    else
    {
        return true;
    }

    Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked ? Qt::Unchecked : Qt::Checked);
    return model->setData(index, state, Qt::CheckStateRole);
}


} // end namespace caf