/*=========================================================================

  Library:   CTK

  Copyright (c) Kitware Inc. 
  All rights reserved.
  Distributed under a BSD License. See LICENSE.txt file.

  This software is distributed "AS IS" WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the above copyright notice for more information.

=========================================================================*/

// Qt includes
#include <QApplication>
#include <QCleanlooksStyle>
#include <QDebug>
#include <QDesktopWidget>
#include <QLayout>
#include <QMouseEvent>
#include <QMenu>
#include <QPainter>
#include <QPointer>
#include <QPushButton>
#include <QStyle>
#include <QStyleOptionButton>
#include <QStylePainter>
#include <QToolBar>

// CTK includes
#include "ctkMenuButton.h"

//-----------------------------------------------------------------------------
class ctkMenuButtonPrivate : public ctkPrivate<ctkMenuButton>
{
public:
  CTK_DECLARE_PUBLIC(ctkMenuButton);
  ctkMenuButtonPrivate();

  QRect indicatorRect() const;
  bool ShowMenu;
};

//-----------------------------------------------------------------------------
ctkMenuButtonPrivate::ctkMenuButtonPrivate()
{
  this->ShowMenu = false;
}

//-----------------------------------------------------------------------------
QRect ctkMenuButtonPrivate::indicatorRect()const
{
  CTK_P(const ctkMenuButton);
  
  QStyleOptionButton option;
  p->initStyleOption(&option);

  QRect downArrowRect = p->style()->visualRect(option.direction, option.rect, option.rect);
  downArrowRect.setRect(downArrowRect.right() - 13, downArrowRect.top(),
                        14, downArrowRect.height());
  downArrowRect = p->style()->visualRect(option.direction, option.rect, downArrowRect);
  return downArrowRect;
}

//-----------------------------------------------------------------------------
ctkMenuButton::ctkMenuButton(QWidget* _parent)
  :QPushButton(_parent)
{
  CTK_INIT_PRIVATE(ctkMenuButton);
}

//-----------------------------------------------------------------------------
ctkMenuButton::ctkMenuButton(const QString& title, QWidget* _parent)
  :QPushButton(title, _parent)
{
  CTK_INIT_PRIVATE(ctkMenuButton);
}

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

//-----------------------------------------------------------------------------
QSize ctkMenuButton::minimumSizeHint()const
{
  QSize min = QPushButton::minimumSizeHint();
  return QSize(min.width() + 13, min.height());
}

//-----------------------------------------------------------------------------
QSize ctkMenuButton::sizeHint()const
{
  QSize buttonSizeHint = QPushButton::sizeHint();
  return QSize(buttonSizeHint.width() + 13, buttonSizeHint.height());
}

//-----------------------------------------------------------------------------
void ctkMenuButton::paintEvent(QPaintEvent * _event)
{
  Q_UNUSED(_event);
  CTK_D(ctkMenuButton);
  QStylePainter painter(this);
  QStyleOptionButton option;
  initStyleOption(&option);
  bool drawIndicatorBackground = 
    option.state & QStyle::State_Sunken || 
    option.state & QStyle::State_On;
  // Draw button
  option.features &= ~QStyleOptionButton::HasMenu;
  if (this->menu() && (this->menu()->isVisible() || d->ShowMenu))
    {
    option.state &= ~QStyle::State_Sunken;
    option.state |= QStyle::State_Raised;
    }
  painter.drawControl(QStyle::CE_PushButtonBevel, option);
  // is PE_PanelButtonCommand better ?
  //painter.drawPrimitive(QStyle::PE_PanelButtonCommand, option);
  QRect downArrowRect = d->indicatorRect();
  if (drawIndicatorBackground)
    {    
    // if the button is down, draw the part under the indicator up
    QPixmap cache = QPixmap(option.rect.size());
    cache.fill(Qt::transparent);
    QPainter cachePainter(&cache);
    option.state &= ~QStyle::State_Sunken;
    option.state |= QStyle::State_Raised;
    option.state &= ~QStyle::State_On;
    option.state |= QStyle::State_Off;
    //option.state &= ~QStyle::State_HasFocus;
    option.state &= ~QStyle::State_MouseOver;
    this->style()->drawControl(QStyle::CE_PushButtonBevel, &option, &cachePainter, this);
    painter.drawItemPixmap(downArrowRect, Qt::AlignLeft | Qt::AlignTop, cache.copy(downArrowRect)); 
    }

  // Separator
  // Freely inspired by the painting of CC_ComboBox in qcleanlooksstyle.cpp 
  
  QColor buttonColor = this->palette().button().color();
  QColor darkColor;
  darkColor.setHsv(buttonColor.hue(),
                   qMin(255, (int)(buttonColor.saturation()*1.9)),
                   qMin(255, (int)(buttonColor.value()*0.7)));
  painter.setPen(buttonColor.darker(130));
  int borderSize = 2;
  painter.drawLine(QPoint(downArrowRect.left() - 1, downArrowRect.top() + borderSize),
                   QPoint(downArrowRect.left() - 1, downArrowRect.bottom() - borderSize));
  painter.setPen(this->palette().light().color());
  painter.drawLine(QPoint(downArrowRect.left(), downArrowRect.top() + borderSize),
                   QPoint(downArrowRect.left(), downArrowRect.bottom() - borderSize));
  // Draw arrow
  QStyleOption indicatorOpt;
  indicatorOpt.init(this);
  indicatorOpt.rect = downArrowRect.adjusted(borderSize, borderSize, -borderSize, -borderSize);
  painter.drawPrimitive(QStyle::PE_IndicatorArrowDown, indicatorOpt);

  // Draw Icon & Text
  option.rect.setRight( downArrowRect.left());
  painter.drawControl(QStyle::CE_PushButtonLabel, option);
}

//-----------------------------------------------------------------------------
bool ctkMenuButton::hitButton(const QPoint & _pos)const
{
  CTK_D(const ctkMenuButton);
  return !d->indicatorRect().contains(_pos) 
    && this->QPushButton::hitButton(_pos);
}

//-----------------------------------------------------------------------------
void ctkMenuButton::initStyleOption(QStyleOptionButton* option)const
{
  this->QPushButton::initStyleOption(option);
}

//-----------------------------------------------------------------------------
void ctkMenuButton::mousePressEvent(QMouseEvent *e)
{
  CTK_D(ctkMenuButton);
  // we don't want to open the menu if the mouse is clicked anywhere on
  // the button, only if it's clicked on the indecator
  this->disconnect(this,SIGNAL(pressed()), this, SLOT(_q_popupPressed()));
  this->QPushButton::mousePressEvent(e);
  if (e->isAccepted())
    {
    return;
    }
  if (d->indicatorRect().contains(e->pos()))
    {
    d->ShowMenu = true;
    this->showMenu();
    d->ShowMenu = false;
    e->accept();
    }
}