//////////////////////////////////////////////////////////////////////////////
// nitrogenbutton.cpp
// -------------------
// 
// Copyright (c) 2006, 2007 Riccardo Iaconelli <riccardo@kde.org>
// Copyright (c) 2006, 2007 Casper Boemann <cbr@boemann.dk>
// Copyright (c) 2009, 2010 Hugo Pereira Da Costa <hugo.pereira@free.fr>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.                 
//////////////////////////////////////////////////////////////////////////////

#include <cmath>

#include <QPainterPath>
#include <QPainter>
#include <QPen>

#include <KColorUtils>
#include <KColorScheme>
#include <kcommondecoration.h>
#include "nitrogenbutton.h"
#include "nitrogenclient.h"
#include "nitrogen.h"

namespace Nitrogen
{
  //_______________________________________________
  NitrogenButton::NitrogenButton(NitrogenClient &parent,
    const QString& tip, ButtonType type):
    KCommonDecorationButton((::ButtonType)type, &parent), 
    client_(parent), 
    helper_( parent.helper() ), 
    type_(type), 
    colorCacheInvalid_(true)
  {
    setAutoFillBackground(false);
    setAttribute(Qt::WA_OpaquePaintEvent, false);
    
    {
      unsigned int size( client_.configuration().buttonSize() );
      setFixedSize( size, size );
    }
    
    setCursor(Qt::ArrowCursor);
    setToolTip(tip);
  }
  
  //_______________________________________________
  NitrogenButton::~NitrogenButton()
  {}
  
  //declare function from Nitrogenclient.cpp
  QColor reduceContrast(const QColor &c0, const QColor &c1, double t);
   
  //_______________________________________________
  QColor NitrogenButton::buttonDetailColor(const QPalette &palette)
  {
    
    if (client_.isActive()) return palette.color(QPalette::Active, QPalette::ButtonText);
    else {
      
      if (colorCacheInvalid_) 
      {
        QColor ab = palette.color(QPalette::Active, QPalette::Button);
        QColor af = palette.color(QPalette::Active, QPalette::ButtonText);
        QColor nb = palette.color(QPalette::Inactive, QPalette::Button);
        QColor nf = palette.color(QPalette::Inactive, QPalette::ButtonText);
          
        colorCacheInvalid_ = false;
        cachedButtonDetailColor_ = reduceContrast(nb, nf, qMax(qreal(2.5), KColorUtils::contrastRatio(ab, KColorUtils::mix(ab, af, 0.4))));
      }
      
      return cachedButtonDetailColor_;
    }
  }
    
  //___________________________________________________
  QSize NitrogenButton::sizeHint() const
  { 
    unsigned int size( client_.configuration().buttonSize() );
    return QSize( size, size );
  }
    
  //___________________________________________________
  void NitrogenButton::enterEvent(QEvent *e)
  {
    KCommonDecorationButton::enterEvent(e);
    if (status_ != Nitrogen::Pressed) status_ = Nitrogen::Hovered;
    update();
  }
    
  //___________________________________________________
  void NitrogenButton::leaveEvent(QEvent *e)
  {
    KCommonDecorationButton::leaveEvent(e);
    status_ = Nitrogen::Normal;
    update();
  }
    
  //___________________________________________________
  void NitrogenButton::mousePressEvent(QMouseEvent *e)
  {
    
    status_ = Nitrogen::Pressed;
    update();
    
    KCommonDecorationButton::mousePressEvent(e);
  }
  
  //___________________________________________________
  void NitrogenButton::mouseReleaseEvent(QMouseEvent *e)
  {
    status_ = Nitrogen::Normal;
    update();
    
    KCommonDecorationButton::mouseReleaseEvent(e);
  }
  
  //___________________________________________________
  void NitrogenButton::paintEvent(QPaintEvent *event)
  {
    
    QPainter painter(this);
    painter.setClipRect(this->rect().intersected( event->rect() ) );

    QPalette palette = NitrogenButton::palette(); 
    
    if( client_.isActive() ) palette.setCurrentColorGroup(QPalette::Active);
    else palette.setCurrentColorGroup(QPalette::Inactive);
            
    client_.renderWindowBackground( &painter, rect(), this, palette );
    
    // draw dividing line
    painter.setRenderHints(QPainter::Antialiasing);
    QRect frame = client_.widget()->rect();
    int x = -this->geometry().x()+1;
    int w = frame.width()-2;
    
    const int titleHeight = client_.layoutMetric(KCommonDecoration::LM_TitleHeight);
    QColor color = ( client_.configuration().overwriteColors() ) ? 
      palette.window().color() : 
      client_.options()->color( KDecorationDefines::ColorTitleBar, client_.isActive());

    QColor light = helper_.calcLightColor( color );
    QColor dark = helper_.calcDarkColor( color );
    
    dark.setAlpha(120);
    
    if(client_.isActive() && client_.configuration().drawSeparator() ) 
    { helper_.drawSeparator(&painter, QRect(x, titleHeight-1.5, w, 2), color, Qt::Horizontal); }
    
    if (type_ == ButtonMenu) 
    {
      
      // we paint the mini icon using 0.72xbuttonsize() as a scale
      // this roughtly corresponds to 16 for default button size
      double scale = 0.72;
      const QPixmap& pixmap( client_.icon().pixmap( scale*width() ) );
      double offset = 0.5*(width()-pixmap.width() );
      painter.drawPixmap(offset, offset, pixmap );
      return;
    }
        
    color = buttonDetailColor(palette);
    if(status_ == Nitrogen::Hovered || status_ == Nitrogen::Pressed) 
    {
      if(type_ == ButtonClose) color = KColorScheme(palette.currentColorGroup()).foreground(KColorScheme::NegativeText).color();
      else color = KColorScheme(palette.currentColorGroup()).decoration(KColorScheme::HoverColor).color();
    }
    
    // translate buttons up if window is not maximized
    if(client_.maximizeMode() == NitrogenClient::MaximizeRestore)
    { painter.translate( 0, -1 ); }

    // button shape color
    QColor bt = client_.configuration().overwriteColors() ?
      palette.window().color():
      client_.options()->color(KDecorationDefines::ColorTitleBar, client_.isActive());

    // draw button shape
    painter.drawPixmap(0, 0, helper_.windecoButton(bt, status_ == Nitrogen::Pressed, client_.configuration().buttonType(), (21.0*client_.configuration().buttonSize())/22 ) );
    
    // draw glow on hover
    if( status_ == Nitrogen::Hovered ) 
    { painter.drawPixmap(0, 0, helper_.windecoButtonGlow(color, (21.0*client_.configuration().buttonSize())/22)); }
    
    // draw button icon
    if (client_.isActive()) 
    {
      
      QLinearGradient lg = helper_.decoGradient( QRect( 4, 4, 13, 13 ), color);
      painter.setRenderHints(QPainter::Antialiasing);
      qreal width( client_.configuration().buttonType() == NitrogenConfiguration::ButtonKde43 ? 1.4:2.2 );

      painter.setBrush(Qt::NoBrush);
      if( client_.configuration().buttonType() == NitrogenConfiguration::ButtonKde42 )
      {
        
        painter.setPen(QPen(lg, width, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        
      } else {
        
        painter.setPen(QPen(color, width, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        
      }
      drawIcon(&painter, palette, type_);
    
    } else {

      // outlined mode
      QPixmap pixmap(size());
      pixmap.fill(Qt::transparent);
      QPainter pp(&pixmap);
      pp.setRenderHints(QPainter::Antialiasing);
      pp.setBrush(Qt::NoBrush);
      pp.setPen(QPen(color, 3.0, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
      drawIcon(&pp, palette, type_);
      
      pp.setCompositionMode(QPainter::CompositionMode_DestinationOut);
      pp.setPen(QPen(color, 1.0, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
      drawIcon(&pp, palette, type_);
      
      painter.drawPixmap(QPoint(0,0), pixmap);
 
    }
  }
  
  //___________________________________________________
  void NitrogenButton::drawIcon(QPainter *painter, QPalette &palette, ButtonType &type)
  {
    
    painter->save();    
    painter->setWindow( 0, 0, 22, 22 );
    
    QPen newPen = painter->pen();
    switch(type)
    {
      
      case ButtonSticky:
      if(isChecked()) {
        newPen.setColor(KColorScheme(palette.currentColorGroup()).decoration(KColorScheme::HoverColor).color());
        painter->setPen(newPen);
      }
      painter->drawPoint(QPointF(10.5,10.5));
      break;
      
      case ButtonHelp:
      painter->translate(1.5, 1.5);
      painter->drawArc(7,5,4,4,135*16, -180*16);
      painter->drawArc(9,8,4,4,135*16,45*16);
      painter->drawPoint(9,12);
      painter->translate(-1.5, -1.5);
      break;
      
      case ButtonMin:
      painter->drawLine(QPointF( 7.5, 9.5), QPointF(10.5,12.5));
      painter->drawLine(QPointF(10.5,12.5), QPointF(13.5, 9.5));
      break;
      
      case ButtonMax:
      switch(client_.maximizeMode())
      {
        case NitrogenClient::MaximizeRestore:
        case NitrogenClient::MaximizeVertical:
        case NitrogenClient::MaximizeHorizontal:
        painter->drawLine(QPointF( 7.5,11.5), QPointF(10.5, 8.5));
        painter->drawLine(QPointF(10.5, 8.5), QPointF(13.5,11.5));
        break;
        
        case NitrogenClient::MaximizeFull:
        {
          painter->translate(1.5, 1.5);
          QPoint points[4] = {QPoint(9, 6), QPoint(12, 9), QPoint(9, 12), QPoint(6, 9)};
          painter->drawPolygon(points, 4);
          painter->translate(-1.5, -1.5);
          break;
        }
      }
      break;
      
      case ButtonClose:
      painter->drawLine(QPointF( 7.5,7.5), QPointF(13.5,13.5));
      painter->drawLine(QPointF(13.5,7.5), QPointF( 7.5,13.5));
      break;
      
      case ButtonAbove:
      if(isChecked()) {
        QPen newPen = painter->pen();
        newPen.setColor(KColorScheme(palette.currentColorGroup()).decoration(KColorScheme::HoverColor).color());
        painter->setPen(newPen);
      }
      
      painter->drawLine(QPointF( 7.5,14), QPointF(10.5,11));
      painter->drawLine(QPointF(10.5,11), QPointF(13.5,14));
      painter->drawLine(QPointF( 7.5,10), QPointF(10.5, 7));
      painter->drawLine(QPointF(10.5, 7), QPointF(13.5,10));
      break;
      
      case ButtonBelow:
      if(isChecked()) {
        QPen newPen = painter->pen();
        newPen.setColor(KColorScheme(palette.currentColorGroup()).decoration(KColorScheme::HoverColor).color());
        painter->setPen(newPen);
      }
      
      painter->drawLine(QPointF( 7.5,11), QPointF(10.5,14));
      painter->drawLine(QPointF(10.5,14), QPointF(13.5,11));
      painter->drawLine(QPointF( 7.5, 7), QPointF(10.5,10));
      painter->drawLine(QPointF(10.5,10), QPointF(13.5, 7));
      break;
      
      case ButtonShade:
      if (!isChecked()) 
      {
        
        // shade button
        painter->drawLine(QPointF( 7.5, 7.5), QPointF(10.5,10.5));
        painter->drawLine(QPointF(10.5,10.5), QPointF(13.5, 7.5));
        painter->drawLine(QPointF( 7.5,13.0), QPointF(13.5,13.0));
        
      } else { 
        
        // unshade button
        painter->drawLine(QPointF( 7.5,10.5), QPointF(10.5, 7.5));
        painter->drawLine(QPointF(10.5, 7.5), QPointF(13.5,10.5));
        painter->drawLine(QPointF( 7.5,13.0), QPointF(13.5,13.0));
        
      }
      break;
      
      default:
      break;
    }
    painter->restore();
    return;
  }
    
}