/*************************************************************************
 * Copyright (C) 2014 by Hugo Pereira Da Costa <hugo.pereira@free.fr>    *
 *                                                                       *
 * This program 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 2 of the License, or     *
 * (at your option) any later version.                                   *
 *                                                                       *
 * This program 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 for more details.                          *
 *                                                                       *
 * You should have received a copy of the GNU General Public License     *
 * along with this program; if not, write to the                         *
 * Free Software Foundation, Inc.,                                       *
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA .        *
 *************************************************************************/

#include "adwaitahelper.h"

#include "adwaita.h"
#include "fakeadwaitastyleconfigdata.h"

#include <QApplication>
#include <QPainter>
#include <QLibrary>

#if ADWAITA_HAVE_X11 && QT_VERSION < 0x050000
#include <X11/Xlib-xcb.h>
#endif

namespace Adwaita
{

    //* contrast for arrow and treeline rendering
    static const qreal arrowShade = 0.15;

    //____________________________________________________________________
    Helper::Helper( )
    { init(); }

    //____________________________________________________________________
    #if ADWAITA_USE_KDE4
    Helper::Helper( const QByteArray& name )
    { init(); }
    #endif

    //____________________________________________________________________
    QColor Helper::frameOutlineColor( const QPalette& palette, bool mouseOver, bool hasFocus, qreal opacity, AnimationMode mode ) const
    {

        // I really can't remember why we have differed these two cases. This seems right.
        return inputOutlineColor(palette, mouseOver, hasFocus, opacity, mode);

    }

    QColor Helper::inputOutlineColor(const QPalette &palette, bool mouseOver, bool hasFocus, qreal opacity, AnimationMode mode) const
    {
        QColor outline( buttonOutlineColor( palette, mouseOver, false ) );
        QColor focus( palette.color( QPalette::Active, QPalette::Highlight ) );


        // focus takes precedence over hover
        if( mode == AnimationFocus )
        {

            outline = mix( outline, focus, opacity );

        } else if( hasFocus ) {

            outline = focusColor( palette );

        }

        return outline;
    }

    //____________________________________________________________________
    QColor Helper::focusOutlineColor( const QPalette& palette ) const
    { return mix( focusColor( palette ), palette.color( QPalette::WindowText ), 0.15 ); }

    //____________________________________________________________________
    QColor Helper::hoverOutlineColor( const QPalette& palette ) const
    { return mix( hoverColor( palette ), palette.color( QPalette::WindowText ), 0.15 ); }

    //____________________________________________________________________
    QColor Helper::buttonFocusOutlineColor( const QPalette& palette ) const
    { return mix( focusColor( palette ), palette.color( QPalette::ButtonText ), 0.15 ); }

    //____________________________________________________________________
    QColor Helper::buttonHoverOutlineColor( const QPalette& palette ) const
    { return mix( hoverColor( palette ), palette.color( QPalette::ButtonText ), 0.15 ); }

    //____________________________________________________________________
    QColor Helper::sidePanelOutlineColor( const QPalette& palette, bool hasFocus, qreal opacity, AnimationMode mode ) const
    {

        QColor outline( palette.color( QPalette::Inactive, QPalette::Highlight ) );
        QColor focus( palette.color( QPalette::Active, QPalette::Highlight ) );

        if( mode == AnimationFocus )
        {

            outline = mix( outline, focus, opacity );

        } else if( hasFocus ) {

            outline = focus;

        }

        return outline;

    }

    //____________________________________________________________________
    QColor Helper::frameBackgroundColor( const QPalette& palette, QPalette::ColorGroup group ) const
    { return mix( palette.color( group, QPalette::Window ), palette.color( group, QPalette::Base ), 0.3 ); }

    //____________________________________________________________________
    QColor Helper::arrowColor( const QPalette& palette, QPalette::ColorGroup group, QPalette::ColorRole role ) const
    {
        switch( role )
        {
            case QPalette::Text: return mix( palette.color( group, QPalette::Text ), palette.color( group, QPalette::Base ), arrowShade );
            case QPalette::WindowText: return mix( palette.color( group, QPalette::WindowText ), palette.color( group, QPalette::Window ), arrowShade );
            case QPalette::ButtonText: return mix( palette.color( group, QPalette::ButtonText ), palette.color( group, QPalette::Button ), arrowShade );
            default: return palette.color( group, role );
        }

    }

    //____________________________________________________________________
    QColor Helper::arrowColor( const QPalette& palette, bool mouseOver, bool hasFocus, qreal opacity, AnimationMode mode ) const
    {

        Q_UNUSED(mouseOver);
        Q_UNUSED(hasFocus);
        Q_UNUSED(opacity);
        Q_UNUSED(mode);
        return palette.text().color();

    }

    //____________________________________________________________________
    QColor Helper::buttonOutlineColor( const QPalette& palette, bool mouseOver, bool hasFocus, qreal opacity, AnimationMode mode ) const
    {

        QColor outline( mix( palette.color( QPalette::Button ), palette.color( QPalette::Shadow ), 0.3 ) );

        return outline;

    }

    //____________________________________________________________________
    QColor Helper::buttonBackgroundColor( const QPalette& palette, bool mouseOver, bool hasFocus, bool sunken, qreal opacity, AnimationMode mode ) const
    {

        QColor background( palette.color( QPalette::Button ) );

        if ( mode == AnimationPressed) {
            background = background.darker(100 + 15.0 * opacity);
        } else if ( sunken ) {
            background = background.darker(115);
        } else if( mode == AnimationHover )
        {
            background = mix(background, background.lighter( 120 ), opacity);
            //if( hasFocus ) background = mix( focus, hover, opacity );

        } else if( mouseOver ) {

            background = background.lighter( 120 );
            //background = hoverColor( palette );
        }

        return background;

    }

    //____________________________________________________________________
    QColor Helper::toolButtonColor( const QPalette& palette, bool mouseOver, bool hasFocus, bool sunken, qreal opacity, AnimationMode mode ) const
    {

        if (sunken || (mode != AnimationNone && mode != AnimationHover) )
            return buttonBackgroundColor(palette, mouseOver, hasFocus, sunken, opacity, mode);
        return Qt::transparent;

    }

    //____________________________________________________________________
    QColor Helper::sliderOutlineColor( const QPalette& palette, bool mouseOver, bool hasFocus, qreal opacity, AnimationMode mode ) const
    {

        QColor outline( mix( palette.color( QPalette::Window ), palette.color( QPalette::Shadow ), 0.5 ) );

        // hover takes precedence over focus
        if( mode == AnimationHover )
        {

            QColor hover( hoverColor( palette ) );
            QColor focus( focusColor( palette ) );
            if( hasFocus ) outline = mix( focus, hover, opacity );
            else outline = mix( outline, hover, opacity );

        } else if( mouseOver ) {

            outline = hoverColor( palette );

        } else if( mode == AnimationFocus ) {

            QColor focus( focusColor( palette ) );
            outline = mix( outline, focus, opacity );

        } else if( hasFocus ) {

            outline = focusColor( palette );

        }

        return outline;

    }

    //____________________________________________________________________
    QColor Helper::scrollBarHandleColor( const QPalette& palette, bool mouseOver, bool hasFocus, qreal opacity, AnimationMode mode ) const
    {

        QColor color( alphaColor( palette.color( QPalette::WindowText ), 0.5 ) );

        // hover takes precedence over focus
        if( mode == AnimationHover )
        {

            QColor hover( hoverColor( palette ) );
            QColor focus( focusColor( palette ) );
            if( hasFocus ) color = mix( focus, hover, opacity );
            else color = mix( color, hover, opacity );

        } else if( mouseOver ) {

            color = hoverColor( palette );

        } else if( mode == AnimationFocus ) {

            QColor focus( focusColor( palette ) );
            color = mix( color, focus, opacity );

        } else if( hasFocus ) {

            color = focusColor( palette );

        }

        return color;

    }

    //______________________________________________________________________________
    QColor Helper::checkBoxIndicatorColor( const QPalette& palette, bool mouseOver, bool active, qreal opacity, AnimationMode mode ) const
    {

        Q_UNUSED(mouseOver);
        Q_UNUSED(active);
        Q_UNUSED(opacity);
        Q_UNUSED(mode);
        return palette.text().color();

    }

    //______________________________________________________________________________
    QColor Helper::separatorColor( const QPalette& palette ) const
    { return mix( palette.color( QPalette::Window ), palette.color( QPalette::WindowText ), 0.25 ); }

    //____________________________________________________________________
    QColor Helper::headerTextColor( const QPalette& palette, const QStyle::State state ) const
    {
        QColor col(palette.color(QPalette::WindowText));

        if (state & QStyle::State_Enabled)
        {
             if (state & QStyle::State_Sunken)
                return alphaColor( col, 0.9 );
             else if (state & QStyle::State_MouseOver)
                return alphaColor( col, 0.7 );
        }
        return alphaColor( col, 0.5 );
    }

    QColor Helper::tabBarColor(const QPalette &palette, const QStyle::State state) const
    {

        QColor background( mix(palette.window().color(), palette.shadow().color(), 0.15) );
        if (!(state & QStyle::State_Enabled))
            background = background.lighter(115);
        if (!(state & QStyle::State_Active))
            background = background.lighter(115);
        return background;

    }

    //______________________________________________________________________________
    QPalette Helper::disabledPalette( const QPalette& source, qreal ratio ) const
    {

        QPalette copy( source );

        const QList<QPalette::ColorRole> roles = { QPalette::Background, QPalette::Highlight, QPalette::WindowText, QPalette::ButtonText, QPalette::Text, QPalette::Button };
        foreach( const QPalette::ColorRole& role, roles )
        { copy.setColor( role, mix( source.color( QPalette::Active, role ), source.color( QPalette::Disabled, role ), 1.0-ratio ) ); }

        return copy;
    }

    //____________________________________________________________________
    QColor Helper::alphaColor( QColor color, qreal alpha ) const
    {
        if( alpha >= 0 && alpha < 1.0 )
        { color.setAlphaF( alpha*color.alphaF() ); }
        return color;
    }

    //______________________________________________________________________________
    void Helper::renderDebugFrame( QPainter* painter, const QRect& rect ) const
    {
        painter->save();
        painter->setRenderHints( QPainter::Antialiasing );
        painter->setBrush( Qt::NoBrush );
        painter->setPen( Qt::red );
        painter->drawRect( QRectF( rect ).adjusted( 0.5, 0.5, -0.5, -0.5 ) );
        painter->restore();
    }

    //______________________________________________________________________________
    void Helper::renderFocusRect( QPainter* painter, const QRect& rect, const QColor& color, const QColor& outline, Sides sides ) const
    {
        if( !color.isValid() ) return;

        painter->save();
        painter->setRenderHints( QPainter::Antialiasing );
        painter->setBrush( color );

        if( !( outline.isValid() && sides ) )
        {

            painter->setPen( Qt::NoPen );
            painter->drawRect( rect );

        } else {

            painter->setClipRect( rect );

            QRectF copy( rect );
            copy.adjust( 0.5, 0.5, -0.5, -0.5 );

            qreal radius( frameRadius( -1.0 ) );
            if( !(sides&SideTop) ) copy.adjust( 0, -radius, 0, 0 );
            if( !(sides&SideBottom) ) copy.adjust( 0, 0, 0, radius );
            if( !(sides&SideLeft) ) copy.adjust( -radius, 0, 0, 0 );
            if( !(sides&SideRight) ) copy.adjust( 0, 0, radius, 0 );

            painter->setPen( outline );
            // painter->setBrush( Qt::NoBrush );
            painter->drawRoundedRect( copy, radius, radius );

        }

        painter->restore();
        return;
    }

    //______________________________________________________________________________
    void Helper::renderFocusLine( QPainter* painter, const QRect& rect, const QColor& color ) const
    {
        if( !color.isValid() ) return;

        painter->save();

        QPen pen(color, 1);
        pen.setStyle(Qt::DotLine);

        painter->setRenderHint( QPainter::Antialiasing, false );
        painter->setPen( pen );
        painter->setBrush( Qt::NoBrush );

        painter->drawRoundedRect( rect, 1, 1 );

        painter->restore();
    }

    //______________________________________________________________________________
    void Helper::renderFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor& outline, bool hasFocus ) const
    {

        painter->setRenderHint( QPainter::Antialiasing );

        QRectF frameRect( rect.adjusted( 1, 1, -1, -1 ) );
        qreal radius( frameRadius() );

        // set pen
        if( outline.isValid() )
        {

            if (hasFocus) {
                painter->setPen( QPen( outline, 2 ) );
                frameRect.adjust(0.5, 0.5, -0.5, -0.5);
            }
            else {
                painter->setPen( outline );
            }
            frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );
            radius = qMax( radius - 1, qreal( 0.0 ) );

        } else {

            painter->setPen( Qt::NoPen );

        }

        // set brush
        if( color.isValid() ) painter->setBrush( color );
        else painter->setBrush( Qt::NoBrush );

        // render
        painter->drawRoundedRect( frameRect, radius, radius );

    }

    //______________________________________________________________________________
    void Helper::renderSquareFrame(
        QPainter* painter, const QRect& rect,
        QColor color, bool hasFocus ) const
    {
        painter->setPen( color );
        painter->drawRect( rect.adjusted(1, 1, -2, -2) );
        if (hasFocus) {
            color.setAlphaF( 0.5 );
            painter->setPen( color );
            painter->drawRect( rect.adjusted(0, 0, -1, -1) );
        }
    }

    //______________________________________________________________________________
    void Helper::renderFlatFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor& outline, bool hasFocus ) const
    {

        painter->setRenderHint( QPainter::Antialiasing );

        QRectF frameRect( rect.adjusted( 1, 1, -1, -1 ) );
        qreal radius( frameRadius() );

        // set pen
        if( outline.isValid() )
        {

            if (hasFocus) {
                painter->setPen( QPen( outline, 2 ) );
                frameRect.adjust(0.5, 0.5, -0.5, -0.5);
            }
            else {
                painter->setPen( outline );
            }
            frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );
            radius = qMax( radius - 1, qreal( 0.0 ) );

        } else {

            painter->setPen( Qt::NoPen );

        }

        // set brush
        if( color.isValid() ) painter->setBrush( color );
        else painter->setBrush( Qt::NoBrush );

        QPainterPath path;
        path.setFillRule( Qt::WindingFill );
        path.addRect( frameRect.adjusted(2 * radius, 0, 0, 0) );
        path.addRoundedRect( frameRect.adjusted(0, 0, - 2 *radius, 0), radius, radius);

        painter->drawPath( path.simplified() );

        // render
        //painter->drawRoundedRect( frameRect, radius, radius );

    }

    //______________________________________________________________________________
    void Helper::renderSidePanelFrame( QPainter* painter, const QRect& rect, const QColor& outline, Side side ) const
    {

        // check color
        if( !outline.isValid() ) return;

        // adjust rect
        QRectF frameRect( rect.adjusted( 1, 1, -1, -1 ) );
        frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing );
        painter->setPen( outline );

        // render
        switch( side )
        {
            default:
            case SideLeft:
            frameRect.adjust( 0, 1, 0, -1 );
            painter->drawLine( frameRect.topRight(), frameRect.bottomRight() );
            break;

            case SideTop:
            frameRect.adjust( 1, 0, -1, 0 );
            painter->drawLine( frameRect.topLeft(), frameRect.topRight() );
            break;

            case SideRight:
            frameRect.adjust( 0, 1, 0, -1 );
            painter->drawLine( frameRect.topLeft(), frameRect.bottomLeft() );
            break;

            case SideBottom:
            frameRect.adjust( 1, 0, -1, 0 );
            painter->drawLine( frameRect.bottomLeft(), frameRect.bottomRight() );
            break;

            case AllSides:
            {
                qreal radius( frameRadius( -1.0 ) );
                painter->drawRoundedRect( frameRect, radius, radius );
                break;
            }

        }

    }

    //______________________________________________________________________________
    void Helper::renderMenuFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor& outline, bool roundCorners ) const
    {


        // set brush
        if( color.isValid() ) painter->setBrush( color );
        else painter->setBrush( Qt::NoBrush );


        painter->setRenderHint( QPainter::Antialiasing, false );
        QRect frameRect( rect );
        if( outline.isValid() )
        {

            painter->setPen( outline );
            frameRect.adjust( 0, 0, -1, -1 );

        } else painter->setPen( Qt::NoPen );

        painter->drawRect( frameRect );

    }

    //______________________________________________________________________________
    void Helper::renderButtonFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor& outline, const QColor& shadow,
        bool hasFocus, bool sunken, bool mouseOver, bool active ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect
        QRectF frameRect( rect );
        frameRect.adjust( 1, 1, -1, -1 );
        qreal radius( frameRadius() );

        if( outline.isValid() )
        {

            painter->setPen( QPen( outline, 1.0 ) );

            frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );
            radius = qMax( radius - 1, qreal( 0.0 ) );

        } else painter->setPen( Qt::NoPen );

        // content
        if( color.isValid() )
        {

            QLinearGradient gradient( frameRect.topLeft(), frameRect.bottomLeft() );
            //gradient.setColorAt( 0, color.darker( sunken ? 110 : (hasFocus|mouseOver) ? 85 : 100 ) );
            //gradient.setColorAt( 1, color.darker( sunken ? 130 : (hasFocus|mouseOver) ? 95 : 110 ) );
            if (!active) {
                gradient.setColorAt( 0, color );
            }
            else if (sunken) {
                gradient.setColorAt( 0, color );
            }
            else {
                gradient.setColorAt( 0, mix(color, Qt::white, 0.07) );
                gradient.setColorAt( 1, mix(color, Qt::black, 0.1) );
            }
            painter->setBrush( gradient );

        } else painter->setBrush( Qt::NoBrush );

        // render
        painter->drawRoundedRect( frameRect, radius, radius );

        if (!sunken && active && color.isValid()) {
            painter->setPen(color.lighter(140));
            painter->drawLine(frameRect.topLeft() + QPoint(3, 1), frameRect.topRight() + QPoint(-3, 1));
            painter->setPen(outline.darker(114));
            painter->drawLine(frameRect.bottomLeft() + QPointF(2.7, 0), frameRect.bottomRight() + QPointF(-2.7, 0));
        }

    }

    //______________________________________________________________________________
    void Helper::renderFlatButtonFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor& outline, const QColor& shadow,
        bool hasFocus, bool sunken, bool mouseOver, bool active ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect
        QRectF frameRect( rect );
        frameRect.adjust( 1, 1, -1, -1 );
        qreal radius( frameRadius() );

        if( outline.isValid() )
        {

            painter->setPen( QPen( outline, 1.0 ) );

            frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );
            radius = qMax( radius - 1, qreal( 0.0 ) );

        } else painter->setPen( Qt::NoPen );

        // content
        if( color.isValid() )
        {

            QLinearGradient gradient( frameRect.topLeft(), frameRect.bottomLeft() );
            //gradient.setColorAt( 0, color.darker( sunken ? 110 : (hasFocus|mouseOver) ? 85 : 100 ) );
            //gradient.setColorAt( 1, color.darker( sunken ? 130 : (hasFocus|mouseOver) ? 95 : 110 ) );

            if (!active) {
                gradient.setColorAt( 0, color );
            }
            else if (sunken) {
                gradient.setColorAt( 0, color);
            }
            else {
                gradient.setColorAt( 0, mix(color, Qt::white, 0.07) );
                gradient.setColorAt( 1, mix(color, Qt::black, 0.1) );
            }
            painter->setBrush( gradient );

        } else painter->setBrush( Qt::NoBrush );

        QPainterPath path;
        path.setFillRule( Qt::WindingFill );
        path.addRoundedRect( frameRect.adjusted(2*radius, 0, 0, 0), radius, radius );
        path.addRect( frameRect.adjusted(0, 0, -2*radius, 0) );
        painter->drawPath( path.simplified() );

        if (!sunken && active) {
            painter->setPen(color.lighter(140));
            painter->drawLine(frameRect.topLeft() + QPoint(1, 1), frameRect.topRight() + QPoint(-3, 1));
            painter->setPen(outline.darker(114));
            painter->drawLine(frameRect.bottomLeft() + QPointF(0.7, 0), frameRect.bottomRight() + QPointF(-2.7, 0));
        }

        // render
        //painter->drawRoundedRect( frameRect, radius, radius );

    }

    //______________________________________________________________________________
    void Helper::renderToolButtonFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, bool sunken ) const
    {

        // do nothing for invalid color
        if( !color.isValid() ) return;

        // setup painter
        painter->setRenderHints( QPainter::Antialiasing );

        QRectF baseRect( rect );

        if( sunken )
        {

            qreal radius( frameRadius() );

            painter->setPen( Qt::NoPen );
            painter->setBrush( color );

            QRectF contentRect( baseRect.adjusted( 1, 1, -1, -1 ) );
            painter->drawRoundedRect( contentRect, radius, radius );

        } else {

            qreal radius( frameRadius(-0.5) );

            painter->setPen( color );
            painter->setBrush( Qt::NoBrush );
            QRectF outlineRect( baseRect.adjusted( 1.5, 1.5, -1.5, -1.5 ) );
            painter->drawRoundedRect( outlineRect, radius, radius );

        }

    }

    //______________________________________________________________________________
    void Helper::renderToolBoxFrame(
        QPainter* painter, const QRect& rect, int tabWidth,
        const QColor& outline ) const
    {

        if( !outline.isValid() ) return;

        // round radius
        qreal radius( frameRadius() );
        QSizeF cornerSize( 2*radius, 2*radius );

        // if rect - tabwidth is even, need to increase tabWidth by 1 unit
        // for anti aliasing
        if( !((rect.width() - tabWidth)%2) ) ++tabWidth;

        // adjust rect for antialiasing
        QRectF baseRect( rect );
        baseRect.adjust( 0.5, 0.5, -0.5, -0.5 );

        // create path
        QPainterPath path;
        path.moveTo( 0, baseRect.height()-1 );
        path.lineTo( ( baseRect.width() - tabWidth )/2 - radius, baseRect.height()-1 );
        path.arcTo( QRectF( QPointF( ( baseRect.width() - tabWidth )/2 - 2*radius, baseRect.height()-1 - 2*radius ), cornerSize ), 270, 90 );
        path.lineTo( ( baseRect.width() - tabWidth )/2, radius );
        path.arcTo( QRectF( QPointF( ( baseRect.width() - tabWidth )/2, 0 ), cornerSize ), 180, -90 );
        path.lineTo( ( baseRect.width() + tabWidth )/2 -1 - radius, 0 );
        path.arcTo( QRectF(  QPointF( ( baseRect.width() + tabWidth )/2  - 1 - 2*radius, 0 ), cornerSize ), 90, -90 );
        path.lineTo( ( baseRect.width() + tabWidth )/2 -1, baseRect.height()-1 - radius );
        path.arcTo( QRectF( QPointF( ( baseRect.width() + tabWidth )/2 -1, baseRect.height()-1 - 2*radius ), cornerSize ), 180, 90 );
        path.lineTo( baseRect.width()-1, baseRect.height()-1 );

        // render
        painter->save();
        painter->setRenderHints( QPainter::Antialiasing );
        painter->setBrush( Qt::NoBrush );
        painter->setPen( outline );
        painter->translate( baseRect.topLeft() );
        painter->drawPath( path );
        painter->restore();

        return;

    }

    //______________________________________________________________________________
    void Helper::renderTabWidgetFrame(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor& outline, Corners corners ) const
    {

        painter->setRenderHint( QPainter::Antialiasing );

        QRectF frameRect( rect.adjusted( 1, 1, -1, -1 ) );
        qreal radius( frameRadius() );

        // set pen
        if( outline.isValid() )
        {

            painter->setPen( outline );
            frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );
            radius = qMax( radius-1, qreal( 0.0 ) );

        } else painter->setPen( Qt::NoPen );

        // set brush
        if( color.isValid() ) painter->setBrush( color );
        else painter->setBrush( Qt::NoBrush );

        // render
        QPainterPath path( roundedPath( frameRect, corners, radius ) );
        painter->drawPath( path );

    }


    //______________________________________________________________________________
    void Helper::renderSelection(
        QPainter* painter, const QRect& rect,
        const QColor& color ) const
    {

        painter->setRenderHint( QPainter::Antialiasing );
        painter->setPen( Qt::NoPen );
        painter->setBrush( color );
        painter->drawRect( rect );

    }

    //______________________________________________________________________________
    void Helper::renderSeparator(
        QPainter* painter, const QRect& rect,
        const QColor& color, bool vertical ) const
    {

        painter->save();
        painter->setRenderHint( QPainter::Antialiasing, false );
        painter->setBrush( Qt::NoBrush );
        painter->setPen( color );

        if( vertical )
        {

            painter->translate( rect.width()/2, 0 );
            painter->drawLine( rect.topLeft(), rect.bottomLeft() );

        } else {

            painter->translate( 0, rect.height()/2 );
            painter->drawLine( rect.topLeft(), rect.topRight() );


        }

        painter->restore();

        return;

    }

    //______________________________________________________________________________
    void Helper::renderCheckBoxBackground(
        QPainter* painter, const QRect& rect,
        const QColor& color, const QColor &outline, bool sunken ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect and radius
        QRectF frameRect( rect );
        frameRect.adjust( 3, 3, -3, -3 );

        painter->setPen( outline );
        painter->setBrush( color );
        painter->drawRect( frameRect );

    }

    //______________________________________________________________________________
    void Helper::renderCheckBox(
        QPainter* painter, const QRect& rect,
        const QColor& background, const QColor& outline, const QColor& tickColor,
        bool sunken, CheckBoxState state, qreal animation, bool active ) const
    {

        // setup painter
        painter->save();
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect and radius
        QRectF frameRect( rect );
        frameRect.adjust( 2, 2, -2, -2 );
        qreal radius( frameRadius() );

        // content
        {

            renderButtonFrame(painter, rect, background, outline, Qt::transparent, false, sunken, false, active);

        }

        // mark
        if( state == CheckOn )
        {
            painter->save();
            painter->setRenderHint(QPainter::Antialiasing);
            painter->setBrush( Qt::NoBrush );
            QPen pen( tickColor, 3 );
            pen.setJoinStyle(Qt::MiterJoin);
            painter->setPen( pen );

            QRectF markerRect(frameRect);

            QPainterPath path;
            path.moveTo( markerRect.right(), markerRect.top() + markerRect.height() / 4 );
            path.lineTo( markerRect.center().x(), markerRect.bottom() - markerRect.height() / 3.0 );
            path.lineTo( markerRect.left() + markerRect.width() / 3.0, markerRect.center().y() );

            painter->setClipRect(markerRect);
            painter->drawPath( path );
            painter->restore();

        } else if( state == CheckPartial ) {

            QPen pen( tickColor, 4 );
            pen.setCapStyle( Qt::RoundCap );
            painter->setPen( pen );

            QRectF markerRect( frameRect.adjusted( 4, 4, -4, -4 ) );

            painter->drawLine( markerRect.center() - QPoint(3, 0), markerRect.center() + QPoint(3, 0) );

        } else if( state == CheckAnimated ) {

            painter->save();
            painter->setRenderHint(QPainter::Antialiasing);
            painter->setBrush( Qt::NoBrush );
            QPen pen( tickColor, 3 );
            pen.setJoinStyle(Qt::MiterJoin);
            painter->setPen( pen );

            QRectF markerRect(frameRect);

            QPainterPath path;
            path.moveTo( markerRect.right(), markerRect.top() + markerRect.height() / 4 );
            path.lineTo( markerRect.center().x(), markerRect.bottom() - markerRect.height() / 3.0 );
            path.lineTo( markerRect.left() + markerRect.width() / 3.0, markerRect.center().y() );
            path.translate(-markerRect.right(), -markerRect.top());

            painter->setClipRect(markerRect.adjusted(1, 1, -1, -1));
            painter->translate(markerRect.right(), markerRect.top());
            painter->scale(animation, 0.5 + 0.5 * animation);
            painter->drawPath( path );
            painter->restore();

        }

        painter->restore();
    }

    //______________________________________________________________________________
    void Helper::renderRadioButtonBackground( QPainter* painter, const QRect& rect, const QColor& color, const QColor& outline, bool sunken ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect
        QRectF frameRect( rect );
        frameRect.adjust( 3, 3, -3, -3 );
        if( sunken ) frameRect.translate(1, 1);

        painter->setPen( outline );
        painter->setBrush( color );
        painter->drawEllipse( frameRect );

    }

    //______________________________________________________________________________
    void Helper::renderRadioButton(
        QPainter* painter, const QRect& rect,
        const QColor& background, const QColor& outline, const QColor& tickColor,
        bool sunken, bool enabled, RadioButtonState state, qreal animation ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect
        QRectF frameRect( rect );
        frameRect.adjust( 2, 2, -2, -2 );

        // content
        {

            if (background.isValid()) {
                if (enabled) {
                    QLinearGradient gradient( frameRect.topLeft(), frameRect.bottomLeft() );
                    if (sunken) {
                        gradient.setColorAt( 0, background);
                    }
                    else {
                        gradient.setColorAt( 0, mix(background, Qt::white, 0.07) );
                        gradient.setColorAt( 1, mix(background, Qt::black, 0.1) );
                    }
                    painter->setBrush( gradient );
                }
                else {
                    painter->setBrush( background );
                }
            } else {
                painter->setBrush( Qt::NoBrush );
            }

            painter->setPen( QPen( outline, 1 ) );

            QRectF contentRect( frameRect.adjusted( 0.5, 0.5, -0.5, -0.5 ) );
            painter->drawEllipse( contentRect );

        }

        // mark
        if( state == RadioOn )
        {

            painter->setBrush( tickColor );
            painter->setPen( Qt::NoPen );

            QRectF markerRect( frameRect.adjusted( 5, 5, -5, -5 ) );
            painter->drawEllipse( markerRect );

        } else if( state == RadioAnimated ) {

            painter->setBrush( tickColor );
            painter->setPen( Qt::NoPen );
            QRectF markerRect( frameRect.adjusted( 5, 5, -5, -5 ) );
            qreal remaining = markerRect.width() / 2.0 * (1.0 - animation);
            markerRect.adjust(remaining, remaining, -remaining, -remaining);

            painter->drawEllipse( markerRect );

        }

    }

    //______________________________________________________________________________
    void Helper::renderSliderGroove(
        QPainter* painter, const QRect& rect,
        const QColor& color ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        QRectF baseRect( rect );
        qreal radius( 0.5*Metrics::Slider_GrooveThickness );

        // content
        if( color.isValid() )
        {
            painter->setPen( Qt::NoPen );
            painter->setBrush( color );
            painter->drawRoundedRect( baseRect, radius, radius );
        }

        return;

    }

    //______________________________________________________________________________
    void Helper::renderDialGroove(
        QPainter* painter, const QRect& rect,
        const QColor& color ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        QRectF baseRect( rect );

        // content
        if( color.isValid() )
        {
            qreal penWidth( Metrics::Slider_GrooveThickness );
            QRectF grooveRect( rect.adjusted( penWidth/2, penWidth/2, -penWidth/2, -penWidth/2 ) );

            painter->setPen( QPen( color, penWidth ) );
            painter->setBrush( Qt::NoBrush );
            painter->drawEllipse( grooveRect );
        }

        return;

    }

    //______________________________________________________________________________
    void Helper::renderDialContents(
        QPainter* painter, const QRect& rect,
        const QColor& color,
        qreal first, qreal second ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        QRectF baseRect( rect );

        // content
        if( color.isValid() )
        {

            // setup groove rect
            qreal penWidth( Metrics::Slider_GrooveThickness );
            QRectF grooveRect( rect.adjusted( penWidth/2, penWidth/2, -penWidth/2, -penWidth/2 ) );

            // setup angles
            int angleStart( first * 180 * 16 / M_PI );
            int angleSpan( (second - first ) * 180 * 16 / M_PI );

            // setup pen
            if( angleSpan != 0 )
            {
                QPen pen( color, penWidth );
                pen.setCapStyle( Qt::RoundCap );
                painter->setPen( pen );
                painter->setBrush( Qt::NoBrush );
                painter->drawArc( grooveRect, angleStart, angleSpan );
            }

        }

        return;

    }

    //______________________________________________________________________________
    void Helper::renderSliderHandle(QPainter* painter, const QRect& rect,
        const QColor& color,
        const QColor& outline,
        const QColor& shadow,
        bool sunken,
        bool enabled,
        Side ticks,
        qreal angle) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        // copy rect
        QRectF frameRect( rect );
        frameRect.adjust( 1, 1, -1, -1 );

        // set pen
        if( outline.isValid() )
        {

            QPen pen(outline);
            pen.setCapStyle( Qt::FlatCap );
            pen.setJoinStyle( Qt::MiterJoin );
            painter->setPen(pen);

            frameRect.adjust( 0.5, 0.5, -0.5, -0.5 );

        } else painter->setPen( Qt::NoPen );

        // set brush
        if( color.isValid() ) {

            if (enabled) {
                QLinearGradient gradient( frameRect.topLeft(), frameRect.bottomLeft() );
                if (sunken) {
                    gradient.setColorAt( 0, color);
                }
                else {
                    gradient.setColorAt( 0, mix(color, Qt::white, 0.07) );
                    gradient.setColorAt( 1, mix(color, Qt::black, 0.1) );
                }
                painter->setBrush(gradient);
            }
            else {
                painter->setBrush(color);
            }

        }
        else painter->setBrush( Qt::NoBrush );

        QRect r(rect.right() - rect.height(), rect.top(), rect.height(), rect.height());
        r.adjust(4.5, 3.5, -2.5, -3.5);

        QPainterPath circle;
        circle.addEllipse(r);
        circle.closeSubpath();

        if (ticks & SideBottom) {
            QPainterPath triangle(r.center());
            triangle.moveTo(r.left() + 1.5, r.center().y() + 5.5);
            triangle.lineTo(r.center().x() + 1, r.bottom() + 4.5);
            triangle.lineTo(r.right() - 0.5, r.center().y() + 5.5);
            triangle.closeSubpath();
            circle = circle.united(triangle);
        }
        else if (ticks & SideTop) {
            QPainterPath triangle(r.center());
            triangle.moveTo(r.left() + 1.5, r.center().y() - 3.5);
            triangle.lineTo(r.center().x() + 1, r.top() - 2.5);
            triangle.lineTo(r.right() - 0.5, r.center().y() - 3.5);
            triangle.closeSubpath();
            circle = circle.united(triangle);
        }
        else if (ticks & SideLeft) {
            QPainterPath triangle(r.center());
            triangle.moveTo(r.center().x() - 3.5, r.top() + 1.5);
            triangle.lineTo(r.left() - 2.5, r.center().y() + 1);
            triangle.lineTo(r.center().x() - 3.5, r.bottom() - 0.5);
            triangle.closeSubpath();
            circle = circle.united(triangle);
        }
        else if (ticks & SideRight) {
            QPainterPath triangle(r.center());
            triangle.moveTo(r.center().x() + 3.5, r.top() + 1.5);
            triangle.lineTo(r.right() + 2.5, r.center().y() + 1);
            triangle.lineTo(r.center().x() + 3.5, r.bottom() - 0.5);
            triangle.closeSubpath();
            circle = circle.united(triangle);
        }

        QTransform rotate;
        rotate.translate(frameRect.center().x(), frameRect.center().y());
        rotate.rotate(angle);
        rotate.translate(-frameRect.center().x(), -frameRect.center().y());
        painter->drawPolygon(circle.toFillPolygon(rotate));

    }

    //______________________________________________________________________________
    void Helper::renderProgressBarGroove(QPainter* painter, const QRect& rect,
        const QColor& color , const QColor& outline) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );
        painter->setRenderHint( QPainter::SmoothPixmapTransform, true );

        QRectF baseRect( rect );
        qreal radius( 0.5 );

        // content
        if( color.isValid() )
        {
            painter->setPen( outline );
            painter->setBrush( color );
            painter->drawRoundedRect( baseRect.translated(0.5, 0.5), radius, radius );
        }

        return;

    }


    //______________________________________________________________________________
    void Helper::renderProgressBarBusyContents(
        QPainter* painter, const QRect& rect,
        const QColor& color,
        const QColor& outline,
        bool horizontal,
        bool reverse,
        int progress
        ) const
    {
        Q_UNUSED(reverse);

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        QRectF baseRect( rect );
        qreal radius( 0.25*Metrics::ProgressBar_Thickness );
        QRectF contentRect;
        if (horizontal) {
            contentRect = QRect(baseRect.left(), baseRect.top(), Metrics::ProgressBar_BusyIndicatorSize, baseRect.height());
            contentRect.translate(fabs(progress - 50) / 50.0 * (baseRect.width() - contentRect.width()), 0);
        }
        else {
            contentRect = QRect(baseRect.left(), baseRect.top(), baseRect.width(), Metrics::ProgressBar_BusyIndicatorSize);
            contentRect.translate(0, fabs(progress - 50) / 50.0 * (baseRect.height() - contentRect.height()));
        }

        painter->setBrush(color);
        painter->setPen(outline);
        painter->drawRoundedRect(contentRect.translated(0.5, 0.5), radius, radius);

        return;

    }

    //______________________________________________________________________________
    void Helper::renderScrollBarHandle(
        QPainter* painter, const QRect& rect,
        const QColor& color ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, true );

        QRectF baseRect( rect );
        qreal metric( rect.width() < rect.height() ? rect.width() : rect.height());
        qreal radius( 0.5*metric );

        // content
        if( color.isValid() )
        {
            painter->setPen( Qt::NoPen );
            painter->setBrush( color );
            painter->drawRoundedRect( baseRect, radius, radius );
        }

        return;

    }

    //______________________________________________________________________________
    void Helper::renderTabBarTab( QPainter* painter, const QRect& rect, const QColor& background, const QColor& color, const QColor& outline, Corners corners, bool renderFrame ) const
    {

        // setup painter
        painter->setRenderHint( QPainter::Antialiasing, false );

        QRectF frameRect( rect );
        qreal adjustment;

        // pen
        if( outline.isValid() )
        {

            painter->setPen( outline );
            frameRect.adjust( 1.0, 1.0, -1.0, -1.0 );
            adjustment = 0;

            painter->setBrush( background );

            // render
            painter->drawRect( frameRect );

        } else if (!renderFrame) {
            adjustment = 9;
        }

        painter->setPen( QPen( color, 6 ) );

        switch (corners) {
            case CornerTopLeft|CornerTopRight:
                painter->drawLine(frameRect.left() + adjustment, frameRect.bottom(), frameRect.right() - adjustment, frameRect.bottom());
                break;

            case CornerBottomLeft|CornerBottomRight:
                painter->drawLine(frameRect.left() + adjustment, frameRect.top(), frameRect.right() - adjustment, frameRect.top());
                break;

            case CornerTopLeft|CornerBottomLeft:
                painter->drawLine(frameRect.right(), frameRect.top() + adjustment, frameRect.right(), frameRect.bottom() - adjustment);
                break;

            case CornerTopRight|CornerBottomRight:
                painter->drawLine(frameRect.left(), frameRect.top() + adjustment, frameRect.left(), frameRect.bottom() - adjustment);
                break;
    
        }


    }

    //______________________________________________________________________________
    // TODO blurry edges
    void Helper::renderArrow( QPainter* painter, const QRect& rect, const QColor& color, ArrowOrientation orientation ) const
    {

        // define polygon
        QPolygonF arrow;
        switch( orientation )
        {
            case ArrowUp: arrow << QPointF( -4, 2 ) << QPointF( 0, -2 ) << QPointF( 4, 2 ); break;
            case ArrowDown: arrow << QPointF( -4, -2 ) << QPointF( 0, 2 ) << QPointF( 4, -2 ); break;
            case ArrowLeft: arrow << QPointF( 2, -4 ) << QPointF( -2, 0 ) << QPointF( 2, 4 ); break;
            case ArrowRight: arrow << QPointF( -2, -4 ) << QPointF( 2, 0 ) << QPointF( -2, 4 ); break;
            default: break;
        }

        QPen pen(color, 1.2);
        pen.setCapStyle( Qt::FlatCap );
        pen.setJoinStyle( Qt::MiterJoin );

        painter->save();
        painter->setRenderHints( QPainter::Antialiasing );
        painter->translate( QRectF( rect ).center() );
        painter->setBrush( color );
        painter->setPen( pen );
        painter->drawPolygon( arrow );

        painter->restore();

        return;
    }

    void Helper::renderSign(QPainter *painter, const QRect &rect, const QColor &color, bool orientation) const {
        QPen pen( color, 2 );
        pen.setCapStyle( Qt::FlatCap );

        QRect r = rect.adjusted(1, 2, 0, 0);

        painter->setPen(pen);
        painter->drawLine(r.center() - QPointF(5, 0), r.center() + QPointF(5, 0));
        if (orientation)
            painter->drawLine(r.center() - QPointF(0, 5), r.center() + QPointF(0, 5));
    }

    //______________________________________________________________________________
    void Helper::renderDecorationButton( QPainter* painter, const QRect& rect, const QColor& color, ButtonType buttonType, bool inverted ) const
    {

        painter->save();
        painter->setViewport( rect );
        painter->setWindow( 0, 0, 18, 18 );
        painter->setRenderHints( QPainter::Antialiasing, false );

        // initialize pen
        QPen pen;
        pen.setCapStyle( Qt::RoundCap );
        pen.setJoinStyle( Qt::MiterJoin );

        painter->setBrush( Qt::NoBrush );

        pen.setColor( color );
        pen.setCapStyle( Qt::RoundCap );
        pen.setJoinStyle( Qt::MiterJoin );
        pen.setWidthF( 2.0*qMax(1.0, 18.0/rect.width() ) );
        painter->setPen( pen );

        switch( buttonType )
        {
            case ButtonClose:
            {
                painter->setRenderHints( QPainter::Antialiasing, true );
                painter->drawLine( QPointF( 5, 5 ), QPointF( 13, 13 ) );
                painter->drawLine( 13, 5, 5, 13 );
                break;
            }

            case ButtonMaximize:
            {
                painter->drawPolyline( QPolygonF()
                    << QPointF( 4, 4 )
                    << QPointF( 4, 14 )
                    << QPointF( 14, 14 )
                    << QPointF( 14, 4 ) );
                break;
            }

            case ButtonMinimize:
            {

                painter->drawPolyline( QPolygonF()
                    << QPointF( 4, 14 )
                    << QPointF( 14, 14 ) );
                break;
            }

            case ButtonRestore:
            {
                painter->setPen( pen );
                QPolygonF rect = QPolygonF() << QPointF( 0, 0 ) << QPointF( 8, 0 ) << QPointF( 8, 8 ) << QPointF( 0, 8 );
                painter->drawPolygon( rect.translated(7, 3) );
                painter->drawPolygon( rect.translated(3, 7) );
                break;
            }

            default: break;
        }

        painter->restore();
        return;

    }

    //______________________________________________________________________________
    bool Helper::isX11( void )
    {
        #if QT_VERSION >= 0x050000
        static const bool s_isX11 = qApp->platformName()==QLatin1String("xcb");
        return s_isX11;
        #else
        return false;
        #endif
    }

    bool Helper::isWayland( void )
    {
        #if QT_VERSION >= 0x050000
        static const bool s_isWayland = qApp->platformName().startsWith(QLatin1String("wayland"));
        return s_isWayland;
        #else
        return false;
        #endif
    }

    //______________________________________________________________________________
    QRectF Helper::shadowRect( const QRectF& rect ) const
    { return rect; }

    //______________________________________________________________________________
    QPainterPath Helper::roundedPath( const QRectF& rect, Corners corners, qreal radius ) const
    {

        QPainterPath path;

        // simple cases
        if( corners == 0 )
        {

            path.addRect( rect );
            return path;

        }

        if( corners == AllCorners ) {

            path.addRoundedRect( rect, radius, radius );
            return path;

        }

        QSizeF cornerSize( 2*radius, 2*radius );

        // rotate counterclockwise
        // top left corner
        if( corners & CornerTopLeft )
        {

            path.moveTo( rect.topLeft() + QPointF( radius, 0 ) );
            path.arcTo( QRectF( rect.topLeft(), cornerSize ), 90, 90 );

        } else path.moveTo( rect.topLeft() );

        // bottom left corner
        if( corners & CornerBottomLeft )
        {

            path.lineTo( rect.bottomLeft() - QPointF( 0, radius ) );
            path.arcTo( QRectF( rect.bottomLeft() - QPointF( 0, 2*radius ), cornerSize ), 180, 90 );

        } else path.lineTo( rect.bottomLeft() );

        // bottom right corner
        if( corners & CornerBottomRight )
        {

            path.lineTo( rect.bottomRight() - QPointF( radius, 0 ) );
            path.arcTo( QRectF( rect.bottomRight() - QPointF( 2*radius, 2*radius ), cornerSize ), 270, 90 );

        } else path.lineTo( rect.bottomRight() );

        // top right corner
        if( corners & CornerTopRight )
        {

            path.lineTo( rect.topRight() + QPointF( 0, radius ) );
            path.arcTo( QRectF( rect.topRight() - QPointF( 2*radius, 0 ), cornerSize ), 0, 90 );

        } else path.lineTo( rect.topRight() );

        path.closeSubpath();
        return path;

    }

    //________________________________________________________________________________________________________
    bool Helper::compositingActive( void ) const
    {

        #if ADWAITA_HAVE_X11
        if( isX11() )
        {
            // direct call to X
            xcb_get_selection_owner_cookie_t cookie( xcb_get_selection_owner( connection(), _compositingManagerAtom ) );
            ScopedPointer<xcb_get_selection_owner_reply_t> reply( xcb_get_selection_owner_reply( connection(), cookie, nullptr ) );
            return reply && reply->owner;

        }
        #endif

        // use KWindowSystem
        //return KWindowSystem::compositingActive();
        return false;

    }

    //____________________________________________________________________
    bool Helper::hasAlphaChannel( const QWidget* widget ) const
    { return compositingActive() && widget && widget->testAttribute( Qt::WA_TranslucentBackground ); }

    //______________________________________________________________________________________
    QPixmap Helper::highDpiPixmap( int width, int height ) const
    {
        #if QT_VERSION >= 0x050300
        qreal dpiRatio( qApp->devicePixelRatio() );
        QPixmap pixmap( width*dpiRatio, height*dpiRatio );
        pixmap.setDevicePixelRatio( dpiRatio );
        return pixmap;
        #else
        return QPixmap( width, height );
        #endif
    }

    //______________________________________________________________________________________
    qreal Helper::devicePixelRatio( const QPixmap& pixmap ) const
    {
        #if QT_VERSION >= 0x050300
        return pixmap.devicePixelRatio();
        #else
        Q_UNUSED(pixmap);
        return 1;
        #endif
    }

    #if ADWAITA_HAVE_X11

    //____________________________________________________________________
    xcb_connection_t* Helper::connection( void )
    {

        #if QT_VERSION >= 0x050000
        return QX11Info::connection();
        #else
        static xcb_connection_t* connection = nullptr;
        if( !connection )
        {
            Display* display = QX11Info::display();
            if( display ) connection = XGetXCBConnection( display );
        }
        return connection;
        #endif
    }

    //____________________________________________________________________
    xcb_atom_t Helper::createAtom( const QString& name ) const
    {
        if( isX11() )
        {

            xcb_connection_t* connection( Helper::connection() );
            xcb_intern_atom_cookie_t cookie( xcb_intern_atom( connection, false, name.size(), qPrintable( name ) ) );
            ScopedPointer<xcb_intern_atom_reply_t> reply( xcb_intern_atom_reply( connection, cookie, nullptr) );
            return reply ? reply->atom:0;

        } else return 0;

    }

    #endif

    //____________________________________________________________________
    void Helper::init( void )
    {
        #if ADWAITA_HAVE_X11

        if( isX11() )
        {
            // create compositing screen
            QString atomName( QStringLiteral( "_NET_WM_CM_S%1" ).arg( QX11Info::appScreen() ) );
            _compositingManagerAtom = createAtom( atomName );
        }

        #endif

    }

    //____________________________________________________________________
    void Helper::setVariant(QWidget *widget, const QByteArray &variant)
    {
        if (isX11() && widget) { //  && !widget->testAttribute(Qt::WA_)) {
            static const char *_GTK_THEME_VARIANT="_GTK_THEME_VARIANT";

            // Check if already set
            QVariant var=widget->property("_GTK_THEME_VARIANT");
            if (var.isValid() && var.toByteArray()==variant) {
                return;
            }

            // Typedef's from xcb/xcb.h - copied so that there is no
            // direct xcb dependency
            typedef quint32 XcbAtom;

            struct XcbInternAtomCookie {
                unsigned int sequence;
            };

            struct XcbInternAtomReply {
                quint8  response_type;
                quint8  pad0;
                quint16 sequence;
                quint32 length;
                XcbAtom atom;
            };

            typedef void * (*XcbConnectFn)(int, int);
            typedef XcbInternAtomCookie (*XcbInternAtomFn)(void *, int, int, const char *);
            typedef XcbInternAtomReply * (*XcbInternAtomReplyFn)(void *, XcbInternAtomCookie, int);
            typedef int (*XcbChangePropertyFn)(void *, int, int, XcbAtom, XcbAtom, int, int, const void *);
            typedef int (*XcbFlushFn)(void *);

            static QLibrary *lib = 0;
            static XcbAtom variantAtom = 0;
            static XcbAtom utf8TypeAtom = 0;
            static void *xcbConn = 0;
            static XcbChangePropertyFn XcbChangePropertyFnPtr = 0;
            static XcbFlushFn XcbFlushFnPtr = 0;

            if (!lib) {
                lib = new QLibrary("libxcb", qApp);

                if (lib->load()) {
                    XcbConnectFn XcbConnectFnPtr=(XcbConnectFn)lib->resolve("xcb_connect");
                    XcbInternAtomFn XcbInternAtomFnPtr=(XcbInternAtomFn)lib->resolve("xcb_intern_atom");
                    XcbInternAtomReplyFn XcbInternAtomReplyFnPtr=(XcbInternAtomReplyFn)lib->resolve("xcb_intern_atom_reply");

                    XcbChangePropertyFnPtr=(XcbChangePropertyFn)lib->resolve("xcb_change_property");
                    XcbFlushFnPtr=(XcbFlushFn)lib->resolve("xcb_flush");
                    if (XcbConnectFnPtr && XcbInternAtomFnPtr && XcbInternAtomReplyFnPtr && XcbChangePropertyFnPtr && XcbFlushFnPtr) {
                        xcbConn=(*XcbConnectFnPtr)(0, 0);
                        if (xcbConn) {
                            XcbInternAtomReply *typeReply = (*XcbInternAtomReplyFnPtr)(xcbConn, (*XcbInternAtomFnPtr)(xcbConn, 0, 11, "UTF8_STRING"), 0);

                            if (typeReply) {
                                XcbInternAtomReply *gtkVarReply = (*XcbInternAtomReplyFnPtr)(xcbConn,
                                                                                             (*XcbInternAtomFnPtr)(xcbConn, 0, strlen(_GTK_THEME_VARIANT),
                                                                                                                   _GTK_THEME_VARIANT), 0);
                                if (gtkVarReply) {
                                    utf8TypeAtom = typeReply->atom;
                                    variantAtom = gtkVarReply->atom;
                                    free(gtkVarReply);
                                }
                                free(typeReply);
                            }
                        }
                    }
                }
            }

            if (0!=variantAtom) {
                (*XcbChangePropertyFnPtr)(xcbConn, 0, widget->effectiveWinId(), variantAtom, utf8TypeAtom, 8,
                                          variant.length(), (const void *)variant.constData());
                (*XcbFlushFnPtr)(xcbConn);
                widget->setProperty(_GTK_THEME_VARIANT, variant);
            }
        }
    }

}
