/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 2007 Lubos Lunak <l.lunak@kde.org>

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, see <http://www.gnu.org/licenses/>.
*********************************************************************/

#include "desktopgrid.h"

#include <math.h>

#include <kaction.h>
#include <kactioncollection.h>
#include <klocale.h>
#include <kconfiggroup.h>
#include <netwm_def.h>
#include <QEvent>
#include <QMouseEvent>

namespace KWin
{

KWIN_EFFECT( desktopgrid, DesktopGridEffect )

DesktopGridEffect::DesktopGridEffect()
    : activated( false )
    , keyboard_grab( false )
    , was_window_move( false )
    , window_move( NULL )
    , slide( false )
    {
    KActionCollection* actionCollection = new KActionCollection( this );
    KAction* a = static_cast< KAction* >( actionCollection->addAction( "ShowDesktopGrid" ));
    a->setText( i18n("Show Desktop Grid" ));
    a->setGlobalShortcut( KShortcut( Qt::CTRL + Qt::Key_F8 ));
    connect( a, SIGNAL( triggered( bool )), this, SLOT( toggle()));
    KConfigGroup conf = effects->effectConfig("DesktopGrid");
    slideEnabled = conf.readEntry( "Slide", true );

    borderActivate = (ElectricBorder)conf.readEntry("BorderActivate", (int)ElectricNone);
    effects->reserveElectricBorder( borderActivate );
    mTimeLine.setCurveShape(TimeLine::EaseInOutCurve);
    }

DesktopGridEffect::~DesktopGridEffect()
    {
    effects->unreserveElectricBorder( borderActivate );
    }

void DesktopGridEffect::prePaintScreen( ScreenPrePaintData& data, int time )
    {
    if( slide )
        {
        mTimeLine.addTime(time);

        // PAINT_SCREEN_BACKGROUND_FIRST is needed because screen will be actually painted more than once,
        // so with normal screen painting second screen paint would erase parts of the first paint
        if( mTimeLine.value() != 1 )
            data.mask |= PAINT_SCREEN_TRANSFORMED | PAINT_SCREEN_BACKGROUND_FIRST;
        else
            {
            slide = false;
            mTimeLine.setProgress(0);
            }
        }
    else if( mTimeLine.value() != 0 || activated )
        {
        if( activated )
            mTimeLine.addTime(time);
        else
            mTimeLine.removeTime(time);
        // PAINT_SCREEN_BACKGROUND_FIRST is needed because screen will be actually painted more than once,
        // so with normal screen painting second screen paint would erase parts of the first paint
        if( mTimeLine.value() != 0 )
            data.mask |= PAINT_SCREEN_TRANSFORMED | PAINT_SCREEN_BACKGROUND_FIRST;
        if( !activated && mTimeLine.value() == 0 )
            finish();
        }
    effects->prePaintScreen( data, time );
    }

void DesktopGridEffect::prePaintWindow( EffectWindow* w, WindowPrePaintData& data, int time )
    {
    if( slide )
        {
        if( w->isOnAllDesktops())
            {
            if( slide_painting_sticky )
                data.setTransformed();
            else
                w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
            }
        else if( w->isOnDesktop( painting_desktop ))
            w->enablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
        else
            w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
        }
    else if( mTimeLine.value() != 0 )
        {
        if( w->isOnDesktop( painting_desktop ))
            w->enablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
        else
            w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
        if( w == window_move )
            {
            data.setTransformed();
            if( w->isOnAllDesktops() && painting_desktop != posToDesktop( window_move_pos - window_move_diff ))
                w->disablePainting( EffectWindow::PAINT_DISABLED_BY_DESKTOP );
            }
        }
    effects->prePaintWindow( w, data, time );
    }

void DesktopGridEffect::paintScreen( int mask, QRegion region, ScreenPaintData& data )
    {
    if( mTimeLine.value() == 0 )
        {
        effects->paintScreen( mask, region, data );
        return;
        }
    if( slide )
        {
        paintSlide( mask, region, data );
        return;
        }
    int desktop_with_move = -1;
    if( window_move != NULL )
        desktop_with_move = window_move->isOnAllDesktops()
            ? posToDesktop( window_move_pos - window_move_diff ) : window_move->desktop();
    for( int desktop = 1;
         desktop <= effects->numberOfDesktops();
         ++desktop )
        {
        if( desktop != desktop_with_move )
            {
            PaintClipper pc( desktopRect( desktop, true ));
            paintScreenDesktop( desktop, mask, region, data );
            }
        }
    // paint the desktop with the window being moved as the last one, i.e. on top of others
    if( desktop_with_move != -1 )
        {
        QRegion paintreg = desktopRect( desktop_with_move, true ); // paint only the desktop
        paintreg |= windowRect( window_move ); // and wherever the moved window is
        PaintClipper pc( paintreg );
        paintScreenDesktop( desktop_with_move, mask, region, data );
        }
    }

void DesktopGridEffect::paintScreenDesktop( int desktop, int mask, QRegion region, ScreenPaintData data )
    {
    QRect rect = desktopRect( desktop, true );
    if( region.contains( rect )) // this desktop needs painting
        {
        painting_desktop = desktop;
        ScreenPaintData d = data;
        QRect normal = desktopRect( effects->currentDesktop(), false );
        d.xTranslate += rect.x(); // - normal.x();
        d.yTranslate += rect.y(); // - normal.y();
        d.xScale *= rect.width() / double( normal.width());
        d.yScale *= rect.height() / double( normal.height());
        // TODO mask parts that are not visible?
        effects->paintScreen( mask, region, d );
        }
    }

void DesktopGridEffect::paintSlide( int mask, QRegion region, const ScreenPaintData& data )
    {
    /*
     Transformations are done by remembering starting position of the change and the progress
     of it, the destination is computed from the current desktop. Positions of desktops
     are done using their topleft corner.
    */
    QPoint destPos = desktopRect( effects->currentDesktop(), false ).topLeft();
    QPoint diffPos = destPos - slide_start_pos;
    int w = 0;
    int h = 0;
    if( effects->optionRollOverDesktops())
        {
        int x, y;
        Qt::Orientation orientation;
        effects->calcDesktopLayout( &x, &y, &orientation );
        w = x * displayWidth();
        h = y * displayHeight();
        // wrap around if shorter
        if( diffPos.x() > 0 && diffPos.x() > w / 2 )
            diffPos.setX( diffPos.x() - w );
        if( diffPos.x() < 0 && abs( diffPos.x()) > w / 2 )
            diffPos.setX( diffPos.x() + w );
        if( diffPos.y() > 0 && diffPos.y() > h / 2 )
            diffPos.setY( diffPos.y() - h );
        if( diffPos.y() < 0 && abs( diffPos.y()) > h / 2 )
            diffPos.setY( diffPos.y() + h );
        }
    QPoint currentPos = slide_start_pos + mTimeLine.value() * diffPos;
    QSize displaySize( displayWidth(), displayHeight());
    QRegion currentRegion = QRect( currentPos, displaySize );
    if( effects->optionRollOverDesktops())
        {
        currentRegion |= ( currentRegion & QRect( -w, 0, w, h )).translated( w, 0 );
        currentRegion |= ( currentRegion & QRect( 0, -h, w, h )).translated( 0, h );
        currentRegion |= ( currentRegion & QRect( w, 0, w, h )).translated( -w, 0 );
        currentRegion |= ( currentRegion & QRect( 0, h, w, h )).translated( 0, -h );
        }
    bool do_sticky = true;
    for( int desktop = 1;
         desktop <= effects->numberOfDesktops();
         ++desktop )
        {
        QRect rect = desktopRect( desktop, false );
        if( currentRegion.contains( rect )) // part of the desktop needs painting
            {
            painting_desktop = desktop;
            slide_painting_sticky = do_sticky;
            slide_painting_diff = rect.topLeft() - currentPos;
            if( effects->optionRollOverDesktops())
                {
                if( slide_painting_diff.x() > displayWidth())
                    slide_painting_diff.setX( slide_painting_diff.x() - w );
                if( slide_painting_diff.x() < -displayWidth())
                    slide_painting_diff.setX( slide_painting_diff.x() + w );
                if( slide_painting_diff.y() > displayHeight())
                    slide_painting_diff.setY( slide_painting_diff.y() - h );
                if( slide_painting_diff.y() < -displayHeight())
                    slide_painting_diff.setY( slide_painting_diff.y() + h );
                }
            do_sticky = false; // paint on-all-desktop windows only once
            ScreenPaintData d = data;
            d.xTranslate += slide_painting_diff.x();
            d.yTranslate += slide_painting_diff.y();
            // TODO mask parts that are not visible?
            effects->paintScreen( mask, region, d );
            }
        }
    }

void DesktopGridEffect::paintWindow( EffectWindow* w, int mask, QRegion region, WindowPaintData& data )
    {
    if( slide )
        { // don't move windows on all desktops (compensate screen transformation)
        if( w->isOnAllDesktops()) // TODO also fix 'Workspace::movingClient'
            {
            data.xTranslate -= slide_painting_diff.x();
            data.yTranslate -= slide_painting_diff.y();
            }
        }
    else if( mTimeLine.value() != 0 )
        {
        if( w == window_move )
            {
            int x, y;
            Qt::Orientation orientation;
            effects->calcDesktopLayout( &x, &y, &orientation );
            QRect desktop = desktopRect( painting_desktop, false );
            data.xTranslate += window_move_pos.x() * x - ( desktop.x() + w->x());
            data.yTranslate += window_move_pos.y() * y - ( desktop.y() + w->y());
            }
        else if( painting_desktop != highlighted_desktop )
            data.brightness *= 0.7;
        }
    effects->paintWindow( w, mask, region, data );    
    }

void DesktopGridEffect::postPaintScreen()
    {
    if( slide )
        effects->addRepaintFull();
    if( activated ? mTimeLine.value() != 1 : mTimeLine.value() != 0 )
        effects->addRepaintFull(); // trigger next animation repaint
    effects->postPaintScreen();
    }

// Gives a position of the given desktop when all desktops are arranged in a grid
QRect DesktopGridEffect::desktopRect( int desktop, bool scaled ) const
    {
    int x, y;
    Qt::Orientation orientation;
    effects->calcDesktopLayout( &x, &y, &orientation );
    --desktop; // make it start with 0
    QRect rect;
    if( orientation == Qt::Horizontal )
        rect = QRect(( desktop % x ) * displayWidth(), ( desktop / x ) * displayHeight(),
            displayWidth(), displayHeight());
    else
        rect = QRect(( desktop / y ) * displayWidth(), ( desktop % y ) * displayHeight(),
            displayWidth(), displayHeight());
    if( !scaled )
        return rect;
    QRect current = desktopRect( effects->currentDesktop(), false );
    double progress = mTimeLine.value();
    rect = QRect( qRound( interpolate( rect.x() - current.x(), rect.x() / double( x ), progress )),
        qRound( interpolate( rect.y() - current.y(), rect.y() / double( y ), progress )),
        qRound( interpolate( rect.width(), displayWidth() / double( x ), progress )),
        qRound( interpolate( rect.height(), displayHeight() / double( y ), progress )));
    return rect;
    }

int DesktopGridEffect::posToDesktop( const QPoint& pos ) const
    {
    for( int desktop = 1; // TODO could be perhaps optimized
         desktop <= effects->numberOfDesktops();
         ++desktop )
        {
        if( desktopRect( desktop, true ).contains( pos ))
            return desktop;
        }
    return 0;
    }

QRect DesktopGridEffect::windowRect( EffectWindow* w ) const
    {
    int x, y;
    Qt::Orientation orientation;
    effects->calcDesktopLayout( &x, &y, &orientation );
    if( w == window_move ) // it's being moved, return moved position
        return QRect( window_move_pos, QSize( w->width() / x, w->height() / y ));
    QRect desktop = desktopRect( w->isOnCurrentDesktop()
        ? effects->currentDesktop() : w->desktop(), true );
    return QRect( desktop.x() + w->x() / x, desktop.y() + w->y() / y,
        w->width() / x, w->height() / y );
    }

EffectWindow* DesktopGridEffect::windowAt( const QPoint& pos, QRect* rect ) const
    {
    if( window_move != NULL && windowRect( window_move ).contains( pos ))
        {
        if( rect != NULL )
            *rect = windowRect( window_move );
        return window_move; // has special position and is on top
        }
    EffectWindowList windows = effects->stackingOrder();
    // qReverse()
    EffectWindowList::Iterator begin = windows.begin();
    EffectWindowList::Iterator end = windows.end();
    --end;
    while( begin < end )
        qSwap( *begin++, *end-- );
    int x, y;
    Qt::Orientation orientation;
    effects->calcDesktopLayout( &x, &y, &orientation );
    foreach( EffectWindow* w, windows )
        {
        // don't use windowRect(), take special care of on-all-desktop windows
        QRect desktop = desktopRect( w->isOnAllDesktops()
            ? posToDesktop( pos ) : w->desktop(), true );
        QRect r( desktop.x() + w->x() / x, desktop.y() + w->y() / y,
            w->width() / x, w->height() / y );
        if( r.contains( pos ))
            {
            if( rect != NULL )
                *rect = r;
            return w;
            }
        }
    return NULL;
    }

void DesktopGridEffect::desktopChanged( int old )
    {
    if( effects->activeFullScreenEffect() && effects->activeFullScreenEffect() != this )
        return;
    if( activated )
        setActive( false );
    else
        slideDesktopChanged( old );
    }

void DesktopGridEffect::slideDesktopChanged( int old )
    {
    if( !slideEnabled )
        return;
    if( slide ) // old slide still in progress
        {
        QPoint diffPos = desktopRect( old, false ).topLeft() - slide_start_pos;
        int w = 0;
        int h = 0;
        if( effects->optionRollOverDesktops())
            {
            int x, y;
            Qt::Orientation orientation;
            effects->calcDesktopLayout( &x, &y, &orientation );
            w = x * displayWidth();
            h = y * displayHeight();
            // wrap around if shorter
            if( diffPos.x() > 0 && diffPos.x() > w / 2 )
                diffPos.setX( diffPos.x() - w );
            if( diffPos.x() < 0 && abs( diffPos.x()) > w / 2 )
                diffPos.setX( diffPos.x() + w );
            if( diffPos.y() > 0 && diffPos.y() > h / 2 )
                diffPos.setY( diffPos.y() - h );
            if( diffPos.y() < 0 && abs( diffPos.y()) > h / 2 )
                diffPos.setY( diffPos.y() + h );
            }
        QPoint currentPos = slide_start_pos + mTimeLine.value() * diffPos;
        QRegion currentRegion = QRect( currentPos, QSize( displayWidth(), displayHeight()));
        if( effects->optionRollOverDesktops())
            {
            currentRegion |= ( currentRegion & QRect( -w, 0, w, h )).translated( w, 0 );
            currentRegion |= ( currentRegion & QRect( 0, -h, w, h )).translated( 0, h );
            currentRegion |= ( currentRegion & QRect( w, 0, w, h )).translated( -w, 0 );
            currentRegion |= ( currentRegion & QRect( 0, h, w, h )).translated( 0, -h );
            }
        QRect rect = desktopRect( effects->currentDesktop(), false );
        if( currentRegion.contains( rect ))
            { // current position is in new current desktop (e.g. quickly changing back),
              // don't do full progress
            if( abs( currentPos.x() - rect.x()) > abs( currentPos.y() - rect.y()))
                mTimeLine.setProgress(1 - abs( currentPos.x() - rect.x()) / double( displayWidth()));
            else
                mTimeLine.setProgress(1 - abs( currentPos.y() - rect.y()) / double( displayHeight()));
            }
        else // current position is not on current desktop, do full progress
            mTimeLine.setProgress(0);
        diffPos = rect.topLeft() - currentPos;
        if( mTimeLine.value() <= 0 )
            {
            // Compute starting point for this new move (given current and end positions)
            slide_start_pos = rect.topLeft() - diffPos * 1 / ( 1 - mTimeLine.value() );
            }
        else
            { // at the end, stop
            slide = false;
            mTimeLine.setProgress(0);
            }
        }
    else
        {
        mTimeLine.setProgress(0);
        slide_start_pos = desktopRect( old, false ).topLeft();
        slide = true;
        }
    effects->addRepaintFull();
    }

void DesktopGridEffect::toggle()
    {
    setActive( !activated );
    }
    
void DesktopGridEffect::setActive( bool active )
    {
    if( effects->activeFullScreenEffect() && effects->activeFullScreenEffect() != this )
        return;
    if( activated == active )
        return;
    activated = active;
    if( activated && mTimeLine.value() == 0 )
        setup();
    effects->addRepaintFull();
    }

void DesktopGridEffect::setup()
    {
    keyboard_grab = effects->grabKeyboard( this );
    input = effects->createInputWindow( this, 0, 0, displayWidth(), displayHeight(),
        Qt::PointingHandCursor );
    effects->setActiveFullScreenEffect( this );
    setHighlightedDesktop( effects->currentDesktop());
    }

void DesktopGridEffect::finish()
    {
    if( keyboard_grab )
        effects->ungrabKeyboard();
    keyboard_grab = false;
    if( window_move != NULL )
        effects->setElevatedWindow( window_move, false );
    window_move = NULL;
    effects->destroyInputWindow( input );
    effects->setActiveFullScreenEffect( 0 );
    effects->addRepaintFull(); // to get rid of highlight
    }

void DesktopGridEffect::windowInputMouseEvent( Window, QEvent* e )
    {
    if( e->type() != QEvent::MouseMove
        && e->type() != QEvent::MouseButtonPress
        && e->type() != QEvent::MouseButtonRelease )
        return;
    QMouseEvent* me = static_cast< QMouseEvent* >( e );
    if( e->type() == QEvent::MouseMove )
        {
        // highlight desktop under mouse
        int d = posToDesktop( me->pos());
        if( d != highlighted_desktop )
            setHighlightedDesktop( d );
        if( window_move != NULL ) // handle window moving
            {
            was_window_move = true;
            // windowRect() handles window_move specially
            effects->addRepaint( windowRect( window_move ));
            window_move_pos = me->pos() + window_move_diff;
            effects->addRepaint( windowRect( window_move ));
            }
        }
    if( e->type() == QEvent::MouseButtonPress )
        {
        if( me->buttons() == Qt::LeftButton )
            {
            QRect rect;
            EffectWindow* w = windowAt( me->pos(), &rect );
            if( w != NULL && w->isMovable())
                { // prepare it for moving
                window_move_pos = rect.topLeft();
                window_move_diff = window_move_pos - me->pos();
                window_move = w;
                effects->setElevatedWindow( window_move, true );
                }
            }
        else if(( me->buttons() == Qt::MidButton || me->buttons() == Qt::RightButton ) && window_move == NULL )
            {
            EffectWindow* w = windowAt( me->pos());
            if( w != NULL )
                {
                if( w->isOnAllDesktops())
                    effects->windowToDesktop( w, posToDesktop( me->pos()));
                else
                    effects->windowToDesktop( w, NET::OnAllDesktops );
                effects->addRepaintFull();
                }
            }
        }
    if( e->type() == QEvent::MouseButtonRelease && me->buttons() == 0 )
        {
        if( was_window_move )
            {
            if( window_move != NULL )
                {
                QRect rect = windowRect( window_move );
                int desktop = posToDesktop( rect.center());
                // to desktop's coordinates
                rect.translate( -desktopRect( desktop, true ).topLeft());
                int x, y;
                Qt::Orientation orientation;
                effects->calcDesktopLayout( &x, &y, &orientation );
                effects->moveWindow( window_move, QPoint( rect.x() * x, rect.y() * y ));
                effects->windowToDesktop( window_move, desktop );
                effects->setElevatedWindow( window_move, false );
                window_move = NULL;
                }
            }
        if( !was_window_move && me->button() == Qt::LeftButton )
            {
            effects->setCurrentDesktop( posToDesktop( me->pos()));
            setActive( false );
            }
        was_window_move = false;
        }
    }

void DesktopGridEffect::windowClosed( EffectWindow* w )
    {
    if( w == window_move )
        {
        effects->setElevatedWindow( window_move, false );
        window_move = NULL;
        }
    }

void DesktopGridEffect::grabbedKeyboardEvent( QKeyEvent* e )
    {
    if( e->type() == QEvent::KeyPress )
        {
        int desktop = -1;
        // switch by F<number> or just <number>
        if( e->key() >= Qt::Key_F1 && e->key() <= Qt::Key_F35 )
            desktop = e->key() - Qt::Key_F1 + 1;
        else if( e->key() >= Qt::Key_0 && e->key() <= Qt::Key_9 )
            desktop = e->key() == Qt::Key_0 ? 10 : e->key() - Qt::Key_0;
        if( desktop != -1 )
            {
            if( desktop <= effects->numberOfDesktops())
                {
                setHighlightedDesktop( desktop );
                effects->setCurrentDesktop( desktop );
                setActive( false );
                }
            return;
            }
        switch( e->key())
            { // wrap only on autorepeat
            case Qt::Key_Left:
                setHighlightedDesktop( effects->desktopToLeft( highlighted_desktop,
                    !e->isAutoRepeat()));
                break;
            case Qt::Key_Right:
                setHighlightedDesktop( effects->desktopToRight( highlighted_desktop,
                    !e->isAutoRepeat()));
                break;
            case Qt::Key_Up:
                setHighlightedDesktop( effects->desktopUp( highlighted_desktop,
                    !e->isAutoRepeat()));
                break;
            case Qt::Key_Down:
                setHighlightedDesktop( effects->desktopDown( highlighted_desktop,
                    !e->isAutoRepeat()));
                break;
            case Qt::Key_Escape:
                setActive( false );
                return;
            case Qt::Key_Enter:
            case Qt::Key_Return:
            case Qt::Key_Space:
                effects->setCurrentDesktop( highlighted_desktop );
                setActive( false );
                return;
            default:
                break;
            }
        }
    }

void DesktopGridEffect::setHighlightedDesktop( int d )
    {
    if( d == highlighted_desktop || d <= 0 || d > effects->numberOfDesktops())
        return;
    effects->addRepaint( desktopRect( highlighted_desktop, true ));
    highlighted_desktop = d;
    effects->addRepaint( desktopRect( highlighted_desktop, true ));
    }

bool DesktopGridEffect::borderActivated( ElectricBorder border )
    {
    if( effects->activeFullScreenEffect() && effects->activeFullScreenEffect() != this )
        return false;
    if( border == borderActivate && !activated )
        {
        toggle();
        return true;
        }
    return false;
    }

} // namespace

#include "desktopgrid.moc"