/****************************************************************************
    Copyright (C) 2005 - 2011  Filipe AZEVEDO & The Monkey Studio Team
    http://monkeystudio.org licensing under the GNU GPL.

    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 St, Fifth Floor, Boston, MA  02110-1301  USA
****************************************************************************/
#include "pTreeComboBox.h"

#include <QVBoxLayout>
#include <QTreeView>
#include <QAbstractItemModel>
#include <QComboBox>
#include <QHeaderView>
#include <QStyleOptionComboBox>
#include <QStylePainter>
#include <QMouseEvent>
#include <QApplication>
#include <QDesktopWidget>
#include <QStatusBar>

int recursiveCount( const QModelIndex& it )
{
    int j = 0;
    if ( !it.parent().isValid() )
        j++;
    for ( int i = 0; i < it.model()->rowCount( it ); i++ )
    {
        j++;
        if ( it.model()->rowCount( it.child( i, 0 ) ) )
            j += recursiveCount( it.child( i, 0 ) );
    }
    return j;
}

/*!
    \details Create a new pTreeComboBox object
    \param parent The parent widget
*/
pTreeComboBox::pTreeComboBox( QWidget* parent )
    : QWidget( parent ), mFrame( new QFrame( this ) ), mView( 0 ), mModel( 0 ), mForce( false )
{
    mFrame->setWindowFlags( Qt::Dialog | Qt::FramelessWindowHint );
    QVBoxLayout* vl = new QVBoxLayout( mFrame );
    vl->setSpacing( 0 );
    vl->setMargin( 3 );
    
    mIconSize = QSize( 16, 16 );
    mSizeHint = QComboBox().sizeHint();
    setSizePolicy( QSizePolicy( QSizePolicy::Preferred, QSizePolicy::Fixed ) );
    setView( new QTreeView );
    mView->header()->hide();
    mView->resize( mView->viewport()->size() );
    mFrame->installEventFilter( this );
}

pTreeComboBox::~pTreeComboBox()
{ delete mView; }

bool pTreeComboBox::eventFilter( QObject* object, QEvent* event )
{
    if ( object == mFrame )
    {
        if ( event->type() == QEvent::WindowDeactivate )
            if ( !rect().contains( mapFromGlobal( QCursor::pos() ) ) )
                hidePopup();
        return QWidget::eventFilter( object, event );
    }

    QEvent::Type t = event->type();
    if ( t == QEvent::Hide )
    {
        if ( currentIndex() != mIndex )
        {
            mForce = false;
            mView->clearSelection();
            mView->setCurrentIndex( mIndex );
            mForce = true;
        }
        update();
    }
    else if ( t == QEvent::MouseMove )
    {
        if ( QMouseEvent* me = static_cast<QMouseEvent*>( event ) )
        {
            QModelIndex i = mView->indexAt( mView->mapFromGlobal( me->globalPos() ) );
            if ( mView->currentIndex() != i )
            {
                emit highlighted( i );
                mForce = false;
                mView->clearSelection();
                mView->setCurrentIndex( i );
                mForce = true;
            }
        }
    }
    return QWidget::eventFilter( object, event );
}

/*!
    \details Return the widget size hint
*/
QSize pTreeComboBox::sizeHint() const
{ return mSizeHint; }

/*!
    \details Return the number of row in the model
*/
int pTreeComboBox::count() const
{ return recursiveCount( mModel->index( 0, 0 ) ); }

/*!
    \details Return the iconSize
*/
QSize pTreeComboBox::iconSize() const
{ return mIconSize; }

/*!
    \details Set the icon size
*/
void pTreeComboBox::setIconSize( const QSize& s )
{
    if ( mIconSize != s )
    {
        mIconSize = s;
        update();
    }
}

void pTreeComboBox::paintEvent( QPaintEvent* /*event*/ )
{
    QStyleOptionComboBox o;

    // QStyleOption
    o.initFrom( this );
    
    // QStyleOptionComplex
    o.activeSubControls = 0;
    o.subControls = QStyle::SC_ComboBoxEditField | QStyle::SC_ComboBoxArrow | QStyle::SC_ComboBoxFrame;

    // QStyleOptionComboBox
    QModelIndex i = currentIndex();
    o.currentIcon = i.data( Qt::DecorationRole ).value<QIcon>();
    o.iconSize = mView && mView->iconSize() != QSize( -1, -1 ) ? mView->iconSize() : iconSize();
    o.currentText = i.data( Qt::DisplayRole ).toString();
    o.editable = false;
    o.frame = true;
    o.popupRect = QRect();
    
    if ( !mFrame->isVisible() && rect().contains( mapFromGlobal( QCursor::pos() ) ) )
        o.state |= QStyle::State_MouseOver;
    
    if ( mFrame->isVisible() )
        o.state |= QStyle::State_On;
    
    QStylePainter p( this );
    p.drawComplexControl( QStyle::CC_ComboBox, o );
    p.drawControl( QStyle::CE_ComboBoxLabel, o );
}

void pTreeComboBox::hideEvent( QHideEvent* /*event*/ )
{ hidePopup(); }

void pTreeComboBox::enterEvent( QEvent* /*event*/ )
{ update(); }

void pTreeComboBox::leaveEvent( QEvent* /*event*/ )
{ update(); }

void pTreeComboBox::mousePressEvent( QMouseEvent* /*event*/ )
{
    if ( !mView )
        return;
    mFrame->isVisible() ? hidePopup() : showPopup();
}

/*!
    \details Hide the popup
*/
void pTreeComboBox::hidePopup()
{
    if ( mFrame->isVisible() )
        mFrame->hide();
}

void pTreeComboBox::calculPopupGeometry()
// code copied from QComboBox  original class from Trolltech, arrange to feet my needs
{
    //int itemHeight = mView->sizeHintForIndex( mModel->index( 0, 0 ) ).height();
    QRect listRect( rect() );
    //listRect.setHeight(itemHeight * count() +( 2 *mFrame->layout()->spacing() ) +( 2 *mFrame->frameWidth() ) );
    QRect screen = QApplication::desktop()->screenGeometry(this);
    QPoint below = mapToGlobal(listRect.bottomLeft());
    int belowHeight = screen.bottom() - below.y();
    QPoint above = mapToGlobal(listRect.topLeft());
    int aboveHeight = above.y() - screen.y();
    
    // make sure the widget fits on screen
        if (listRect.width() > screen.width() )
        listRect.setWidth(screen.width());
    if (mapToGlobal(listRect.bottomRight()).x() > screen.right()) {
        below.setX(screen.x() + screen.width() - listRect.width());
        above.setX(screen.x() + screen.width() - listRect.width());
    }
    if (mapToGlobal(listRect.topLeft()).x() < screen.x() ) {
        below.setX(screen.x());
        above.setX(screen.x());
    }
        
    if (listRect.height() <= belowHeight) {
        listRect.moveTopLeft(below);
    } else if (listRect.height() <= aboveHeight) {
        listRect.moveBottomLeft(above);
    } else if (belowHeight >= aboveHeight) {
        listRect.setHeight(belowHeight);
        listRect.moveTopLeft(below);
    } else {
        listRect.setHeight(aboveHeight);
        listRect.moveBottomLeft(above);
    }

    mFrame->setGeometry( listRect );
}

/*!
    \details Show the popup
*/
void pTreeComboBox::showPopup()
{
    if ( !mFrame->isVisible() && mView )
    {
        mIndex = currentIndex();
        calculPopupGeometry();
        mFrame->show();
        update();
    }
}

/*!
    \details Return the view widget
*/
QTreeView* pTreeComboBox::view() const
{ return mView; }

/*!
    \details Set the view widget
*/
void pTreeComboBox::setView( QTreeView* view )
{
    if ( mView == view )
        return;
    delete mView;
    mView = view;
    if ( mView )
    {
        if ( mFrame->layout()->count() )
            qobject_cast<QVBoxLayout*>( mFrame->layout() )->insertWidget( 0, mView );
        else
        {
            mFrame->layout()->addWidget( mView );
            QStatusBar* sb = new QStatusBar( mFrame );
            sb->setFixedHeight( 16 );
            mFrame->layout()->addWidget( sb );
        }
        mView->setEditTriggers( QAbstractItemView::NoEditTriggers );
        mView->setMouseTracking( true );
        mView->viewport()->installEventFilter( this );
        setModel( mModel );
        connect( mView, SIGNAL( activated( const QModelIndex& ) ), this, SLOT( internal_activated( const QModelIndex& ) ) );
        connect( mView, SIGNAL( clicked( const QModelIndex& ) ), this, SLOT( internal_clicked( const QModelIndex& ) ) );
    }
}

/*!
    \details Return the used model
*/
QAbstractItemModel* pTreeComboBox::model() const
{ return mModel; }

/*!
    \details Set the model
*/
void pTreeComboBox::setModel( QAbstractItemModel* model )
{
    if ( mModel != model )
        mModel = model;
    if ( mView && mView->model() != mModel )
    {
        mView->setModel( mModel );
        connect( mView->selectionModel(), SIGNAL( currentChanged( const QModelIndex&, const QModelIndex& ) ), this, SLOT( internal_currentChanged( const QModelIndex&, const QModelIndex& ) ) );
    }
}

/*!
    \details Return the root index
*/
QModelIndex pTreeComboBox::rootIndex() const
{ return mView ? mView->rootIndex() : QModelIndex(); }

/*!
    \details Set the root index
*/
void pTreeComboBox::setRootIndex( const QModelIndex& index )
{ if ( mView ) mView->setRootIndex( index ); }

/*!
    \details Return the current index
*/
QModelIndex pTreeComboBox::currentIndex() const
{
    if ( mView )
        return mFrame->isVisible() ? mIndex : mView->currentIndex();
    return QModelIndex();
}

/*!
    \details Set the current index
*/
void pTreeComboBox::setCurrentIndex( const QModelIndex& index )
{
    if ( mView && ( currentIndex() != index || !index.isValid() ) )
    {
        mIndex = index;
        mForce = true;
        mView->clearSelection();
        mView->setCurrentIndex( index );
        mForce = false;
        update();
    }
}

/*!
    \details Expand all rows
*/
void pTreeComboBox::expandAll()
{ if ( mView ) mView->expandAll(); }

void pTreeComboBox::internal_activated( const QModelIndex& index )
{
    if ( !( index.flags() & Qt::ItemIsEnabled ) || !( index.flags() & Qt::ItemIsSelectable ) )
    {
        return;
    }
    
    if ( mIndex != index )
    {
        mIndex = index;
        emit currentChanged( index );
    }
    emit activated( index );
    hidePopup();
}

void pTreeComboBox::internal_clicked( const QModelIndex& index )
{
    if ( !( index.flags() & Qt::ItemIsEnabled ) || !( index.flags() & Qt::ItemIsSelectable ) )
    {
        return;
    }
    
    if ( mIndex != index )
    {
        mIndex = index;
        emit currentChanged( index );
    }
    emit clicked( index );
    hidePopup();
}

void pTreeComboBox::internal_currentChanged( const QModelIndex& current, const QModelIndex& )
{
    if ( mForce )
        emit currentChanged( current );
}