/******************************************************************************
*
* Copyright (C) 2002 Hugo PEREIRA <mailto: hugo.pereira@free.fr>
*
* This 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 software 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 <QAbstractTextDocumentLayout>
#include <QTextDocument>
#include <QTextBlock>

#include "BlockHighlight.h"
#include "TextEditor.h"
#include "TextBlockData.h"

//_______________________________________________________________________
BlockHighlight::BlockHighlight( TextEditor* parent ):
QObject( parent ),
Counter( "BlockHighlight" ),
parent_( parent )
{ Debug::Throw( "BlockHighlight::BlockHighlight.\n" ); }

//______________________________________________________________________
void BlockHighlight::clear()
{

    if( cleared_ ) return;

    // loop over all blocks
    for( auto&& block = parent_->document()->begin(); block.isValid(); block = block.next() )
    {

        if( parent_->textCursor().block() == block && isEnabled() ) continue;

        TextBlockData* data( static_cast<TextBlockData*>( block.userData() ) );
        if( data && data->hasFlag( TextBlock::CurrentBlock ) )
        {

            // reset flag
            data->setFlag( TextBlock::CurrentBlock, false );

            // mark contents dirty to trigger document update
            _updateEditors();

        }

    }

    cleared_ = true;

}

//______________________________________________________________________
void BlockHighlight::highlight()
{

    if( !isEnabled() ) return;

    clear();
    timer_.start(50, this );

}

//______________________________________________________________________
void BlockHighlight::timerEvent( QTimerEvent* event )
{

    if( event->timerId() != timer_.timerId() ) return QObject::timerEvent( event );
    timer_.stop();
    _highlight();

}

//______________________________________________________________________
void BlockHighlight::_highlight()
{

    if( !isEnabled() ) return;

    // retrieve current block
    QTextBlock block( parent_->textCursor().block() );

    TextBlockData* data = static_cast<TextBlockData*>( block.userData() );
    if( !data )
    {
        data = new TextBlockData;
        block.setUserData( data );
    } else if( data->hasFlag( TextBlock::CurrentBlock ) ) return;

    // need to redo the clear a second time, forced,
    // in case the previous draw action occured after the previous clear.
    cleared_ = false;
    clear();

    // mark block as current
    data->setFlag( TextBlock::CurrentBlock, true );

    // mark contents dirty to trigger document update
    _updateEditors();

    cleared_ = false;

}

//______________________________________________________________________
void BlockHighlight::_updateEditors()
{

    Base::KeySet<TextEditor> editors( parent_ );
    editors.insert( parent_ );
    for( const auto& editor:editors ) editor->viewport()->update();
}