source: trunk/examples/dragdrop/dropsite.cpp@ 168

/****************************************************************************
** $Id: dropsite.cpp 160 2006-12-11 20:15:57Z dmik $
**
** Drop site example implementation
**
** Created : 979899
**
** Copyright (C) 1997 by Trolltech AS.  All rights reserved.
**
** This file is part of an example program for Qt.  This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/

#include "dropsite.h"
#include "secret.h"
#include <qevent.h>
#include <qpixmap.h>
#include <qdragobject.h>
#include <qimage.h>
#include <qdir.h>


DropSite::DropSite( QWidget * parent, const char * name )
    : QLabel( parent, name )
{
    setAcceptDrops(TRUE);
}


DropSite::~DropSite()
{
    // nothing necessary
}


void DropSite::dragMoveEvent( QDragMoveEvent *e )
{
    // Check if you want the drag at e->pos()...
    // Give the user some feedback - only copy is possible
    e->acceptAction( e->action() == QDropEvent::Copy );
}


void DropSite::dragEnterEvent( QDragEnterEvent *e )
{
    // Check if you want the drag...
    if ( SecretDrag::canDecode( e )
      || QTextDrag::canDecode( e )
      || QImageDrag::canDecode( e )
      || QUriDrag::canDecode( e ) )
    {
        e->accept();
    }


    // Give the user some feedback...
    QString t;
    const char *f;
    for( int i=0; (f=e->format( i )); i++ ) {
        if ( *(f) ) {
            if ( !t.isEmpty() )
                t += "\n";
            t += f;
        }
    }
    emit message( t );
    setBackgroundColor(white);
}

void DropSite::dragLeaveEvent( QDragLeaveEvent * )
{
    // Give the user some feedback...
    emit message("");
    setBackgroundColor(lightGray);
}


void DropSite::dropEvent( QDropEvent * e )
{
    setBackgroundColor(lightGray);

    // Try to decode to the data you understand...
    QStrList strings;
    if ( QUriDrag::decode( e, strings ) ) {
        QString m("Full URLs:\n");
        for (const char* u=strings.first(); u; u=strings.next())
            m = m + "   " + u + '\n';
        QStringList files;
        if ( QUriDrag::decodeLocalFiles( e, files ) ) {
            m += "Files:\n";
            for (QStringList::Iterator i=files.begin(); i!=files.end(); ++i)
                m = m + "   " + QDir::convertSeparators(*i) + '\n';
        }
        setText( m );
        setMinimumSize( minimumSize().expandedTo( sizeHint() ) );
        return;
    }

    QString str;
    if ( QTextDrag::decode( e, str ) ) {
        setText( str );
        setMinimumSize( minimumSize().expandedTo( sizeHint() ) );
        return;
    }

    QPixmap pm;
    if ( QImageDrag::decode( e, pm ) ) {
        setPixmap( pm );
        setMinimumSize( minimumSize().expandedTo( sizeHint() ) );
        return;
    }

    if ( SecretDrag::decode( e, str ) ) {
        setText( str );
        setMinimumSize( minimumSize().expandedTo( sizeHint() ) );
        return;
    }
}

DragMoviePlayer::DragMoviePlayer( QDragObject* p ) :
    QObject(p),
    dobj(p),
    movie("trolltech.gif" )
{
    movie.connectUpdate(this,SLOT(updatePixmap(const QRect&)));
}

void DragMoviePlayer::updatePixmap( const QRect& )
{
    dobj->setPixmap(movie.framePixmap());
}

void DropSite::mousePressEvent( QMouseEvent * /*e*/ )
{
    QDragObject *drobj;
    if ( pixmap() ) {
        drobj = new QImageDrag( pixmap()->convertToImage(), this );
#if 1
        QPixmap pm;
        pm.convertFromImage(pixmap()->convertToImage().smoothScale(
            pixmap()->width()/3,pixmap()->height()/3));
        drobj->setPixmap(pm,QPoint(-5,-7));
#else
        // Try it.
        (void)new DragMoviePlayer(drobj);
#endif
    } else {
        drobj = new QTextDrag( text(), this );
    }
    drobj->dragCopy();
}


void DropSite::backgroundColorChange( const QColor & )
{
    // Reduce flicker by using repaint() rather than update()
    repaint();
}