Source: channelscanner.h

// -*- c++ -*-

/*
 *
 * Copyright (C) 2002 Richard Moore 
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef CHANNELSCANNER_H
#define CHANNELSCANNER_H

#include 
#include 

class V4LDev;
class Channel;
class ChannelStore;
class ChannelScannerRegion;

/**
 * Channel scanner backend.
 *
 * @version $Id: channelscanner.h,v 1.2 2002/03/17 02:08:18 rich Exp $
 * @author Richard Moore, rich@kde.org
 */
class ChannelScanner : public QObject
{
    Q_OBJECT

public:
    ChannelScanner( QObject *parent=0, const char *name=0 );
    virtual ~ChannelScanner();

    void setDevice( V4LDev *device );
    V4LDev *device() const { return dev; }

    void setStore( ChannelStore *store );
    ChannelStore *store() const { return chanStore; }

    /**
     * Loads an XML region definition using ChannelScannerRegion.
     */
    bool loadRegionFile( const QString &filename );

    /**
     * Returns the last channel found (or 0 if we haven't found one).
     */
    Channel *channel() const { return chan; }

public slots:
    /**
     * Scans the current device and stores any channels found in the
     * current store. This slot only kicks of the scan, so it returns
     * quickly, the actual scanning is done with timers so the GUI
     * doesn't block.
     */
    void scan();

signals:
    /**
     * Emitted when we start scanning.
     */
    void started();

    /**
     * Emitted when we make one percent of progress.
     */
    void progress( int );

    /**
     * Emitted when the scan is complete.
     */
    void done();

    /**
     * Emitted when the scan is complete.
     *
     * @param success true iff we found any channels.
     */
    void done( bool success );

    /**
     * Emitted whenever we find a channel.
     */
    void foundChannel();

protected:
    /**
     * Prepare for a scan. Returns true if we're set to go.
     */
    bool first();

    /**
     * Advance the scan by one. Returns true if we can continue, and
     * false if we hit the end of the range.
     */
    bool next();

    /**
     * Tidy up after the full range has been scanned.
     */
    bool last();

    /**
     * Scans the current frequency and returns true if a channel is found.
     * Note that this relies on being inside the first(), next(), last()
     * loop and can't just scan an arbitrary place.
     */
    bool scanCurrent();

    /**
     * Initialise the frequency according to the region settings.
     */
    bool regionFirst();

    /**
     * Advance the frequency according to the region settings.
     */
    bool regionNext();

protected slots:
    /**
     * Adds the current frequency as a channel.
     */
    void addChannel();

    /**
     * Scans a chunk of the frequency range, then schedulers a timer to
     * call itself to process the next chunk.
     */
    void scanChunk();

private:
    V4LDev *dev;
    unsigned long freq;
    unsigned long min;
    unsigned long max;
    unsigned long start;
    int adj;

    int percentDone;
    unsigned long lastProgress;
    unsigned long onePercent;
    unsigned long oneChunk;

    ChannelStore *chanStore;
    Channel *chan;
    ChannelScannerRegion *region;
};

#endif // CHANNELSCANNER_H