qmvolumebar.cpp

可以播放MP3,wma等文件格式的播放器

/* qmvolumebar.cpp
 *
 * $Id: qmvolumebar.cpp,v 1.9 2002/03/07 03:44:17 mariuss Exp $
 *
 * Apollo sound player: http://www.apolloplayer.org
 * Copyright(C) 2000-2002 Apollo Team.  See CREDITS file.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The GNU General Public License is also available online at:
 *
 * http://www.gnu.org/copyleft/gpl.html
 */

#include "qmvolumebar.h"
#include "qmmainwindow.h"
#include "qmmixer.h"
#include "qmstatusbar.h"

#include <qlabel.h>
#include <qslider.h>
#include <qtimer.h>
#include <qtoolbar.h>
#include <qtooltip.h>

/*!
  \file qmvolumebar.cpp
  Volume widget
 */

/*!
  \class QmVolumeBar qmvolumebar.h
  \brief Represents the volume bar.

  This class provides functionality for showing a volume bar in the main window.
  Note that, despite the name, this class is derived from QToolBar.  So, it's really
  a tool bar, but it's used as a volume bar.
*/


/*!
  Constructs a volume bar.  The \a status argument is needed for the communication
  with the status bar.
 */

QmVolumeBar::QmVolumeBar(
	QmMainWindow *parent,
	QmStatusBar *status)
	: QToolBar(parent),
	  m_pStatusBar(status),
	  m_VolumePressed(false),
	  m_ShortMessageTime(2000)
{
	m_pMixer = QmMixer::instance();
	setHorizontalStretchable(true);

	(void) new QLabel(tr(" Volume "), this);
	m_pVolume = new QSlider(0, 100, 1, 0, Horizontal, this);
    m_pVolume->setValue( m_pMixer->volume() );

	connect(m_pVolume, SIGNAL(valueChanged(int)), this, SLOT(volumeChanged(int)));
	connect(m_pVolume, SIGNAL(sliderPressed()), this, SLOT(volumePressed()));
	connect(m_pVolume, SIGNAL(sliderReleased()), this, SLOT(volumeReleased()));
	
    m_pVolumeTimer = new QTimer(this);
    connect(m_pVolumeTimer, SIGNAL(timeout()), this, SLOT(refreshVolume()));
    m_pVolumeTimer->start(100, false);
}


/*!

*/

QmVolumeBar::~QmVolumeBar()
{
}


/*!
  Adjust the volume to \a v, this is called whenever the volume slider changes.
*/

void
QmVolumeBar::volumeChanged(
	int v)
{
    if ( ! m_VolumePressed )
        m_pVolumeTimer->blockSignals( true );
	
	m_pMixer->setVolume(v);
	
    if ( ! m_VolumePressed )
        m_pVolumeTimer->blockSignals( false );

    QToolTip::remove( m_pVolume );
    QToolTip::add( m_pVolume, volumeText()  );
    m_pStatusBar->showMessage( volumeText(), 2000 );
}


/*!
  Refreshes the volume slider by reading from the mixer, this is done each 100 ms.
  Adjust the timer value of m_pVolumeTimer to get a better update.
*/

void
QmVolumeBar::refreshVolume()
{
    if ( ! m_VolumePressed )
    {
        m_pVolume->blockSignals( true );
        int vol = m_pMixer->volume();
		
        if ( vol != m_pVolume->value() )
        {
            m_pVolume->setValue( vol );
            updateVolume( true, m_ShortMessageTime );
        }
		
        m_pVolume->blockSignals( false );
    }
}


/*!
  Returns a text string saying "Volume: " and the current volume setting in percentage.
  This is used for tooltips and status bars.
*/

QString
QmVolumeBar::volumeText() const
{
	return QString( "Volume: %1%" ).arg( m_pVolume->value() );
}


/*!
  This is called when the volume slider is pressed.  This makes sure that the volume
  is not updated when it changes externally, i.e. the user can change the volume.
  
  \sa updateVolume()
*/

void
QmVolumeBar::volumePressed()
{
    m_pVolumeTimer->blockSignals( true );
    m_VolumePressed = true;
    updateVolume( true );
}


/*!
  This is called when the volume slider is released.  This makes sure that the volume
  can be updated when it changes externally.
  
  \sa updateVolume()
*/

void
QmVolumeBar::volumeReleased()
{
    m_pVolumeTimer->blockSignals( false );
    m_VolumePressed = false;
    m_pStatusBar->showNameStatus(true);;
    updateVolume( false );
}


/*!
  Updates the volume information tooltip on the slider.
  If \a in_status is true it will show show the volume information
  in the status bar as well using \a time as the timeout.

  \sa updateVolume()
*/

void
QmVolumeBar::updateVolume(
	bool in_status,
	int time)
{
    QToolTip::remove( m_pVolume );
    QToolTip::add( m_pVolume, volumeText() );

    if ( in_status )
        m_pStatusBar->showMessage( volumeText(), time );
    else
        m_pStatusBar->showSongInfo();
}


/*!
  Updates the volume to show the current value of the mixer.

  \sa updateVolume(bool, int)
*/

void
QmVolumeBar::updateVolume()
{
	m_pVolume->setValue(m_pMixer->volume());
}