Constructing QWidget in QWidget

[highlightsong]

I'm trying to play MPlayer in QWidget.

#include "moviemainwindow.h"
 
#include <qvariant.h>
#include <qlayout.h>
#include <qtooltip.h>
#include <qwhatsthis.h>
#include <qaction.h>
#include <qmenubar.h>
#include <qpopupmenu.h>
#include <qtoolbar.h>
#include <qpoint.h>
 
/*
 *  Constructs a MovieMainWindow as a child of 'parent', with the
 *  name 'name' and widget flags set to 'f'.
 *
 */
MovieMainWindow::MovieMainWindow( QWidget* parent, const char* name, WFlags fl )
    : QWidget( parent, name, fl )
{
//    (void)statusBar();
    if ( !name )
	setName( "MovieMainWindow" );
 
//Part for Constucting inner QWidget(screen).
	this->screen = new ScreenMainWindow(this, "", WStyle_Customize|WStyle_NormalBorder);
	this->screen->move( QPoint(0, 0) );
	this->screen->show();
 
//Constructing PushButtons
	this->playBtn = new QPushButton("play", this);
	this->playBtn->setGeometry( 60, 180, 40, 30 );
 
	this->pauseBtn = new QPushButton("pause", this);
	this->pauseBtn->setGeometry( 100, 180, 40, 30 );
 
	this->stopBtn = new QPushButton("stop", this);
	this->stopBtn->setGeometry( 140, 180, 40, 30);
 
//SIGNAL and SLOT
	QObject::connect(playBtn, SIGNAL(clicked()), this, SLOT(play()));
	QObject::connect(pauseBtn, SIGNAL(clicked()), this, SLOT(pause()));
	QObject::connect(stopBtn, SIGNAL(clicked()), this, SLOT(stop()));
 
    languageChange();
    resize( QSize(240, 210).expandedTo(minimumSizeHint()) );
    clearWState( WState_Polished );
 
}
 
/*
 *  Destroys the object and frees any allocated resources
 */
MovieMainWindow::~MovieMainWindow()
{
    // no need to delete child widgets, Qt does it all for us
}
 
/*
 *  Sets the strings of the subwidgets using the current
 *  language.
 */
void MovieMainWindow::languageChange()
{
    setCaption( tr( "Movie" ) );
}
 
//Part for play
void MovieMainWindow::play()
{
	this->proc1 = new QProcess(this);
	this->proc1->addArgument( "mplayer" );
	this->proc1->addArgument( "-slave" );
	this->proc1->addArgument( "-identify" );
	this->proc1->addArgument( "-quiet" );
	this->proc1->addArgument( "-wid" );
	this->proc1->addArgument( this->WID.setNum((int)(this->screen->winId())) );
	this->proc1->addArgument( "/MPlayer/MPlayer-1.0pre8/[P]test.avi" );
	this->proc1->start();
}
 
//Part for pause
void MovieMainWindow::pause()
{
	this->proc1->writeToStdin( "pause\n" );	
}
 
//Part for stop/quit
void MovieMainWindow::stop()
{
	this->proc1->writeToStdin( "quit\n" );
}

#include "moviemainwindow.h"

#include <qvariant.h>
#include <qlayout.h>
#include <qtooltip.h>
#include <qwhatsthis.h>
#include <qaction.h>
#include <qmenubar.h>
#include <qpopupmenu.h>
#include <qtoolbar.h>
#include <qpoint.h>

/*
 *  Constructs a MovieMainWindow as a child of 'parent', with the
 *  name 'name' and widget flags set to 'f'.
 *
 */
MovieMainWindow::MovieMainWindow( QWidget* parent, const char* name, WFlags fl )
    : QWidget( parent, name, fl )
{
//    (void)statusBar();
    if ( !name )
	setName( "MovieMainWindow" );

//Part for Constucting inner QWidget(screen).
	this->screen = new ScreenMainWindow(this, "", WStyle_Customize|WStyle_NormalBorder);
	this->screen->move( QPoint(0, 0) );
	this->screen->show();

//Constructing PushButtons
	this->playBtn = new QPushButton("play", this);
	this->playBtn->setGeometry( 60, 180, 40, 30 );

	this->pauseBtn = new QPushButton("pause", this);
	this->pauseBtn->setGeometry( 100, 180, 40, 30 );

	this->stopBtn = new QPushButton("stop", this);
	this->stopBtn->setGeometry( 140, 180, 40, 30);

//SIGNAL and SLOT
	QObject::connect(playBtn, SIGNAL(clicked()), this, SLOT(play()));
	QObject::connect(pauseBtn, SIGNAL(clicked()), this, SLOT(pause()));
	QObject::connect(stopBtn, SIGNAL(clicked()), this, SLOT(stop()));
	
    languageChange();
    resize( QSize(240, 210).expandedTo(minimumSizeHint()) );
    clearWState( WState_Polished );

}

/*
 *  Destroys the object and frees any allocated resources
 */
MovieMainWindow::~MovieMainWindow()
{
    // no need to delete child widgets, Qt does it all for us
}

/*
 *  Sets the strings of the subwidgets using the current
 *  language.
 */
void MovieMainWindow::languageChange()
{
    setCaption( tr( "Movie" ) );
}

//Part for play
void MovieMainWindow::play()
{
	this->proc1 = new QProcess(this);
	this->proc1->addArgument( "mplayer" );
	this->proc1->addArgument( "-slave" );
	this->proc1->addArgument( "-identify" );
	this->proc1->addArgument( "-quiet" );
	this->proc1->addArgument( "-wid" );
	this->proc1->addArgument( this->WID.setNum((int)(this->screen->winId())) );
	this->proc1->addArgument( "/MPlayer/MPlayer-1.0pre8/[P]test.avi" );
	this->proc1->start();
}

//Part for pause
void MovieMainWindow::pause()
{
	this->proc1->writeToStdin( "pause\n" );	
}

//Part for stop/quit
void MovieMainWindow::stop()
{
	this->proc1->writeToStdin( "quit\n" );
}

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I succeeded to control MPlayer by using QProcess.
My problem is when I clicked "play" button,
I intended to play MPlayer in inner QWidget(screen).
but when I did, MPlayer was played center of monitor.
To do that I intended, what should I do?? Help me plz......