Why modeless dialog block keyboard input

Hi to all,
I wrote a very simple informative dialog:

.h

Code:

#ifndef __INFODLG_H__
#define __INFODLG_H__
 
#include "GeneratedFiles/ui_infoDlg.h"
 
#include <QDialog>
 
class MainWindow;
class QTimer;
 
class InfoDlg : public QDialog
{
	Q_OBJECT
 
public:
	InfoDlg( QWidget *parent );
	virtual ~InfoDlg();
 
public slots:
	void SetText(const QString&);
	void CloseDialogAfter(int msec);
 
protected:
 
private:
	Ui::infoDlg ui;
};
 
#endif __INFODLG_H__

and the .cpp

Code:

#include "InfoDlg.h"
#include <QTimer>
 
InfoDlg::InfoDlg( QWidget *parent )
: QDialog(parent)
{
	ui.setupUi(this);
	setWindowFlags( Qt::FramelessWindowHint | Qt::Dialog );
	setAttribute( Qt::WA_DeleteOnClose );
	setWindowOpacity(0.8);
}
 
InfoDlg::~InfoDlg()
{
}
 
void InfoDlg::SetText(const QString& text)
{
	ui.infoLabel->setText(text);
}
 
// close the dialog after x msec
void InfoDlg::CloseDialogAfter(int msec)
{
	QTimer::singleShot( msec, this, SLOT(close() ) );
}

Here the ui file for those that would reproduce the dialog

Code:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>infoDlg</class>
 <widget class="QDialog" name="infoDlg">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>382</width>
    <height>92</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Dialog</string>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout">
   <item>
    <widget class="QLabel" name="infoLabel">
     <property name="text">
      <string/>
     </property>
     <property name="alignment">
      <set>Qt::AlignCenter</set>
     </property>
    </widget>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections/>
</ui>

Here an example of usage of the dialog

Code:

void WaveWidget::EncodingStart()
{
	dlg = new InfoDlg(this);
	dlg->SetText("Encoding process started");
	dlg->show();
}
 
void WaveWidget::EncodingEnd()
{
	if( !m_WaveDisplay->m_ListaMarcatori.isEmpty() )
	{
		m_WaveDisplay->deteleMarkers();
	}
 
	m_WaveDisplay->waveSelectionStarted = false;
 
	dlg->SetText("Encoding process finished");	
	dlg->CloseDialogAfter( 2000 );
}

The EncodingStart() and EncodingEnd() are two slot of WaveWidget connected to a separated thread so:

Code:

void WaveWidget::CutSound()
{
   bool bg = false;
   if( m_bgSndCheckBox->isChecked() )
	bg = true;
 
  WaveEncoder* encoderThread = new WaveEncoder( m_SoundName, m_outputDir, m_bgFile, bg, m_wave,   m_WaveDisplay );
  connect( encoderThread, SIGNAL( started() ), this, SLOT( CodificaStart() ) );
  connect( encoderThread, SIGNAL( finished() ), this, SLOT( CodificaEnd() ) );
 
  encoderThread->setOffset(m_soundOffset);
  encoderThread->start();
}

I run the infoDlg in modeless mode with show() but unfortunately it block my gui ( gui doesn't accept further keyboard input and it's blocked ) I don't understand why.