QAudioInput stops send data in tabWidged when tab changed - c++

Question

All!
I have some application with 3 tabs, one tab initialized QWidget from other tab. I start QAudioInput in constructor(read to memory, I don't need file) - it starts works. But when I change tab to my widget, data stops and audioInput has status isActive still.
I have changed and minimized sources. It is a cross-compilation for ARM Linux platform. Now it is works usiallu, but few changes active tab crash stream.
int main(int argc, char *argv[])
{
QApplication myapp(argc, argv);
Widget wid;
wid.show();
return myapp.exec();
}
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
// Default widget in new tab
wMetod = new Vnimi(this);//this
ui->tabWidget->insertTab(1, wMetod, "Empty"); // Set Tab's name
ui->pButton_Vnimi->setChecked(true);
/*QButtonGroup **/
grMetod = new QButtonGroup(this);
grMetod->addButton(ui->pButton_Vnimi );
grMetod->addButton(ui->pButton_ExpVibro);
grMetod->setExclusive(true);
connect(grMetod, static_cast<void(QButtonGroup::*)(QAbstractButton *)>(&QButtonGroup::buttonPressed),
[=](QAbstractButton *button){ metChanged(button); });
ui->tabWidget->setCurrentIndex(0);
}
Widget::~Widget()
{
delete ui;
}
void Widget::metChanged(QAbstractButton *button)
{
/* switch for strings */
if( button->objectName() =="pButton_Empty" ) {
ui->tabWidget->removeTab(1);
wMetod->disconnect(); delete wMetod;
wMetod = new Vnimi(this);//this
ui->tabWidget->insertTab(1, wMetod, "Empty"); // Set Tab's name
}else if( button->objectName() =="pButton_Input" ) {
ui->tabWidget->removeTab(1);
wMetod->disconnect(); delete wMetod;
wMetod = new VibrExpr(this);//this
ui->tabWidget->insertTab(1, wMetod, "Input"); // Set Tab's name
}else {
qDebug() << "Unknow method!";
}
qDebug() << button->objectName() << " pressed";
}
VibrExpr::VibrExpr(QWidget *parent) :
QWidget(parent),
ui(new Ui::VibrExpr)
{
ui->setupUi(this);
ui->lb_level->setText( QString().number(minLevel) );
QAudioFormat frmt;
frmt.setCodec( "audio/pcm"), frmt.setChannelCount( 2);
frmt.setSampleRate( 44100), frmt.setSampleType( QAudioFormat::SignedInt);
frmt.setSampleSize( 16);
rawSrc = new QAudioInput(QAudioDeviceInfo::defaultInputDevice(), frmt, this);
rawSrc->setNotifyInterval(250);
connect(rawSrc, SIGNAL(notify()), this, SLOT(slot()));
connect(rawSrc, SIGNAL(stateChanged(QAudio::State)), this, SLOT(iStateChanged(QAudio::State)));
buff = new QBuffer(this);
buff->open(QBuffer::ReadWrite);
connect(buff, SIGNAL(readyRead()), this, SLOT(newData()) );
rawSrc->start(buff);
timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), this, SLOT(timSlot()) );
timer->start(1000);
qDebug() << "Created";
}
void VibrExpr::timSlot()
{
int sbVal = ui->lb_level->text().toInt();
if(sbVal < -6 ) {
sbVal += 1;
}
if(buff != nullptr) \
if(buff->isOpen() && sbVal >= -10) {
qDebug() << "Sz " << buff->size();
rawSrc->stop();
buff->close();
qDebug() << " Input closed";
}
ui->lb_level->setText( QString().number(sbVal));
if(rawSrc != nullptr) qDebug() << "iStat " << rawSrc->state();
}
void VibrExpr::newData(void)
{
int k = buff->size();
QByteArray qba = buff->read(k);
buff->seek(0);
buff->buffer().remove(0, k);
qDebug() << "n=" << k;
}
void VibrExpr::slot(void)
{
qDebug() << "USec:" << rawSrc->processedUSecs() ;
}
void VibrExpr::iStateChanged(QAudio::State state)
{
qDebug() << "Now state: " << state;
}