[SOLVED] Reload contents of QTableView from textfile

amban

Hi Friends,
I have a QTableView which is generated by reading a text file line-by-line. This text file is changing pretty often. I have a refresh button with which i want to reload the table i.e. again read the textfile and generate the table.....
I followed previous discussions and added this :

@QTimer *mytimer = new QTimer(this);

//code to read a txt file line by line and generating a QTableView

connect(mytimer, SIGNAL(timeout()),
         this, SLOT(update()) );
         guitimer->start(1000);

@
But this is not working. Pls suggest how to correct this ?

Thanks

giesbert

you are triggering the wrong timer...

amban

I made an error in posting ....
@QTimer *mytimer = new QTimer(this);

//code to read a txt file line by line and generating a QTableView

connect(mytimer, SIGNAL(timeout()),
         this, SLOT(update()) );
         mytimer->start(1000);

@

But it doesnt work.....

giesbert

It is a bit less code to say what's wrong.

what is this?

has this a sot called update?

do you get some debugger messages?

amban

This is the code
@
PendingTab::PendingTab(QWidget *parent)
:QWidget(parent)
{

QTimer *guitimer = new QTimer(this);
QVBoxLayout *mainLayout = new QVBoxLayout;

refreshbutton = new QPushButton(tr("Refresh"));
findbutton = new QPushButton(tr("Find"));
findstring = new QLineEdit;

QHBoxLayout *findLayout = new QHBoxLayout;
findLayout->addWidget(findstring);
findLayout->addWidget(findbutton);

mytable = new QTableView();
mytablemodel = new QStandardItemModel();
mytablemodel->setRowCount(0);

int Max_num_of_Columns(10);
int Max_Number_of_Lines(0);
mytablemodel->setColumnCount(Max_num_of_Columns);

QStringList header_list ;
header_list << ......
mytablemodel->setHorizontalHeaderLabels(header_list);

QProcess *proc = new QProcess();

QFile file&#40;"/path/to/a/text/file"&#41;;
if (!file.open(QIODevice::ReadWrite | QIODevice::Text))
     qDebug() << "Error opening file";

proc->setStandardOutputFile&#40;"/path/"&#41;;
proc->start("/path/to/the/script/file");
proc->waitForFinished();

QTextStream InputDataFile&#40;&file&#41;;
while (!InputDataFile.atEnd())
{

    QString line = InputDataFile.readLine();

    line = line.trimmed();
    QStringList fields = line.split(QRegExp("\\s+"));

    if (fields.size() == Max_num_of_Columns)
    {
        for (int column=0; column< Max_num_of_Columns; column++)
        {
            QStandardItem *item = new QStandardItem(fields[column]);
            mytablemodel->setItem(Max_Number_of_Lines, column, item);

        }
        Max_Number_of_Lines++ ;
    }

}

mytable->setModel(mytablemodel);
mytable->setAlternatingRowColors(true);
mainLayout->addWidget(mytable);
mainLayout->addWidget(refreshbutton);
mainLayout->addLayout(findLayout);
setLayout(mainLayout);

file.close();

connect(guitimer, SIGNAL(timeout()),
         this, SLOT(update()) );
         guitimer->start(1000);

connect(refreshbutton, SIGNAL(clicked()),
          this, SLOT(update()));

connect(findbutton, SIGNAL(clicked()),
        this, SLOT(findButtonClicked()));

connect(findstring, SIGNAL(textChanged(QString)), // For changing the background of the searched key
        this, SLOT(clearColoredRows()));

mytable->setSortingEnabled(true);

}
@

I am using the default update() slot which autopopulated for slots related to "this" i.e. my widget

tobias.hunger

Maybe a "QFileSystemWatcher":http://doc.trolltech.com/4.7/qfilesystemwatcher.html would be better than doing timer-based polling of the file?

wongk

Update causes the widget to repaint, which has nothing to do with the data in your model. Where are you updating the data in your model?

amban

Thanks all for your help. I was unaware that repainting widget doesnt do anything to the data model. So i created a new slot loadTable() and moved the loading table data to the slot. So now i do

@connect(guitimer, SIGNAL(timeout()), this, SLOT(loadTable())); @

Thanks a lot. It works fine.