QDialog show method's wierd problem on signal slot mechanism.

[JohannesMunk]

Hi!

Please use the forums-code-tags! In the advanced edit there is a "#"-button!

I think that one of your slots is called on first show, because the value has changed between initialization and then.

Your code is not compilable as is.. so you will have to track down the source of the problem yourself. Remove the Show Hide Workaround. remove all connects - comment them out. And uncomment them one by one.

Maybe it has to do with values you set in Designer? A plain QDoubleSpinboxes ValueChanged doesn't fire on creation..

#include <QApplication>
#include <QDebug>
#include <QtGui>
#include <QtCore>
 
class MainForm : public QDialog
{    Q_OBJECT
public:
    MainForm() {
        spinbox = new QDoubleSpinBox(this);
        connect(spinbox,SIGNAL(valueChanged(double)),this,SLOT(SpinBoxValueChanged(double)));
    }
protected slots:
    void SpinBoxValueChanged(double value) {
        qDebug() << "Value changed";
    }
private:
    QDoubleSpinBox* spinbox;
};
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit()));
 
    MainForm form;
    form.setGeometry(100,100,800,600);
    form.show();
 
    return app.exec();
}
 
#include "main.moc"

#include <QApplication>
#include <QDebug>
#include <QtGui>
#include <QtCore>

class MainForm : public QDialog
{    Q_OBJECT
public:
    MainForm() {
        spinbox = new QDoubleSpinBox(this);
        connect(spinbox,SIGNAL(valueChanged(double)),this,SLOT(SpinBoxValueChanged(double)));
    }
protected slots:
    void SpinBoxValueChanged(double value) {
        qDebug() << "Value changed";
    }
private:
    QDoubleSpinBox* spinbox;
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit()));

    MainForm form;
    form.setGeometry(100,100,800,600);
    form.show();

    return app.exec();
}

#include "main.moc"

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Good luck!

Johannes

[JohannesMunk]

Aah..!! You do it yourself:

void SettingWindow::showEvent(QShowEvent *event)
{
    updateAxisValues();
    updateCurveValues();
    updateCurveSettings();
    QDialog::showEvent(event);
}

void SettingWindow::showEvent(QShowEvent *event)
{
    updateAxisValues();
    updateCurveValues();
    updateCurveSettings();
    QDialog::showEvent(event);
}

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On first show.. this is called.. Thus updating all values.. Thus all ValueChanged-Slots are called..

If you want some other behaviour, you will have to change this :->

Johannes

[umituzun84]

Hi Johannes,

I have realized the explicit value change on controls in my update functions How dummy I am! Thanks so much for your helps. I solved this problem by kind of this codes;

ui.comboBoxCurveName->blockSignals(true); // For stop signal creation
    ui.comboBoxCurveName->clear();
 
    QwtPlotItemList plotItemList = graph->itemList(QwtPlotItem::Rtti_PlotCurve);
 
    for(QwtPlotItemIterator it = plotItemList.begin(); it != plotItemList.end(); it++)
    {
        QwtPlotCurve *curve = (QwtPlotCurve*)(*it);
        ui.comboBoxCurveName->addItem(curve->title().text());
    }
   ui.comboBoxCurveName->blockSignals(false); // For start signal creation

ui.comboBoxCurveName->blockSignals(true); // For stop signal creation
    ui.comboBoxCurveName->clear();

    QwtPlotItemList plotItemList = graph->itemList(QwtPlotItem::Rtti_PlotCurve);

    for(QwtPlotItemIterator it = plotItemList.begin(); it != plotItemList.end(); it++)
    {
        QwtPlotCurve *curve = (QwtPlotCurve*)(*it);
        ui.comboBoxCurveName->addItem(curve->title().text());
    }
   ui.comboBoxCurveName->blockSignals(false); // For start signal creation

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So there is no signal while I am manipulating controls attributes.

Thanks again.
Regards.