CODEWITHSUNDEEP
c++qtqt4qt-creator
Valla
Valla

Reputation: 2442

How to load data on tab click in qt creator

I am using the QtabWidget in Qt creator and created three tabs(tab-1,tab-2,tab-3).Each tab has around 30 fields.Now when I run the application initially the user would be on tab-1.At present all the data which is displayed in all the three tabs is pulled at once. Is there any way that when the user clicks on Tab-2 only then the data corresponding to tab-2 is loaded and the same for tab-3. I am looking for some function like "onTabClick". I checked the slots associated with the tab widget and could not find any.

Code for my form in Qt:

Mainwindow.cpp 

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <ctime>
#include <iostream>
#include <QPixmap>
#include <stdio.h>
#include <QProcess>
#include <QString>
#include <QPainter>
#include <QPen>
#include <QBrush>
#include <QLabel>
#include <QTimer>
#include <ctime>


using namespace std;

void MainWindow::onTabChanged(int tabIndex) {

    cout<<"the tab index is:"<<tabIndex<<endl;
    if (tabIndex == 0) {
        // Create the first tab elements

        cout<<"tab 0"<<endl;
    } else if (tabIndex == 1) {
        // ...

        cout<<"tab 1"<<endl;

    }
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{


    time_t now = time(0);
    char* dt = ctime(&now);

    ui->setupUi(this);
    this->setWindowTitle("First Qt Project");
    connect(ui->tabWidget, SIGNAL(currentChanged(int)), this, SLOT(onTabChanged(int)));    

}



MainWindow::~MainWindow()
{
    delete ui;
}

MainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:


    void onTabChanged(int tabIndex);



private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

Upvotes: 1

Views: 2657

Answers (2)

Valla
Valla

Reputation: 2442

I found the solution for this issue:

by default any slots which are created are under the section of "private slots" in the MainWindow.h file as shown below:

private slots:
//default slots created from the ui(when the user right clicks on a button and then connects to a     slot)

So in my case since the function onTabChanges is a user defined function and I manually created a SLOT for this function this should be in public slots section. So including it this way resolved the issue.

public slots:

void onTabChanged(int tabIndex);

Upvotes: 0

vahancho
vahancho

Reputation: 21220

You can use QTabWidget::currentChanged(int) signal to handle the tab changing event. I.e:

Connect signal with corresponding slot:

connect(tabWidget, SIGNAL(currentChanged(int)), this, SLOT(onTabChanged(int)));

and in the slot:

void MyClass::onTabChanged(int tabIndex) {
    if (tabIndex == 0) {
        // Create the first tab elements
    } else if (tabIndex == 1) {
        // ...
    }
}

Upvotes: 1

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