Getting started with Qt for Symbian

From Forum Nokia Wiki

Introduction

This article is for beginners who want to start development in Qt for Symbian. Before following the steps given here please make sure that Carbide.c++, S60 SDK and Qt for Symbian are properly installed.

Prerequisite

Download and Install latest version Qt for Symbian - Installation packages which has links on how to install the latest version

Carbide.c++ 2.0 does not automatically locate your Qt installation, so you need to tell it where Qt is installed. This is done through the following settings:

  Carbide.c++ preferences: Window > Preferences > Qt > Add...

In the above screen you will need to use the directory path for
the current version e.g. c:\Qt\4.6.0-beta\bin and c:\Qt\4.6.0-beta\include

First Step

Open the Carbide IDE and click File > New > Qt Project.

Second Step

A new window will open on the screen. This will show the application types that can be created. Click Qt GUI Widget and then click Next.

Third Step

Enter a name for the project and click Next.

Fourth Step

Select the SDK to create the project for and click Next.

Fifth Step

Select the module(s) and click Next. For our example, click Next without selecting any extra modules.

Sixth Step

The class name is required. By default it is the application name. Click Finish to proceed.

After finishing these steps, the project is ready. Several files are created automatically as shown in the following screenshot.

If you have more than one version of Qt for Symbian installed on your machine, choose the correct version as shown here:

Include Qt Views

Include views for Qt from:

  Carbide.c++ > Windows > Show View > Other... > Qt

View selection depends on the application. However, at least the following views must be selected:

Qt C++ Widget Box
Qt C++ Property Editor
Qt C++ Signal Slot Editor

Adding controls

Open Hello.ui and place the control from the Qt C++ Widget Box.

In this example, two push buttons and one text label will be added.
The display text of an object can be changed by right clicking on object > Change text...
The name of an object can be changed as shown in the following screenshots.

Text label

Hello push button

Exit push button

Implementing Signal and Slot mechanism for Exit push button

Open Hello.ui.
Open the Qt C++ Signal Slot Editor view.

Click to add an entry for handling events on control.
In this example, we will handle events on the Exit push button
The application will terminate when the user clicks the Exit push button

Sender

exitButton is the sender of the signal.

Signal

Select the signal clicked() to be sent by exitButton.

Receiver

HelloClass is the receiver of this event handling mechanism.

Slot

Slot is the action performed when exitButton is clicked(). To exit from the application, select close().

Implementing the Hello push button

In this example, we implement the Hello button event by coding in the files Hello.h and Hello.cpp.

Header file

#ifndef HELLO_H
#define HELLO_H
 
#include <QtGui/QWidget>
#include "ui_Hello.h"
 
class Hello : public QWidget
{
    Q_OBJECT
 
public:
    Hello(QWidget *parent = 0);
    ~Hello();
 
public slots: //We have added this section to handle "clicked()" event on "helloButton"
    void ShowHelloText(); // Fill the label text on clicking "Hello" button 
 
private:
    Ui::HelloClass ui;
};
 
#endif // HELLO_H

Source file

#include "Hello.h"
 
Hello::Hello(QWidget *parent)
    : QWidget(parent)
{
	ui.setupUi(this);
 
        // Signal and slot mechanism for "helloButton"
	QObject::connect(ui.helloButton, SIGNAL(clicked()), this, SLOT(ShowHelloText()));
}
 
Hello::~Hello()
{
 
}
 
//We have implemented the following function to display "HelloWorld!!!" text in TextLabel
void Hello::ShowHelloText()
{
	ui.label->setText("HelloWorld!!!");
}

Output

Initial state

Hello button pressed state

Example application

Extract this example application: Hello.zip
Import the .pro file from the previously extracted application in your Carbide.c++ IDE.

  Carbide.c++ >> Import >> Qt >> Qt Project >> Hello.pro

Feedback

If you encounter any problems in creating your HelloWorld application in Qt, please enter your feedback in the Comment page of this article.

Raise any other Qt for Symbian related questions on the Qt for Symbian Discussion Boards.

ID		Creation date	29 December 2008
Platform	S60 3rd Edition, S60 5th Edition	Tested on devices	Emulator
Category	Qt for Symbian	Subcategory	Getting started

Community: Wiki