GUI PROGRAMMING USING QT TOOLKIT :: open source lab

EX NO:3b

GUI PROGRAMMING USING QT TOOLKIT

17.07.12

AIM

To write a simple GUI program using QT toolkit

PREREQUISITE:

C/C++ - QT

INTRODUCTION:

Qt is a cross-platform application development framework. Some of the well known applications developed with Qt are KDE, Opera, Google Earth and Skype. Qt was first publicly released on May 1995. It is dual licensed. That means, it can be used for creating open source applications as well as commercial ones. Qt toolkit is a very powerful toolkit. It is well established in the open source community

GUI programs using the Qt toolkit:

To install Qt Toolkit:

[root@localhost Desktop]# yum install qt-devel qt-demos qt-examples qt-doc

Loaded plugins: langpacks, presto, refresh-packagekit

Adding en_US to language list

Setting up Install Process

Package 1:qt-devel-4.7.4-7.fc14.i686 already installed and latest version

Package 1:qt-demos-4.7.4-7.fc14.i686 already installed and latest version

Package 1:qt-examples-4.7.4-7.fc14.i686 already installed and latest version

Package 1:qt-doc-4.7.4-7.fc14.noarch already installed and latest version

Nothing to do

Follow the steps to write a simple hello world program:

[root@localhost Desktop]# mkdir qthello

[root@localhost Desktop]# cd qthello

[root@localhost qthello]# vi qthello.cpp

PROGRAM:

#include <qapplication.h>
#include <qpushbutton.h>

int main( int argc, char **argv )
{

QApplication a( argc, argv );
QPushButton hello( "Hello world!", 0 );
hello.resize( 100, 30 );
a.setMainWidget( &hello );
hello.show();
return a.exec();

}

[root@localhost qthello]# vi qthello.pro

[root@localhost qthello]# qmake -o Makefile qthello.pro

[root@localhost qthello]# make

g++ -c -pipe -Wall -W -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -DQT_NO_DEBUG -DQT_SHARED -DQT_TABLET_SUPPORT -DQT_THREAD_SUPPORT -I/usr/lib/qt-3.3/mkspecs/default -I. -I/usr/lib/qt-3.3/include -o qthello.o qthello.cpp

g++ -o qthello qthello.o -L/usr/lib/qt-3.3/lib -lqt-mt -lXext -lX11 -lm

[root@localhost qthello]# ./qthello

Session management error: None of the authentication protocols specified are supported

RESULT

Thus ,using qt toolkit a button had been created and the output was verified.