Qt logo

Yesterday I decided to investigate Qt from Trolltech and get something working with it.

Very briefly, Qt is a library that allows you to create interfaces. Lots of programs use it (a lot of KDE programs do) and i’ve heard a lot of good things about it but alway thought naaa, this is too complicated. So yesterday i downloaded all the libraries of Qt4 (Qt4 is free for open-source development) and tired a tutorial and … it wouldn’t work – I got some error messages saying that it wouldn’t recognise some libraries (qapplication.h: No such file or directory)!

What the hell had I got wrong?
Actually I don’t know. I had installed most of the Qt4 stuff in adept I deemed necessary but it seems that I had not installed all Qt4 stuff (in my foolishness I tried removing some Qt3 stuff – somethin not to do – and it removed amarok as a result. Had to reinstall it).
After installing all (or most) of the Qt4 stuff it worked and I was really surprised as to how easy it is to create interface code.

qt adept

The best tutorial is I think on the Qt website.

Getting started

First of all get all (or most) of the Qt4 stuff in adpet installed.

Then type the following code that is available from tutorial 1:

 #include <QApplication>
#include <QPushButton>

int main(int argc, char *argv[])
{
QApplication app(argc, argv);

QPushButton hello("Hello world!");
hello.resize(100, 30);

hello.show();
return app.exec();
}

Then save the file as (for example) main.cpp.

Next at the prompt type:

$qmake -project (creates a .pro file)
$qmake (creates a platform specific makefile)
$make (calls the makefile and produce the exe)

Run the exe to get your first app working. It’s really easy.

Have Fun and Tranks Trolltech!