CMake + Qt4 + XCode on OSX

After joining TW , the MacBookPro has become my primary dev machine (
including my open source work which is mainly KDE ). I end up using OS X
Leopard most of the time and I love it.

Qt4 is widely used GUI
library. KDE is built on top of Qt4. Many well-known GUI applications such
as Google Earth, Google Talk, Picassa, Skype are all Qt applications.

CMake is a cross-platform
make system. It is used by many big open source projects such as KDE4 and VTK

Using Qt4 you can write rich GUI applications in C++ and in Java ( using Jambi
). Qt4 supports Windows, Linux, OSX , BSD and Solaris.

You can get Qt4 for Mac from here

XCode is the default IDE on OSX.

So I decided to find out a way to use
- CMake as my build system
- Qt4 as my GUI library ( IMO its the best GUI library out there )
- XCode as my IDE

And here's how you do it.

Download CMake from here

Create a folder; let's call it HelloWorld

Create a file called main.cpp in that folder.

Let's write a simple Hello World in Qt4

=======================
#include <QApplication>
#include <QPushButton>
#include <QString>


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

QPushButton hello ("Hello World");

QString string = "my Object name is " + app.objectName();

return app.


}
=======================

Now create a file called CMakeLists.txt in the same folder and write the following:
(comments inline )

=======================
PROJECT ( HelloWorld )

SET ( HelloWorld_SRCS ./main.cpp )

#enable all warnings
ADD_DEFINITIONS ( -Wall )

#This command find Qt4 and all required variables
FIND_PACKAGE (Qt4 REQUIRED)

#The QT_USE_FILE macro is defined by FIND_PACKAGE that contains a path to the CMake script
INCLUDE (${QT_USE_FILE})

INCLUDE_DIRECTORIES( ${CMAKE_BINARY_DIR} )

#Here we instruct to build sample executable from all the source files
ADD_EXECUTABLE ( HelloWorld ${HelloWorld_SRCS} )

#last thing that we need to do is to tell CMake what libraries our executable needs
#Luckily FIND_PACKAGE preparted QT_LIBRARIES variable for us
TARGET_LINK_LIBRARIES( HelloWorld ${QT_LIBRARIES})
=======================

Now for the magic

Run " cmake -G Xcode"

CMake will generate an XCode project for you :)

Just open the HelloWorld.xcodeproj in XCode and you are done.

The obligatory screenshot is attached :)



--
Manish Chakravarty
http://manish-chaks.livejournal.com/