Development/Tutorials/First program
Your first program shall greet the world with a friendly "hello world", what else ? For that, we will use a KMessageBox. To get more information about the KMessageBox-Class, type "kde: kmessagebox" in your konqueror and it will redirect you to http://developer.kde.org/documentation/library/cvs-api/kdelibs-apidocs/kdeui/html/classKMessageBox.html
- include <QString>
- include <kapplication.h>
- include <kaboutdata.h>
- include <kmessagebox.h>
- include <kcmdlineargs.h>
int main (int argc, char *argv[])
{
KAboutData aboutData( "tutorial1", "Tutorial 2",
"1.0", "KMessageBox popup",
KAboutData::License_GPL, "(c) 2006" );
KCmdLineArgs::init( argc, argv, &aboutData );
KApplication app;
KGuiItem guiItem( QString( "Hello" ), QString(),
QString( "this is a tooltip" ),
QString( "this is whatsthis" ) );
KMessageBox::questionYesNo( 0, "text", "caption", guiItem );
}
If you set up your environment as described in Build/Unstable Version, you can compile this code with
gcc main.cpp -o tutorial1 -I/home/kde-devel/qt-unstable/include/Qt \ -I/home/kde-devel/qt-unstable/include/Qt-Core \ -I/home/kde-devel/qt-unstable/include -I/home/kde-devel/kde/include \ -L/home/kde-devel/kde/lib \ -L/home/kde-devel/qt-unstable/lib -lkdeui -lkdecore -ldl
and then run it with
./tutorial1
If that worked, you may want to use cmake, just like the rest of KDE.
Create a file named CMakeLists.txt with this content:
- name of the project
project (tutorial1)
- find and use the necessary libraries and headers
find_package(KDE4 REQUIRED)
include_directories( ${KDE4_INCLUDES} )
- compile
- using a variable is not really necessary:
- using the single line
- kde4_add_executable(tutorial1 main.cpp)
- does the same, but when you add more stuff to the project,
- using the variable makes things a bit easier.
set(tutorial1_SRCS hello.cpp)
kde4_add_executable(tutorial1 ${helloSources})
- and link properly
target_link_libraries(tutorial1 ${KDE4_KDEUI_LIBS})