= qt =
Qt is a cross-platform application and UI framework for developers

http://qt-project.org/

== Sample C++ Qt program in Slackware Linux ==
{{{#!highlight c++
/* 
Include path in Slackware 14:
/usr/lib/qt/include/Qt

Compile on Slackware 14: 
g++ -lQtCore -lQtGui -I/usr/lib/qt/include/Qt helloWorldQt.cpp -o helloWorldQt

Run with ./helloWorldQt
*/

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

int main(int argc,char** argv){
    QApplication app(argc,argv);
    QMainWindow mw;
    mw.setMinimumSize(200,100);
    mw.setMaximumSize(200,100);

    QPushButton pb("Push it, Hello world",&mw);
    pb.setGeometry(20,20,160,60);
    mw.setCentralWidget(&pb);
    mw.show();
    return app.exec();
}
}}}

== Sample CMake + Qt ==
Adapted from http://cor-net.org/wp-content/uploads/2009/10/HelloWorldQt.tar

Structure:
 * CMakeLists.txt
  * src\HelloWidget.cpp    
  * src\HelloWidget.h    
  * src\MainWindow.cpp    
  * src\MainWindow.h    
  * src\main.cpp

File CMakeLists.txt
{{{#!highlight cmake
CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
PROJECT(HelloWorldQt)

SET(CMAKE_BUILD_TYPE Release)
SET(CMAKE_CXX_FLAGS "-Wall")

# QT4 Handling
FIND_PACKAGE(Qt4 REQUIRED)

INCLUDE(${QT_USE_FILE})

SET( HWQ_Qt4_SRC
        src/MainWindow.h
        src/HelloWidget.h
)
SET( HWQ_Qt4_UI
)
SET( HWQ_Qt4_RES
)

QT4_WRAP_CPP(HWQ_MOC_CPP ${HWQ_Qt4_SRC})
QT4_WRAP_UI(HWQ_UI_CPP ${HWQ_Qt4_UI})
QT4_ADD_RESOURCES(HWQ_RES_H ${HWQ_Qt4_RES})

INCLUDE_DIRECTORIES( . )

# General
SET( HWQ_SRC
        src/main.cpp
        src/MainWindow.cpp
        src/HelloWidget.cpp
        ${HWQ_MOC_CPP}
        ${HWQ_UI_CPP}
        ${HWQ_RES_H}
)

SET( HWQ_LIB
        ${QT_LIBRARIES}
)

ADD_EXECUTABLE(HelloWorldQt ${HWQ_SRC} )
TARGET_LINK_LIBRARIES(HelloWorldQt ${HWQ_LIB} )

INSTALL_TARGETS( /bin HelloWorldQt)
}}}

File HelloWidget.cpp
{{{#!highlight cpp
#include "HelloWidget.h"

HelloWidget::HelloWidget(QWidget * parent) :
        QLabel(parent),
        _msg("Hello World !"),
        _pos(0) {
}

HelloWidget::~HelloWidget() {
}

void HelloWidget::showNewLetter() {
        _pos++;
        setText(_msg.left(_pos));
}
}}}

File HelloWidget.h
{{{#!highlight cpp
#include <QLabel>
#include <QString>

#ifndef HELLOWIDGET_H_
#define HELLOWIDGET_H_

class HelloWidget : public QLabel {
        Q_OBJECT

public:
        HelloWidget(QWidget * parent = 0);
        ~HelloWidget();

public slots:
        void showNewLetter();

protected:
        QString _msg;
        unsigned short _pos;
};

#endif /* HELLOWIDGET_H_ */
}}}


File MainWindow.cpp
{{{#!highlight cpp
#include "MainWindow.h"
#include <QVBoxLayout>

MainWindow::MainWindow(QWidget *parent) {
        // Making a central Widget for our Window
        QWidget * centralWidget = new QWidget(this);
        setCentralWidget(centralWidget);

        // Building our widgets
        _helloWidget = new HelloWidget(this);
        _button = new QPushButton(this);
        _button->setText("++");

        connect(_button, SIGNAL(clicked()), _helloWidget, SLOT(showNewLetter()));

        // Setting the content and disposition of our central Widget
        QVBoxLayout * layout = new QVBoxLayout();
        layout->addWidget(_helloWidget);
        layout->addWidget(_button);
        centralWidget->setLayout(layout);
}

MainWindow::~MainWindow() {
}
}}}

File MainWindow.h
{{{#!highlight cpp
#include <QtGui/QMainWindow>
#include <QPushButton>
#include "HelloWidget.h"

#ifndef MAINWINDOW_H_
#define MAINWINDOW_H_

class MainWindow : public QMainWindow {
        Q_OBJECT

public:
        MainWindow(QWidget *parent = 0);
        ~MainWindow();

protected:
        HelloWidget * _helloWidget;
        QPushButton * _button;
};

#endif /* MAINWINDOW_H_ */
}}}

File main.cpp
{{{#!highlight cpp
#include <QtGui/QApplication>
#include "MainWindow.h"

int main(int argc, char *argv[])
{
        QApplication a(argc, argv);
        MainWindow w;
        w.show();
        return a.exec();
}
}}}

=== Build ===
 * find . -name "*.cmake" | xargs -i rm {}
 * cmake .
 * make clean
 * make 
 * make install