Development/Tutorials/KDE2/KHello/Tutorial 3: Difference between revisions
Neverendingo (talk | contribs) m (Text replace - "<code cppqt n>" to "<syntaxhighlight lang="cpp-qt" line>") |
Neverendingo (talk | contribs) m (Text replace - "</code>" to "</syntaxhighlight>") |
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QPushButton *btnExit; | QPushButton *btnExit; | ||
}; | }; | ||
</ | </syntaxhighlight> | ||
<syntaxhighlight lang="cpp-qt" line> | <syntaxhighlight lang="cpp-qt" line> | ||
/************* khello.cc ******************/ | /************* khello.cc ******************/ | ||
| Line 56: | Line 56: | ||
close(); | close(); | ||
} | } | ||
</ | </syntaxhighlight> | ||
==Explaining the code== | ==Explaining the code== | ||
I'll only explain what I believe is necessary this time. | I'll only explain what I believe is necessary this time. | ||
<syntaxhighlight lang="cpp-qt"> | <syntaxhighlight lang="cpp-qt"> | ||
public slots: | public slots: | ||
</ | </syntaxhighlight> | ||
This section is new, and it used by the meta object compiler. In the QT world, slots are event-handlers and signals are events. Put all your event handlers in this section. | This section is new, and it used by the meta object compiler. In the QT world, slots are event-handlers and signals are events. Put all your event handlers in this section. | ||
<syntaxhighlight lang="cpp-qt"> | <syntaxhighlight lang="cpp-qt"> | ||
connect(btnHello, SIGNAL(clicked()), this, SLOT(slotHello())); | connect(btnHello, SIGNAL(clicked()), this, SLOT(slotHello())); | ||
</ | </syntaxhighlight> | ||
Connect the event "clicked" from the btnHello object to the event handler "slotHello". | Connect the event "clicked" from the btnHello object to the event handler "slotHello". | ||
Latest revision as of 20:52, 29 June 2011
Description
Now is the time to add a few buttons.
Source code
The old code is gray. I have not included main.cc below, because it is the same as in KHello #2.
/************* khello.h *******************/
#include <kapp.h> // From KHello2
#include <kmainwindow.h> // From KHello2
#include <qpushbutton.h>
class KHello : public KMainWindow // From KHello2
{ // |
Q_OBJECT // |
public: // From KHello2
KHello();
void closeEvent(QCloseEvent *); // From KHello2
public slots:
void slotHello();
void slotExit();
private:
QPushButton *btnHello;
QPushButton *btnExit;
};/************* khello.cc ******************/
#include "khello.moc" // From KHello2
#include <kmessagebox.h>
KHello::KHello() : KMainWindow()
{
btnHello = new QPushButton("Hello", this);
btnHello->setGeometry(45,30,50,25);
btnHello->show();
connect(btnHello, SIGNAL(clicked()), this, SLOT(slotHello()));
btnExit = new QPushButton("Exit", this);
btnExit->setGeometry(105,30,50,25);
btnExit->show();
connect(btnExit, SIGNAL(clicked()), this, SLOT(slotExit()));
}
void KHello::closeEvent(QCloseEvent *e) // From KHello2
{ // |
kapp->beep(); // |
KMainWindow::closeEvent(e); // |
} // From KHello2
void KHello::slotHello()
{
KMessageBox::messageBox(0, KMessageBox::Information, "Hello World!");
}
void KHello::slotExit()
{
close();
}Explaining the code
I'll only explain what I believe is necessary this time.
public slots:This section is new, and it used by the meta object compiler. In the QT world, slots are event-handlers and signals are events. Put all your event handlers in this section.
connect(btnHello, SIGNAL(clicked()), this, SLOT(slotHello()));Connect the event "clicked" from the btnHello object to the event handler "slotHello".
Compiling
[on linux where KDEDIR and QTDIR contain the paths to where KDE and Qt are installed respectively] [FreeBSD 5.x users may omit the -ldl]
g++ -c -I$KDEDIR/include -I$QTDIR/include -fno-rtti main.cc moc khello.h -o khello.moc g++ -c -I$KDEDIR/include -I$QTDIR/include -fno-rtti khello.cc g++ -L$KDEDIR/lib -L$QTDIR/lib -lkdeui -lkdecore -lqt -ldl -o khello main.o khello.o
[if moc is not in your path try $QTDIR/bin/moc]