connecting a signal of widget in a plasmoid - qt

Question

I am new to Qt and am trying to connect the cilicked signal o a push button with a function hile writing a plasmoid. I am trying to use an external function as a public with Plasma::PushButton type object so that I can use it to connect it with the clicked signal? With gtk it was as simple as on_...._clicked do this but isnt there a simple way in qt, where we can do away with the need to use slots?
#include "plasma-tutorial1.h"
#include<string.h>
#include <stdlib.h>
#include <QGraphicsLinearLayout>
#include <QPainter>
#include <QFontMetrics>
#include <QSizeF>
#include <QTextEdit>
#include <plasma/svg.h>
#include <plasma/theme.h>
#include <plasma/widgets/lineedit.h>
#include <plasma/widgets/pushbutton.h>
#include <plasma/widgets/textedit.h>
//PlasmaTutorial1 mainf;
themainfunction(int choice,Plasma::LineEdit *m_lineEdit,
Plasma::TextEdit *m_displaytext)
{
char buffer[100];
const char *inp=(const char *)malloc(sizeof(char)*100);
QString input;
input=m_lineEdit->text();
QByteArray byteArray = input.toUtf8();
inp = byteArray.constData();
char *expression;
expression=(char *)malloc(sizeof(char)*100);
strcpy(expression,"sudo apt-");
switch(choice)
{
case 1:{
strcat(expression,"get install ");
strcat(expression,inp);
break;
};
case 2:{
strcat(expression,"get remove ");
strcat(expression,inp);
break;
};
case 3:{
strcat(expression,"cache search ");
strcat(expression,inp);
break;
};
};
/*
FILE* in;
FILE* ptr=fopen("new.txt","w");
FILE *popen();
if(!(in = popen("cal","r")))
{return;}
while(fgets(buffer, 100, in) != NULL) {
*/
m_displaytext->append("yeah!");
// fprintf(ptr,"%s",buffer);
//}
//pclose(in);
//fclose(ptr);
}
PlasmaTutorial1::PlasmaTutorial1(QObject *parent, const QVariantList &args)
: Plasma::Applet(parent, args),
m_svg(this),
m_icon("document")
{
m_svg.setImagePath("widgets/background");
// this will get us the standard applet background, for free!
setBackgroundHints(DefaultBackground);
resize(200, 200);
}
PlasmaTutorial1::~PlasmaTutorial1()
{
if (hasFailedToLaunch()) {
// Do some cleanup here
} else {
// Save settings
}
}
void PlasmaTutorial1::init()
{
/* // A small demonstration of the setFailedToLaunch function
if (m_icon.isNull()) {
setFailedToLaunch(true, "No world to say hello");
}*/
Counter rt;
QGraphicsLinearLayout *layout = new QGraphicsLinearLayout(this);
layout->setOrientation(Qt::Vertical); //so widgets will be stacked up/down
m_lineEdit = new Plasma::LineEdit(this);
m_lineEdit->setText("Enter the package name here");
m_displaytext = new Plasma::TextEdit(this);
m_displaytext->setText("Terminal");
m_installButton = new Plasma::PushButton(this);
m_installButton->setText("Install");
connect(m_installButton, SIGNAL(clicked()),&rt,SLOT(themainfunction(1,m_lineEdit,m_displaytext)));
m_removeButton = new Plasma::PushButton(this);
m_removeButton->setText("Remove");
// m_removeButton->clicked()
connect(m_removeButton, SIGNAL(clicked()),&rt,SLOT(themainfunction(2,m_lineEdit,m_displaytext)));
m_searchButton = new Plasma::PushButton(this);
m_searchButton->setText("Search");
connect(m_searchButton, SIGNAL(clicked()),&rt,SLOT(themainfunction(3,m_lineEdit,m_displaytext)));
layout->addItem(m_lineEdit);
layout->addItem(m_installButton);
layout->addItem(m_removeButton);
layout->addItem(m_searchButton);
layout->addItem(m_displaytext);
m_displaytext->append("yo baby!");
}
/*
void PlasmaTutorial1::paintInterface(QPainter *p,
const QStyleOptionGraphicsItem *option, const QRect &contentsRect)
{
p->setRenderHint(QPainter::SmoothPixmapTransform);
p->setRenderHint(QPainter::Antialiasing);
// Now we draw the applet, starting with our svg
m_svg.resize((int)contentsRect.width(), (int)contentsRect.height());
m_svg.paint(p, (int)contentsRect.left(), (int)contentsRect.top());
// We place the icon and text
p->drawPixmap(7, 0, m_icon.pixmap((int)contentsRect.width(),(int)contentsRect.width()-14));
p->save();
p->setPen(Qt::white);
p->drawText(contentsRect,
Qt::AlignBottom | Qt::AlignHCenter,
"Hello Plasmoid!");
p->restore();
}
*/
// This is the command that links your applet to the .desktop file
K_EXPORT_PLASMA_APPLET(tutorial1, PlasmaTutorial1)
#include "plasma-tutorial1.moc"
say i want to connect themainfunction() upon clicked signal of install button . how do i do it? how can I derive a class in plasma?

Answer 1

i got where was i missing out. We cannot pass objects as arguments in slot functions. Now it is running smooth. thanx for all your replies.