How to perform addition in qml by calling .cpp function?

[mkhpad]

I am having a .qml file which contains four buttons as: first button with text: "3", second button with "5", third with the operator symbol "+" and the fourth button with "=" .... Now what i need is when i clicked on first/second button it must store the value int a variable and when clicked on "+",i had created a function that should be calling from qml to cpp file,where it should perform the addition operation. Then,the value must be passed again to the qml and display it in a textarea.when pressed the = button.

Here is how i have tried on this:

.qml file

@
property string i;
property string c;

Button {
id: button1
x: 203
y: 258
text: "5"

        onClicked: {

                i = text
                t.text = t.text + i

        }
    }

Button {
id: button2
x: 203
y: 258
text: "3"

        onClicked: {

                i = text
                t.text = t.text + i

        }
    }

Button {
id: buttonplus
x: 136
y: 320
text: "+"

onClicked: {
StringHelper.apple()

}
}

Button {
id: equal
x: 195
y: 320
width: 116
height: 42
text: "="

        onClicked: {


          t.text = c

        }
    }

TextField {
id: t
x: 81
y: 60
width: 225
height: 50
text: ""
maximumLength: 32765

}
@

stringhelper.h

@
#ifndef STRINGHELPER_H
#define STRINGHELPER_H
#include<QObject>

class StringHelper : public QObject
{
Q_OBJECT
public slots:
Q_INVOKABLE int apple(int x,int y)

    {

int c = x + y;

????????????????????????
}
@

main.cpp:

@
#include <QApplication>
#include <QDeclarativeView>
#include <QDeclarativeContext>
#include "stringhelper.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);

StringHelper stringHelper;

QDeclarativeView view;
view.setResizeMode(QDeclarativeView::SizeRootObjectToView);
view.rootContext()->setContextProperty("StringHelper", &stringHelper);
view.setSource(QUrl("qml/main.qml"));

#if defined(Q_WS_S60) || defined(Q_WS_MAEMO)
view.showMaximized();
#else
view.setGeometry(100, 100, 800, 480);
view.show();
#endif

return a.exec;

}
@

So, Kindly help in finding out!!!

Thanks and Regards

[EDIT: code formatting, please wrap in @-tags, Volker]

[lgeyer]

Just return the value in <code>int apple(int x, int y) { ... return c;}</code> and pass it to the desired variable or item in QML <code>onClicked: { t.text = StringHelper.apple(button1.text, button2.text) }</code>.

Is there any particular reason you are performing the addition in C++? QML event handlers take any kind of JavaScript code, including mathematical expressions.

As to the your post: Your code formatting is seriously broken. Wrap code in @ tags so its gets formatted properly. Even your non-code part is seriously broken due to the hypens. Either use the preview function or the edit function to make sure your post is actually readable next time.

[mkhpad]

Thank you for your reply Sir....

I tried what you have said sir but it shows -> Error: Insufficient arguments

I have changed my coding as:

onClicked: {

            t.text = StringHelper.apple();

and also as:

onClicked: {

            t.text = StringHelper.apple(c);

        }

        }

I am trying to add calculator in my app sir thats why i am in need of it and i am not using Javascript code.

any comments.....

[lgeyer]

You will have, of course, pass <code>button1.text</code> and <code>button2.text</code> to <code>StringHelper::apple(int a, int b)</code>.
@
onClicked: {
t.text = StringHelper.apple(button1.text, button2.text);
}
@

[mkhpad]

Thank You for your answer....

You are really great sir i was trying this for the past 2 days and you are the one who had come out with the solution...

Thank you again Sir....:)
:)

Sir suppose if i am having 0-9 buttons and in this case if i need to perform addition operation how could i declare the result function....

onClicked: {

            t.text = StringHelper.apple(????????????????);

        }

Thanks,
Harish