How to perform calculator functions in qt qml?

[wysota]

So what have you tried?

[harish]

I had tried the operation by clicking "=" and not "+" but still i was not able to get the required output.

[wysota]

How does the code look like? Did you implement the stack of operations?

[harish]

If I change my coding as:

a = t.text

b = t.text

c = a + b

for eg: a = t.text = "2"
b = t.text = "3"

c = a + b.......i.e. c = 2 + 3

and when clicked on "=" my answer should be "5" but i am getting the values appended as "2323"..


Can someone please help me....?



Whether the calculation done in .qml file is right or else i should i create a function call to .cpp file and do the calculation there....I had tried that too but still i was not able to get the result.....

Is there anyone to solve my problem?

[wysota]

You are working on text so the + operator concatenates. Your program doesn't know you want it to convert text to integers.

Doing calculations in qml is fine. Have you seen the Calculator example?

[harish]

I had already found the link which have given sir.In this they are using javascript code but i am using C++.

Now i had tried anotherway of doing my app as:

I had made a function call to .cpp file and done the calcultion there and passed that value to the .qml file.

Here is my code:

.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: { 
t.text = a;
t.text = b;
 
StringHelper.apple(a,b);
 }
 }
 
Button { 
id: equal
 x: 195
 y: 320 
width: 116
 height: 42
 text: “=”
onClicked: { 
 
                t.text = StringHelper.apple(button1.text,button2.text);
 
}
 }
 
TextField { id: t
 x: 81
y: 60
 width: 225 
height: 50 
text: “” maximumLength: 32765
 
}

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: { 
t.text = a;
t.text = b;

StringHelper.apple(a,b);
 }
 }

Button { 
id: equal
 x: 195
 y: 320 
width: 116
 height: 42
 text: “=”
onClicked: { 

                t.text = StringHelper.apple(button1.text,button2.text);

}
 }

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

}

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stringhelper.h

#ifndef STRINGHELPER_H
#define STRINGHELPER_H
 
#include<QObject>
 
class StringHelper : public QObject
    {
        Q_OBJECT
    public slots:
        int apple(int a,int b)
 
        {
 
         int c = a + b;
 
         return c;
 
}
 
 
};
 
#endif // STRINGHELPER_H

#ifndef STRINGHELPER_H
#define STRINGHELPER_H

#include<QObject>

class StringHelper : public QObject
    {
        Q_OBJECT
    public slots:
        int apple(int a,int b)

        {

         int c = a + b;

         return c;

}


};

#endif // STRINGHELPER_H

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main.cpp:

#include <QApplication>
#include <QDeclarativeView>
#include <QDeclarativeContext>
#include "stringhelper.h"
#include<QDateTime>
 
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/sad/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();
}

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

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/sad/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();
}

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From this i was able to get the addition operation performed and displayed but in case if i am having 10 buttons with integers from 0-9 how to declare the result function:


in .qml file:

onClicked: { 
t.text = StringHelper.apple(????????????????); 
}

onClicked: { 
t.text = StringHelper.apple(????????????????); 
}

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???????


Could you please come out with a solution for my problem.....?

[wysota]

I had already found the link which have given sir.In this they are using javascript code but i am using C++.

Last code you pasted was definitely using javascript.

From this i was able to get the addition operation performed and displayed but in case if i am having 10 buttons with integers from 0-9 how to declare the result function:


in .qml file:

onClicked: { 
t.text = StringHelper.apple(????????????????); 
}

onClicked: { 
t.text = StringHelper.apple(????????????????); 
}

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Could you please come out with a solution for my problem.....?

t.text = (Number(a)+Number(b)).toString()

t.text = (Number(a)+Number(b)).toString()

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[harish]

Ya thank you sir i got it....

Its been a good guidance given by you sir...


Thanks a lot again...