How to integrate QGraphicsPolygonItem with QtXML.

[ShrikantAmbade]

Hello Everyone,
Need help for my project. I am working on import and export of XML file. For this I am using Qt XML. My Task is to read XML file so, I am trying for XML parser which will convert it into tree structure and further this generated tree structure I have to connect with the symbols like circle, squares etc. theses symbols are already designed by using QGraphicsPolygonItem class but I am getting how can I connect generated tree structre which is repsentation of my xml with these grahical element.

Thank you so much in advance

[SGaist]

Hi,

Well, technically it's up to you to parse that XML and generate QGraphicsPolygonItem from the data you get. There's not much more to it unless I misunderstood your question.

[ShrikantAmbade]

@SGaist but how to generate QGraphicsPolygonItem?? I am am able to parse the XML file
following is the code for reading XML file just a little example this code I got and understood it. But now suppose I want to connect root element with the one of the graphical element like square. How to do that? please help with little code if you can just as example

//DOM methode of reading XML file

void ListElements(QDomElement root, QString tagname, QString attribute)
{
QDomNodeList items = root.elementsByTagName(tagname);

qDebug()<<"Total items = " << items.count();
for(int i=0; i<items.count(); i++){
    QDomNode itemnode = items.at(i);

    //convert to element
    if(itemnode.isElement())
    {
        QDomElement itemele = itemnode.toElement();
        qDebug()<<itemele.attribute(attribute);
    }
}

}

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

QDomDocument document;

// Load the XML file or open the XML file

QFile file("C:/Users/Shri/Desktop/QT/Myxmlexample/writexml.xml");
if(!file.open(QIODevice::ReadOnly |QIODevice::Text)){
    qDebug() << "Failed to open the file";
    return -1;
}
else{
    if(!document.setContent(&file)){
        qDebug()<<"Failed to get the content";
        return -1;
    }
    file.close();
}

//get the root elements
QDomElement root = document.firstChildElement();

//List the book element
ListElements(root,"Book","Name");

qDebug()<<"\r\n More Advance \r\n";

QDomNodeList books = root.elementsByTagName("Book");
for(int i=0; i<books.count();i++)
{
    QDomNode booknode = books.at(i);
    //convert to an element
    if(booknode.isElement())
    {
        QDomElement book = booknode.toElement();
        qDebug()<<"Chapter in " << book.attribute("Name");
        ListElements(book,"Chapter","Name");
    }
}

qDebug()<<"End Success";




return a.exec();

}

[ShrikantAmbade]

@SGaist This is GUI application on touch screen

[SGaist]

Being on a touch screen or desktop has no influence here.

In order to help get started (except taking a look at the Graphics View Framework documentation)
What do you get from your XML ? Geometries ? Coordinates ? Do you want to represent an arbitrary piece of data with some sort of picture ? e.g. a node represents a book so you want to draw a book to represent it on your scene ?

[ShrikantAmbade]

@SGaist Thank you so much.

For example: XML contain text data like root element and then inside that some other element and so on. When I read XML file and parse it, it store it into tree data structure with the help of DOM parser. Now after this I have root element store somewhere and also complete hierarchy is build accordingly into tree. On the other hand I have Graphical element which are just dummy symbols like circle (While I called set, this is just a name of symbol), Square (Which is represent tuples) etc. But these symbol have no identity or semantics now and Semantics is in XML which I save into Tree so I want to some how connect this two so that When I import XML file then this symbols connect with each other according to the data in XML.

I hope you understand what I want to say.. I am sorry I am bad in explaining my concept but I tried.
Many Thanks once again

[SGaist]

Yes I do.

For the linking part, take a look at the "Elastic Nodes" example.

As for translating your XML, you can create a subclass of QGraphicsItem which will contain the type of data it represent and draw itself accordingly.

[ShrikantAmbade]

@SGaist Thank you so much. Can you please give me little example any code so that I can understand it better as I am new in programming and trying to do it at my level

Many Thanks

[mrjj]

Hi
Maybe you can start with
http://doc.qt.io/qt-5/qtwidgets-graphicsview-diagramscene-example.html

[ShrikantAmbade]

@mrjj Thank you I will look into it