Make tree folder from QTreeView or QTreeWidget

read folder tree from a Rest API, then show them to user

Example json response after call API:

[
{"name":"/folder1/file1.txt";"size":"1KB"},
{"name":"/folder1/file2.txt";"size":"1KB"},
{"name":"/folder1/sub/file3.txt";"size":"1KB"},
{"name":"/folder2/file4.txt";"size":"1KB"},
{"name":"/folder2/file5.txt";"size":"1KB"}
]

I only want to make GUI like below image:

There are 2 options:

1. QTreeView

2. QTreeWidget

In this photo, I used QTreeWidget (with static data). Currently, I don't know make data model for this.

I made TreeModel to set data for QtreeView. But When them shown in GUI, All of the data only show in column Name. I copied the code from http://doc.qt.io/qt-5/qtwidgets-itemviews-simpletreemodel-example.html

But now I can't resolve this problem. I need an example source code for this. Plus, I also only want show a tree view simply.

don't use QFileSystem because data get from Rest API.

What you have to do is parsing the json by getting the name of the file and the size, then you separate the name using the "/", and add it to the model in an appropriate way.

#include <QApplication>
#include <QJsonDocument>
#include <QJsonArray>
#include <QJsonObject>
#include <QStandardItemModel>
#include <QTreeView>
#include <QFileIconProvider>

QStandardItem * findChilItem(QStandardItem *it, const QString & text){
    if(!it->hasChildren())
        return nullptr;
    for(int i=0; i< it->rowCount(); i++){
        if(it->child(i)->text() == text)
            return it->child(i);
    }
    return nullptr;
}

static void appendToModel(QStandardItemModel *model, const QStringList & list, const QString & size){
    QStandardItem *parent = model->invisibleRootItem();
    QFileIconProvider provider;

    for(QStringList::const_iterator it = list.begin(); it != list.end(); ++it)
    {
        QStandardItem *item = findChilItem(parent, *it);
        if(item){
            parent = item;
            continue;
        }
        item = new QStandardItem(*it);
        if(std::next(it) == list.end()){
            item->setIcon(provider.icon(QFileIconProvider::File));
            parent->appendRow({item, new QStandardItem(size)});
        }
        else{
            item->setIcon(provider.icon(QFileIconProvider::Folder));
            parent->appendRow(item);
        }
        parent = item;
    }
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QStandardItemModel model;
    model.setHorizontalHeaderLabels({"Name", "Size"});
    const std::string json = R"([
                             {"name":"/folder1/file1.txt";"size":"1KB"},
                             {"name":"/folder1/file2.txt";"size":"1KB"},
                             {"name":"/folder1/sub/file3.txt";"size":"1KB"},
                             {"name":"/folder2/file4.txt";"size":"1KB"},
                             {"name":"/folder2/file5.txt";"size":"1KB"}
                             ])";

    QJsonParseError parse;
    // The string is not a valid json, the separator must be a comma
    // and not a semicolon, which is why it is being replaced
    QByteArray data = QByteArray::fromStdString(json).replace(";", ",");
    QJsonDocument const& jdoc =  QJsonDocument::fromJson(data, &parse);
    Q_ASSERT(parse.error == QJsonParseError::NoError);
    if(jdoc.isArray()){
        for(const QJsonValue &element : jdoc.array() ){
            QJsonObject obj = element.toObject();
            QString name = obj["name"].toString();
            QString size = obj["size"].toString();
            appendToModel(&model, name.split("/", QString::SkipEmptyParts), size);
        }
    }

    QTreeView view;
    view.setModel(&model);
    view.show();
    return a.exec();
}

Note: the semicolon is not a valid separator for the json, so I had to change it.