Writing a Tree model.

Hi,

Can anyone help me in writing a Tree model from QStandardItemModel.
I have all the required data in a seperate QStandardItemModel.
i need to create a new Tree model or may be a proxy tree model.
How do i implement a rowCount function for the TreeModel.
I have already gone through SimpleTreeModel example but cound not complete my tree model.

Please do help me with some code snippets...

Regards,
GK

any body....
any idea...

there is an example in Qt Assistant at QStandardItemModel

Quote:

---

An example usage of QStandardItemModel to create a tree:

QStandardItemModel model;
QStandardItem *parentItem = model.invisibleRootItem();
for (int i = 0; i < 4; ++i) {
QStandardItem *item = new QStandardItem(QString("item %0").arg(i));
parentItem->appendRow(item);
parentItem = item;
}

---

also lool at Qt's example QTDIR/examples/itemviews/simpletreemodel/

I have written the followinf code to create a tree.

Code:

---

for (int i = 0; i < m_manufacturerList.count(); ++i)
   {
      QStandardItem *item = new QStandardItem(m_manufacturerList.at(i));
      parentItem = item;
      QList<QString> modelList = m_pPrivate->m_ManufacturerModel.values(item->text());
      parentItem->appendRow(modelList);
 
      for(j = 0; j < modelList.count(); ++j)
      {
         parentItem = modelList.at(i);
         parentItem->appendRow(m_pPrivate->m_ModelBand.values(modelList.at(i)));
      }
   }

---

I have a list m_manufacturerList which contins some items.
then in have two multi maps..m_ManufacturerModel and m_ModelBand

I need to show data in the list views... see the attachment.

this is something like MAC finder...view...

how do i implement fucntions... rowCount, index(), parent() etc..

Regards,
GK

Hi,

I have done this so far...

TreeModel.h

Code:

---

#ifndef ADD_DEVICES_TREE_PROXY_MODEL_H
#define ADD_DEVICES_TREE_PROXY_MODEL_H
 
#include <QAbstractItemModel>
#include <QModelIndex>
#include <QVariant>
 
class AddDeviceTreeProxyModel : public QAbstractItemModel
{
   Q_OBJECT
 
public:
   AddDeviceTreeProxyModel(QObject *parent = 0);
   ~AddDeviceTreeProxyModel();
 
   QVariant data(const QModelIndex &index, int role) const;
   Qt::ItemFlags flags(const QModelIndex &index) const;
   QModelIndex index(int row, int column,
      const QModelIndex &parent = QModelIndex()) const;
   QModelIndex parent(const QModelIndex &index) const;
   int rowCount(const QModelIndex &parent = QModelIndex()) const;
   int columnCount(const QModelIndex &parent = QModelIndex()) const;
 
private:
   class Private;
   Private* const m_pPrivate;
};
 
#endif // ADD_DEVICES_TREE_PROXY_MODEL_H

---

TreeModel.cpp

Code:

---

#include "TreeModel.h"
#include <QStandardItem>
 
class AddDeviceTreeProxyModel::Private
{
public:
   // Constructor.
   Private( AddDeviceTreeProxyModel* deviceTree )
      : m_AddDeviceTreeProxyModel(deviceTree)
   {
   }
 
   void setupModelData();
   QStringList m_manufacturerList;  // Manufacturer List.
   QMultiMap <QString, QString> m_ManufacturerModel; // Multimap of Manufacturer and Model.
   QMultiMap <QString, QString> m_ModelBand; // Multimap of Model and band.
 
private:
   AddDeviceTreeProxyModel* const m_AddDeviceTreeProxyModel;
};
 
AddDeviceTreeProxyModel::AddDeviceTreeProxyModel(QObject *parent)
   : QAbstractItemModel(parent),
   m_pPrivate( new Private( this ))
{
   for (int i = 0; i < 5 ; ++i)
   {
      m_pPrivate->m_manufacturerList.append(tr("Manf%1").arg(i));
   }
 
   for (int i = 0; i < m_pPrivate->m_manufacturerList.count() ; ++i)
   {
      m_pPrivate->m_ManufacturerModel.insert(tr("Manf%1").arg(i), "Model1");
      m_pPrivate->m_ManufacturerModel.insert(tr("Manf%1").arg(i), "Model2");
   }
 
   for (int i = 0; i < m_pPrivate->m_manufacturerList.count() ; ++i)
   {
      m_pPrivate->m_ModelBand.insert(tr("Model1").arg(i), "Band1");
      m_pPrivate->m_ModelBand.insert(tr("Model1").arg(i), "Band2");
      m_pPrivate->m_ModelBand.insert(tr("Model2").arg(i), "Band1");
      m_pPrivate->m_ModelBand.insert(tr("Model2").arg(i), "Band2");
   }
 
   m_pPrivate->setupModelData();
}
 
AddDeviceTreeProxyModel::~AddDeviceTreeProxyModel()
{
   delete m_pPrivate;
}
 
int AddDeviceTreeProxyModel::columnCount(const QModelIndex &parent) const
{
   return 0;
}
 
QVariant AddDeviceTreeProxyModel::data(const QModelIndex &index, int role) const
{
   return QVariant();
}
 
Qt::ItemFlags AddDeviceTreeProxyModel::flags(const QModelIndex &index) const
{
   return Qt::ItemIsEditable;
 
}
 
QModelIndex AddDeviceTreeProxyModel::index(int row, int column, const QModelIndex &parent) const
{
   return QModelIndex();
}
 
QModelIndex AddDeviceTreeProxyModel::parent(const QModelIndex &index) const
{
   return QModelIndex();
}
 
int AddDeviceTreeProxyModel::rowCount(const QModelIndex &parent) const
{
   return 0;
}
 
void AddDeviceTreeProxyModel::Private::setupModelData()
{
}

---

Main.cpp

Code:

---

#include <QApplication>
#include "TreeModel.h"
#include "ui_Form.h"
 
int main(int argc, char** argv)
{
   QApplication a(argc, argv);
 
   QWidget form;
   Ui::Form ui;
   ui.setupUi(&form);
   form.show();
 
   AddDeviceTreeProxyModel model;
   ui.listView->setModel( &model );
   ui.treeView->setModel( &model );
 
   return a.exec();
}

---

Please tell me how do i implement rowCount(), columnCount(), index(), parent() functions....

I am stuck... badly

Regards,
GK

Did you have a look at examples in Qt Demo ??

yes i have seen ... but could not mould it to implement mine funcitons....