I am having trouble with showing items from a model defined in c++ in a SelectionDialog in qml. I'm trying to make an application for the Meego operating system.
If I display the items in a ListView, everything works as expected and the items are shown. However, if I try to show them in a SelectionDialog I get an empty list.
Here is some code:
languagemodel.h:
#ifndef LANGUAGEMODEL_H
#define LANGUAGEMODEL_H
#include <baza/language.h>
#include <QObject>
#include <QAbstractListModel>
class LanguageModel: public QAbstractListModel
{
Q_OBJECT
public:
enum LanguageRoles {
RoleLanguageName = Qt::DisplayRole,
RoleLanguageCode = Qt::UserRole,
RoleId = Qt::UserRole+1,
RoleChosen = Qt::UserRole+2
};
LanguageModel(QObject *parent = 0);
void addLanguge(const Language &language);
void clear();
int rowCount(const QModelIndex & parent = QModelIndex()) const;
QVariant data(const QModelIndex & index, int role = Qt::DisplayRole) const;
private:
QList<Language> m_languages;
};
#endif // LANGUAGEMODEL_H
languagemodel.cpp:
#include "languagemodel.h"
#include <QDebug>
LanguageModel::LanguageModel(QObject *parent)
: QAbstractListModel(parent)
{
QHash<int, QByteArray> roles;
roles[RoleLanguageName]="name";
roles[RoleLanguageCode]="code";
roles[RoleId]="id";
roles[RoleChosen]="chosen";
setRoleNames(roles);
}
void LanguageModel::addLanguge(const Language &language){
beginInsertRows(QModelIndex(), rowCount(), rowCount());
m_languages << language;
endInsertRows();
}
int LanguageModel::rowCount(const QModelIndex & parent) const {
return m_languages.count();
}
void LanguageModel::clear(){
for (int i=0; i<m_languages.count(); i++)
{
beginRemoveRows(QModelIndex(), 0, 0);
m_languages.removeAt(0);
endRemoveRows();
}
}
QVariant LanguageModel::data(const QModelIndex & index, int role) const {
if (index.row() < 0 || index.row() > m_languages.count())
return QVariant();
const Language &language = m_languages[index.row()];
if (role == RoleLanguageName)
return language.getName();
else if (role == RoleLanguageCode)
return language.getCode();
else if (role == RoleChosen)
return language.isChosen();
else if (role == RoleId)
return language.getId();
return QVariant();
}
adding languages in done from handler.cpp like:
//(...)
for(unsigned int i = 0; i < listLanguages.size(); i++)
{
Language language = listLanguages.at(i);
modelLanguages.addLanguge(language);
}
//(...)
ctxt->setContextProperty("modelLanguages", &modelLanguages);
where modelLanguages is a LanguageModel.
And I would like to display the list in Settings.qml:
//(...)
SelectionDialog {
id: dialogLanguages
titleText: qsTr("Select language")
model: modelLanguages
delegate: Text { text: name}
}
When I open the dialogLanguages, I can only see the title "Select language" without any of the items from the model.
If I use this as a model, it works fine:
model: ListModel {
ListElement { name: "ListElement #1" }
ListElement { name: "ListElement #2" }
ListElement { name: "ListElement #3" }
}
Also, as I have already mentioned, if I set modelLanguages as a model in a ListView, al the items are displayed correctly.
can anyone help and tell me what am I doing wrong here and what do I have to change to get it working.
Any help is appreciated!
Thank you!
OK, I managed to solve it! I found a hint for the soultion here in the comments: https://qt.gitorious.org/qt-components/qt-components/merge_requests/887#
I needed to add a count property to my model inheriting QAbstractListModel.
My LanguageModel.h now looks something like this:
class LanguageModel: public QAbstractListModel
{
Q_OBJECT
Q_PROPERTY(int count READ count NOTIFY countChanged)
//(...)
public:
//(...)
int count();
//(...)
signals:
void countChanged(int newCount);
//(...)
I added the needed method in LanguageModel.cpp:
//(...)
int LanguageModel::count(){
return m_languages.count();
}
//(...)
I also emitted a signal when the count changes (when adding languages and clearing the model) with:
emit countChanged(m_languages.count());
And now it's working. :)
I hope this helps someone.
Bye!