How to use QAbstractListModel: Difference between revisions
QAbstractItemModel::rowCount and QAbstractItemModel::columnCount return int, not void. |
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We want to display a user list. First create a simple User class as follow : | We want to display a user list. First create a simple User class as follow : | ||
class User | |||
class User | { | ||
{ | |||
public : | public : | ||
User(); | User(); | ||
| Line 13: | Line 12: | ||
QString mLastName; | QString mLastName; | ||
QDate mBirthday; | QDate mBirthday; | ||
} | |||
} | |||
We are now going to create a model based on QAbstractItemModel. A model is an interface between the view and the data. In the following example, data are a list of User. | We are now going to create a model based on QAbstractItemModel. A model is an interface between the view and the data. In the following example, data are a list of User. | ||
class UserModel : public QAbstractItemModel | |||
class UserModel : public QAbstractItemModel | { | ||
{ | |||
Q_OBJECT | Q_OBJECT | ||
public : | public : | ||
| Line 29: | Line 25: | ||
QVariant data(const QModelIndex &index, int role) const; | QVariant data(const QModelIndex &index, int role) const; | ||
void populate(); | void populate(); | ||
private: | private: | ||
QList<User> mDatas; | QList<User> mDatas; | ||
} | |||
int UserModel::rowCount(const QModelIndex& parent = QModelIndex()) const | |||
{ | { | ||
return mDatas.size(); | return mDatas.size(); | ||
} | } | ||
int UserModel::columnCount(const QModelIndex& parent = QModelIndex()) const | int UserModel::columnCount(const QModelIndex& parent = QModelIndex()) const | ||
{ | { | ||
| Line 47: | Line 38: | ||
} | } | ||
QVariant UserModel::data(const QModelIndex &index, int role) const | |||
{ | { | ||
if (!index.isValid()) | if (!index.isValid()) | ||
return QVariant(); | return QVariant(); | ||
if ( role == Qt::DisplayRole) | if ( role == Qt::DisplayRole) | ||
{ | { | ||
if ( index.column() == 0) | if ( index.column() == 0) | ||
return mDatas[index.row()].firstname(); | return mDatas[index.row()].firstname(); | ||
if ( index.column() == 1) | if ( index.column() == 1) | ||
return mDatas[index.row()].lastname(); | return mDatas[index.row()].lastname(); | ||
if ( index.column() == 2) | if ( index.column() == 2) | ||
return mDatas[index.row()].birthday(); | return mDatas[index.row()].birthday(); | ||
} | } | ||
return QVariant(); | return QVariant(); | ||
} | |||
void UserModel::populate() | |||
{ | { | ||
beginResetModel(); | beginResetModel(); | ||
| Line 77: | Line 63: | ||
endResetModel(); | endResetModel(); | ||
} | } | ||
Now use your mode : | Now use your mode : | ||
QTableView * view = new QTableView; | |||
UserModel * model = new UserModel; | |||
QTableView * view = new QTableView; | view->setModel(model); | ||
UserModel * model = new UserModel; | model->populate() | ||
view->setModel(model); | |||
model->populate() | |||
Revision as of 06:30, 16 February 2021
The following tutorial explains how to create a custom Qt model and use it inside a QTableView.
We want to display a user list. First create a simple User class as follow :
class User
{
public :
User();
User(const QString& firstname, const QString& lastname, const QDate& birthday);
private:
QString mFirstname;
QString mLastName;
QDate mBirthday;
}
We are now going to create a model based on QAbstractItemModel. A model is an interface between the view and the data. In the following example, data are a list of User.
class UserModel : public QAbstractItemModel
{
Q_OBJECT
public :
UserModel(QObject * parent = 0);
int rowCount(const QModelIndex& parent = QModelIndex()) const;
int columnCount(const QModelIndex& parent = QModelIndex()) const;
QVariant data(const QModelIndex &index, int role) const;
void populate();
private:
QList<User> mDatas;
}
int UserModel::rowCount(const QModelIndex& parent = QModelIndex()) const
{
return mDatas.size();
}
int UserModel::columnCount(const QModelIndex& parent = QModelIndex()) const
{
return 3;
}
QVariant UserModel::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();
if ( role == Qt::DisplayRole)
{
if ( index.column() == 0)
return mDatas[index.row()].firstname();
if ( index.column() == 1)
return mDatas[index.row()].lastname();
if ( index.column() == 2)
return mDatas[index.row()].birthday();
}
return QVariant();
}
void UserModel::populate()
{
beginResetModel();
mDatas.clear();
mDatas.append(User("Charles","Darwin", QDate(1812,22,23));
mDatas.append(User("Lars","Knoll,"QDate(1976,22,12));
mDatas.append(User("Boby","Lapointe",QDate(1951,21,31));
endResetModel();
}
Now use your mode :
QTableView * view = new QTableView; UserModel * model = new UserModel; view->setModel(model); model->populate()