How to use QAbstractListModel: Difference between revisions
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(QAbstractItemModel::rowCount and QAbstractItemModel::columnCount return int, not void.) |
(Fix broken <code> in this page :)) |
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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()