Mega Code Archive
How selections can be used directly on a model
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#ifndef MODEL_H
#define MODEL_H
#include <QAbstractTableModel>
#include <QStringList>
#include <QVariant>
class TableModel : public QAbstractTableModel
{
Q_OBJECT
public:
TableModel(int rows = 1, int columns = 1, 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;
QVariant headerData(int section, Qt::Orientation orientation,
int role = Qt::DisplayRole) const;
Qt::ItemFlags flags(const QModelIndex &index) const;
bool setData(const QModelIndex &index, const QVariant &value,
int role = Qt::EditRole);
bool insertRows(int position, int rows, const QModelIndex &parent = QModelIndex());
bool insertColumns(int position, int columns, const QModelIndex &parent = QModelIndex());
bool removeRows(int position, int rows, const QModelIndex &parent = QModelIndex());
bool removeColumns(int position, int columns, const QModelIndex &parent = QModelIndex());
private:
QList<QStringList> rowList;
};
#endif
/*
model.cpp
Provides a table model for use in various examples.
*/
#include <QtGui>
#include "model.h"
/*!
Constructs a table model with at least one row and one column.
*/
TableModel::TableModel(int rows, int columns, QObject *parent)
: QAbstractTableModel(parent)
{
QStringList newList;
for (int column = 0; column < qMax(1, columns); ++column) {
newList.append("");
}
for (int row = 0; row < qMax(1, rows); ++row) {
rowList.append(newList);
}
}
/*!
Returns the number of items in the row list as the number of rows
in the model.
*/
int TableModel::rowCount(const QModelIndex &/*parent*/) const
{
return rowList.size();
}
/*!
Returns the number of items in the first list item as the number of
columns in the model. All rows should have the same number of columns.
*/
int TableModel::columnCount(const QModelIndex &/*parent*/) const
{
return rowList[0].size();
}
/*!
Returns an appropriate value for the requested data.
If the view requests an invalid index, an invalid variant is returned.
Any valid index that corresponds to a string in the list causes that
string to be returned for the display role; otherwise an invalid variant
is returned.
*/
QVariant TableModel::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();
if (role == Qt::DisplayRole)
return rowList[index.row()][index.column()];
else
return QVariant();
}
/*!
Returns the appropriate header string depending on the orientation of
the header and the section. If anything other than the display role is
requested, we return an invalid variant.
*/
QVariant TableModel::headerData(int section, Qt::Orientation orientation,
int role) const
{
if (role != Qt::DisplayRole)
return QVariant();
if (orientation == Qt::Horizontal)
return QString("Column %1").arg(section);
else
return QString("Row %1").arg(section);
}
/*!
Returns an appropriate value for the item's flags. Valid items are
enabled, selectable, and editable.
*/
Qt::ItemFlags TableModel::flags(const QModelIndex &index) const
{
if (!index.isValid())
return Qt::ItemIsEnabled;
return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
}
/*!
Changes an item in the model, but only if the following conditions
are met:
* The index supplied is valid.
* The role associated with editing text is specified.
The dataChanged() signal is emitted if the item is changed.
*/
bool TableModel::setData(const QModelIndex &index,
const QVariant &value, int role)
{
if (!index.isValid() || role != Qt::EditRole)
return false;
rowList[index.row()][index.column()] = value.toString();
emit dataChanged(index, index);
return true;
}
/*!
Inserts a number of rows into the model at the specified position.
*/
bool TableModel::insertRows(int position, int rows, const QModelIndex &parent)
{
int columns = columnCount();
beginInsertRows(parent, position, position + rows - 1);
for (int row = 0; row < rows; ++row) {
QStringList items;
for (int column = 0; column < columns; ++column)
items.append("");
rowList.insert(position, items);
}
endInsertRows();
return true;
}
/*!
Inserts a number of columns into the model at the specified position.
Each entry in the list is extended in turn with the required number of
empty strings.
*/
bool TableModel::insertColumns(int position, int columns,
const QModelIndex &parent)
{
int rows = rowCount();
beginInsertColumns(parent, position, position + columns - 1);
for (int row = 0; row < rows; ++row) {
for (int column = position; column < columns; ++column) {
rowList[row].insert(position, "");
}
}
endInsertColumns();
return true;
}
/*!
Removes a number of rows from the model at the specified position.
*/
bool TableModel::removeRows(int position, int rows, const QModelIndex &parent)
{
beginRemoveRows(parent, position, position + rows - 1);
for (int row = 0; row < rows; ++row) {
rowList.removeAt(position);
}
endRemoveRows();
return true;
}
/*!
Removes a number of columns from the model at the specified position.
Each row is shortened by the number of columns specified.
*/
bool TableModel::removeColumns(int position, int columns,
const QModelIndex &parent)
{
int rows = rowCount();
beginRemoveColumns(parent, position, position + columns - 1);
for (int row = 0; row < rows; ++row) {
for (int column = 0; column < columns; ++column) {
rowList[row].removeAt(position);
}
}
endRemoveColumns();
return true;
}
#ifndef WINDOW_H
#define WINDOW_H
#include <QItemSelection>
#include <QMainWindow>
#include <QAbstractItemModel>
#include <QWidget>
#include <QTableView>
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = 0);
private slots:
void fillSelection();
void clearSelection();
void selectAll();
private:
QAbstractItemModel *model;
QItemSelectionModel *selectionModel;
QTableView *table;
};
#endif
/*
window.cpp
A minimal subclass of QTableView with slots to allow the selection model
to be monitored.
*/
#include <QAbstractItemModel>
#include <QItemSelection>
#include <QItemSelectionModel>
#include <QMenu>
#include <QMenuBar>
#include <QStatusBar>
#include "model.h"
#include "window.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
setWindowTitle("Selected Items in a Table Model");
model = new TableModel(8, 4, this);
table = new QTableView(this);
table->setModel(model);
QMenu *actionMenu = new QMenu(tr("&Actions"), this);
QAction *fillAction = actionMenu->addAction(tr("&Fill Selection"));
QAction *clearAction = actionMenu->addAction(tr("&Clear Selection"));
QAction *selectAllAction = actionMenu->addAction(tr("&Select All"));
menuBar()->addMenu(actionMenu);
connect(fillAction, SIGNAL(triggered()), this, SLOT(fillSelection()));
connect(clearAction, SIGNAL(triggered()), this, SLOT(clearSelection()));
connect(selectAllAction, SIGNAL(triggered()), this, SLOT(selectAll()));
selectionModel = table->selectionModel();
statusBar();
setCentralWidget(table);
}
void MainWindow::fillSelection()
{
QModelIndexList indexes = selectionModel->selectedIndexes();
QModelIndex index;
foreach(index, indexes) {
QString text = QString("(%1,%2)").arg(index.row()).arg(index.column());
model->setData(index, text);
}
}
void MainWindow::clearSelection()
{
QModelIndexList indexes = selectionModel->selectedIndexes();
QModelIndex index;
foreach(index, indexes)
model->setData(index, "");
}
void MainWindow::selectAll()
{
QModelIndex parent = QModelIndex();
QModelIndex topLeft = model->index(0, 0, parent);
QModelIndex bottomRight = model->index(model->rowCount(parent)-1,
model->columnCount(parent)-1, parent);
QItemSelection selection(topLeft, bottomRight);
selectionModel->select(selection, QItemSelectionModel::Select);
}
/*
main.cpp
A simple example that shows how selections can be used directly on a model.
It shows the result of some selections made using a table view.
*/
#include <QApplication>
#include "window.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QMainWindow *window = new MainWindow;
window->show();
window->resize(640, 480);
return app.exec();
}
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