QTreeView drag and drop
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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of an example program for Qt.
** EDITIONS: NOLIMITS
**
****************************************************************************/
#ifndef DRAGDROPMODEL_H
#define DRAGDROPMODEL_H
#include "treemodel.h"
class DragDropModel : public TreeModel
{
Q_OBJECT
public:
DragDropModel(const QStringList &strings, QObject *parent = 0);
Qt::ItemFlags flags(const QModelIndex &index) const;
bool dropMimeData(const QMimeData *data, Qt::DropAction action,
int row, int column, const QModelIndex &parent);
QMimeData *mimeData(const QModelIndexList &indexes) const;
QStringList mimeTypes() const;
Qt::DropActions supportedDropActions() const;
};
#endif
#include <QtGui>
#include "dragdropmodel.h"
DragDropModel::DragDropModel(const QStringList &strings, QObject *parent)
: TreeModel(strings, parent)
{
}
bool DragDropModel::dropMimeData(const QMimeData *data,
Qt::DropAction action, int row, int column, const QModelIndex &parent)
{
if (action == Qt::IgnoreAction)
return true;
if (!data->hasFormat("text/plain"))
return false;
int beginRow;
if (row != -1)
beginRow = row;
else if (parent.isValid())
beginRow = 0;
else
beginRow = rowCount(QModelIndex());
QByteArray encodedData = data->data("text/plain");
QDataStream stream(&encodedData, QIODevice::ReadOnly);
QHash<qint64, QMap<int,QHash<int,QString> > > newItems;
while (!stream.atEnd()) {
qint64 id;
int row;
int column;
QString text;
stream >> id >> row >> column >> text;
newItems[id][row][column] = text;
}
int rows = newItems.count();
insertRows(beginRow, rows, parent);
QMap<int,QHash<int,QString> > childItems;
foreach (childItems, newItems.values()) {
QHash<int,QString> rowItems;
foreach (rowItems, childItems.values()) {
foreach (int column, rowItems.keys()) {
QModelIndex idx = index(beginRow, column, parent);
setData(idx, rowItems[column]);
}
++beginRow;
}
}
return true;
}
Qt::ItemFlags DragDropModel::flags(const QModelIndex &index) const
{
Qt::ItemFlags defaultFlags = TreeModel::flags(index);
if (index.isValid())
return Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled | defaultFlags;
else
return Qt::ItemIsDropEnabled | defaultFlags;
}
QMimeData *DragDropModel::mimeData(const QModelIndexList &indexes) const
{
QMimeData *mimeData = new QMimeData();
QByteArray encodedData;
QDataStream stream(&encodedData, QIODevice::WriteOnly);
foreach (QModelIndex index, indexes) {
if (index.isValid()) {
QString text = data(index, Qt::DisplayRole).toString();
stream << index.internalId() << index.row() << index.column() << text;
}
}
mimeData->setData("text/plain", encodedData);
return mimeData;
}
QStringList DragDropModel::mimeTypes() const
{
QStringList types;
types << "text/plain";
return types;
}
Qt::DropActions DragDropModel::supportedDropActions() const
{
return Qt::CopyAction | Qt::MoveAction;
}
#ifndef TREEITEM_H
#define TREEITEM_H
#include <QList>
#include <QVariant>
class TreeItem
{
public:
TreeItem(const QList<QVariant> &data, TreeItem *parent = 0);
~TreeItem();
void appendChild(TreeItem *child);
TreeItem *child(int row);
int childCount() const;
int columnCount() const;
QVariant data(int column) const;
bool insertChild(int row, TreeItem *item);
TreeItem *parent();
bool removeChild(int row);
int row() const;
bool setData(int column, const QVariant &data);
private:
QList<TreeItem*> childItems;
QList<QVariant> itemData;
TreeItem *parentItem;
};
#endif
/*
treeitem.cpp
A container for items of data supplied by the simple tree model.
*/
#include <QStringList>
#include "treeitem.h"
TreeItem::TreeItem(const QList<QVariant> &data, TreeItem *parent)
{
parentItem = parent;
itemData = data;
}
TreeItem::~TreeItem()
{
qDeleteAll(childItems);
}
void TreeItem::appendChild(TreeItem *item)
{
childItems.append(item);
}
TreeItem *TreeItem::child(int row)
{
return childItems.value(row);
}
int TreeItem::childCount() const
{
return childItems.count();
}
int TreeItem::columnCount() const
{
return itemData.count();
}
QVariant TreeItem::data(int column) const
{
return itemData.value(column);
}
bool TreeItem::insertChild(int row, TreeItem *item)
{
if (row < 0 || row > childItems.count())
return false;
childItems.insert(row, item);
return true;
}
TreeItem *TreeItem::parent()
{
return parentItem;
}
bool TreeItem::removeChild(int row)
{
if (row < 0 || row >= childItems.count())
return false;
delete childItems.takeAt(row);
return true;
}
int TreeItem::row() const
{
if (parentItem)
return parentItem->childItems.indexOf(const_cast<TreeItem*>(this));
return 0;
}
bool TreeItem::setData(int column, const QVariant &data)
{
if (column < 0 || column >= itemData.count())
return false;
itemData.replace(column, data);
return true;
}
#ifndef TREEMODEL_H
#define TREEMODEL_H
#include <QAbstractItemModel>
#include <QModelIndex>
#include <QVariant>
class TreeItem;
class TreeModel : public QAbstractItemModel
{
Q_OBJECT
public:
TreeModel(const QStringList &strings, QObject *parent = 0);
~TreeModel();
QVariant data(const QModelIndex &index, int role) const;
Qt::ItemFlags flags(const QModelIndex &index) const;
QVariant headerData(int section, Qt::Orientation orientation,
int role = Qt::DisplayRole) 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;
bool insertRows(int position, int rows, const QModelIndex &parent = QModelIndex());
bool removeRows(int position, int rows, const QModelIndex &parent = QModelIndex());
bool setData(const QModelIndex &index, const QVariant &value,
int role = Qt::EditRole);
private:
void setupModelData(const QStringList &lines, TreeItem *parent);
TreeItem *rootItem;
};
#endif
/*
treemodel.cpp
Provides a simple tree model to show how to create and use hierarchical
models.
*/
#include <QtGui>
#include "treeitem.h"
#include "treemodel.h"
TreeModel::TreeModel(const QStringList &strings, QObject *parent)
: QAbstractItemModel(parent)
{
QList<QVariant> rootData;
rootData << "Title" << "Summary";
rootItem = new TreeItem(rootData);
setupModelData(strings, rootItem);
}
TreeModel::~TreeModel()
{
delete rootItem;
}
int TreeModel::columnCount(const QModelIndex &parent) const
{
if (parent.isValid())
return static_cast<TreeItem*>(parent.internalPointer())->columnCount();
else
return rootItem->columnCount();
}
QVariant TreeModel::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();
if (role != Qt::DisplayRole)
return QVariant();
TreeItem *item = static_cast<TreeItem*>(index.internalPointer());
return item->data(index.column());
}
Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const
{
if (!index.isValid())
return Qt::ItemIsEnabled;
return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
}
QVariant TreeModel::headerData(int section, Qt::Orientation orientation,
int role) const
{
if (orientation == Qt::Horizontal && role == Qt::DisplayRole)
return rootItem->data(section);
return QVariant();
}
QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent)
const
{
TreeItem *parentItem;
if (!parent.isValid())
parentItem = rootItem;
else
parentItem = static_cast<TreeItem*>(parent.internalPointer());
TreeItem *childItem = parentItem->child(row);
if (childItem)
return createIndex(row, column, childItem);
else
return QModelIndex();
}
bool TreeModel::insertRows(int position, int rows, const QModelIndex &parent)
{
TreeItem *parentItem;
if (!parent.isValid())
parentItem = rootItem;
else
parentItem = static_cast<TreeItem*>(parent.internalPointer());
if (position < 0 || position > parentItem->childCount())
return false;
QList<QVariant> blankList;
for (int column = 0; column < columnCount(); ++column)
blankList << QVariant("");
beginInsertRows(parent, position, position + rows - 1);
for (int row = 0; row < rows; ++row) {
TreeItem *newItem = new TreeItem(blankList, parentItem);
if (!parentItem->insertChild(position, newItem))
break;
}
endInsertRows();
return true;
}
QModelIndex TreeModel::parent(const QModelIndex &index) const
{
if (!index.isValid())
return QModelIndex();
TreeItem *childItem = static_cast<TreeItem*>(index.internalPointer());
TreeItem *parentItem = childItem->parent();
if (parentItem == rootItem)
return QModelIndex();
return createIndex(parentItem->row(), 0, parentItem);
}
bool TreeModel::removeRows(int position, int rows, const QModelIndex &parent)
{
TreeItem *parentItem;
if (!parent.isValid())
parentItem = rootItem;
else
parentItem = static_cast<TreeItem*>(parent.internalPointer());
if (position < 0 || position > parentItem->childCount())
return false;
beginRemoveRows(parent, position, position + rows - 1);
for (int row = 0; row < rows; ++row) {
if (!parentItem->removeChild(position))
break;
}
endRemoveRows();
return true;
}
int TreeModel::rowCount(const QModelIndex &parent) const
{
TreeItem *parentItem;
if (!parent.isValid())
parentItem = rootItem;
else
parentItem = static_cast<TreeItem*>(parent.internalPointer());
return parentItem->childCount();
}
bool TreeModel::setData(const QModelIndex &index,
const QVariant &value, int role)
{
if (!index.isValid() || role != Qt::EditRole)
return false;
TreeItem *item = static_cast<TreeItem*>(index.internalPointer());
if (item->setData(index.column(), value))
emit dataChanged(index, index);
else
return false;
return true;
}
void TreeModel::setupModelData(const QStringList &lines, TreeItem *parent)
{
QList<TreeItem*> parents;
QList<int> indentations;
parents << parent;
indentations << 0;
int number = 0;
while (number < lines.count()) {
int position = 0;
while (position < lines[number].length()) {
if (lines[number].mid(position, 1) != " ")
break;
position++;
}
QString lineData = lines[number].mid(position).trimmed();
if (!lineData.isEmpty()) {
// Read the column data from the rest of the line.
QStringList columnStrings = lineData.split("\t", QString::SkipEmptyParts);
QList<QVariant> columnData;
for (int column = 0; column < columnStrings.count(); ++column)
columnData << columnStrings[column];
if (position > indentations.last()) {
// The last child of the current parent is now the new parent
// unless the current parent has no children.
if (parents.last()->childCount() > 0) {
parents << parents.last()->child(parents.last()->childCount()-1);
indentations << position;
}
} else {
while (position < indentations.last() && parents.count() > 0) {
parents.pop_back();
indentations.pop_back();
}
}
// Append a new item to the current parent's list of children.
parents.last()->appendChild(new TreeItem(columnData, parents.last()));
}
number++;
}
}
#ifndef WINDOW_H
#define WINDOW_H
#include <QMainWindow>
class QTreeView;
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow();
private:
void setupItems();
QTreeView *treeView;
};
#endif
#include <QtGui>
#include "mainwindow.h"
#include "dragdropmodel.h"
MainWindow::MainWindow()
{
QMenu *fileMenu = new QMenu(tr("&File"));
QAction *quitAction = fileMenu->addAction(tr("E&xit"));
quitAction->setShortcut(tr("Ctrl+Q"));
menuBar()->addMenu(fileMenu);
// For convenient quoting:
QTreeView *treeView = new QTreeView(this);
treeView->setSelectionMode(QAbstractItemView::ExtendedSelection);
treeView->setDragEnabled(true);
treeView->setAcceptDrops(true);
treeView->setDropIndicatorShown(true);
this->treeView = treeView;
connect(quitAction, SIGNAL(triggered()), this, SLOT(close()));
setupItems();
setCentralWidget(treeView);
setWindowTitle(tr("Tree View"));
}
void MainWindow::setupItems()
{
QStringList items;
items << tr("Widgets\tUser interface objects used to create GUI applications.")
<< tr(" QWidget\tThe basic building block for all other widgets.")
<< tr(" QDialog\tThe base class for dialog windows.")
<< tr("Tools\tUtilities and applications for Qt developers.")
<< tr(" Qt Designer\tA GUI form designer for Qt applications.")
<< tr(" Qt Assistant\tA documentation browser for Qt documentation.");
DragDropModel *model = new DragDropModel(items, this);
QModelIndex index = model->index(0, 0, QModelIndex());
model->insertRows(2, 3, index);
index = model->index(0, 0, QModelIndex());
index = model->index(2, 0, index);
model->setData(index, QVariant("QFrame"));
model->removeRows(3, 2, index.parent());
treeView->setModel(model);
}
#include <QtGui>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MainWindow *window = new MainWindow;
window->show();
return app.exec();
}
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