qt5base-lts/src/corelib/itemmodels/qitemselectionmodel.cpp
Marc Mutz 6d44fa53e1 QItemSelection: fix a quadratic loop
QList::erase(it) is a linear operation. Calling it in a loop
constitutes quadratic behavior.

Fix by using the erase-remove idiom.

Write a generic function object QtFunctionObjects::IsNotValid, instead
of a lambda, because I am building up a collection of such function
objects in my tree, to be submitted any time now™, so this will reduce
the churn once that gets merged. Wrap it in the unnamed namespace to
avoid ODR violations in case this pattern repeats.

Replace an existing erase-remove idiom's isNotValid lambda function
with the new function object.

Change-Id: I4f0af04e7b201eb168e79beeda332eee3c6f33c3
Reviewed-by: Anton Kudryavtsev <antkudr@mail.ru>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
2017-05-22 18:16:38 +00:00

1922 lines
66 KiB
C++

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#include "qitemselectionmodel.h"
#include <private/qitemselectionmodel_p.h>
#include <qdebug.h>
#include <algorithm>
#include <functional>
#ifndef QT_NO_ITEMVIEWS
QT_BEGIN_NAMESPACE
/*!
\class QItemSelectionRange
\inmodule QtCore
\brief The QItemSelectionRange class manages information about a
range of selected items in a model.
\ingroup model-view
A QItemSelectionRange contains information about a range of
selected items in a model. A range of items is a contiguous array
of model items, extending to cover a number of adjacent rows and
columns with a common parent item; this can be visualized as a
two-dimensional block of cells in a table. A selection range has a
top(), left() a bottom(), right() and a parent().
The QItemSelectionRange class is one of the \l{Model/View Classes}
and is part of Qt's \l{Model/View Programming}{model/view framework}.
The model items contained in the selection range can be obtained
using the indexes() function. Use QItemSelectionModel::selectedIndexes()
to get a list of all selected items for a view.
You can determine whether a given model item lies within a
particular range by using the contains() function. Ranges can also
be compared using the overloaded operators for equality and
inequality, and the intersects() function allows you to determine
whether two ranges overlap.
\sa {Model/View Programming}, QAbstractItemModel, QItemSelection,
QItemSelectionModel
*/
/*!
\fn QItemSelectionRange::QItemSelectionRange()
Constructs an empty selection range.
*/
/*!
\fn QItemSelectionRange::QItemSelectionRange(const QItemSelectionRange &other)
Copy constructor. Constructs a new selection range with the same contents
as the \a other range given.
*/
/*!
\fn QItemSelectionRange::QItemSelectionRange(const QModelIndex &topLeft, const QModelIndex &bottomRight)
Constructs a new selection range containing only the index specified
by the \a topLeft and the index \a bottomRight.
*/
/*!
\fn QItemSelectionRange::QItemSelectionRange(const QModelIndex &index)
Constructs a new selection range containing only the model item specified
by the model index \a index.
*/
/*!
\fn QItemSelectionRange::swap(QItemSelectionRange &other)
\since 5.6
Swaps this selection range's contents with \a other.
This function is very fast and never fails.
*/
/*!
\fn int QItemSelectionRange::top() const
Returns the row index corresponding to the uppermost selected row in the
selection range.
*/
/*!
\fn int QItemSelectionRange::left() const
Returns the column index corresponding to the leftmost selected column in the
selection range.
*/
/*!
\fn int QItemSelectionRange::bottom() const
Returns the row index corresponding to the lowermost selected row in the
selection range.
*/
/*!
\fn int QItemSelectionRange::right() const
Returns the column index corresponding to the rightmost selected column in
the selection range.
*/
/*!
\fn int QItemSelectionRange::width() const
Returns the number of selected columns in the selection range.
*/
/*!
\fn int QItemSelectionRange::height() const
Returns the number of selected rows in the selection range.
*/
/*!
\fn const QAbstractItemModel *QItemSelectionRange::model() const
Returns the model that the items in the selection range belong to.
*/
/*!
\fn QModelIndex QItemSelectionRange::topLeft() const
Returns the index for the item located at the top-left corner of
the selection range.
\sa top(), left(), bottomRight()
*/
/*!
\fn QModelIndex QItemSelectionRange::bottomRight() const
Returns the index for the item located at the bottom-right corner
of the selection range.
\sa bottom(), right(), topLeft()
*/
/*!
\fn QModelIndex QItemSelectionRange::parent() const
Returns the parent model item index of the items in the selection range.
*/
/*!
\fn bool QItemSelectionRange::contains(const QModelIndex &index) const
Returns \c true if the model item specified by the \a index lies within the
range of selected items; otherwise returns \c false.
*/
/*!
\fn bool QItemSelectionRange::contains(int row, int column,
const QModelIndex &parentIndex) const
\overload
Returns \c true if the model item specified by (\a row, \a column)
and with \a parentIndex as the parent item lies within the range
of selected items; otherwise returns \c false.
*/
/*!
\fn bool QItemSelectionRange::intersects(const QItemSelectionRange &other) const
Returns \c true if this selection range intersects (overlaps with) the \a other
range given; otherwise returns \c false.
*/
bool QItemSelectionRange::intersects(const QItemSelectionRange &other) const
{
return (isValid() && other.isValid()
&& parent() == other.parent()
&& model() == other.model()
&& ((top() <= other.top() && bottom() >= other.top())
|| (top() >= other.top() && top() <= other.bottom()))
&& ((left() <= other.left() && right() >= other.left())
|| (left() >= other.left() && left() <= other.right())));
}
/*!
\fn QItemSelectionRange QItemSelectionRange::intersect(const QItemSelectionRange &other) const
\obsolete
Use intersected(\a other) instead.
*/
/*!
\fn QItemSelectionRange QItemSelectionRange::intersected(const QItemSelectionRange &other) const
\since 4.2
Returns a new selection range containing only the items that are found in
both the selection range and the \a other selection range.
*/
QItemSelectionRange QItemSelectionRange::intersected(const QItemSelectionRange &other) const
{
if (model() == other.model() && parent() == other.parent()) {
QModelIndex topLeft = model()->index(qMax(top(), other.top()),
qMax(left(), other.left()),
other.parent());
QModelIndex bottomRight = model()->index(qMin(bottom(), other.bottom()),
qMin(right(), other.right()),
other.parent());
return QItemSelectionRange(topLeft, bottomRight);
}
return QItemSelectionRange();
}
/*!
\fn bool QItemSelectionRange::operator==(const QItemSelectionRange &other) const
Returns \c true if the selection range is exactly the same as the \a other
range given; otherwise returns \c false.
*/
/*!
\fn bool QItemSelectionRange::operator!=(const QItemSelectionRange &other) const
Returns \c true if the selection range differs from the \a other range given;
otherwise returns \c false.
*/
/*!
Returns \c true if the selection range is less than the \a other
range given; otherwise returns \c false.
The less than calculation is not directly useful to developers - the way that ranges
with different parents compare is not defined. This operator only exists so that the
class can be used with QMap.
*/
bool QItemSelectionRange::operator<(const QItemSelectionRange &other) const
{
// ### Qt 6: This is inconsistent with op== and needs to be fixed, nay,
// ### removed, but cannot, because it was inline up to and including 5.9
// Comparing parents will compare the models, but if two equivalent ranges
// in two different models have invalid parents, they would appear the same
if (other.tl.model() == tl.model()) {
// parent has to be calculated, so we only do so once.
const QModelIndex topLeftParent = tl.parent();
const QModelIndex otherTopLeftParent = other.tl.parent();
if (topLeftParent == otherTopLeftParent) {
if (other.tl.row() == tl.row()) {
if (other.tl.column() == tl.column()) {
if (other.br.row() == br.row()) {
return br.column() < other.br.column();
}
return br.row() < other.br.row();
}
return tl.column() < other.tl.column();
}
return tl.row() < other.tl.row();
}
return topLeftParent < otherTopLeftParent;
}
std::less<const QAbstractItemModel *> less;
return less(tl.model(), other.tl.model());
}
/*!
\fn bool QItemSelectionRange::isValid() const
Returns \c true if the selection range is valid; otherwise returns \c false.
*/
static void rowLengthsFromRange(const QItemSelectionRange &range, QVector<QPair<QPersistentModelIndex, uint> > &result)
{
if (range.isValid() && range.model()) {
const QModelIndex topLeft = range.topLeft();
const int bottom = range.bottom();
const uint width = range.width();
const int column = topLeft.column();
for (int row = topLeft.row(); row <= bottom; ++row) {
// We don't need to keep track of ItemIsSelectable and ItemIsEnabled here. That is
// required in indexesFromRange() because that method is called from public API
// which requires the limitation.
result.push_back(qMakePair(QPersistentModelIndex(topLeft.sibling(row, column)), width));
}
}
}
template<typename ModelIndexContainer>
static void indexesFromRange(const QItemSelectionRange &range, ModelIndexContainer &result)
{
if (range.isValid() && range.model()) {
const QModelIndex topLeft = range.topLeft();
const int bottom = range.bottom();
const int right = range.right();
for (int row = topLeft.row(); row <= bottom; ++row) {
const QModelIndex columnLeader = topLeft.sibling(row, topLeft.column());
for (int column = topLeft.column(); column <= right; ++column) {
QModelIndex index = columnLeader.sibling(row, column);
Qt::ItemFlags flags = range.model()->flags(index);
if ((flags & Qt::ItemIsSelectable) && (flags & Qt::ItemIsEnabled))
result.push_back(index);
}
}
}
}
template<typename ModelIndexContainer>
static ModelIndexContainer qSelectionIndexes(const QItemSelection &selection)
{
ModelIndexContainer result;
for (const auto &range : selection)
indexesFromRange(range, result);
return result;
}
/*!
Returns \c true if the selection range contains no selectable item
\since 4.7
*/
bool QItemSelectionRange::isEmpty() const
{
if (!isValid() || !model())
return true;
for (int column = left(); column <= right(); ++column) {
for (int row = top(); row <= bottom(); ++row) {
QModelIndex index = model()->index(row, column, parent());
Qt::ItemFlags flags = model()->flags(index);
if ((flags & Qt::ItemIsSelectable) && (flags & Qt::ItemIsEnabled))
return false;
}
}
return true;
}
/*!
Returns the list of model index items stored in the selection.
*/
QModelIndexList QItemSelectionRange::indexes() const
{
QModelIndexList result;
indexesFromRange(*this, result);
return result;
}
/*!
\class QItemSelection
\inmodule QtCore
\brief The QItemSelection class manages information about selected items in a model.
\ingroup model-view
A QItemSelection describes the items in a model that have been
selected by the user. A QItemSelection is basically a list of
selection ranges, see QItemSelectionRange. It provides functions for
creating and manipulating selections, and selecting a range of items
from a model.
The QItemSelection class is one of the \l{Model/View Classes}
and is part of Qt's \l{Model/View Programming}{model/view framework}.
An item selection can be constructed and initialized to contain a
range of items from an existing model. The following example constructs
a selection that contains a range of items from the given \c model,
beginning at the \c topLeft, and ending at the \c bottomRight.
\snippet code/src_gui_itemviews_qitemselectionmodel.cpp 0
An empty item selection can be constructed, and later populated as
required. So, if the model is going to be unavailable when we construct
the item selection, we can rewrite the above code in the following way:
\snippet code/src_gui_itemviews_qitemselectionmodel.cpp 1
QItemSelection saves memory, and avoids unnecessary work, by working with
selection ranges rather than recording the model item index for each
item in the selection. Generally, an instance of this class will contain
a list of non-overlapping selection ranges.
Use merge() to merge one item selection into another without making
overlapping ranges. Use split() to split one selection range into
smaller ranges based on a another selection range.
\sa {Model/View Programming}, QItemSelectionModel
*/
/*!
\fn QItemSelection::QItemSelection()
Constructs an empty selection.
*/
/*!
Constructs an item selection that extends from the top-left model item,
specified by the \a topLeft index, to the bottom-right item, specified
by \a bottomRight.
*/
QItemSelection::QItemSelection(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
select(topLeft, bottomRight);
}
/*!
Adds the items in the range that extends from the top-left model
item, specified by the \a topLeft index, to the bottom-right item,
specified by \a bottomRight to the list.
\note \a topLeft and \a bottomRight must have the same parent.
*/
void QItemSelection::select(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
if (!topLeft.isValid() || !bottomRight.isValid())
return;
if ((topLeft.model() != bottomRight.model())
|| topLeft.parent() != bottomRight.parent()) {
qWarning("Can't select indexes from different model or with different parents");
return;
}
if (topLeft.row() > bottomRight.row() || topLeft.column() > bottomRight.column()) {
int top = qMin(topLeft.row(), bottomRight.row());
int bottom = qMax(topLeft.row(), bottomRight.row());
int left = qMin(topLeft.column(), bottomRight.column());
int right = qMax(topLeft.column(), bottomRight.column());
QModelIndex tl = topLeft.sibling(top, left);
QModelIndex br = bottomRight.sibling(bottom, right);
append(QItemSelectionRange(tl, br));
return;
}
append(QItemSelectionRange(topLeft, bottomRight));
}
/*!
Returns \c true if the selection contains the given \a index; otherwise
returns \c false.
*/
bool QItemSelection::contains(const QModelIndex &index) const
{
if (index.flags() & Qt::ItemIsSelectable) {
QList<QItemSelectionRange>::const_iterator it = begin();
for (; it != end(); ++it)
if ((*it).contains(index))
return true;
}
return false;
}
/*!
Returns a list of model indexes that correspond to the selected items.
*/
QModelIndexList QItemSelection::indexes() const
{
return qSelectionIndexes<QModelIndexList>(*this);
}
static QVector<QPair<QPersistentModelIndex, uint> > qSelectionPersistentRowLengths(const QItemSelection &sel)
{
QVector<QPair<QPersistentModelIndex, uint> > result;
for (const QItemSelectionRange &range : sel)
rowLengthsFromRange(range, result);
return result;
}
/*!
Merges the \a other selection with this QItemSelection using the
\a command given. This method guarantees that no ranges are overlapping.
Note that only QItemSelectionModel::Select,
QItemSelectionModel::Deselect, and QItemSelectionModel::Toggle are
supported.
\sa split()
*/
void QItemSelection::merge(const QItemSelection &other, QItemSelectionModel::SelectionFlags command)
{
if (other.isEmpty() ||
!(command & QItemSelectionModel::Select ||
command & QItemSelectionModel::Deselect ||
command & QItemSelectionModel::Toggle))
return;
QItemSelection newSelection = other;
// Collect intersections
QItemSelection intersections;
QItemSelection::iterator it = newSelection.begin();
while (it != newSelection.end()) {
if (!(*it).isValid()) {
it = newSelection.erase(it);
continue;
}
for (int t = 0; t < count(); ++t) {
if ((*it).intersects(at(t)))
intersections.append(at(t).intersected(*it));
}
++it;
}
// Split the old (and new) ranges using the intersections
for (int i = 0; i < intersections.count(); ++i) { // for each intersection
for (int t = 0; t < count();) { // splitt each old range
if (at(t).intersects(intersections.at(i))) {
split(at(t), intersections.at(i), this);
removeAt(t);
} else {
++t;
}
}
// only split newSelection if Toggle is specified
for (int n = 0; (command & QItemSelectionModel::Toggle) && n < newSelection.count();) {
if (newSelection.at(n).intersects(intersections.at(i))) {
split(newSelection.at(n), intersections.at(i), &newSelection);
newSelection.removeAt(n);
} else {
++n;
}
}
}
// do not add newSelection for Deselect
if (!(command & QItemSelectionModel::Deselect))
operator+=(newSelection);
}
/*!
Splits the selection \a range using the selection \a other range.
Removes all items in \a other from \a range and puts the result in \a result.
This can be compared with the semantics of the \e subtract operation of a set.
\sa merge()
*/
void QItemSelection::split(const QItemSelectionRange &range,
const QItemSelectionRange &other, QItemSelection *result)
{
if (range.parent() != other.parent() || range.model() != other.model())
return;
QModelIndex parent = other.parent();
int top = range.top();
int left = range.left();
int bottom = range.bottom();
int right = range.right();
int other_top = other.top();
int other_left = other.left();
int other_bottom = other.bottom();
int other_right = other.right();
const QAbstractItemModel *model = range.model();
Q_ASSERT(model);
if (other_top > top) {
QModelIndex tl = model->index(top, left, parent);
QModelIndex br = model->index(other_top - 1, right, parent);
result->append(QItemSelectionRange(tl, br));
top = other_top;
}
if (other_bottom < bottom) {
QModelIndex tl = model->index(other_bottom + 1, left, parent);
QModelIndex br = model->index(bottom, right, parent);
result->append(QItemSelectionRange(tl, br));
bottom = other_bottom;
}
if (other_left > left) {
QModelIndex tl = model->index(top, left, parent);
QModelIndex br = model->index(bottom, other_left - 1, parent);
result->append(QItemSelectionRange(tl, br));
left = other_left;
}
if (other_right < right) {
QModelIndex tl = model->index(top, other_right + 1, parent);
QModelIndex br = model->index(bottom, right, parent);
result->append(QItemSelectionRange(tl, br));
right = other_right;
}
}
void QItemSelectionModelPrivate::initModel(QAbstractItemModel *m)
{
struct Cx {
const char *signal;
const char *slot;
};
static const Cx connections[] = {
{ SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)) },
{ SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)) },
{ SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)),
SLOT(_q_rowsAboutToBeInserted(QModelIndex,int,int)) },
{ SIGNAL(columnsAboutToBeInserted(QModelIndex,int,int)),
SLOT(_q_columnsAboutToBeInserted(QModelIndex,int,int)) },
{ SIGNAL(rowsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int)),
SLOT(_q_layoutAboutToBeChanged()) },
{ SIGNAL(columnsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int)),
SLOT(_q_layoutAboutToBeChanged()) },
{ SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
SLOT(_q_layoutChanged()) },
{ SIGNAL(columnsMoved(QModelIndex,int,int,QModelIndex,int)),
SLOT(_q_layoutChanged()) },
{ SIGNAL(layoutAboutToBeChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
SLOT(_q_layoutAboutToBeChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)) },
{ SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)) },
{ SIGNAL(modelReset()),
SLOT(reset()) },
{ 0, 0 }
};
if (model == m)
return;
Q_Q(QItemSelectionModel);
if (model) {
for (const Cx *cx = &connections[0]; cx->signal; cx++)
QObject::disconnect(model, cx->signal, q, cx->slot);
q->reset();
}
model = m;
if (model) {
for (const Cx *cx = &connections[0]; cx->signal; cx++)
QObject::connect(model, cx->signal, q, cx->slot);
}
}
/*!
\internal
returns a QItemSelection where all ranges have been expanded to:
Rows: left: 0 and right: columnCount()-1
Columns: top: 0 and bottom: rowCount()-1
*/
QItemSelection QItemSelectionModelPrivate::expandSelection(const QItemSelection &selection,
QItemSelectionModel::SelectionFlags command) const
{
if (selection.isEmpty() && !((command & QItemSelectionModel::Rows) ||
(command & QItemSelectionModel::Columns)))
return selection;
QItemSelection expanded;
if (command & QItemSelectionModel::Rows) {
for (int i = 0; i < selection.count(); ++i) {
QModelIndex parent = selection.at(i).parent();
int colCount = model->columnCount(parent);
QModelIndex tl = model->index(selection.at(i).top(), 0, parent);
QModelIndex br = model->index(selection.at(i).bottom(), colCount - 1, parent);
//we need to merge because the same row could have already been inserted
expanded.merge(QItemSelection(tl, br), QItemSelectionModel::Select);
}
}
if (command & QItemSelectionModel::Columns) {
for (int i = 0; i < selection.count(); ++i) {
QModelIndex parent = selection.at(i).parent();
int rowCount = model->rowCount(parent);
QModelIndex tl = model->index(0, selection.at(i).left(), parent);
QModelIndex br = model->index(rowCount - 1, selection.at(i).right(), parent);
//we need to merge because the same column could have already been inserted
expanded.merge(QItemSelection(tl, br), QItemSelectionModel::Select);
}
}
return expanded;
}
/*!
\internal
*/
void QItemSelectionModelPrivate::_q_rowsAboutToBeRemoved(const QModelIndex &parent,
int start, int end)
{
Q_Q(QItemSelectionModel);
finalize();
// update current index
if (currentIndex.isValid() && parent == currentIndex.parent()
&& currentIndex.row() >= start && currentIndex.row() <= end) {
QModelIndex old = currentIndex;
if (start > 0) // there are rows left above the change
currentIndex = model->index(start - 1, old.column(), parent);
else if (model && end < model->rowCount(parent) - 1) // there are rows left below the change
currentIndex = model->index(end + 1, old.column(), parent);
else // there are no rows left in the table
currentIndex = QModelIndex();
emit q->currentChanged(currentIndex, old);
emit q->currentRowChanged(currentIndex, old);
if (currentIndex.column() != old.column())
emit q->currentColumnChanged(currentIndex, old);
}
QItemSelection deselected;
QItemSelection newParts;
QItemSelection::iterator it = ranges.begin();
while (it != ranges.end()) {
if (it->topLeft().parent() != parent) { // Check parents until reaching root or contained in range
QModelIndex itParent = it->topLeft().parent();
while (itParent.isValid() && itParent.parent() != parent)
itParent = itParent.parent();
if (itParent.isValid() && start <= itParent.row() && itParent.row() <= end) {
deselected.append(*it);
it = ranges.erase(it);
} else {
++it;
}
} else if (start <= it->bottom() && it->bottom() <= end // Full inclusion
&& start <= it->top() && it->top() <= end) {
deselected.append(*it);
it = ranges.erase(it);
} else if (start <= it->top() && it->top() <= end) { // Top intersection
deselected.append(QItemSelectionRange(it->topLeft(), model->index(end, it->right(), it->parent())));
*it = QItemSelectionRange(model->index(end + 1, it->left(), it->parent()), it->bottomRight());
++it;
} else if (start <= it->bottom() && it->bottom() <= end) { // Bottom intersection
deselected.append(QItemSelectionRange(model->index(start, it->left(), it->parent()), it->bottomRight()));
*it = QItemSelectionRange(it->topLeft(), model->index(start - 1, it->right(), it->parent()));
++it;
} else if (it->top() < start && end < it->bottom()) { // Middle intersection
// If the parent contains (1, 2, 3, 4, 5, 6, 7, 8) and [3, 4, 5, 6] is selected,
// and [4, 5] is removed, we need to split [3, 4, 5, 6] into [3], [4, 5] and [6].
// [4, 5] is appended to deselected, and [3] and [6] remain part of the selection
// in ranges.
const QItemSelectionRange removedRange(model->index(start, it->left(), it->parent()),
model->index(end, it->right(), it->parent()));
deselected.append(removedRange);
QItemSelection::split(*it, removedRange, &newParts);
it = ranges.erase(it);
} else
++it;
}
ranges.append(newParts);
if (!deselected.isEmpty())
emit q->selectionChanged(QItemSelection(), deselected);
}
/*!
\internal
*/
void QItemSelectionModelPrivate::_q_columnsAboutToBeRemoved(const QModelIndex &parent,
int start, int end)
{
Q_Q(QItemSelectionModel);
// update current index
if (currentIndex.isValid() && parent == currentIndex.parent()
&& currentIndex.column() >= start && currentIndex.column() <= end) {
QModelIndex old = currentIndex;
if (start > 0) // there are columns to the left of the change
currentIndex = model->index(old.row(), start - 1, parent);
else if (model && end < model->columnCount() - 1) // there are columns to the right of the change
currentIndex = model->index(old.row(), end + 1, parent);
else // there are no columns left in the table
currentIndex = QModelIndex();
emit q->currentChanged(currentIndex, old);
if (currentIndex.row() != old.row())
emit q->currentRowChanged(currentIndex, old);
emit q->currentColumnChanged(currentIndex, old);
}
// update selections
QModelIndex tl = model->index(0, start, parent);
QModelIndex br = model->index(model->rowCount(parent) - 1, end, parent);
q->select(QItemSelection(tl, br), QItemSelectionModel::Deselect);
finalize();
}
/*!
\internal
Split selection ranges if columns are about to be inserted in the middle.
*/
void QItemSelectionModelPrivate::_q_columnsAboutToBeInserted(const QModelIndex &parent,
int start, int end)
{
Q_UNUSED(end);
finalize();
QList<QItemSelectionRange> split;
QList<QItemSelectionRange>::iterator it = ranges.begin();
for (; it != ranges.end(); ) {
if ((*it).isValid() && (*it).parent() == parent
&& (*it).left() < start && (*it).right() >= start) {
QModelIndex bottomMiddle = model->index((*it).bottom(), start - 1, (*it).parent());
QItemSelectionRange left((*it).topLeft(), bottomMiddle);
QModelIndex topMiddle = model->index((*it).top(), start, (*it).parent());
QItemSelectionRange right(topMiddle, (*it).bottomRight());
it = ranges.erase(it);
split.append(left);
split.append(right);
} else {
++it;
}
}
ranges += split;
}
/*!
\internal
Split selection ranges if rows are about to be inserted in the middle.
*/
void QItemSelectionModelPrivate::_q_rowsAboutToBeInserted(const QModelIndex &parent,
int start, int end)
{
Q_UNUSED(end);
finalize();
QList<QItemSelectionRange> split;
QList<QItemSelectionRange>::iterator it = ranges.begin();
for (; it != ranges.end(); ) {
if ((*it).isValid() && (*it).parent() == parent
&& (*it).top() < start && (*it).bottom() >= start) {
QModelIndex middleRight = model->index(start - 1, (*it).right(), (*it).parent());
QItemSelectionRange top((*it).topLeft(), middleRight);
QModelIndex middleLeft = model->index(start, (*it).left(), (*it).parent());
QItemSelectionRange bottom(middleLeft, (*it).bottomRight());
it = ranges.erase(it);
split.append(top);
split.append(bottom);
} else {
++it;
}
}
ranges += split;
}
/*!
\internal
Split selection into individual (persistent) indexes. This is done in
preparation for the layoutChanged() signal, where the indexes can be
merged again.
*/
void QItemSelectionModelPrivate::_q_layoutAboutToBeChanged(const QList<QPersistentModelIndex> &, QAbstractItemModel::LayoutChangeHint hint)
{
savedPersistentIndexes.clear();
savedPersistentCurrentIndexes.clear();
savedPersistentRowLengths.clear();
savedPersistentCurrentRowLengths.clear();
// optimization for when all indexes are selected
// (only if there is lots of items (1000) because this is not entirely correct)
if (ranges.isEmpty() && currentSelection.count() == 1) {
QItemSelectionRange range = currentSelection.constFirst();
QModelIndex parent = range.parent();
tableRowCount = model->rowCount(parent);
tableColCount = model->columnCount(parent);
if (tableRowCount * tableColCount > 1000
&& range.top() == 0
&& range.left() == 0
&& range.bottom() == tableRowCount - 1
&& range.right() == tableColCount - 1) {
tableSelected = true;
tableParent = parent;
return;
}
}
tableSelected = false;
if (hint == QAbstractItemModel::VerticalSortHint) {
// Special case when we know we're sorting vertically. We can assume that all indexes for columns
// are displaced the same way, and therefore we only need to track an index from one column per
// row with a QPersistentModelIndex together with the length of items to the right of it
// which are displaced the same way.
// An algorithm which contains the same assumption is used to process layoutChanged.
savedPersistentRowLengths = qSelectionPersistentRowLengths(ranges);
savedPersistentCurrentRowLengths = qSelectionPersistentRowLengths(currentSelection);
} else {
savedPersistentIndexes = qSelectionIndexes<QVector<QPersistentModelIndex>>(ranges);
savedPersistentCurrentIndexes = qSelectionIndexes<QVector<QPersistentModelIndex>>(currentSelection);
}
}
/*!
\internal
*/
static QItemSelection mergeRowLengths(const QVector<QPair<QPersistentModelIndex, uint> > &rowLengths)
{
if (rowLengths.isEmpty())
return QItemSelection();
QItemSelection result;
int i = 0;
while (i < rowLengths.count()) {
const QPersistentModelIndex &tl = rowLengths.at(i).first;
if (!tl.isValid()) {
++i;
continue;
}
QPersistentModelIndex br = tl;
const uint length = rowLengths.at(i).second;
while (++i < rowLengths.count()) {
const QPersistentModelIndex &next = rowLengths.at(i).first;
if (!next.isValid())
continue;
const uint nextLength = rowLengths.at(i).second;
if ((nextLength == length)
&& (next.row() == br.row() + 1)
&& (next.column() == br.column())
&& (next.parent() == br.parent())) {
br = next;
} else {
break;
}
}
result.append(QItemSelectionRange(tl, br.sibling(br.row(), br.column() + length - 1)));
}
return result;
}
/*!
\internal
Merges \a indexes into an item selection made up of ranges.
Assumes that the indexes are sorted.
*/
static QItemSelection mergeIndexes(const QVector<QPersistentModelIndex> &indexes)
{
QItemSelection colSpans;
// merge columns
int i = 0;
while (i < indexes.count()) {
const QPersistentModelIndex &tl = indexes.at(i);
if (!tl.isValid()) {
++i;
continue;
}
QPersistentModelIndex br = tl;
QModelIndex brParent = br.parent();
int brRow = br.row();
int brColumn = br.column();
while (++i < indexes.count()) {
const QPersistentModelIndex &next = indexes.at(i);
if (!next.isValid())
continue;
const QModelIndex nextParent = next.parent();
const int nextRow = next.row();
const int nextColumn = next.column();
if ((nextParent == brParent)
&& (nextRow == brRow)
&& (nextColumn == brColumn + 1)) {
br = next;
brParent = nextParent;
brRow = nextRow;
brColumn = nextColumn;
} else {
break;
}
}
colSpans.append(QItemSelectionRange(tl, br));
}
// merge rows
QItemSelection rowSpans;
i = 0;
while (i < colSpans.count()) {
QModelIndex tl = colSpans.at(i).topLeft();
QModelIndex br = colSpans.at(i).bottomRight();
QModelIndex prevTl = tl;
while (++i < colSpans.count()) {
QModelIndex nextTl = colSpans.at(i).topLeft();
QModelIndex nextBr = colSpans.at(i).bottomRight();
if (nextTl.parent() != tl.parent())
break; // we can't merge selection ranges from different parents
if ((nextTl.column() == prevTl.column()) && (nextBr.column() == br.column())
&& (nextTl.row() == prevTl.row() + 1) && (nextBr.row() == br.row() + 1)) {
br = nextBr;
prevTl = nextTl;
} else {
break;
}
}
rowSpans.append(QItemSelectionRange(tl, br));
}
return rowSpans;
}
/*!
\internal
Sort predicate function for QItemSelectionModelPrivate::_q_layoutChanged(),
sorting by parent first in addition to operator<(). This is to prevent
fragmentation of the selection by grouping indexes with the same row, column
of different parents next to each other, which may happen when a selection
spans sub-trees.
*/
static bool qt_PersistentModelIndexLessThan(const QPersistentModelIndex &i1, const QPersistentModelIndex &i2)
{
const QModelIndex parent1 = i1.parent();
const QModelIndex parent2 = i2.parent();
return parent1 == parent2 ? i1 < i2 : parent1 < parent2;
}
/*!
\internal
Merge the selected indexes into selection ranges again.
*/
void QItemSelectionModelPrivate::_q_layoutChanged(const QList<QPersistentModelIndex> &, QAbstractItemModel::LayoutChangeHint hint)
{
// special case for when all indexes are selected
if (tableSelected && tableColCount == model->columnCount(tableParent)
&& tableRowCount == model->rowCount(tableParent)) {
ranges.clear();
currentSelection.clear();
int bottom = tableRowCount - 1;
int right = tableColCount - 1;
QModelIndex tl = model->index(0, 0, tableParent);
QModelIndex br = model->index(bottom, right, tableParent);
currentSelection << QItemSelectionRange(tl, br);
tableParent = QModelIndex();
tableSelected = false;
return;
}
if ((hint != QAbstractItemModel::VerticalSortHint && savedPersistentCurrentIndexes.isEmpty() && savedPersistentIndexes.isEmpty())
|| (hint == QAbstractItemModel::VerticalSortHint && savedPersistentRowLengths.isEmpty() && savedPersistentCurrentRowLengths.isEmpty())) {
// either the selection was actually empty, or we
// didn't get the layoutAboutToBeChanged() signal
return;
}
// clear the "old" selection
ranges.clear();
currentSelection.clear();
if (hint != QAbstractItemModel::VerticalSortHint) {
// sort the "new" selection, as preparation for merging
std::stable_sort(savedPersistentIndexes.begin(), savedPersistentIndexes.end(),
qt_PersistentModelIndexLessThan);
std::stable_sort(savedPersistentCurrentIndexes.begin(), savedPersistentCurrentIndexes.end(),
qt_PersistentModelIndexLessThan);
// update the selection by merging the individual indexes
ranges = mergeIndexes(savedPersistentIndexes);
currentSelection = mergeIndexes(savedPersistentCurrentIndexes);
// release the persistent indexes
savedPersistentIndexes.clear();
savedPersistentCurrentIndexes.clear();
} else {
// sort the "new" selection, as preparation for merging
std::stable_sort(savedPersistentRowLengths.begin(), savedPersistentRowLengths.end());
std::stable_sort(savedPersistentCurrentRowLengths.begin(), savedPersistentCurrentRowLengths.end());
// update the selection by merging the individual indexes
ranges = mergeRowLengths(savedPersistentRowLengths);
currentSelection = mergeRowLengths(savedPersistentCurrentRowLengths);
// release the persistent indexes
savedPersistentRowLengths.clear();
savedPersistentCurrentRowLengths.clear();
}
}
/*!
\class QItemSelectionModel
\inmodule QtCore
\brief The QItemSelectionModel class keeps track of a view's selected items.
\ingroup model-view
A QItemSelectionModel keeps track of the selected items in a view, or
in several views onto the same model. It also keeps track of the
currently selected item in a view.
The QItemSelectionModel class is one of the \l{Model/View Classes}
and is part of Qt's \l{Model/View Programming}{model/view framework}.
The selected items are stored using ranges. Whenever you want to
modify the selected items use select() and provide either a
QItemSelection, or a QModelIndex and a QItemSelectionModel::SelectionFlag.
The QItemSelectionModel takes a two layer approach to selection
management, dealing with both selected items that have been committed
and items that are part of the current selection. The current
selected items are part of the current interactive selection (for
example with rubber-band selection or keyboard-shift selections).
To update the currently selected items, use the bitwise OR of
QItemSelectionModel::Current and any of the other SelectionFlags.
If you omit the QItemSelectionModel::Current command, a new current
selection will be created, and the previous one added to the whole
selection. All functions operate on both layers; for example,
\l {QTableWidget::selectedItems()}{selecteditems()} will return items from both layers.
\note Since 5.5, \l{QItemSelectionModel::model()}{model},
\l{QItemSelectionModel::hasSelection()}{hasSelection}, and
\l{QItemSelectionModel::currentIndex()}{currentIndex} are meta-object properties.
\sa {Model/View Programming}, QAbstractItemModel, {Chart Example}
*/
/*!
Constructs a selection model that operates on the specified item \a model.
*/
QItemSelectionModel::QItemSelectionModel(QAbstractItemModel *model)
: QObject(*new QItemSelectionModelPrivate, model)
{
d_func()->initModel(model);
}
/*!
Constructs a selection model that operates on the specified item \a model with \a parent.
*/
QItemSelectionModel::QItemSelectionModel(QAbstractItemModel *model, QObject *parent)
: QObject(*new QItemSelectionModelPrivate, parent)
{
d_func()->initModel(model);
}
/*!
\internal
*/
QItemSelectionModel::QItemSelectionModel(QItemSelectionModelPrivate &dd, QAbstractItemModel *model)
: QObject(dd, model)
{
dd.initModel(model);
}
/*!
Destroys the selection model.
*/
QItemSelectionModel::~QItemSelectionModel()
{
}
/*!
Selects the model item \a index using the specified \a command, and emits
selectionChanged().
\sa QItemSelectionModel::SelectionFlags
*/
void QItemSelectionModel::select(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)
{
QItemSelection selection(index, index);
select(selection, command);
}
/*!
\fn void QItemSelectionModel::currentChanged(const QModelIndex &current, const QModelIndex &previous)
This signal is emitted whenever the current item changes. The \a previous
model item index is replaced by the \a current index as the selection's
current item.
Note that this signal will not be emitted when the item model is reset.
\sa currentIndex(), setCurrentIndex(), selectionChanged()
*/
/*!
\fn void QItemSelectionModel::currentColumnChanged(const QModelIndex &current, const QModelIndex &previous)
This signal is emitted if the \a current item changes and its column is
different to the column of the \a previous current item.
Note that this signal will not be emitted when the item model is reset.
\sa currentChanged(), currentRowChanged(), currentIndex(), setCurrentIndex()
*/
/*!
\fn void QItemSelectionModel::currentRowChanged(const QModelIndex &current, const QModelIndex &previous)
This signal is emitted if the \a current item changes and its row is
different to the row of the \a previous current item.
Note that this signal will not be emitted when the item model is reset.
\sa currentChanged(), currentColumnChanged(), currentIndex(), setCurrentIndex()
*/
/*!
\fn void QItemSelectionModel::selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)
This signal is emitted whenever the selection changes. The change in the
selection is represented as an item selection of \a deselected items and
an item selection of \a selected items.
Note the that the current index changes independently from the selection.
Also note that this signal will not be emitted when the item model is reset.
\sa select(), currentChanged()
*/
/*!
\fn void QItemSelectionModel::modelChanged(QAbstractItemModel *model)
\since 5.5
This signal is emitted when the \a model is successfully set with setModel().
\sa model(), setModel()
*/
/*!
\enum QItemSelectionModel::SelectionFlag
This enum describes the way the selection model will be updated.
\value NoUpdate No selection will be made.
\value Clear The complete selection will be cleared.
\value Select All specified indexes will be selected.
\value Deselect All specified indexes will be deselected.
\value Toggle All specified indexes will be selected or
deselected depending on their current state.
\value Current The current selection will be updated.
\value Rows All indexes will be expanded to span rows.
\value Columns All indexes will be expanded to span columns.
\value SelectCurrent A combination of Select and Current, provided for
convenience.
\value ToggleCurrent A combination of Toggle and Current, provided for
convenience.
\value ClearAndSelect A combination of Clear and Select, provided for
convenience.
*/
namespace {
namespace QtFunctionObjects {
struct IsNotValid {
typedef bool result_type;
struct is_transparent : std::true_type {};
template <typename T>
Q_DECL_CONSTEXPR bool operator()(T &t) const Q_DECL_NOEXCEPT_EXPR(noexcept(t.isValid()))
{ return !t.isValid(); }
template <typename T>
Q_DECL_CONSTEXPR bool operator()(T *t) const Q_DECL_NOEXCEPT_EXPR(noexcept(t->isValid()))
{ return !t->isValid(); }
};
}
} // unnamed namespace
/*!
Selects the item \a selection using the specified \a command, and emits
selectionChanged().
\sa QItemSelectionModel::SelectionFlag
*/
void QItemSelectionModel::select(const QItemSelection &selection, QItemSelectionModel::SelectionFlags command)
{
Q_D(QItemSelectionModel);
if (!d->model) {
qWarning("QItemSelectionModel: Selecting when no model has been set will result in a no-op.");
return;
}
if (command == NoUpdate)
return;
// store old selection
QItemSelection sel = selection;
// If d->ranges is non-empty when the source model is reset the persistent indexes
// it contains will be invalid. We can't clear them in a modelReset slot because that might already
// be too late if another model observer is connected to the same modelReset slot and is invoked first
// it might call select() on this selection model before any such QItemSelectionModelPrivate::_q_modelReset() slot
// is invoked, so it would not be cleared yet. We clear it invalid ranges in it here.
using namespace QtFunctionObjects;
d->ranges.erase(std::remove_if(d->ranges.begin(), d->ranges.end(), IsNotValid()),
d->ranges.end());
QItemSelection old = d->ranges;
old.merge(d->currentSelection, d->currentCommand);
// expand selection according to SelectionBehavior
if (command & Rows || command & Columns)
sel = d->expandSelection(sel, command);
// clear ranges and currentSelection
if (command & Clear) {
d->ranges.clear();
d->currentSelection.clear();
}
// merge and clear currentSelection if Current was not set (ie. start new currentSelection)
if (!(command & Current))
d->finalize();
// update currentSelection
if (command & Toggle || command & Select || command & Deselect) {
d->currentCommand = command;
d->currentSelection = sel;
}
// generate new selection, compare with old and emit selectionChanged()
QItemSelection newSelection = d->ranges;
newSelection.merge(d->currentSelection, d->currentCommand);
emitSelectionChanged(newSelection, old);
}
/*!
Clears the selection model. Emits selectionChanged() and currentChanged().
*/
void QItemSelectionModel::clear()
{
clearSelection();
clearCurrentIndex();
}
/*!
Clears the current index. Emits currentChanged().
*/
void QItemSelectionModel::clearCurrentIndex()
{
Q_D(QItemSelectionModel);
QModelIndex previous = d->currentIndex;
d->currentIndex = QModelIndex();
if (previous.isValid()) {
emit currentChanged(d->currentIndex, previous);
emit currentRowChanged(d->currentIndex, previous);
emit currentColumnChanged(d->currentIndex, previous);
}
}
/*!
Clears the selection model. Does not emit any signals.
*/
void QItemSelectionModel::reset()
{
const QSignalBlocker blocker(this);
clear();
}
/*!
\since 4.2
Clears the selection in the selection model. Emits selectionChanged().
*/
void QItemSelectionModel::clearSelection()
{
Q_D(QItemSelectionModel);
if (d->ranges.count() == 0 && d->currentSelection.count() == 0)
return;
select(QItemSelection(), Clear);
}
/*!
Sets the model item \a index to be the current item, and emits
currentChanged(). The current item is used for keyboard navigation and
focus indication; it is independent of any selected items, although a
selected item can also be the current item.
Depending on the specified \a command, the \a index can also become part
of the current selection.
\sa select()
*/
void QItemSelectionModel::setCurrentIndex(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)
{
Q_D(QItemSelectionModel);
if (!d->model) {
qWarning("QItemSelectionModel: Setting the current index when no model has been set will result in a no-op.");
return;
}
if (index == d->currentIndex) {
if (command != NoUpdate)
select(index, command); // select item
return;
}
QPersistentModelIndex previous = d->currentIndex;
d->currentIndex = index; // set current before emitting selection changed below
if (command != NoUpdate)
select(d->currentIndex, command); // select item
emit currentChanged(d->currentIndex, previous);
if (d->currentIndex.row() != previous.row() ||
d->currentIndex.parent() != previous.parent())
emit currentRowChanged(d->currentIndex, previous);
if (d->currentIndex.column() != previous.column() ||
d->currentIndex.parent() != previous.parent())
emit currentColumnChanged(d->currentIndex, previous);
}
/*!
Returns the model item index for the current item, or an invalid index
if there is no current item.
*/
QModelIndex QItemSelectionModel::currentIndex() const
{
return static_cast<QModelIndex>(d_func()->currentIndex);
}
/*!
Returns \c true if the given model item \a index is selected.
*/
bool QItemSelectionModel::isSelected(const QModelIndex &index) const
{
Q_D(const QItemSelectionModel);
if (d->model != index.model() || !index.isValid())
return false;
bool selected = false;
// search model ranges
QList<QItemSelectionRange>::const_iterator it = d->ranges.begin();
for (; it != d->ranges.end(); ++it) {
if ((*it).isValid() && (*it).contains(index)) {
selected = true;
break;
}
}
// check currentSelection
if (d->currentSelection.count()) {
if ((d->currentCommand & Deselect) && selected)
selected = !d->currentSelection.contains(index);
else if (d->currentCommand & Toggle)
selected ^= d->currentSelection.contains(index);
else if ((d->currentCommand & Select) && !selected)
selected = d->currentSelection.contains(index);
}
if (selected) {
Qt::ItemFlags flags = d->model->flags(index);
return (flags & Qt::ItemIsSelectable);
}
return false;
}
/*!
Returns \c true if all items are selected in the \a row with the given
\a parent.
Note that this function is usually faster than calling isSelected()
on all items in the same row and that unselectable items are
ignored.
*/
bool QItemSelectionModel::isRowSelected(int row, const QModelIndex &parent) const
{
Q_D(const QItemSelectionModel);
if (!d->model)
return false;
if (parent.isValid() && d->model != parent.model())
return false;
// return false if row exist in currentSelection (Deselect)
if (d->currentCommand & Deselect && d->currentSelection.count()) {
for (int i=0; i<d->currentSelection.count(); ++i) {
if (d->currentSelection.at(i).parent() == parent &&
row >= d->currentSelection.at(i).top() &&
row <= d->currentSelection.at(i).bottom())
return false;
}
}
// return false if ranges in both currentSelection and ranges
// intersect and have the same row contained
if (d->currentCommand & Toggle && d->currentSelection.count()) {
for (int i=0; i<d->currentSelection.count(); ++i)
if (d->currentSelection.at(i).top() <= row &&
d->currentSelection.at(i).bottom() >= row)
for (int j=0; j<d->ranges.count(); ++j)
if (d->ranges.at(j).top() <= row && d->ranges.at(j).bottom() >= row
&& d->currentSelection.at(i).intersected(d->ranges.at(j)).isValid())
return false;
}
// add ranges and currentSelection and check through them all
QList<QItemSelectionRange>::const_iterator it;
QList<QItemSelectionRange> joined = d->ranges;
if (d->currentSelection.count())
joined += d->currentSelection;
int colCount = d->model->columnCount(parent);
for (int column = 0; column < colCount; ++column) {
for (it = joined.constBegin(); it != joined.constEnd(); ++it) {
if ((*it).contains(row, column, parent)) {
bool selectable = false;
for (int i = column; !selectable && i <= (*it).right(); ++i) {
Qt::ItemFlags flags = d->model->index(row, i, parent).flags();
selectable = flags & Qt::ItemIsSelectable;
}
if (selectable){
column = qMax(column, (*it).right());
break;
}
}
}
if (it == joined.constEnd())
return false;
}
return colCount > 0; // no columns means no selected items
}
/*!
Returns \c true if all items are selected in the \a column with the given
\a parent.
Note that this function is usually faster than calling isSelected()
on all items in the same column and that unselectable items are
ignored.
*/
bool QItemSelectionModel::isColumnSelected(int column, const QModelIndex &parent) const
{
Q_D(const QItemSelectionModel);
if (!d->model)
return false;
if (parent.isValid() && d->model != parent.model())
return false;
// return false if column exist in currentSelection (Deselect)
if (d->currentCommand & Deselect && d->currentSelection.count()) {
for (int i = 0; i < d->currentSelection.count(); ++i) {
if (d->currentSelection.at(i).parent() == parent &&
column >= d->currentSelection.at(i).left() &&
column <= d->currentSelection.at(i).right())
return false;
}
}
// return false if ranges in both currentSelection and the selection model
// intersect and have the same column contained
if (d->currentCommand & Toggle && d->currentSelection.count()) {
for (int i = 0; i < d->currentSelection.count(); ++i) {
if (d->currentSelection.at(i).left() <= column &&
d->currentSelection.at(i).right() >= column) {
for (int j = 0; j < d->ranges.count(); ++j) {
if (d->ranges.at(j).left() <= column && d->ranges.at(j).right() >= column
&& d->currentSelection.at(i).intersected(d->ranges.at(j)).isValid()) {
return false;
}
}
}
}
}
// add ranges and currentSelection and check through them all
QList<QItemSelectionRange>::const_iterator it;
QList<QItemSelectionRange> joined = d->ranges;
if (d->currentSelection.count())
joined += d->currentSelection;
int rowCount = d->model->rowCount(parent);
for (int row = 0; row < rowCount; ++row) {
for (it = joined.constBegin(); it != joined.constEnd(); ++it) {
if ((*it).contains(row, column, parent)) {
Qt::ItemFlags flags = d->model->index(row, column, parent).flags();
if ((flags & Qt::ItemIsSelectable) && (flags & Qt::ItemIsEnabled)) {
row = qMax(row, (*it).bottom());
break;
}
}
}
if (it == joined.constEnd())
return false;
}
return rowCount > 0; // no rows means no selected items
}
/*!
Returns \c true if there are any items selected in the \a row with the given
\a parent.
*/
bool QItemSelectionModel::rowIntersectsSelection(int row, const QModelIndex &parent) const
{
Q_D(const QItemSelectionModel);
if (!d->model)
return false;
if (parent.isValid() && d->model != parent.model())
return false;
QItemSelection sel = d->ranges;
sel.merge(d->currentSelection, d->currentCommand);
for (int i = 0; i < sel.count(); ++i) {
QItemSelectionRange range = sel.at(i);
if (range.parent() != parent)
return false;
int top = range.top();
int bottom = range.bottom();
int left = range.left();
int right = range.right();
if (top <= row && bottom >= row) {
for (int j = left; j <= right; j++) {
const Qt::ItemFlags flags = d->model->index(row, j, parent).flags();
if ((flags & Qt::ItemIsSelectable) && (flags & Qt::ItemIsEnabled))
return true;
}
}
}
return false;
}
/*!
Returns \c true if there are any items selected in the \a column with the given
\a parent.
*/
bool QItemSelectionModel::columnIntersectsSelection(int column, const QModelIndex &parent) const
{
Q_D(const QItemSelectionModel);
if (!d->model)
return false;
if (parent.isValid() && d->model != parent.model())
return false;
QItemSelection sel = d->ranges;
sel.merge(d->currentSelection, d->currentCommand);
for (int i = 0; i < sel.count(); ++i) {
int left = sel.at(i).left();
int right = sel.at(i).right();
int top = sel.at(i).top();
int bottom = sel.at(i).bottom();
if (left <= column && right >= column) {
for (int j = top; j <= bottom; j++) {
const Qt::ItemFlags flags = d->model->index(j, column, parent).flags();
if ((flags & Qt::ItemIsSelectable) && (flags & Qt::ItemIsEnabled))
return true;
}
}
}
return false;
}
/*!
\since 4.2
Returns \c true if the selection model contains any selection ranges;
otherwise returns \c false.
*/
bool QItemSelectionModel::hasSelection() const
{
Q_D(const QItemSelectionModel);
if (d->currentCommand & (Toggle | Deselect)) {
QItemSelection sel = d->ranges;
sel.merge(d->currentSelection, d->currentCommand);
return !sel.isEmpty();
} else {
return !(d->ranges.isEmpty() && d->currentSelection.isEmpty());
}
}
/*!
Returns a list of all selected model item indexes. The list contains no
duplicates, and is not sorted.
*/
QModelIndexList QItemSelectionModel::selectedIndexes() const
{
Q_D(const QItemSelectionModel);
QItemSelection selected = d->ranges;
selected.merge(d->currentSelection, d->currentCommand);
return selected.indexes();
}
/*!
\since 4.2
Returns the indexes in the given \a column for the rows where all columns are selected.
\sa selectedIndexes(), selectedColumns()
*/
QModelIndexList QItemSelectionModel::selectedRows(int column) const
{
QModelIndexList indexes;
//the QSet contains pairs of parent modelIndex
//and row number
QSet< QPair<QModelIndex, int> > rowsSeen;
const QItemSelection ranges = selection();
for (int i = 0; i < ranges.count(); ++i) {
const QItemSelectionRange &range = ranges.at(i);
QModelIndex parent = range.parent();
for (int row = range.top(); row <= range.bottom(); row++) {
QPair<QModelIndex, int> rowDef = qMakePair(parent, row);
if (!rowsSeen.contains(rowDef)) {
rowsSeen << rowDef;
if (isRowSelected(row, parent)) {
indexes.append(model()->index(row, column, parent));
}
}
}
}
return indexes;
}
/*!
\since 4.2
Returns the indexes in the given \a row for columns where all rows are selected.
\sa selectedIndexes(), selectedRows()
*/
QModelIndexList QItemSelectionModel::selectedColumns(int row) const
{
QModelIndexList indexes;
//the QSet contains pairs of parent modelIndex
//and column number
QSet< QPair<QModelIndex, int> > columnsSeen;
const QItemSelection ranges = selection();
for (int i = 0; i < ranges.count(); ++i) {
const QItemSelectionRange &range = ranges.at(i);
QModelIndex parent = range.parent();
for (int column = range.left(); column <= range.right(); column++) {
QPair<QModelIndex, int> columnDef = qMakePair(parent, column);
if (!columnsSeen.contains(columnDef)) {
columnsSeen << columnDef;
if (isColumnSelected(column, parent)) {
indexes.append(model()->index(row, column, parent));
}
}
}
}
return indexes;
}
/*!
Returns the selection ranges stored in the selection model.
*/
const QItemSelection QItemSelectionModel::selection() const
{
Q_D(const QItemSelectionModel);
QItemSelection selected = d->ranges;
selected.merge(d->currentSelection, d->currentCommand);
// make sure we have no invalid ranges
// ### should probably be handled more generic somewhere else
using namespace QtFunctionObjects;
selected.erase(std::remove_if(selected.begin(), selected.end(),
IsNotValid()),
selected.end());
return selected;
}
/*!
\since 5.5
\property QItemSelectionModel::hasSelection
\internal
*/
/*!
\since 5.5
\property QItemSelectionModel::currentIndex
\internal
*/
/*!
\since 5.5
\property QItemSelectionModel::selectedIndexes
*/
/*!
\since 5.5
\property QItemSelectionModel::selection
\internal
*/
/*!
\since 5.5
\property QItemSelectionModel::model
\internal
*/
/*!
\since 5.5
Returns the item model operated on by the selection model.
*/
QAbstractItemModel *QItemSelectionModel::model()
{
return d_func()->model;
}
/*!
Returns the item model operated on by the selection model.
*/
const QAbstractItemModel *QItemSelectionModel::model() const
{
return d_func()->model;
}
/*!
\since 5.5
Sets the model to \a model. The modelChanged() signal will be emitted.
\sa model(), modelChanged()
*/
void QItemSelectionModel::setModel(QAbstractItemModel *model)
{
Q_D(QItemSelectionModel);
if (d->model == model)
return;
d->initModel(model);
emit modelChanged(model);
}
/*!
Compares the two selections \a newSelection and \a oldSelection
and emits selectionChanged() with the deselected and selected items.
*/
void QItemSelectionModel::emitSelectionChanged(const QItemSelection &newSelection,
const QItemSelection &oldSelection)
{
// if both selections are empty or equal we return
if ((oldSelection.isEmpty() && newSelection.isEmpty()) ||
oldSelection == newSelection)
return;
// if either selection is empty we do not need to compare
if (oldSelection.isEmpty() || newSelection.isEmpty()) {
emit selectionChanged(newSelection, oldSelection);
return;
}
QItemSelection deselected = oldSelection;
QItemSelection selected = newSelection;
// remove equal ranges
bool advance;
for (int o = 0; o < deselected.count(); ++o) {
advance = true;
for (int s = 0; s < selected.count() && o < deselected.count();) {
if (deselected.at(o) == selected.at(s)) {
deselected.removeAt(o);
selected.removeAt(s);
advance = false;
} else {
++s;
}
}
if (advance)
++o;
}
// find intersections
QItemSelection intersections;
for (int o = 0; o < deselected.count(); ++o) {
for (int s = 0; s < selected.count(); ++s) {
if (deselected.at(o).intersects(selected.at(s)))
intersections.append(deselected.at(o).intersected(selected.at(s)));
}
}
// compare remaining ranges with intersections and split them to find deselected and selected
for (int i = 0; i < intersections.count(); ++i) {
// split deselected
for (int o = 0; o < deselected.count();) {
if (deselected.at(o).intersects(intersections.at(i))) {
QItemSelection::split(deselected.at(o), intersections.at(i), &deselected);
deselected.removeAt(o);
} else {
++o;
}
}
// split selected
for (int s = 0; s < selected.count();) {
if (selected.at(s).intersects(intersections.at(i))) {
QItemSelection::split(selected.at(s), intersections.at(i), &selected);
selected.removeAt(s);
} else {
++s;
}
}
}
if (!selected.isEmpty() || !deselected.isEmpty())
emit selectionChanged(selected, deselected);
}
#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QItemSelectionRange &range)
{
QDebugStateSaver saver(dbg);
dbg.nospace() << "QItemSelectionRange(" << range.topLeft()
<< ',' << range.bottomRight() << ')';
return dbg;
}
#endif
QT_END_NAMESPACE
#include "moc_qitemselectionmodel.cpp"
#endif // QT_NO_ITEMVIEWS