source: trunk/src/gui/itemviews/qitemselectionmodel.cpp@ 138

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#include "qitemselectionmodel.h"
#include <private/qitemselectionmodel_p.h>
#include <qdebug.h>

#ifndef QT_NO_ITEMVIEWS

QT_BEGIN_NAMESPACE

/*!
    \class QItemSelectionRange

    \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 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 true if the model item specified by the \a index lies within the
    range of selected items; otherwise returns false.
*/

/*!
    \fn bool QItemSelectionRange::contains(int row, int column,
                                           const QModelIndex &parentIndex) const
    \overload

    Returns 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 false.
*/

/*!
    \fn bool QItemSelectionRange::intersects(const QItemSelectionRange &other) const

    Returns true if this selection range intersects (overlaps with) the \a other
    range given; otherwise returns false.

*/
bool QItemSelectionRange::intersects(const QItemSelectionRange &other) const
{
    return (isValid() && other.isValid()
            && parent() == other.parent()
            && ((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::intersect(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 true if the selection range is exactly the same as the \a other
    range given; otherwise returns false.

*/

/*!
    \fn bool QItemSelectionRange::operator!=(const QItemSelectionRange &other) const

    Returns true if the selection range differs from the \a other range given;
    otherwise returns false.