source: trunk/doc/src/snippets/modelview-subclasses/view.cpp

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/*!
    view.cpp

    Provides a view to represent a one-dimensional sequence of integers
    obtained from a list model as a series of rows.
*/

#include <QAbstractItemModel>
#include <QBrush>
#include <QItemSelection>
#include <QPainter>
#include <QPaintEvent>
#include <QPen>
#include <QPoint>
#include <QResizeEvent>
#include <QScrollBar>
#include <QSizePolicy>

#include "view.h"

LinearView::LinearView(QWidget *parent)
    : QAbstractItemView(parent)
{
    setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
}

/*!
    Returns the position of the item in viewport coordinates.
*/

QRect LinearView::itemViewportRect(const QModelIndex &index) const
{
    QRect rect = itemRect(index);
    QRect result(rect.left() - horizontalScrollBar()->value(),
                 rect.top() - verticalScrollBar()->value(),
                 rect.width(), viewport()->height());

    return result;
}

/*!
    Returns the rectangle of the item at position \a index in the
    model. The rectangle is in contents coordinates.
*/

QRect LinearView::itemRect(const QModelIndex &index) const
{
    if (!index.isValid())
        return QRect();
    else
        return QRect(index.row(), 0, 1, 1);
}


void LinearView::ensureVisible(const QModelIndex &index)
{
    QRect area = viewport()->rect();
    QRect rect = itemViewportRect(index);

    if (rect.left() < area.left())
        horizontalScrollBar()->setValue(
            horizontalScrollBar()->value() - rect.left());
    else if (rect.right() > area.right())
        horizontalScrollBar()->setValue(
            horizontalScrollBar()->value() + rect.left() - area.width());
}