--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/src/snippets/modelview-subclasses/view.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,315 @@
+/****************************************************************************
+**
+** 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 the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+ 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());
+}
+
+/*!
+ Returns the item that covers the coordinate given in the view.
+*/
+
+QModelIndex LinearView::itemAt(int x, int /* y */) const
+{
+ int row = x + horizontalScrollBar()->value();
+
+ return model()->index(row, 0, QModelIndex());
+}
+
+//void LinearView::dataChanged(const QModelIndex &/* topLeft */,
+// const QModelIndex &/* bottomRight */)
+//{
+// updateGeometries();
+// if (isVisible())
+// repaint();
+//}
+
+void LinearView::rowsInserted(const QModelIndex &/* parent */, int /* start */,
+ int /* end */)
+{
+ updateGeometries();
+ if (isVisible())
+ repaint();
+}
+
+void LinearView::rowsRemoved(const QModelIndex &/* parent */, int /* start */,
+ int /* end */)
+{
+ updateGeometries();
+ if (isVisible())
+ repaint();
+}
+/*
+void LinearView::verticalScrollbarAction(int action)
+{
+}
+
+void LinearView::horizontalScrollbarAction(int action)
+{
+}
+*/
+
+/*!
+ Select the items in the model that lie within the rectangle specified by
+ \a rect, using the selection \a command.
+*/
+
+void LinearView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
+{
+ QModelIndex leftIndex = itemAt(rect.left(), 0);
+ QModelIndex rightIndex = itemAt(rect.right(), 0);
+
+ QItemSelection selection(leftIndex, rightIndex);
+
+ selectionModel()->select(selection, command);
+}
+
+QModelIndex LinearView::moveCursor(QAbstractItemView::CursorAction cursorAction,
+ Qt::KeyboardModifiers)
+{
+ QModelIndex current = currentIndex();
+
+ switch (cursorAction) {
+ case MoveLeft:{
+ if (current.row() > 0)
+ return model()->index(current.row() - 1, 0, QModelIndex());
+ else
+ return model()->index(0, 0, QModelIndex());
+ break;}
+ case MoveRight:{
+ if (current.row() < rows(current) - 1)
+ return model()->index(current.row() + 1, 0, QModelIndex());
+ else
+ return model()->index(rows(current) - 1, 0,QModelIndex());
+ break;}
+ case MoveUp:
+ return current;
+ case MoveDown:
+ return current;
+ case MovePageUp:
+ return current;
+ case MovePageDown:
+ return current;
+ case MoveHome:
+ return model()->index(0, 0, QModelIndex());
+ case MoveEnd:
+ return model()->index(rows(current) - 1, 0, QModelIndex());
+ default:
+ return current;
+ }
+}
+
+int LinearView::horizontalOffset() const
+{
+ return horizontalScrollBar()->value();
+}
+
+int LinearView::verticalOffset() const
+{
+ return verticalScrollBar()->value();
+}
+
+/*!
+ Returns a rectangle corresponding to the selection in viewport cooridinates.
+*/
+
+QRect LinearView::selectionViewportRect(const QItemSelection &selection) const
+{
+ int ranges = selection.count();
+
+ if (ranges == 0)
+ return QRect();
+
+ // Note that we use the top and bottom functions of the selection range
+ // since the data is stored in rows.
+
+ int firstRow = selection.at(0).top();
+ int lastRow = selection.at(0).top();
+
+ for (int i = 0; i < ranges; ++i) {
+ firstRow = qMin(firstRow, selection.at(i).top());
+ lastRow = qMax(lastRow, selection.at(i).bottom());
+ }
+
+ QModelIndex firstItem = model()->index(qMin(firstRow, lastRow), 0,
+ QModelIndex());
+ QModelIndex lastItem = model()->index(qMax(firstRow, lastRow), 0,
+ QModelIndex());
+
+ QRect firstRect = itemViewportRect(firstItem);
+ QRect lastRect = itemViewportRect(lastItem);
+
+ return QRect(firstRect.left(), firstRect.top(),
+ lastRect.right() - firstRect.left(), firstRect.height());
+}
+
+void LinearView::paintEvent(QPaintEvent *event)
+{
+ QPainter painter(viewport());
+
+ QRect updateRect = event->rect();
+ QBrush background(Qt::black);
+ QPen foreground(Qt::white);
+
+ painter.fillRect(updateRect, background);
+ painter.setPen(foreground);
+
+ QModelIndex firstItem = itemAt(updateRect.left(), updateRect.top());
+ if (!firstItem.isValid())
+ firstItem = model()->index(0, 0, QModelIndex());
+
+ QModelIndex lastItem = itemAt(updateRect.right(), updateRect.bottom());
+ if (!lastItem.isValid())
+ lastItem = model()->index(rows() - 1, 0, QModelIndex());
+
+ int x = updateRect.left();
+ //int top = updateRect.top();
+ //int bottom = updateRect.bottom();
+
+ int row = firstItem.row();
+ QModelIndex index = model()->index(row, 0, QModelIndex());
+ int value = model()->data(index, Qt::DisplayRole).toInt();
+ int midPoint = viewport()->height()/2;
+ int y2 = midPoint - int(value * midPoint/255.0);
+
+ while (row <= lastItem.row()) {
+
+ QModelIndex index = model()->index(row, 0, QModelIndex());
+ int value = model()->data(index, Qt::DisplayRole).toInt();
+
+ int y1 = y2;
+ y2 = midPoint - int(value * midPoint/255.0);
+
+ painter.drawLine(x-1, y1, x, y2);
+ ++row; ++x;
+ }
+}
+
+void LinearView::resizeEvent(QResizeEvent * /* event */)
+{
+ updateGeometries();
+}
+
+void LinearView::updateGeometries()
+{
+ if (viewport()->width() < rows()) {
+ horizontalScrollBar()->setPageStep(viewport()->width());
+ horizontalScrollBar()->setRange(0, rows() - viewport()->width() - 1);
+ }
+}
+
+QSize LinearView::sizeHint() const
+{
+ return QSize(rows(), 200);
+}
+
+int LinearView::rows(const QModelIndex &index) const
+{
+ return model()->rowCount(model()->parent(index));
+}
+
+bool LinearView::isIndexHidden(const QModelIndex &index) const
+{
+ return false;
+}