Merge branch 'master' of git://github.com/peterix/MultiMC5

1 files changed, 1696 insertions, 0 deletions

diff --git a/libgroupview/src/kcategorizedview.cpp b/libgroupview/src/kcategorizedview.cpp
new file mode 100644
index 00000000..ba4ae2dc
--- /dev/null
+++ b/libgroupview/src/kcategorizedview.cpp
@@ -0,0 +1,1696 @@
+/**
+  * This file is part of the KDE project
+  * Copyright (C) 2007, 2009 Rafael Fernández López <ereslibre@kde.org>
+  *
+  * This library is free software; you can redistribute it and/or
+  * modify it under the terms of the GNU Library General Public
+  * License as published by the Free Software Foundation; either
+  * version 2 of the License, or (at your option) any later version.
+  *
+  * This library is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  * Library General Public License for more details.
+  *
+  * You should have received a copy of the GNU Library General Public License
+  * along with this library; see the file COPYING.LIB.  If not, write to
+  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+  * Boston, MA 02110-1301, USA.
+  */
+
+/**
+  * IMPLEMENTATION NOTES:
+  *
+  * QListView::setRowHidden() and QListView::isRowHidden() are not taken into
+  * account. This methods should actually not exist. This effect should be handled
+  * by an hypothetical QSortFilterProxyModel which filters out the desired rows.
+  *
+  * In case this needs to be implemented, contact me, but I consider this a faulty
+  * design.
+  */
+
+#include "kcategorizedview.h"
+#include "kcategorizedview_p.h"
+
+#include <math.h> // trunc on C99 compliant systems
+#include <kdefakes.h> // trunc for not C99 compliant systems
+
+#include <QPainter>
+#include <QScrollBar>
+#include <QPaintEvent>
+
+#include "kcategorydrawer.h"
+#include "kcategorizedsortfilterproxymodel.h"
+
+//BEGIN: Private part
+
+struct KCategorizedView::Private::Item
+{
+	Item()
+		: topLeft ( QPoint() )
+		, size ( QSize() )
+	{
+	}
+
+	QPoint topLeft;
+	QSize size;
+};
+
+struct KCategorizedView::Private::Block
+{
+	Block()
+		: topLeft ( QPoint() )
+		, height ( -1 )
+		, firstIndex ( QModelIndex() )
+		, quarantineStart ( QModelIndex() )
+		, items ( QList<Item>() )
+		, outOfQuarantine ( false )
+		, alternate ( false )
+		, collapsed ( false )
+	{
+	}
+
+	bool operator!= ( const Block &rhs ) const
+	{
+		return firstIndex != rhs.firstIndex;
+	}
+
+	static bool lessThan ( const Block &left, const Block &right )
+	{
+		Q_ASSERT ( left.firstIndex.isValid() );
+		Q_ASSERT ( right.firstIndex.isValid() );
+		return left.firstIndex.row() < right.firstIndex.row();
+	}
+
+	QPoint topLeft;
+	int height;
+	QPersistentModelIndex firstIndex;
+	// if we have n elements on this block, and we inserted an element at position i. The quarantine
+	// will start at index (i, column, parent). This means that for all elements j where i <= j <= n, the
+	// visual rect position of item j will have to be recomputed (cannot use the cached point). The quarantine
+	// will only affect the current block, since the rest of blocks can be affected only in the way
+	// that the whole block will have different offset, but items will keep the same relative position
+	// in terms of their parent blocks.
+	QPersistentModelIndex quarantineStart;
+	QList<Item> items;
+
+	// this affects the whole block, not items separately. items contain the topLeft point relative
+	// to the block. Because of insertions or removals a whole block can be moved, so the whole block
+	// will enter in quarantine, what is faster than moving all items in absolute terms.
+	bool outOfQuarantine;
+
+	// should we alternate its color ? is just a hint, could not be used
+	bool alternate;
+	bool collapsed;
+};
+
+KCategorizedView::Private::Private ( KCategorizedView *q )
+	: q ( q )
+	, proxyModel ( 0 )
+	, categoryDrawer ( 0 )
+	, categorySpacing ( 5 )
+	, alternatingBlockColors ( false )
+	, collapsibleBlocks ( false )
+	, hoveredBlock ( new Block() )
+	, hoveredIndex ( QModelIndex() )
+	, pressedPosition ( QPoint() )
+	, rubberBandRect ( QRect() )
+{
+}
+
+KCategorizedView::Private::~Private()
+{
+	delete hoveredBlock;
+}
+
+bool KCategorizedView::Private::isCategorized() const
+{
+	return proxyModel && categoryDrawer && proxyModel->isCategorizedModel();
+}
+
+QStyleOptionViewItemV4 KCategorizedView::Private::blockRect ( const QModelIndex &representative )
+{
+	QStyleOptionViewItemV4 option ( q->viewOptions() );
+	const int height = categoryDrawer->categoryHeight ( representative, option );
+	const QString categoryDisplay = representative.data ( KCategorizedSortFilterProxyModel::CategoryDisplayRole ).toString();
+	QPoint pos = blockPosition ( categoryDisplay );
+	pos.ry() -= height;
+	option.rect.setTopLeft ( pos );
+	option.rect.setWidth ( viewportWidth() + categoryDrawer->leftMargin() + categoryDrawer->rightMargin() );
+	option.rect.setHeight ( height + blockHeight ( categoryDisplay ) );
+	option.rect = mapToViewport ( option.rect );
+
+	return option;
+}
+
+QPair<QModelIndex, QModelIndex> KCategorizedView::Private::intersectingIndexesWithRect ( const QRect &_rect ) const
+{
+	const int rowCount = proxyModel->rowCount();
+
+	const QRect rect = _rect.normalized();
+
+	// binary search to find out the top border
+	int bottom = 0;
+	int top = rowCount - 1;
+	while ( bottom <= top )
+	{
+		const int middle = ( bottom + top ) / 2;
+		const QModelIndex index = proxyModel->index ( middle, q->modelColumn(), q->rootIndex() );
+		QRect itemRect = q->visualRect ( index );
+		const int verticalOff = q->verticalOffset();
+		const int horizontalOff = q->horizontalOffset();
+		itemRect.topLeft().ry() += verticalOff;
+		itemRect.topLeft().rx() += horizontalOff;
+		itemRect.bottomRight().ry() += verticalOff;
+		itemRect.bottomRight().rx() += horizontalOff;
+		if ( itemRect.bottomRight().y() <= rect.topLeft().y() )
+		{
+			bottom = middle + 1;
+		}
+		else
+		{
+			top = middle - 1;
+		}
+	}
+
+	const QModelIndex bottomIndex = proxyModel->index ( bottom, q->modelColumn(), q->rootIndex() );
+
+	// binary search to find out the bottom border
+	bottom = 0;
+	top = rowCount - 1;
+	while ( bottom <= top )
+	{
+		const int middle = ( bottom + top ) / 2;
+		const QModelIndex index = proxyModel->index ( middle, q->modelColumn(), q->rootIndex() );
+		QRect itemRect = q->visualRect ( index );
+		const int verticalOff = q->verticalOffset();
+		const int horizontalOff = q->horizontalOffset();
+		itemRect.topLeft().ry() += verticalOff;
+		itemRect.topLeft().rx() += horizontalOff;
+		itemRect.bottomRight().ry() += verticalOff;
+		itemRect.bottomRight().rx() += horizontalOff;
+		if ( itemRect.topLeft().y() <= rect.bottomRight().y() )
+		{
+			bottom = middle + 1;
+		}
+		else
+		{
+			top = middle - 1;
+		}
+	}
+
+	const QModelIndex topIndex = proxyModel->index ( top, q->modelColumn(), q->rootIndex() );
+
+	return qMakePair ( bottomIndex, topIndex );
+}
+
+QPoint KCategorizedView::Private::blockPosition ( const QString &category )
+{
+	Block &block = blocks[category];
+
+	if ( block.outOfQuarantine && !block.topLeft.isNull() )
+	{
+		return block.topLeft;
+	}
+
+	QPoint res ( categorySpacing, 0 );
+
+	const QModelIndex index = block.firstIndex;
+
+	for ( QHash<QString, Private::Block>::Iterator it = blocks.begin(); it != blocks.end(); ++it )
+	{
+		Block &block = *it;
+		const QModelIndex categoryIndex = block.firstIndex;
+		if ( index.row() < categoryIndex.row() )
+		{
+			continue;
+		}
+		res.ry() += categoryDrawer->categoryHeight ( categoryIndex, q->viewOptions() ) + categorySpacing;
+		if ( index.row() == categoryIndex.row() )
+		{
+			continue;
+		}
+		res.ry() += blockHeight ( it.key() );
+	}
+
+	block.outOfQuarantine = true;
+	block.topLeft = res;
+
+	return res;
+}
+
+int KCategorizedView::Private::blockHeight ( const QString &category )
+{
+	Block &block = blocks[category];
+
+	if ( block.collapsed )
+	{
+		return 0;
+	}
+
+	if ( block.height > -1 )
+	{
+		return block.height;
+	}
+
+	const QModelIndex firstIndex = block.firstIndex;
+	const QModelIndex lastIndex = proxyModel->index ( firstIndex.row() + block.items.count() - 1, q->modelColumn(), q->rootIndex() );
+	const QRect topLeft = q->visualRect ( firstIndex );
+	QRect bottomRight = q->visualRect ( lastIndex );
+
+	if ( hasGrid() )
+	{
+		bottomRight.setHeight ( qMax ( bottomRight.height(), q->gridSize().height() ) );
+	}
+	else
+	{
+		if ( !q->uniformItemSizes() )
+		{
+			bottomRight.setHeight ( highestElementInLastRow ( block ) + q->spacing() * 2 );
+		}
+	}
+
+	const int height = bottomRight.bottomRight().y() - topLeft.topLeft().y() + 1;
+	block.height = height;
+
+	return height;
+}
+
+int KCategorizedView::Private::viewportWidth() const
+{
+	return q->viewport()->width() - categorySpacing * 2 - categoryDrawer->leftMargin() - categoryDrawer->rightMargin();
+}
+
+void KCategorizedView::Private::regenerateAllElements()
+{
+	for ( QHash<QString, Block>::Iterator it = blocks.begin(); it != blocks.end(); ++it )
+	{
+		Block &block = *it;
+		block.outOfQuarantine = false;
+		block.quarantineStart = block.firstIndex;
+		block.height = -1;
+	}
+}
+
+void KCategorizedView::Private::rowsInserted ( const QModelIndex &parent, int start, int end )
+{
+	if ( !isCategorized() )
+	{
+		return;
+	}
+
+	for ( int i = start; i <= end; ++i )
+	{
+		const QModelIndex index = proxyModel->index ( i, q->modelColumn(), parent );
+
+		Q_ASSERT ( index.isValid() );
+
+		const QString category = categoryForIndex ( index );
+
+		Block &block = blocks[category];
+
+		//BEGIN: update firstIndex
+		// save as firstIndex in block if
+		//     - it forced the category creation (first element on this category)
+		//     - it is before the first row on that category
+		const QModelIndex firstIndex = block.firstIndex;
+		if ( !firstIndex.isValid() || index.row() < firstIndex.row() )
+		{
+			block.firstIndex = index;
+		}
+		//END: update firstIndex
+
+		Q_ASSERT ( block.firstIndex.isValid() );
+
+		const int firstIndexRow = block.firstIndex.row();
+
+		block.items.insert ( index.row() - firstIndexRow, Private::Item() );
+		block.height = -1;
+
+		q->visualRect ( index );
+		q->viewport()->update();
+	}
+
+	//BEGIN: update the items that are in quarantine in affected categories
+	{
+		const QModelIndex lastIndex = proxyModel->index ( end, q->modelColumn(), parent );
+		const QString category = categoryForIndex ( lastIndex );
+		Private::Block &block = blocks[category];
+		block.quarantineStart = block.firstIndex;
+	}
+	//END: update the items that are in quarantine in affected categories
+
+	//BEGIN: mark as in quarantine those categories that are under the affected ones
+	{
+		const QModelIndex firstIndex = proxyModel->index ( start, q->modelColumn(), parent );
+		const QString category = categoryForIndex ( firstIndex );
+		const QModelIndex firstAffectedCategory = blocks[category].firstIndex;
+		//BEGIN: order for marking as alternate those blocks that are alternate
+		QList<Block> blockList = blocks.values();
+		qSort ( blockList.begin(), blockList.end(), Block::lessThan );
+		QList<int> firstIndexesRows;
+		foreach ( const Block &block, blockList )
+		{
+			firstIndexesRows << block.firstIndex.row();
+		}
+		//END: order for marking as alternate those blocks that are alternate
+		for ( QHash<QString, Private::Block>::Iterator it = blocks.begin(); it != blocks.end(); ++it )
+		{
+			Private::Block &block = *it;
+			if ( block.firstIndex.row() > firstAffectedCategory.row() )
+			{
+				block.outOfQuarantine = false;
+				block.alternate = firstIndexesRows.indexOf ( block.firstIndex.row() ) % 2;
+			}
+			else if ( block.firstIndex.row() == firstAffectedCategory.row() )
+			{
+				block.alternate = firstIndexesRows.indexOf ( block.firstIndex.row() ) % 2;
+			}
+		}
+	}
+	//END: mark as in quarantine those categories that are under the affected ones
+}
+
+QRect KCategorizedView::Private::mapToViewport ( const QRect &rect ) const
+{
+	const int dx = -q->horizontalOffset();
+	const int dy = -q->verticalOffset();
+	return rect.adjusted ( dx, dy, dx, dy );
+}
+
+QRect KCategorizedView::Private::mapFromViewport ( const QRect &rect ) const
+{
+	const int dx = q->horizontalOffset();
+	const int dy = q->verticalOffset();
+	return rect.adjusted ( dx, dy, dx, dy );
+}
+
+int KCategorizedView::Private::highestElementInLastRow ( const Block &block ) const
+{
+	//Find the highest element in the last row
+	const QModelIndex lastIndex = proxyModel->index ( block.firstIndex.row() + block.items.count() - 1, q->modelColumn(), q->rootIndex() );
+	const QRect prevRect = q->visualRect ( lastIndex );
+	int res = prevRect.height();
+	QModelIndex prevIndex = proxyModel->index ( lastIndex.row() - 1, q->modelColumn(), q->rootIndex() );
+	if ( !prevIndex.isValid() )
+	{
+		return res;
+	}
+	Q_FOREVER
+	{
+		const QRect tempRect = q->visualRect ( prevIndex );
+		if ( tempRect.topLeft().y() < prevRect.topLeft().y() )
+		{
+			break;
+		}
+		res = qMax ( res, tempRect.height() );
+		if ( prevIndex == block.firstIndex )
+		{
+			break;
+		}
+		prevIndex = proxyModel->index ( prevIndex.row() - 1, q->modelColumn(), q->rootIndex() );
+	}
+
+	return res;
+}
+
+bool KCategorizedView::Private::hasGrid() const
+{
+	const QSize gridSize = q->gridSize();
+	return gridSize.isValid() && !gridSize.isNull();
+}
+
+QString KCategorizedView::Private::categoryForIndex ( const QModelIndex &index ) const
+{
+	const QModelIndex categoryIndex = index.model()->index ( index.row(), proxyModel->sortColumn(), index.parent() );
+	return categoryIndex.data ( KCategorizedSortFilterProxyModel::CategoryDisplayRole ).toString();
+}
+
+void KCategorizedView::Private::leftToRightVisualRect ( const QModelIndex &index, Item &item,
+  const Block &block, const QPoint &blockPos ) const
+{
+	const int firstIndexRow = block.firstIndex.row();
+
+	if ( hasGrid() )
+	{
+		const int relativeRow = index.row() - firstIndexRow;
+		const int maxItemsPerRow = qMax ( viewportWidth() / q->gridSize().width(), 1 );
+		if ( q->layoutDirection() == Qt::LeftToRight )
+		{
+			item.topLeft.rx() = ( relativeRow % maxItemsPerRow ) * q->gridSize().width() + blockPos.x() + categoryDrawer->leftMargin();
+		}
+		else
+		{
+			item.topLeft.rx() = viewportWidth() - ( ( relativeRow % maxItemsPerRow ) + 1 ) * q->gridSize().width() + categoryDrawer->leftMargin() + categorySpacing;
+		}
+		item.topLeft.ry() = ( relativeRow / maxItemsPerRow ) * q->gridSize().height();
+	}
+	else
+	{
+		if ( q->uniformItemSizes() )
+		{
+			const int relativeRow = index.row() - firstIndexRow;
+			const QSize itemSize = q->sizeHintForIndex ( index );
+			const int maxItemsPerRow = qMax ( ( viewportWidth() - q->spacing() ) / ( itemSize.width() + q->spacing() ), 1 );
+			if ( q->layoutDirection() == Qt::LeftToRight )
+			{
+				item.topLeft.rx() = ( relativeRow % maxItemsPerRow ) * itemSize.width() + blockPos.x() + categoryDrawer->leftMargin();
+			}
+			else
+			{
+				item.topLeft.rx() = viewportWidth() - ( relativeRow % maxItemsPerRow ) * itemSize.width() + categoryDrawer->leftMargin() + categorySpacing;
+			}
+			item.topLeft.ry() = ( relativeRow / maxItemsPerRow ) * itemSize.height();
+		}
+		else
+		{
+			const QSize currSize = q->sizeHintForIndex ( index );
+			if ( index != block.firstIndex )
+			{
+				const int viewportW = viewportWidth() - q->spacing();
+				QModelIndex prevIndex = proxyModel->index ( index.row() - 1, q->modelColumn(), q->rootIndex() );
+				QRect prevRect = q->visualRect ( prevIndex );
+				prevRect = mapFromViewport ( prevRect );
+				if ( ( prevRect.bottomRight().x() + 1 ) + currSize.width() - blockPos.x() + q->spacing()  > viewportW )
+				{
+					// we have to check the whole previous row, and see which one was the
+					// highest.
+					Q_FOREVER
+					{
+						prevIndex = proxyModel->index ( prevIndex.row() - 1, q->modelColumn(), q->rootIndex() );
+						const QRect tempRect = q->visualRect ( prevIndex );
+						if ( tempRect.topLeft().y() < prevRect.topLeft().y() )
+						{
+							break;
+						}
+						if ( tempRect.bottomRight().y() > prevRect.bottomRight().y() )
+						{
+							prevRect = tempRect;
+						}
+						if ( prevIndex == block.firstIndex )
+						{
+							break;
+						}
+					}
+					if ( q->layoutDirection() == Qt::LeftToRight )
+					{
+						item.topLeft.rx() = categoryDrawer->leftMargin() + blockPos.x() + q->spacing();
+					}
+					else
+					{
+						item.topLeft.rx() = viewportWidth() - currSize.width() + categoryDrawer->leftMargin() + categorySpacing;
+					}
+					item.topLeft.ry() = ( prevRect.bottomRight().y() + 1 ) + q->spacing() - blockPos.y();
+				}
+				else
+				{
+					if ( q->layoutDirection() == Qt::LeftToRight )
+					{
+						item.topLeft.rx() = ( prevRect.bottomRight().x() + 1 ) + q->spacing();
+					}
+					else
+					{
+						item.topLeft.rx() = ( prevRect.bottomLeft().x() - 1 ) - q->spacing() - item.size.width() + categoryDrawer->leftMargin() + categorySpacing;
+					}
+					item.topLeft.ry() = prevRect.topLeft().y() - blockPos.y();
+				}
+			}
+			else
+			{
+				if ( q->layoutDirection() == Qt::LeftToRight )
+				{
+					item.topLeft.rx() = blockPos.x() + categoryDrawer->leftMargin() + q->spacing();
+				}
+				else
+				{
+					item.topLeft.rx() = viewportWidth() - currSize.width() + categoryDrawer->leftMargin() + categorySpacing;
+				}
+				item.topLeft.ry() = q->spacing();
+			}
+		}
+	}
+	item.size = q->sizeHintForIndex ( index );
+}
+
+void KCategorizedView::Private::topToBottomVisualRect ( const QModelIndex &index, Item &item,
+  const Block &block, const QPoint &blockPos ) const
+{
+	const int firstIndexRow = block.firstIndex.row();
+
+	if ( hasGrid() )
+	{
+		const int relativeRow = index.row() - firstIndexRow;
+		item.topLeft.rx() = blockPos.x() + categoryDrawer->leftMargin();
+		item.topLeft.ry() = relativeRow * q->gridSize().height();
+	}
+	else
+	{
+		if ( q->uniformItemSizes() )
+		{
+			const int relativeRow = index.row() - firstIndexRow;
+			const QSize itemSize = q->sizeHintForIndex ( index );
+			item.topLeft.rx() = blockPos.x() + categoryDrawer->leftMargin();
+			item.topLeft.ry() = relativeRow * itemSize.height();
+		}
+		else
+		{
+			if ( index != block.firstIndex )
+			{
+				QModelIndex prevIndex = proxyModel->index ( index.row() - 1, q->modelColumn(), q->rootIndex() );
+				QRect prevRect = q->visualRect ( prevIndex );
+				prevRect = mapFromViewport ( prevRect );
+				item.topLeft.rx() = blockPos.x() + categoryDrawer->leftMargin() + q->spacing();
+				item.topLeft.ry() = ( prevRect.bottomRight().y() + 1 ) + q->spacing() - blockPos.y();
+			}
+			else
+			{
+				item.topLeft.rx() = blockPos.x() + categoryDrawer->leftMargin() + q->spacing();
+				item.topLeft.ry() = q->spacing();
+			}
+		}
+	}
+	item.size = q->sizeHintForIndex ( index );
+	item.size.setWidth ( viewportWidth() );
+}
+
+void KCategorizedView::Private::_k_slotCollapseOrExpandClicked ( QModelIndex )
+{
+}
+
+//END: Private part
+
+//BEGIN: Public part
+
+KCategorizedView::KCategorizedView ( QWidget *parent )
+	: QListView ( parent )
+	, d ( new Private ( this ) )
+{
+}
+
+KCategorizedView::~KCategorizedView()
+{
+	delete d;
+}
+
+void KCategorizedView::setModel ( QAbstractItemModel *model )
+{
+	if ( d->proxyModel == model )
+	{
+		return;
+	}
+
+	d->blocks.clear();
+
+	if ( d->proxyModel )
+	{
+		disconnect ( d->proxyModel, SIGNAL ( layoutChanged() ), this, SLOT ( slotLayoutChanged() ) );
+	}
+
+	d->proxyModel = dynamic_cast<KCategorizedSortFilterProxyModel*> ( model );
+
+	if ( d->proxyModel )
+	{
+		connect ( d->proxyModel, SIGNAL ( layoutChanged() ), this, SLOT ( slotLayoutChanged() ) );
+	}
+
+	QListView::setModel ( model );
+
+	// if the model already had information inserted, update our data structures to it
+	if ( model->rowCount() )
+	{
+		slotLayoutChanged();
+	}
+}
+
+void KCategorizedView::setGridSize ( const QSize &size )
+{
+	setGridSizeOwn ( size );
+}
+
+void KCategorizedView::setGridSizeOwn ( const QSize &size )
+{
+	d->regenerateAllElements();
+	QListView::setGridSize ( size );
+}
+
+QRect KCategorizedView::visualRect ( const QModelIndex &index ) const
+{
+	if ( !d->isCategorized() )
+	{
+		return QListView::visualRect ( index );
+	}
+
+	if ( !index.isValid() )
+	{
+		return QRect();
+	}
+
+	const QString category = d->categoryForIndex ( index );
+
+	if ( !d->blocks.contains ( category ) )
+	{
+		return QRect();
+	}
+
+	Private::Block &block = d->blocks[category];
+	const int firstIndexRow = block.firstIndex.row();
+
+	Q_ASSERT ( block.firstIndex.isValid() );
+
+	if ( index.row() - firstIndexRow < 0 || index.row() - firstIndexRow >= block.items.count() )
+	{
+		return QRect();
+	}
+
+	const QPoint blockPos = d->blockPosition ( category );
+
+	Private::Item &ritem = block.items[index.row() - firstIndexRow];
+
+	if ( ritem.topLeft.isNull() || ( block.quarantineStart.isValid() &&
+	                                 index.row() >= block.quarantineStart.row() ) )
+	{
+		if ( flow() == LeftToRight )
+		{
+			d->leftToRightVisualRect ( index, ritem, block, blockPos );
+		}
+		else
+		{
+			d->topToBottomVisualRect ( index, ritem, block, blockPos );
+		}
+
+		//BEGIN: update the quarantine start
+		const bool wasLastIndex = ( index.row() == ( block.firstIndex.row() + block.items.count() - 1 ) );
+		if ( index.row() == block.quarantineStart.row() )
+		{
+			if ( wasLastIndex )
+			{
+				block.quarantineStart = QModelIndex();
+			}
+			else
+			{
+				const QModelIndex nextIndex = d->proxyModel->index ( index.row() + 1, modelColumn(), rootIndex() );
+				block.quarantineStart = nextIndex;
+			}
+		}
+		//END: update the quarantine start
+	}
+
+	// we get now the absolute position through the relative position of the parent block. do not
+	// save this on ritem, since this would override the item relative position in block terms.
+	Private::Item item ( ritem );
+	item.topLeft.ry() += blockPos.y();
+
+	const QSize sizeHint = item.size;
+
+	if ( d->hasGrid() )
+	{
+		const QSize sizeGrid = gridSize();
+		const QSize resultingSize = sizeHint.boundedTo ( sizeGrid );
+		QRect res ( item.topLeft.x() + ( ( sizeGrid.width() - resultingSize.width() ) / 2 ),
+		            item.topLeft.y(), resultingSize.width(), resultingSize.height() );
+		if ( block.collapsed )
+		{
+			// we can still do binary search, while we "hide" items. We move those items in collapsed
+			// blocks to the left and set a 0 height.
+			res.setLeft ( -resultingSize.width() );
+			res.setHeight ( 0 );
+		}
+		return d->mapToViewport ( res );
+	}
+
+	QRect res ( item.topLeft.x(), item.topLeft.y(), sizeHint.width(), sizeHint.height() );
+	if ( block.collapsed )
+	{
+		// we can still do binary search, while we "hide" items. We move those items in collapsed
+		// blocks to the left and set a 0 height.
+		res.setLeft ( -sizeHint.width() );
+		res.setHeight ( 0 );
+	}
+	return d->mapToViewport ( res );
+}
+
+KCategoryDrawer *KCategorizedView::categoryDrawer() const
+{
+	return d->categoryDrawer;
+}
+
+void KCategorizedView::setCategoryDrawer ( KCategoryDrawer *categoryDrawer )
+{
+	disconnect ( d->categoryDrawer, SIGNAL ( collapseOrExpandClicked ( QModelIndex ) ),
+	             this, SLOT ( slotCollapseOrExpandClicked ( QModelIndex ) ) );
+	d->categoryDrawer = categoryDrawer;
+
+	connect ( d->categoryDrawer, SIGNAL ( collapseOrExpandClicked ( QModelIndex ) ),
+	          this, SLOT ( slotCollapseOrExpandClicked ( QModelIndex ) ) );
+}
+
+int KCategorizedView::categorySpacing() const
+{
+	return d->categorySpacing;
+}
+
+void KCategorizedView::setCategorySpacing ( int categorySpacing )
+{
+	if ( d->categorySpacing == categorySpacing )
+	{
+		return;
+	}
+
+	d->categorySpacing = categorySpacing;
+
+	for ( QHash<QString, Private::Block>::Iterator it = d->blocks.begin(); it != d->blocks.end(); ++it )
+	{
+		Private::Block &block = *it;
+		block.outOfQuarantine = false;
+	}
+}
+
+bool KCategorizedView::alternatingBlockColors() const
+{
+	return d->alternatingBlockColors;
+}
+
+void KCategorizedView::setAlternatingBlockColors ( bool enable )
+{
+	d->alternatingBlockColors = enable;
+}
+
+bool KCategorizedView::collapsibleBlocks() const
+{
+	return d->collapsibleBlocks;
+}
+
+void KCategorizedView::setCollapsibleBlocks ( bool enable )
+{
+	d->collapsibleBlocks = enable;
+}
+
+QModelIndexList KCategorizedView::block ( const QString &category )
+{
+	QModelIndexList res;
+	const Private::Block &block = d->blocks[category];
+	if ( block.height == -1 )
+	{
+		return res;
+	}
+	QModelIndex current = block.firstIndex;
+	const int first = current.row();
+	for ( int i = 1; i <= block.items.count(); ++i )
+	{
+		if ( current.isValid() )
+		{
+			res << current;
+		}
+		current = d->proxyModel->index ( first + i, modelColumn(), rootIndex() );
+	}
+	return res;
+}
+
+QModelIndexList KCategorizedView::block ( const QModelIndex &representative )
+{
+	return block ( representative.data ( KCategorizedSortFilterProxyModel::CategoryDisplayRole ).toString() );
+}
+
+QModelIndex KCategorizedView::indexAt ( const QPoint &point ) const
+{
+	if ( !d->isCategorized() )
+	{
+		return QListView::indexAt ( point );
+	}
+
+	const int rowCount = d->proxyModel->rowCount();
+	if ( !rowCount )
+	{
+		return QModelIndex();
+	}
+
+	// Binary search that will try to spot if there is an index under point
+	int bottom = 0;
+	int top = rowCount - 1;
+	while ( bottom <= top )
+	{
+		const int middle = ( bottom + top ) / 2;
+		const QModelIndex index = d->proxyModel->index ( middle, modelColumn(), rootIndex() );
+		QRect rect = visualRect ( index );
+		const int verticalOff = verticalOffset();
+		int horizontalOff = horizontalOffset();
+		if ( layoutDirection() == Qt::RightToLeft )
+		{
+			horizontalOff *= -1;
+		}
+		rect.topLeft().ry() += verticalOff;
+		rect.topLeft().rx() += horizontalOff;
+		rect.bottomRight().ry() += verticalOff;
+		rect.bottomRight().rx() += horizontalOff;
+		if ( rect.contains ( point ) )
+		{
+			if ( index.model()->flags ( index ) & Qt::ItemIsEnabled )
+			{
+				return index;
+			}
+			return QModelIndex();
+		}
+		bool directionCondition;
+		if ( layoutDirection() == Qt::LeftToRight )
+		{
+			directionCondition = point.x() > rect.bottomRight().x();
+		}
+		else
+		{
+			directionCondition = point.x() < rect.bottomLeft().x();
+		}
+		if ( point.y() > rect.bottomRight().y() ||
+		     ( point.y() > rect.topLeft().y() && point.y() < rect.bottomRight().y() && directionCondition ) )
+		{
+			bottom = middle + 1;
+		}
+		else
+		{
+			top = middle - 1;
+		}
+	}
+	return QModelIndex();
+}
+
+void KCategorizedView::reset()
+{
+	d->blocks.clear();
+	QListView::reset();
+}
+
+void KCategorizedView::paintEvent ( QPaintEvent *event )
+{
+	if ( !d->isCategorized() )
+	{
+		QListView::paintEvent ( event );
+		return;
+	}
+
+	const QPair<QModelIndex, QModelIndex> intersecting = d->intersectingIndexesWithRect ( viewport()->rect().intersected ( event->rect() ) );
+
+	QPainter p ( viewport() );
+	p.save();
+
+	Q_ASSERT ( selectionModel()->model() == d->proxyModel );
+
+	//BEGIN: draw categories
+	QHash<QString, Private::Block>::ConstIterator it ( d->blocks.constBegin() );
+	while ( it != d->blocks.constEnd() )
+	{
+		const Private::Block &block = *it;
+		const QModelIndex categoryIndex = d->proxyModel->index ( block.firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+		QStyleOptionViewItemV4 option ( viewOptions() );
+		option.features |= d->alternatingBlockColors && block.alternate ? QStyleOptionViewItemV4::Alternate
+		                   : QStyleOptionViewItemV4::None;
+		option.state |= !d->collapsibleBlocks || !block.collapsed ? QStyle::State_Open
+		                : QStyle::State_None;
+		const int height = d->categoryDrawer->categoryHeight ( categoryIndex, option );
+		QPoint pos = d->blockPosition ( it.key() );
+		pos.ry() -= height;
+		option.rect.setTopLeft ( pos );
+		option.rect.setWidth ( d->viewportWidth() + d->categoryDrawer->leftMargin() + d->categoryDrawer->rightMargin() );
+		option.rect.setHeight ( height + d->blockHeight ( it.key() ) );
+		option.rect = d->mapToViewport ( option.rect );
+		if ( !option.rect.intersects ( viewport()->rect() ) )
+		{
+			++it;
+			continue;
+		}
+		d->categoryDrawer->drawCategory ( categoryIndex, d->proxyModel->sortRole(), option, &p );
+		++it;
+	}
+	//END: draw categories
+
+	if ( intersecting.first.isValid() && intersecting.second.isValid() )
+	{
+		//BEGIN: draw items
+		int i = intersecting.first.row();
+		int indexToCheckIfBlockCollapsed = i;
+		QModelIndex categoryIndex;
+		QString category;
+		Private::Block *block = 0;
+		while ( i <= intersecting.second.row() )
+		{
+			//BEGIN: first check if the block is collapsed. if so, we have to skip the item painting
+			if ( i == indexToCheckIfBlockCollapsed )
+			{
+				categoryIndex = d->proxyModel->index ( i, d->proxyModel->sortColumn(), rootIndex() );
+				category = categoryIndex.data ( KCategorizedSortFilterProxyModel::CategoryDisplayRole ).toString();
+				block = &d->blocks[category];
+				indexToCheckIfBlockCollapsed = block->firstIndex.row() + block->items.count();
+				if ( block->collapsed )
+				{
+					i = indexToCheckIfBlockCollapsed;
+					continue;
+				}
+			}
+			//END: first check if the block is collapsed. if so, we have to skip the item painting
+
+			Q_ASSERT ( block );
+
+			const bool alternateItem = ( i - block->firstIndex.row() ) % 2;
+
+			const QModelIndex index = d->proxyModel->index ( i, modelColumn(), rootIndex() );
+			const Qt::ItemFlags flags = d->proxyModel->flags ( index );
+			QStyleOptionViewItemV4 option ( viewOptions() );
+			option.rect = visualRect ( index );
+			option.widget = this;
+			option.features |= wordWrap() ? QStyleOptionViewItemV2::WrapText
+			                   : QStyleOptionViewItemV2::None;
+			option.features |= alternatingRowColors() && alternateItem ? QStyleOptionViewItemV4::Alternate
+			                   : QStyleOptionViewItemV4::None;
+			if ( flags & Qt::ItemIsSelectable )
+			{
+				option.state |= selectionModel()->isSelected ( index ) ? QStyle::State_Selected
+				                : QStyle::State_None;
+			}
+			else
+			{
+				option.state &= ~QStyle::State_Selected;
+			}
+			option.state |= ( index == currentIndex() ) ? QStyle::State_HasFocus
+			                : QStyle::State_None;
+			if ( ! ( flags & Qt::ItemIsEnabled ) )
+			{
+				option.state &= ~QStyle::State_Enabled;
+			}
+			else
+			{
+				option.state |= ( index == d->hoveredIndex ) ? QStyle::State_MouseOver
+				                : QStyle::State_None;
+			}
+
+			itemDelegate ( index )->paint ( &p, option, index );
+			++i;
+		}
+		//END: draw items
+	}
+
+	//BEGIN: draw selection rect
+	if ( isSelectionRectVisible() && d->rubberBandRect.isValid() )
+	{
+		QStyleOptionRubberBand opt;
+		opt.initFrom ( this );
+		opt.shape = QRubberBand::Rectangle;
+		opt.opaque = false;
+		opt.rect = d->mapToViewport ( d->rubberBandRect ).intersected ( viewport()->rect().adjusted ( -16, -16, 16, 16 ) );
+		p.save();
+		style()->drawControl ( QStyle::CE_RubberBand, &opt, &p );
+		p.restore();
+	}
+	//END: draw selection rect
+
+	p.restore();
+}
+
+void KCategorizedView::resizeEvent ( QResizeEvent *event )
+{
+	d->regenerateAllElements();
+	QListView::resizeEvent ( event );
+}
+
+void KCategorizedView::setSelection ( const QRect &rect,
+                                      QItemSelectionModel::SelectionFlags flags )
+{
+	if ( !d->isCategorized() )
+	{
+		QListView::setSelection ( rect, flags );
+		return;
+	}
+
+	if ( rect.topLeft() == rect.bottomRight() )
+	{
+		const QModelIndex index = indexAt ( rect.topLeft() );
+		selectionModel()->select ( index, flags );
+		return;
+	}
+
+	const QPair<QModelIndex, QModelIndex> intersecting = d->intersectingIndexesWithRect ( rect );
+
+	QItemSelection selection;
+
+	//TODO: think of a faster implementation
+	QModelIndex firstIndex;
+	QModelIndex lastIndex;
+	for ( int i = intersecting.first.row(); i <= intersecting.second.row(); ++i )
+	{
+		const QModelIndex index = d->proxyModel->index ( i, modelColumn(), rootIndex() );
+		const bool visualRectIntersects = visualRect ( index ).intersects ( rect );
+		if ( firstIndex.isValid() )
+		{
+			if ( visualRectIntersects )
+			{
+				lastIndex = index;
+			}
+			else
+			{
+				selection << QItemSelectionRange ( firstIndex, lastIndex );
+				firstIndex = QModelIndex();
+			}
+		}
+		else if ( visualRectIntersects )
+		{
+			firstIndex = index;
+			lastIndex = index;
+		}
+	}
+
+	if ( firstIndex.isValid() )
+	{
+		selection << QItemSelectionRange ( firstIndex, lastIndex );
+	}
+
+	selectionModel()->select ( selection, flags );
+}
+
+void KCategorizedView::mouseMoveEvent ( QMouseEvent *event )
+{
+	QListView::mouseMoveEvent ( event );
+	d->hoveredIndex = indexAt ( event->pos() );
+	const SelectionMode itemViewSelectionMode = selectionMode();
+	if ( state() == DragSelectingState && isSelectionRectVisible() && itemViewSelectionMode != SingleSelection
+	     && itemViewSelectionMode != NoSelection )
+	{
+		QRect rect ( d->pressedPosition, event->pos() + QPoint ( horizontalOffset(), verticalOffset() ) );
+		rect = rect.normalized();
+		update ( rect.united ( d->rubberBandRect ) );
+		d->rubberBandRect = rect;
+	}
+	QHash<QString, Private::Block>::ConstIterator it ( d->blocks.constBegin() );
+	while ( it != d->blocks.constEnd() )
+	{
+		const Private::Block &block = *it;
+		const QModelIndex categoryIndex = d->proxyModel->index ( block.firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+		QStyleOptionViewItemV4 option ( viewOptions() );
+		const int height = d->categoryDrawer->categoryHeight ( categoryIndex, option );
+		QPoint pos = d->blockPosition ( it.key() );
+		pos.ry() -= height;
+		option.rect.setTopLeft ( pos );
+		option.rect.setWidth ( d->viewportWidth() + d->categoryDrawer->leftMargin() + d->categoryDrawer->rightMargin() );
+		option.rect.setHeight ( height + d->blockHeight ( it.key() ) );
+		option.rect = d->mapToViewport ( option.rect );
+		const QPoint mousePos = viewport()->mapFromGlobal ( QCursor::pos() );
+		if ( option.rect.contains ( mousePos ) )
+		{
+			if ( d->categoryDrawer && d->hoveredBlock->height != -1 && *d->hoveredBlock != block )
+			{
+				const QModelIndex categoryIndex = d->proxyModel->index ( d->hoveredBlock->firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+				const QStyleOptionViewItemV4 option = d->blockRect ( categoryIndex );
+				d->categoryDrawer->mouseLeft ( categoryIndex, option.rect );
+				*d->hoveredBlock = block;
+				d->hoveredCategory = it.key();
+				viewport()->update ( option.rect );
+			}
+			else if ( d->hoveredBlock->height == -1 )
+			{
+				*d->hoveredBlock = block;
+				d->hoveredCategory = it.key();
+			}
+			else if ( d->categoryDrawer )
+			{
+				d->categoryDrawer->mouseMoved ( categoryIndex, option.rect, event );
+			}
+			viewport()->update ( option.rect );
+			return;
+		}
+		++it;
+	}
+	if ( d->categoryDrawer && d->hoveredBlock->height != -1 )
+	{
+		const QModelIndex categoryIndex = d->proxyModel->index ( d->hoveredBlock->firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+		const QStyleOptionViewItemV4 option = d->blockRect ( categoryIndex );
+		d->categoryDrawer->mouseLeft ( categoryIndex, option.rect );
+		*d->hoveredBlock = Private::Block();
+		d->hoveredCategory = QString();
+		viewport()->update ( option.rect );
+	}
+}
+
+void KCategorizedView::mousePressEvent ( QMouseEvent *event )
+{
+	if ( event->button() == Qt::LeftButton )
+	{
+		d->pressedPosition = event->pos();
+		d->pressedPosition.rx() += horizontalOffset();
+		d->pressedPosition.ry() += verticalOffset();
+	}
+	if ( !d->categoryDrawer )
+	{
+		QListView::mousePressEvent ( event );
+		return;
+	}
+	QHash<QString, Private::Block>::ConstIterator it ( d->blocks.constBegin() );
+	while ( it != d->blocks.constEnd() )
+	{
+		const Private::Block &block = *it;
+		const QModelIndex categoryIndex = d->proxyModel->index ( block.firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+		const QStyleOptionViewItemV4 option = d->blockRect ( categoryIndex );
+		const QPoint mousePos = viewport()->mapFromGlobal ( QCursor::pos() );
+		if ( option.rect.contains ( mousePos ) )
+		{
+			if ( d->categoryDrawer )
+			{
+				d->categoryDrawer->mouseButtonPressed ( categoryIndex, option.rect, event );
+			}
+			viewport()->update ( option.rect );
+			if ( !event->isAccepted() )
+			{
+				QListView::mousePressEvent ( event );
+			}
+			return;
+		}
+		++it;
+	}
+	QListView::mousePressEvent ( event );
+}
+
+void KCategorizedView::mouseReleaseEvent ( QMouseEvent *event )
+{
+	d->pressedPosition = QPoint();
+	d->rubberBandRect = QRect();
+	QHash<QString, Private::Block>::ConstIterator it ( d->blocks.constBegin() );
+	while ( it != d->blocks.constEnd() )
+	{
+		const Private::Block &block = *it;
+		const QModelIndex categoryIndex = d->proxyModel->index ( block.firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+		const QStyleOptionViewItemV4 option = d->blockRect ( categoryIndex );
+		const QPoint mousePos = viewport()->mapFromGlobal ( QCursor::pos() );
+		if ( option.rect.contains ( mousePos ) )
+		{
+			if ( d->categoryDrawer )
+			{
+				d->categoryDrawer->mouseButtonReleased ( categoryIndex, option.rect, event );
+			}
+			viewport()->update ( option.rect );
+			if ( !event->isAccepted() )
+			{
+				QListView::mouseReleaseEvent ( event );
+			}
+			return;
+		}
+		++it;
+	}
+	QListView::mouseReleaseEvent ( event );
+}
+
+void KCategorizedView::leaveEvent ( QEvent *event )
+{
+	QListView::leaveEvent ( event );
+	if ( d->hoveredIndex.isValid() )
+	{
+		viewport()->update ( visualRect ( d->hoveredIndex ) );
+		d->hoveredIndex = QModelIndex();
+	}
+	if ( d->categoryDrawer && d->hoveredBlock->height != -1 )
+	{
+		const QModelIndex categoryIndex = d->proxyModel->index ( d->hoveredBlock->firstIndex.row(), d->proxyModel->sortColumn(), rootIndex() );
+		const QStyleOptionViewItemV4 option = d->blockRect ( categoryIndex );
+		d->categoryDrawer->mouseLeft ( categoryIndex, option.rect );
+		*d->hoveredBlock = Private::Block();
+		d->hoveredCategory = QString();
+		viewport()->update ( option.rect );
+	}
+}
+
+void KCategorizedView::startDrag ( Qt::DropActions supportedActions )
+{
+	QListView::startDrag ( supportedActions );
+}
+
+void KCategorizedView::dragMoveEvent ( QDragMoveEvent *event )
+{
+	QListView::dragMoveEvent ( event );
+	d->hoveredIndex = indexAt ( event->pos() );
+}
+
+void KCategorizedView::dragEnterEvent ( QDragEnterEvent *event )
+{
+	QListView::dragEnterEvent ( event );
+}
+
+void KCategorizedView::dragLeaveEvent ( QDragLeaveEvent *event )
+{
+	QListView::dragLeaveEvent ( event );
+}
+
+void KCategorizedView::dropEvent ( QDropEvent *event )
+{
+	QListView::dropEvent ( event );
+}
+
+//TODO: improve se we take into account collapsed blocks
+//TODO: take into account when there is no grid and no uniformItemSizes
+QModelIndex KCategorizedView::moveCursor ( CursorAction cursorAction,
+  Qt::KeyboardModifiers modifiers )
+{
+	if ( !d->isCategorized() )
+	{
+		return QListView::moveCursor ( cursorAction, modifiers );
+	}
+
+	const QModelIndex current = currentIndex();
+	const QRect currentRect = visualRect ( current );
+	if ( !current.isValid() )
+	{
+		const int rowCount = d->proxyModel->rowCount ( rootIndex() );
+		if ( !rowCount )
+		{
+			return QModelIndex();
+		}
+		return d->proxyModel->index ( 0, modelColumn(), rootIndex() );
+	}
+
+	switch ( cursorAction )
+	{
+	case MoveLeft:
+	{
+		if ( !current.row() )
+		{
+			return QModelIndex();
+		}
+		const QModelIndex previous = d->proxyModel->index ( current.row() - 1, modelColumn(), rootIndex() );
+		const QRect previousRect = visualRect ( previous );
+		if ( previousRect.top() == currentRect.top() )
+		{
+			return previous;
+		}
+
+		return QModelIndex();
+	}
+	case MoveRight:
+	{
+		if ( current.row() == d->proxyModel->rowCount() - 1 )
+		{
+			return QModelIndex();
+		}
+		const QModelIndex next = d->proxyModel->index ( current.row() + 1, modelColumn(), rootIndex() );
+		const QRect nextRect = visualRect ( next );
+		if ( nextRect.top() == currentRect.top() )
+		{
+			return next;
+		}
+
+		return QModelIndex();
+	}
+	case MoveDown:
+	{
+		if ( d->hasGrid() || uniformItemSizes() )
+		{
+			const QModelIndex current = currentIndex();
+			const QSize itemSize = d->hasGrid() ? gridSize()
+			                       : sizeHintForIndex ( current );
+			const Private::Block &block = d->blocks[d->categoryForIndex ( current )];
+			const int maxItemsPerRow = qMax ( d->viewportWidth() / itemSize.width(), 1 );
+			const bool canMove = current.row() + maxItemsPerRow < block.firstIndex.row() +
+			                     block.items.count();
+
+			if ( canMove )
+			{
+				return d->proxyModel->index ( current.row() + maxItemsPerRow, modelColumn(), rootIndex() );
+			}
+
+			const int currentRelativePos = ( current.row() - block.firstIndex.row() ) % maxItemsPerRow;
+			const QModelIndex nextIndex = d->proxyModel->index ( block.firstIndex.row() + block.items.count(), modelColumn(), rootIndex() );
+
+			if ( !nextIndex.isValid() )
+			{
+				return QModelIndex();
+			}
+
+			const Private::Block &nextBlock = d->blocks[d->categoryForIndex ( nextIndex )];
+
+			if ( nextBlock.items.count() <= currentRelativePos )
+			{
+				return QModelIndex();
+			}
+
+			if ( currentRelativePos < ( block.items.count() % maxItemsPerRow ) )
+			{
+				return d->proxyModel->index ( nextBlock.firstIndex.row() + currentRelativePos, modelColumn(), rootIndex() );
+			}
+
+			return QModelIndex();
+		}
+	}
+	case MoveUp:
+	{
+		if ( d->hasGrid() || uniformItemSizes() )
+		{
+			const QModelIndex current = currentIndex();
+			const QSize itemSize = d->hasGrid() ? gridSize()
+			                       : sizeHintForIndex ( current );
+			const Private::Block &block = d->blocks[d->categoryForIndex ( current )];
+			const int maxItemsPerRow = qMax ( d->viewportWidth() / itemSize.width(), 1 );
+			const bool canMove = current.row() - maxItemsPerRow >= block.firstIndex.row();
+
+			if ( canMove )
+			{
+				return d->proxyModel->index ( current.row() - maxItemsPerRow, modelColumn(), rootIndex() );
+			}
+
+			const int currentRelativePos = ( current.row() - block.firstIndex.row() ) % maxItemsPerRow;
+			const QModelIndex prevIndex = d->proxyModel->index ( block.firstIndex.row() - 1, modelColumn(), rootIndex() );
+
+			if ( !prevIndex.isValid() )
+			{
+				return QModelIndex();
+			}
+
+			const Private::Block &prevBlock = d->blocks[d->categoryForIndex ( prevIndex )];
+
+			if ( prevBlock.items.count() <= currentRelativePos )
+			{
+				return QModelIndex();
+			}
+
+			const int remainder = prevBlock.items.count() % maxItemsPerRow;
+			if ( currentRelativePos < remainder )
+			{
+				return d->proxyModel->index ( prevBlock.firstIndex.row() + prevBlock.items.count() - remainder + currentRelativePos, modelColumn(), rootIndex() );
+			}
+
+			return QModelIndex();
+		}
+	}
+	default:
+		break;
+	}
+
+	return QModelIndex();
+}
+
+void KCategorizedView::rowsAboutToBeRemoved ( const QModelIndex &parent,
+  int start,
+  int end )
+{
+	if ( !d->isCategorized() )
+	{
+		QListView::rowsAboutToBeRemoved ( parent, start, end );
+		return;
+	}
+
+	*d->hoveredBlock = Private::Block();
+	d->hoveredCategory = QString();
+
+	if ( end - start + 1 == d->proxyModel->rowCount() )
+	{
+		d->blocks.clear();
+		QListView::rowsAboutToBeRemoved ( parent, start, end );
+		return;
+	}
+
+	// Removal feels a bit more complicated than insertion. Basically we can consider there are
+	// 3 different cases when going to remove items. (*) represents an item, Items between ([) and
+	// (]) are the ones which are marked for removal.
+	//
+	// - 1st case:
+	//              ... * * * * * * [ * * * ...
+	//
+	//   The items marked for removal are the last part of this category. No need to mark any item
+	//   of this category as in quarantine, because no special offset will be pushed to items at
+	//   the right because of any changes (since the removed items are those on the right most part
+	//   of the category).
+	//
+	// - 2nd case:
+	//              ... * * * * * * ] * * * ...
+	//
+	//   The items marked for removal are the first part of this category. We have to mark as in
+	//   quarantine all items in this category. Absolutely all. All items will have to be moved to
+	//   the left (or moving up, because rows got a different offset).
+	//
+	// - 3rd case:
+	//              ... * * [ * * * * ] * * ...
+	//
+	//   The items marked for removal are in between of this category. We have to mark as in
+	//   quarantine only those items that are at the right of the end of the removal interval,
+	//   (starting on "]").
+	//
+	// It hasn't been explicitly said, but when we remove, we have to mark all blocks that are
+	// located under the top most affected category as in quarantine (the block itself, as a whole),
+	// because such a change can force it to have a different offset (note that items themselves
+	// contain relative positions to the block, so marking the block as in quarantine is enough).
+	//
+	// Also note that removal implicitly means that we have to update correctly firstIndex of each
+	// block, and in general keep updated the internal information of elements.
+
+	QStringList listOfCategoriesMarkedForRemoval;
+
+	QString lastCategory;
+	int alreadyRemoved = 0;
+	for ( int i = start; i <= end; ++i )
+	{
+		const QModelIndex index = d->proxyModel->index ( i, modelColumn(), parent );
+
+		Q_ASSERT ( index.isValid() );
+
+		const QString category = d->categoryForIndex ( index );
+
+		if ( lastCategory != category )
+		{
+			lastCategory = category;
+			alreadyRemoved = 0;
+		}
+
+		Private::Block &block = d->blocks[category];
+		block.items.removeAt ( i - block.firstIndex.row() - alreadyRemoved );
+		++alreadyRemoved;
+
+		if ( !block.items.count() )
+		{
+			listOfCategoriesMarkedForRemoval << category;
+		}
+
+		block.height = -1;
+
+		viewport()->update();
+	}
+
+	//BEGIN: update the items that are in quarantine in affected categories
+	{
+		const QModelIndex lastIndex = d->proxyModel->index ( end, modelColumn(), parent );
+		const QString category = d->categoryForIndex ( lastIndex );
+		Private::Block &block = d->blocks[category];
+		if ( block.items.count() && start <= block.firstIndex.row() && end >= block.firstIndex.row() )
+		{
+			block.firstIndex = d->proxyModel->index ( end + 1, modelColumn(), parent );
+		}
+		block.quarantineStart = block.firstIndex;
+	}
+	//END: update the items that are in quarantine in affected categories
+
+	Q_FOREACH ( const QString &category, listOfCategoriesMarkedForRemoval )
+	{
+		d->blocks.remove ( category );
+	}
+
+	//BEGIN: mark as in quarantine those categories that are under the affected ones
+	{
+		//BEGIN: order for marking as alternate those blocks that are alternate
+		QList<Private::Block> blockList = d->blocks.values();
+		qSort ( blockList.begin(), blockList.end(), Private::Block::lessThan );
+		QList<int> firstIndexesRows;
+		foreach ( const Private::Block &block, blockList )
+		{
+			firstIndexesRows << block.firstIndex.row();
+		}
+		//END: order for marking as alternate those blocks that are alternate
+		for ( QHash<QString, Private::Block>::Iterator it = d->blocks.begin(); it != d->blocks.end(); ++it )
+		{
+			Private::Block &block = *it;
+			if ( block.firstIndex.row() > start )
+			{
+				block.outOfQuarantine = false;
+				block.alternate = firstIndexesRows.indexOf ( block.firstIndex.row() ) % 2;
+			}
+			else if ( block.firstIndex.row() == start )
+			{
+				block.alternate = firstIndexesRows.indexOf ( block.firstIndex.row() ) % 2;
+			}
+		}
+	}
+	//END: mark as in quarantine those categories that are under the affected ones
+
+	QListView::rowsAboutToBeRemoved ( parent, start, end );
+}
+
+void KCategorizedView::updateGeometries()
+{
+	const int oldVerticalOffset = verticalOffset();
+	const Qt::ScrollBarPolicy verticalP = verticalScrollBarPolicy(), horizontalP = horizontalScrollBarPolicy();
+
+	//BEGIN bugs 213068, 287847 ------------------------------------------------------------
+	/*
+	 * QListView::updateGeometries() has it's own opinion on whether the scrollbars should be visible (valid range) or not
+	 * and triggers a (sometimes additionally timered) resize through ::layoutChildren()
+	 * http://qt.gitorious.org/qt/qt/blobs/4.7/src/gui/itemviews/qlistview.cpp#line1499
+	 * (the comment above the main block isn't all accurate, layoutChldren is called regardless of the policy)
+	 *
+	 * As a result QListView and KCategorizedView occasionally started a race on the scrollbar visibility, effectively blocking the UI
+	 * So we prevent QListView from having an own opinion on the scrollbar visibility by
+	 * fixing it before calling the baseclass QListView::updateGeometries()
+	 *
+	 * Since the implicit show/hide by the followin range setting will cause further resizes if the policy is Qt::ScrollBarAsNeeded
+	 * we keep it static until we're done, then restore the original value and ultimately change the scrollbar visibility ourself.
+	 */
+	if ( d->isCategorized() ) // important! - otherwise we'd pollute the setting if the view is initially not categorized
+	{
+		setVerticalScrollBarPolicy ( ( verticalP == Qt::ScrollBarAlwaysOn || verticalScrollBar()->isVisibleTo ( this ) ) ?
+		                             Qt::ScrollBarAlwaysOn : Qt::ScrollBarAlwaysOff );
+		setHorizontalScrollBarPolicy ( ( horizontalP == Qt::ScrollBarAlwaysOn || horizontalScrollBar()->isVisibleTo ( this ) ) ?
+		                               Qt::ScrollBarAlwaysOn : Qt::ScrollBarAlwaysOff );
+	}
+	//END bugs 213068, 287847 --------------------------------------------------------------
+
+	QListView::updateGeometries();
+
+	if ( !d->isCategorized() )
+	{
+		return;
+	}
+
+	const int rowCount = d->proxyModel->rowCount();
+	if ( !rowCount )
+	{
+		verticalScrollBar()->setRange ( 0, 0 );
+		// unconditional, see function end todo
+		horizontalScrollBar()->setRange ( 0, 0 );
+		return;
+	}
+
+	const QModelIndex lastIndex = d->proxyModel->index ( rowCount - 1, modelColumn(), rootIndex() );
+	Q_ASSERT ( lastIndex.isValid() );
+	QRect lastItemRect = visualRect ( lastIndex );
+
+	if ( d->hasGrid() )
+	{
+		lastItemRect.setSize ( lastItemRect.size().expandedTo ( gridSize() ) );
+	}
+	else
+	{
+		if ( uniformItemSizes() )
+		{
+			QSize itemSize = sizeHintForIndex ( lastIndex );
+			itemSize.setHeight ( itemSize.height() + spacing() );
+			lastItemRect.setSize ( itemSize );
+		}
+		else
+		{
+			QSize itemSize = sizeHintForIndex ( lastIndex );
+			const QString category = d->categoryForIndex ( lastIndex );
+			itemSize.setHeight ( d->highestElementInLastRow ( d->blocks[category] ) + spacing() );
+			lastItemRect.setSize ( itemSize );
+		}
+	}
+
+	const int bottomRange = lastItemRect.bottomRight().y() + verticalOffset() - viewport()->height();
+
+	if ( verticalScrollMode() == ScrollPerItem )
+	{
+		verticalScrollBar()->setSingleStep ( lastItemRect.height() );
+		const int rowsPerPage = qMax ( viewport()->height() / lastItemRect.height(), 1 );
+		verticalScrollBar()->setPageStep ( rowsPerPage * lastItemRect.height() );
+	}
+
+	verticalScrollBar()->setRange ( 0, bottomRange );
+	verticalScrollBar()->setValue ( oldVerticalOffset );
+
+	//TODO: also consider working with the horizontal scroll bar. since at this level I am not still
+	//      supporting "top to bottom" flow, there is no real problem. If I support that someday
+	//      (think how to draw categories), we would have to take care of the horizontal scroll bar too.
+	//      In theory, as KCategorizedView has been designed, there is no need of horizontal scroll bar.
+	horizontalScrollBar()->setRange ( 0, 0 );
+
+	//BEGIN bugs 213068, 287847 ------------------------------------------------------------
+	// restoring values from above ...
+	setVerticalScrollBarPolicy ( verticalP );
+	setHorizontalScrollBarPolicy ( horizontalP );
+	// ... and correct the visibility
+	bool validRange = verticalScrollBar()->maximum() != verticalScrollBar()->minimum();
+	if ( verticalP == Qt::ScrollBarAsNeeded && ( verticalScrollBar()->isVisibleTo ( this ) != validRange ) )
+		verticalScrollBar()->setVisible ( validRange );
+	validRange = horizontalScrollBar()->maximum() > horizontalScrollBar()->minimum();
+	if ( horizontalP == Qt::ScrollBarAsNeeded && ( horizontalScrollBar()->isVisibleTo ( this ) != validRange ) )
+		horizontalScrollBar()->setVisible ( validRange );
+	//END bugs 213068, 287847 --------------------------------------------------------------
+}
+
+void KCategorizedView::currentChanged ( const QModelIndex &current,
+                                        const QModelIndex &previous )
+{
+	QListView::currentChanged ( current, previous );
+}
+
+void KCategorizedView::dataChanged ( const QModelIndex &topLeft,
+                                     const QModelIndex &bottomRight )
+{
+	QListView::dataChanged ( topLeft, bottomRight );
+	if ( !d->isCategorized() )
+	{
+		return;
+	}
+
+	*d->hoveredBlock = Private::Block();
+	d->hoveredCategory = QString();
+
+	//BEGIN: since the model changed data, we need to reconsider item sizes
+	int i = topLeft.row();
+	int indexToCheck = i;
+	QModelIndex categoryIndex;
+	QString category;
+	Private::Block *block;
+	while ( i <= bottomRight.row() )
+	{
+		const QModelIndex currIndex = d->proxyModel->index ( i, modelColumn(), rootIndex() );
+		if ( i == indexToCheck )
+		{
+			categoryIndex = d->proxyModel->index ( i, d->proxyModel->sortColumn(), rootIndex() );
+			category = categoryIndex.data ( KCategorizedSortFilterProxyModel::CategoryDisplayRole ).toString();
+			block = &d->blocks[category];
+			block->quarantineStart = currIndex;
+			indexToCheck = block->firstIndex.row() + block->items.count();
+		}
+		visualRect ( currIndex );
+		++i;
+	}
+	//END: since the model changed data, we need to reconsider item sizes
+}
+
+void KCategorizedView::rowsInserted ( const QModelIndex &parent,
+                                      int start,
+                                      int end )
+{
+	QListView::rowsInserted ( parent, start, end );
+	if ( !d->isCategorized() )
+	{
+		return;
+	}
+
+	*d->hoveredBlock = Private::Block();
+	d->hoveredCategory = QString();
+	d->rowsInserted ( parent, start, end );
+}
+
+void KCategorizedView::slotLayoutChanged()
+{
+	if ( !d->isCategorized() )
+	{
+		return;
+	}
+
+	d->blocks.clear();
+	*d->hoveredBlock = Private::Block();
+	d->hoveredCategory = QString();
+	if ( d->proxyModel->rowCount() )
+	{
+		d->rowsInserted ( rootIndex(), 0, d->proxyModel->rowCount() - 1 );
+	}
+}
+//END: Public part
+
+void KCategorizedView::slotCollapseOrExpandClicked ( QModelIndex idx )
+{
+	d->_k_slotCollapseOrExpandClicked ( idx );
+}
+
+
+#include "kcategorizedview.moc"