MultiMC5/launcher/ui/instanceview/InstanceView.cpp

1002 lines
28 KiB
C++

/* Copyright 2013-2021 MultiMC Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "InstanceView.h"
#include <QPainter>
#include <QApplication>
#include <QtMath>
#include <QMouseEvent>
#include <QListView>
#include <QPersistentModelIndex>
#include <QDrag>
#include <QMimeData>
#include <QCache>
#include <QScrollBar>
#include <QAccessible>
#include "VisualGroup.h"
#include <QDebug>
#include <Application.h>
#include <InstanceList.h>
template <typename T> bool listsIntersect(const QList<T> &l1, const QList<T> t2)
{
for (auto &item : l1)
{
if (t2.contains(item))
{
return true;
}
}
return false;
}
InstanceView::InstanceView(QWidget *parent)
: QAbstractItemView(parent)
{
setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
setAcceptDrops(true);
setAutoScroll(true);
}
InstanceView::~InstanceView()
{
qDeleteAll(m_groups);
m_groups.clear();
}
void InstanceView::setModel(QAbstractItemModel *model)
{
QAbstractItemView::setModel(model);
connect(model, &QAbstractItemModel::modelReset, this, &InstanceView::modelReset);
connect(model, &QAbstractItemModel::rowsRemoved, this, &InstanceView::rowsRemoved);
}
void InstanceView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles)
{
scheduleDelayedItemsLayout();
}
void InstanceView::rowsInserted(const QModelIndex &parent, int start, int end)
{
scheduleDelayedItemsLayout();
}
void InstanceView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)
{
scheduleDelayedItemsLayout();
}
void InstanceView::modelReset()
{
scheduleDelayedItemsLayout();
}
void InstanceView::rowsRemoved()
{
scheduleDelayedItemsLayout();
}
void InstanceView::currentChanged(const QModelIndex& current, const QModelIndex& previous)
{
QAbstractItemView::currentChanged(current, previous);
// TODO: for accessibility support, implement+register a factory, steal QAccessibleTable from Qt and return an instance of it for InstanceView.
#ifndef QT_NO_ACCESSIBILITY
if (QAccessible::isActive() && current.isValid()) {
QAccessibleEvent event(this, QAccessible::Focus);
event.setChild(current.row());
QAccessible::updateAccessibility(&event);
}
#endif /* !QT_NO_ACCESSIBILITY */
}
class LocaleString : public QString
{
public:
LocaleString(const char *s) : QString(s)
{
}
LocaleString(const QString &s) : QString(s)
{
}
};
inline bool operator<(const LocaleString &lhs, const LocaleString &rhs)
{
return (QString::localeAwareCompare(lhs, rhs) < 0);
}
void InstanceView::updateScrollbar()
{
int previousScroll = verticalScrollBar()->value();
if (m_groups.isEmpty())
{
verticalScrollBar()->setRange(0, 0);
}
else
{
int totalHeight = 0;
// top margin
totalHeight += m_categoryMargin;
int itemScroll = 0;
for (auto category : m_groups)
{
category->m_verticalPosition = totalHeight;
totalHeight += category->totalHeight() + m_categoryMargin;
if(!itemScroll && category->totalHeight() != 0)
{
itemScroll = category->contentHeight() / category->numRows();
}
}
// do not divide by zero
if(itemScroll == 0)
itemScroll = 64;
totalHeight += m_bottomMargin;
verticalScrollBar()->setSingleStep ( itemScroll );
const int rowsPerPage = qMax ( viewport()->height() / itemScroll, 1 );
verticalScrollBar()->setPageStep ( rowsPerPage * itemScroll );
verticalScrollBar()->setRange(0, totalHeight - height());
}
verticalScrollBar()->setValue(qMin(previousScroll, verticalScrollBar()->maximum()));
}
void InstanceView::updateGeometries()
{
geometryCache.clear();
QMap<LocaleString, VisualGroup *> cats;
for (int i = 0; i < model()->rowCount(); ++i)
{
const QString groupName = model()->index(i, 0).data(InstanceViewRoles::GroupRole).toString();
if (!cats.contains(groupName))
{
VisualGroup *old = this->category(groupName);
if (old)
{
auto cat = new VisualGroup(old);
cats.insert(groupName, cat);
cat->update();
}
else
{
auto cat = new VisualGroup(groupName, this);
if(fVisibility) {
cat->collapsed = fVisibility(groupName);
}
cats.insert(groupName, cat);
cat->update();
}
}
}
qDeleteAll(m_groups);
m_groups = cats.values();
updateScrollbar();
viewport()->update();
}
bool InstanceView::isIndexHidden(const QModelIndex &index) const
{
VisualGroup *cat = category(index);
if (cat)
{
return cat->collapsed;
}
else
{
return false;
}
}
VisualGroup *InstanceView::category(const QModelIndex &index) const
{
return category(index.data(InstanceViewRoles::GroupRole).toString());
}
VisualGroup *InstanceView::category(const QString &cat) const
{
for (auto group : m_groups)
{
if (group->text == cat)
{
return group;
}
}
return nullptr;
}
VisualGroup *InstanceView::categoryAt(const QPoint &pos, VisualGroup::HitResults & result) const
{
for (auto group : m_groups)
{
result = group->hitScan(pos);
if(result != VisualGroup::NoHit)
{
return group;
}
}
result = VisualGroup::NoHit;
return nullptr;
}
QString InstanceView::groupNameAt(const QPoint &point)
{
executeDelayedItemsLayout();
VisualGroup::HitResults hitresult;
auto group = categoryAt(point + offset(), hitresult);
if(group && (hitresult & (VisualGroup::HeaderHit | VisualGroup::BodyHit)))
{
return group->text;
}
return QString();
}
int InstanceView::calculateItemsPerRow() const
{
return qFloor((qreal)(contentWidth()) / (qreal)(itemWidth() + m_spacing));
}
int InstanceView::contentWidth() const
{
return width() - m_leftMargin - m_rightMargin;
}
int InstanceView::itemWidth() const
{
return m_itemWidth;
}
void InstanceView::mousePressEvent(QMouseEvent *event)
{
executeDelayedItemsLayout();
QPoint visualPos = event->pos();
QPoint geometryPos = event->pos() + offset();
QPersistentModelIndex index = indexAt(visualPos);
m_pressedIndex = index;
m_pressedAlreadySelected = selectionModel()->isSelected(m_pressedIndex);
m_pressedPosition = geometryPos;
VisualGroup::HitResults hitresult;
m_pressedCategory = categoryAt(geometryPos, hitresult);
if (m_pressedCategory && hitresult & VisualGroup::CheckboxHit)
{
setState(m_pressedCategory->collapsed ? ExpandingState : CollapsingState);
event->accept();
return;
}
if (index.isValid() && (index.flags() & Qt::ItemIsEnabled))
{
if(index != currentIndex())
{
// FIXME: better!
m_currentCursorColumn = -1;
}
// we disable scrollTo for mouse press so the item doesn't change position
// when the user is interacting with it (ie. clicking on it)
bool autoScroll = hasAutoScroll();
setAutoScroll(false);
selectionModel()->setCurrentIndex(index, QItemSelectionModel::NoUpdate);
setAutoScroll(autoScroll);
QRect rect(visualPos, visualPos);
setSelection(rect, QItemSelectionModel::ClearAndSelect);
// signal handlers may change the model
emit pressed(index);
}
else
{
// Forces a finalize() even if mouse is pressed, but not on a item
selectionModel()->select(QModelIndex(), QItemSelectionModel::Select);
}
}
void InstanceView::mouseMoveEvent(QMouseEvent *event)
{
executeDelayedItemsLayout();
QPoint topLeft;
QPoint visualPos = event->pos();
QPoint geometryPos = event->pos() + offset();
if (state() == ExpandingState || state() == CollapsingState)
{
return;
}
if (state() == DraggingState)
{
topLeft = m_pressedPosition - offset();
if ((topLeft - event->pos()).manhattanLength() > QApplication::startDragDistance())
{
m_pressedIndex = QModelIndex();
startDrag(model()->supportedDragActions());
setState(NoState);
stopAutoScroll();
}
return;
}
if (selectionMode() != SingleSelection)
{
topLeft = m_pressedPosition - offset();
}
else
{
topLeft = geometryPos;
}
if (m_pressedIndex.isValid() && (state() != DragSelectingState) &&
(event->buttons() != Qt::NoButton) && !selectedIndexes().isEmpty())
{
setState(DraggingState);
return;
}
if ((event->buttons() & Qt::LeftButton) && selectionModel())
{
setState(DragSelectingState);
setSelection(QRect(visualPos, visualPos), QItemSelectionModel::ClearAndSelect);
QModelIndex index = indexAt(visualPos);
// set at the end because it might scroll the view
if (index.isValid() && (index != selectionModel()->currentIndex()) &&
(index.flags() & Qt::ItemIsEnabled))
{
selectionModel()->setCurrentIndex(index, QItemSelectionModel::NoUpdate);
}
}
}
void InstanceView::mouseReleaseEvent(QMouseEvent *event)
{
executeDelayedItemsLayout();
QPoint visualPos = event->pos();
QPoint geometryPos = event->pos() + offset();
QPersistentModelIndex index = indexAt(visualPos);
VisualGroup::HitResults hitresult;
bool click = (index == m_pressedIndex && index.isValid()) ||
(m_pressedCategory && m_pressedCategory == categoryAt(geometryPos, hitresult));
if (click && m_pressedCategory)
{
if (state() == ExpandingState)
{
m_pressedCategory->collapsed = false;
emit groupStateChanged(m_pressedCategory->text, false);
updateGeometries();
viewport()->update();
event->accept();
m_pressedCategory = nullptr;
setState(NoState);
return;
}
else if (state() == CollapsingState)
{
m_pressedCategory->collapsed = true;
emit groupStateChanged(m_pressedCategory->text, true);
updateGeometries();
viewport()->update();
event->accept();
m_pressedCategory = nullptr;
setState(NoState);
return;
}
}
m_ctrlDragSelectionFlag = QItemSelectionModel::NoUpdate;
setState(NoState);
if (click)
{
if (event->button() == Qt::LeftButton)
{
emit clicked(index);
}
QStyleOptionViewItem option = viewOptions();
if (m_pressedAlreadySelected)
{
option.state |= QStyle::State_Selected;
}
if ((model()->flags(index) & Qt::ItemIsEnabled) &&
style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, &option, this))
{
emit activated(index);
}
}
}
void InstanceView::mouseDoubleClickEvent(QMouseEvent *event)
{
executeDelayedItemsLayout();
QModelIndex index = indexAt(event->pos());
if (!index.isValid() || !(index.flags() & Qt::ItemIsEnabled) || (m_pressedIndex != index))
{
QMouseEvent me(
QEvent::MouseButtonPress,
event->localPos(),
event->windowPos(),
event->screenPos(),
event->button(),
event->buttons(),
event->modifiers()
);
mousePressEvent(&me);
return;
}
// signal handlers may change the model
QPersistentModelIndex persistent = index;
emit doubleClicked(persistent);
QStyleOptionViewItem option = viewOptions();
if ((model()->flags(index) & Qt::ItemIsEnabled) && !style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick, &option, this))
{
emit activated(index);
}
}
void InstanceView::paintEvent(QPaintEvent *event)
{
executeDelayedItemsLayout();
QPainter painter(this->viewport());
QStyleOptionViewItem option(viewOptions());
option.widget = this;
int wpWidth = viewport()->width();
option.rect.setWidth(wpWidth);
for (int i = 0; i < m_groups.size(); ++i)
{
VisualGroup *category = m_groups.at(i);
int y = category->verticalPosition();
y -= verticalOffset();
QRect backup = option.rect;
int height = category->totalHeight();
option.rect.setTop(y);
option.rect.setHeight(height);
option.rect.setLeft(m_leftMargin);
option.rect.setRight(wpWidth - m_rightMargin);
category->drawHeader(&painter, option);
y += category->totalHeight() + m_categoryMargin;
option.rect = backup;
}
for (int i = 0; i < model()->rowCount(); ++i)
{
const QModelIndex index = model()->index(i, 0);
if (isIndexHidden(index))
{
continue;
}
Qt::ItemFlags flags = index.flags();
option.rect = visualRect(index);
option.features |= QStyleOptionViewItem::WrapText;
if (flags & Qt::ItemIsSelectable && selectionModel()->isSelected(index))
{
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;
}
itemDelegate()->paint(&painter, option, index);
}
/*
* Drop indicators for manual reordering...
*/
#if 0
if (!m_lastDragPosition.isNull())
{
QPair<Group *, int> pair = rowDropPos(m_lastDragPosition);
Group *category = pair.first;
int row = pair.second;
if (category)
{
int internalRow = row - category->firstItemIndex;
QLine line;
if (internalRow >= category->numItems())
{
QRect toTheRightOfRect = visualRect(category->lastItem());
line = QLine(toTheRightOfRect.topRight(), toTheRightOfRect.bottomRight());
}
else
{
QRect toTheLeftOfRect = visualRect(model()->index(row, 0));
line = QLine(toTheLeftOfRect.topLeft(), toTheLeftOfRect.bottomLeft());
}
painter.save();
painter.setPen(QPen(Qt::black, 3));
painter.drawLine(line);
painter.restore();
}
}
#endif
}
void InstanceView::resizeEvent(QResizeEvent *event)
{
int newItemsPerRow = calculateItemsPerRow();
if(newItemsPerRow != m_currentItemsPerRow)
{
m_currentCursorColumn = -1;
m_currentItemsPerRow = newItemsPerRow;
updateGeometries();
}
else
{
updateScrollbar();
}
}
void InstanceView::dragEnterEvent(QDragEnterEvent *event)
{
executeDelayedItemsLayout();
if (!isDragEventAccepted(event))
{
return;
}
m_lastDragPosition = event->pos() + offset();
viewport()->update();
event->accept();
}
void InstanceView::dragMoveEvent(QDragMoveEvent *event)
{
executeDelayedItemsLayout();
if (!isDragEventAccepted(event))
{
return;
}
m_lastDragPosition = event->pos() + offset();
viewport()->update();
event->accept();
}
void InstanceView::dragLeaveEvent(QDragLeaveEvent *event)
{
executeDelayedItemsLayout();
m_lastDragPosition = QPoint();
viewport()->update();
}
void InstanceView::dropEvent(QDropEvent *event)
{
executeDelayedItemsLayout();
m_lastDragPosition = QPoint();
stopAutoScroll();
setState(NoState);
auto mimedata = event->mimeData();
if (event->source() == this)
{
if(event->possibleActions() & Qt::MoveAction)
{
QPair<VisualGroup *, VisualGroup::HitResults> dropPos = rowDropPos(event->pos());
const VisualGroup *group = dropPos.first;
auto hitresult = dropPos.second;
if (hitresult == VisualGroup::HitResult::NoHit)
{
viewport()->update();
return;
}
auto instanceId = QString::fromUtf8(mimedata->data("application/x-instanceid"));
auto instanceList = APPLICATION->instances().get();
instanceList->setInstanceGroup(instanceId, group->text);
event->setDropAction(Qt::MoveAction);
event->accept();
updateGeometries();
viewport()->update();
}
return;
}
// check if the action is supported
if (!mimedata)
{
return;
}
// files dropped from outside?
if (mimedata->hasUrls())
{
auto urls = mimedata->urls();
event->accept();
emit droppedURLs(urls);
}
}
void InstanceView::startDrag(Qt::DropActions supportedActions)
{
executeDelayedItemsLayout();
QModelIndexList indexes = selectionModel()->selectedIndexes();
if(indexes.count() == 0)
return;
QMimeData *data = model()->mimeData(indexes);
if (!data)
{
return;
}
QRect rect;
QPixmap pixmap = renderToPixmap(indexes, &rect);
QDrag *drag = new QDrag(this);
drag->setPixmap(pixmap);
drag->setMimeData(data);
drag->setHotSpot(m_pressedPosition - rect.topLeft());
Qt::DropAction defaultDropAction = Qt::IgnoreAction;
if (this->defaultDropAction() != Qt::IgnoreAction && (supportedActions & this->defaultDropAction()))
{
defaultDropAction = this->defaultDropAction();
}
/*auto action = */
drag->exec(supportedActions, defaultDropAction);
}
QRect InstanceView::visualRect(const QModelIndex &index) const
{
const_cast<InstanceView*>(this)->executeDelayedItemsLayout();
return geometryRect(index).translated(-offset());
}
QRect InstanceView::geometryRect(const QModelIndex &index) const
{
const_cast<InstanceView*>(this)->executeDelayedItemsLayout();
if (!index.isValid() || isIndexHidden(index) || index.column() > 0)
{
return QRect();
}
int row = index.row();
if(geometryCache.contains(row))
{
return *geometryCache[row];
}
const VisualGroup *cat = category(index);
QPair<int, int> pos = cat->positionOf(index);
int x = pos.first;
// int y = pos.second;
QRect out;
out.setTop(cat->verticalPosition() + cat->headerHeight() + 5 + cat->rowTopOf(index));
out.setLeft(m_spacing + x * (itemWidth() + m_spacing));
out.setSize(itemDelegate()->sizeHint(viewOptions(), index));
geometryCache.insert(row, new QRect(out));
return out;
}
QModelIndex InstanceView::indexAt(const QPoint &point) const
{
const_cast<InstanceView*>(this)->executeDelayedItemsLayout();
for (int i = 0; i < model()->rowCount(); ++i)
{
QModelIndex index = model()->index(i, 0);
if (visualRect(index).contains(point))
{
return index;
}
}
return QModelIndex();
}
void InstanceView::setSelection(const QRect &rect, const QItemSelectionModel::SelectionFlags commands)
{
executeDelayedItemsLayout();
for (int i = 0; i < model()->rowCount(); ++i)
{
QModelIndex index = model()->index(i, 0);
QRect itemRect = visualRect(index);
if (itemRect.intersects(rect))
{
selectionModel()->select(index, commands);
update(itemRect.translated(-offset()));
}
}
}
QPixmap InstanceView::renderToPixmap(const QModelIndexList &indices, QRect *r) const
{
Q_ASSERT(r);
auto paintPairs = draggablePaintPairs(indices, r);
if (paintPairs.isEmpty())
{
return QPixmap();
}
QPixmap pixmap(r->size());
pixmap.fill(Qt::transparent);
QPainter painter(&pixmap);
QStyleOptionViewItem option = viewOptions();
option.state |= QStyle::State_Selected;
for (int j = 0; j < paintPairs.count(); ++j)
{
option.rect = paintPairs.at(j).first.translated(-r->topLeft());
const QModelIndex &current = paintPairs.at(j).second;
itemDelegate()->paint(&painter, option, current);
}
return pixmap;
}
QList<QPair<QRect, QModelIndex>> InstanceView::draggablePaintPairs(const QModelIndexList &indices, QRect *r) const
{
Q_ASSERT(r);
QRect &rect = *r;
QList<QPair<QRect, QModelIndex>> ret;
for (int i = 0; i < indices.count(); ++i)
{
const QModelIndex &index = indices.at(i);
const QRect current = geometryRect(index);
ret += qMakePair(current, index);
rect |= current;
}
return ret;
}
bool InstanceView::isDragEventAccepted(QDropEvent *event)
{
return true;
}
QPair<VisualGroup *, VisualGroup::HitResults> InstanceView::rowDropPos(const QPoint &pos)
{
VisualGroup::HitResults hitresult;
auto group = categoryAt(pos + offset(), hitresult);
return qMakePair<VisualGroup*, int>(group, hitresult);
}
QPoint InstanceView::offset() const
{
return QPoint(horizontalOffset(), verticalOffset());
}
QRegion InstanceView::visualRegionForSelection(const QItemSelection &selection) const
{
QRegion region;
for (auto &range : selection)
{
int start_row = range.top();
int end_row = range.bottom();
for (int row = start_row; row <= end_row; ++row)
{
int start_column = range.left();
int end_column = range.right();
for (int column = start_column; column <= end_column; ++column)
{
QModelIndex index = model()->index(row, column, rootIndex());
region += visualRect(index); // OK
}
}
}
return region;
}
QModelIndex InstanceView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers)
{
auto current = currentIndex();
if(!current.isValid())
{
return current;
}
auto cat = category(current);
int group_index = m_groups.indexOf(cat);
if(group_index < 0)
return current;
QPair<int, int> pos = cat->positionOf(current);
int column = pos.first;
int row = pos.second;
if(m_currentCursorColumn < 0)
{
m_currentCursorColumn = column;
}
switch(cursorAction)
{
case MoveUp:
{
if(row == 0)
{
int prevgroupindex = group_index-1;
while(prevgroupindex >= 0)
{
auto prevgroup = m_groups[prevgroupindex];
if(prevgroup->collapsed)
{
prevgroupindex--;
continue;
}
int newRow = prevgroup->numRows() - 1;
int newRowSize = prevgroup->rows[newRow].size();
int newColumn = m_currentCursorColumn;
if (m_currentCursorColumn >= newRowSize)
{
newColumn = newRowSize - 1;
}
return prevgroup->rows[newRow][newColumn];
}
}
else
{
int newRow = row - 1;
int newRowSize = cat->rows[newRow].size();
int newColumn = m_currentCursorColumn;
if (m_currentCursorColumn >= newRowSize)
{
newColumn = newRowSize - 1;
}
return cat->rows[newRow][newColumn];
}
return current;
}
case MoveDown:
{
if(row == cat->rows.size() - 1)
{
int nextgroupindex = group_index+1;
while (nextgroupindex < m_groups.size())
{
auto nextgroup = m_groups[nextgroupindex];
if(nextgroup->collapsed)
{
nextgroupindex++;
continue;
}
int newRowSize = nextgroup->rows[0].size();
int newColumn = m_currentCursorColumn;
if (m_currentCursorColumn >= newRowSize)
{
newColumn = newRowSize - 1;
}
return nextgroup->rows[0][newColumn];
}
}
else
{
int newRow = row + 1;
int newRowSize = cat->rows[newRow].size();
int newColumn = m_currentCursorColumn;
if (m_currentCursorColumn >= newRowSize)
{
newColumn = newRowSize - 1;
}
return cat->rows[newRow][newColumn];
}
return current;
}
case MoveLeft:
{
if(column > 0)
{
m_currentCursorColumn = column - 1;
return cat->rows[row][column - 1];
}
// TODO: moving to previous line
return current;
}
case MoveRight:
{
if(column < cat->rows[row].size() - 1)
{
m_currentCursorColumn = column + 1;
return cat->rows[row][column + 1];
}
// TODO: moving to next line
return current;
}
case MoveHome:
{
m_currentCursorColumn = 0;
return cat->rows[row][0];
}
case MoveEnd:
{
auto last = cat->rows[row].size() - 1;
m_currentCursorColumn = last;
return cat->rows[row][last];
}
default:
break;
}
return current;
}
int InstanceView::horizontalOffset() const
{
return horizontalScrollBar()->value();
}
int InstanceView::verticalOffset() const
{
return verticalScrollBar()->value();
}
void InstanceView::scrollContentsBy(int dx, int dy)
{
scrollDirtyRegion(dx, dy);
viewport()->scroll(dx, dy);
}
void InstanceView::scrollTo(const QModelIndex &index, ScrollHint hint)
{
if (!index.isValid())
return;
const QRect rect = visualRect(index);
if (hint == EnsureVisible && viewport()->rect().contains(rect))
{
viewport()->update(rect);
return;
}
verticalScrollBar()->setValue(verticalScrollToValue(index, rect, hint));
}
int InstanceView::verticalScrollToValue(const QModelIndex &index, const QRect &rect, QListView::ScrollHint hint) const
{
const QRect area = viewport()->rect();
const bool above = (hint == QListView::EnsureVisible && rect.top() < area.top());
const bool below = (hint == QListView::EnsureVisible && rect.bottom() > area.bottom());
int verticalValue = verticalScrollBar()->value();
QRect adjusted = rect.adjusted(-spacing(), -spacing(), spacing(), spacing());
if (hint == QListView::PositionAtTop || above)
verticalValue += adjusted.top();
else if (hint == QListView::PositionAtBottom || below)
verticalValue += qMin(adjusted.top(), adjusted.bottom() - area.height() + 1);
else if (hint == QListView::PositionAtCenter)
verticalValue += adjusted.top() - ((area.height() - adjusted.height()) / 2);
return verticalValue;
}