dolphin/Source/Core/DolphinQt/QtUtils/ViewScrollLock.cpp

36 lines
1.2 KiB
C++

// Copyright 2024 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include <QAbstractItemModel>
#include <QAbstractItemView>
#include "DolphinQt/QtUtils/ViewScrollLock.h"
ViewScrollLock::ViewScrollLock(QObject* parent, QAbstractItemModel* model, QAbstractItemView* view)
: QObject(parent), m_view(view)
{
connect(model, &QAbstractItemModel::rowsAboutToBeInserted, this,
&ViewScrollLock::AboutToBeModified);
connect(model, &QAbstractItemModel::rowsAboutToBeRemoved, this,
&ViewScrollLock::AboutToBeModified);
connect(model, &QAbstractItemModel::rowsInserted, this, &ViewScrollLock::Modified);
connect(model, &QAbstractItemModel::rowsRemoved, this, &ViewScrollLock::Modified);
}
void ViewScrollLock::AboutToBeModified()
{
QSize size = m_view->size();
m_first = m_view->indexAt(QPoint(0, 0));
m_last = m_view->indexAt(QPoint(size.height(), size.width()));
}
void ViewScrollLock::Modified()
{
// Try to keep the first row at the top.
// If that fails, try to keep the last row at the bottom.
if (m_first.isValid())
m_view->scrollTo(m_first, QAbstractItemView::PositionAtTop);
else if (m_last.isValid())
m_view->scrollTo(m_last, QAbstractItemView::PositionAtBottom);
}