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newspark110/ui/qg_scrollbar.h
Chenwenxuan edac2715f0 init
2024-03-06 14:54:30 +08:00

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2.2 KiB
C++

/****************************************************************************
**
** This file is part of the LibreCAD project, a 2D CAD program
**
** Copyright (C) 2010 R. van Twisk (librecad@rvt.dds.nl)
** Copyright (C) 2001-2003 RibbonSoft. All rights reserved.
**
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file gpl-2.0.txt included in the
** packaging of this file.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
**
** This copyright notice MUST APPEAR in all copies of the script!
**
**********************************************************************/
#ifndef QG_SCROLLBAR_H
#define QG_SCROLLBAR_H
#include <QScrollBar>
#include <QWheelEvent>
/**
* A small wrapper for the Qt scrollbar. This class offers a slot
* for scroll events.
*/
class QG_ScrollBar: public QScrollBar {
Q_OBJECT
public:
QG_ScrollBar(QWidget* parent=0)
: QScrollBar(parent) {
sizeHintCache = QScrollBar::sizeHint();
}
QG_ScrollBar(Qt::Orientation orientation,
QWidget* parent=0)
: QScrollBar(orientation, parent) {
sizeHintCache = QScrollBar::sizeHint();
}
// This sizeHint caches the height value. Out of profiling (see #727),
// it appears that sizeHint calls all the way down to the underlying
// windowing system to check the size.
QSize sizeHint() const override final {
return sizeHintCache;
}
public slots:
void slotWheelEvent(QWheelEvent* e) {
wheelEvent(e);
}
void resizeEvent(QResizeEvent* event) override {
sizeHintCache = QScrollBar::sizeHint();
QScrollBar::resizeEvent(event);
}
private:
QSize sizeHintCache;
};
#endif