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Diffstat (limited to 'doc/src/snippets/myscrollarea.cpp')
-rw-r--r-- | doc/src/snippets/myscrollarea.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/doc/src/snippets/myscrollarea.cpp b/doc/src/snippets/myscrollarea.cpp new file mode 100644 index 0000000..6cb1233 --- /dev/null +++ b/doc/src/snippets/myscrollarea.cpp @@ -0,0 +1,129 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QtGui> + +class MyScrollArea : public QAbstractScrollArea +{ +public: + MyScrollArea(QWidget *w); + void setWidget(QWidget *w); + +protected: + void scrollContentsBy(int dx, int dy); + void resizeEvent(QResizeEvent *event); + +private: + void updateWidgetPosition(); + void updateArea(); + + QWidget *widget; +}; + +MyScrollArea::MyScrollArea(QWidget *widget) + : QAbstractScrollArea() +{ + setWidget(widget); +} + +void MyScrollArea::setWidget(QWidget *w) +{ + widget = w; + widget->setParent(viewport()); + if (!widget->testAttribute(Qt::WA_Resized)) + widget->resize(widget->sizeHint()); + + verticalScrollBar()->setValue(0); + verticalScrollBar()->setValue(0); + + updateArea(); +} + +void MyScrollArea::updateWidgetPosition() +{ +//! [0] + int hvalue = horizontalScrollBar()->value(); + int vvalue = verticalScrollBar()->value(); + QPoint topLeft = viewport()->rect().topLeft(); + + widget->move(topLeft.x() - hvalue, topLeft.y() - vvalue); +//! [0] +} + +void MyScrollArea::scrollContentsBy(int /*dx*/, int /*dy*/) +{ + updateWidgetPosition(); +} + +void MyScrollArea::updateArea() +{ +//! [1] + QSize areaSize = viewport()->size(); + QSize widgetSize = widget->size(); + + verticalScrollBar()->setPageStep(widgetSize.height()); + horizontalScrollBar()->setPageStep(widgetSize.width()); + verticalScrollBar()->setRange(0, widgetSize.height() - areaSize.height()); + horizontalScrollBar()->setRange(0, widgetSize.width() - areaSize.width()); + updateWidgetPosition(); +//! [1] +} + +void MyScrollArea::resizeEvent(QResizeEvent *event) +{ + updateArea(); +} + +int main(int argv, char **args) +{ + QApplication app(argv, args); + + QPixmap pixmap("mypixmap.png"); + QLabel label; + label.setPixmap(pixmap); + MyScrollArea area(&label); + area.resize(300, 300); + area.show(); + + area.setWidget(&label); + + return app.exec(); +} |