qt5base-lts/examples/gui/rasterwindow/rasterwindow.cpp
Liang Qi 69ef0481fc Merge remote-tracking branch 'origin/5.6' into 5.7
Conflicts:
	tests/auto/widgets/itemviews/qtreeview/tst_qtreeview.cpp

Change-Id: I6f3878b204464313aa2f9d988d3b35121d4d9867
2016-08-05 08:58:48 +02:00

135 lines
3.9 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
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****************************************************************************/
#include "rasterwindow.h"
//! [1]
RasterWindow::RasterWindow(QWindow *parent)
: QWindow(parent)
, m_update_pending(false)
{
create();
m_backingStore = new QBackingStore(this);
setGeometry(100, 100, 300, 200);
}
//! [1]
//! [7]
bool RasterWindow::event(QEvent *event)
{
if (event->type() == QEvent::UpdateRequest) {
m_update_pending = false;
renderNow();
return true;
}
return QWindow::event(event);
}
//! [7]
//! [6]
void RasterWindow::renderLater()
{
if (!m_update_pending) {
m_update_pending = true;
QCoreApplication::postEvent(this, new QEvent(QEvent::UpdateRequest));
}
}
//! [6]
//! [5]
void RasterWindow::resizeEvent(QResizeEvent *resizeEvent)
{
m_backingStore->resize(resizeEvent->size());
if (isExposed())
renderNow();
}
//! [5]
//! [2]
void RasterWindow::exposeEvent(QExposeEvent *)
{
if (isExposed()) {
renderNow();
}
}
//! [2]
//! [3]
void RasterWindow::renderNow()
{
if (!isExposed())
return;
QRect rect(0, 0, width(), height());
m_backingStore->beginPaint(rect);
QPaintDevice *device = m_backingStore->paintDevice();
QPainter painter(device);
painter.fillRect(0, 0, width(), height(), Qt::white);
render(&painter);
m_backingStore->endPaint();
m_backingStore->flush(rect);
}
//! [3]
//! [4]
void RasterWindow::render(QPainter *painter)
{
painter->drawText(QRectF(0, 0, width(), height()), Qt::AlignCenter, QStringLiteral("QWindow"));
}
//! [4]