qt5base-lts/examples/tools/plugandpaint/paintarea.cpp

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/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
** the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written
** permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
** $QT_END_LICENSE$
**
****************************************************************************/
#include "interfaces.h"
#include "paintarea.h"
#include <QPainter>
#include <QMouseEvent>
PaintArea::PaintArea(QWidget *parent) :
QWidget(parent),
theImage(500, 400, QImage::Format_RGB32),
color(Qt::blue),
thickness(3),
brushInterface(0),
lastPos(-1, -1)
{
setAttribute(Qt::WA_StaticContents);
setAttribute(Qt::WA_NoBackground);
theImage.fill(qRgb(255, 255, 255));
}
bool PaintArea::openImage(const QString &fileName)
{
QImage image;
if (!image.load(fileName))
return false;
setImage(image);
return true;
}
bool PaintArea::saveImage(const QString &fileName, const char *fileFormat)
{
return theImage.save(fileName, fileFormat);
}
void PaintArea::setImage(const QImage &image)
{
theImage = image.convertToFormat(QImage::Format_RGB32);
update();
updateGeometry();
}
void PaintArea::insertShape(const QPainterPath &path)
{
pendingPath = path;
#ifndef QT_NO_CURSOR
setCursor(Qt::CrossCursor);
#endif
}
void PaintArea::setBrushColor(const QColor &color)
{
this->color = color;
}
void PaintArea::setBrushWidth(int width)
{
thickness = width;
}
//! [0]
void PaintArea::setBrush(BrushInterface *brushInterface, const QString &brush)
{
this->brushInterface = brushInterface;
this->brush = brush;
}
//! [0]
QSize PaintArea::sizeHint() const
{
return theImage.size();
}
void PaintArea::paintEvent(QPaintEvent * /* event */)
{
QPainter painter(this);
painter.drawImage(QPoint(0, 0), theImage);
}
void PaintArea::mousePressEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton) {
if (!pendingPath.isEmpty()) {
QPainter painter(&theImage);
setupPainter(painter);
const QRectF boundingRect = pendingPath.boundingRect();
QLinearGradient gradient(boundingRect.topRight(),
boundingRect.bottomLeft());
gradient.setColorAt(0.0, QColor(color.red(), color.green(),
color.blue(), 63));
gradient.setColorAt(1.0, QColor(color.red(), color.green(),
color.blue(), 191));
painter.setBrush(gradient);
painter.translate(event->pos() - boundingRect.center());
painter.drawPath(pendingPath);
pendingPath = QPainterPath();
#ifndef QT_NO_CURSOR
unsetCursor();
#endif
update();
} else {
if (brushInterface) {
QPainter painter(&theImage);
setupPainter(painter);
const QRect rect = brushInterface->mousePress(brush, painter,
event->pos());
update(rect);
}
lastPos = event->pos();
}
}
}
//! [1]
void PaintArea::mouseMoveEvent(QMouseEvent *event)
{
if ((event->buttons() & Qt::LeftButton) && lastPos != QPoint(-1, -1)) {
if (brushInterface) {
QPainter painter(&theImage);
setupPainter(painter);
const QRect rect = brushInterface->mouseMove(brush, painter, lastPos,
event->pos());
update(rect);
}
lastPos = event->pos();
}
}
//! [1]
void PaintArea::mouseReleaseEvent(QMouseEvent *event)
{
if (event->button() == Qt::LeftButton && lastPos != QPoint(-1, -1)) {
if (brushInterface) {
QPainter painter(&theImage);
setupPainter(painter);
QRect rect = brushInterface->mouseRelease(brush, painter,
event->pos());
update(rect);
}
lastPos = QPoint(-1, -1);
}
}
void PaintArea::setupPainter(QPainter &painter)
{
painter.setRenderHint(QPainter::Antialiasing, true);
painter.setPen(QPen(color, thickness, Qt::SolidLine, Qt::RoundCap,
Qt::RoundJoin));
}