paintarea.cpp Example File
tools/plugandpaint/app/paintarea.cpp
#include "interfaces.h"
#include "paintarea.h"
#include <QMouseEvent>
#include <QPainter>
PaintArea::PaintArea(QWidget *parent) :
QWidget(parent)
{
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;
}
void PaintArea::setBrush(BrushInterface *brushInterface, const QString &brush)
{
this->brushInterface = brushInterface;
this->brush = brush;
}
QSize PaintArea::sizeHint() const
{
return theImage.size();
}
void PaintArea::paintEvent(QPaintEvent * )
{
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();
}
}
}
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();
}
}
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));
}