Home · All Classes · All Functions · Overviews

scribblearea.cpp Example File
widgets/scribble/scribblearea.cpp

 /****************************************************************************
 **
 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation ([email protected])
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 ** 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 1.1, 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 have questions regarding the use of this file, please contact
 ** Nokia at [email protected].
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtGui>

 #include "scribblearea.h"

 ScribbleArea::ScribbleArea(QWidget *parent)
     : QWidget(parent)
 {
     setAttribute(Qt::WA_StaticContents);
     modified = false;
     scribbling = false;
     myPenWidth = 1;
     myPenColor = Qt::blue;
 }

 bool ScribbleArea::openImage(const QString &fileName)
 {
     QImage loadedImage;
     if (!loadedImage.load(fileName))
         return false;

     QSize newSize = loadedImage.size().expandedTo(size());
     resizeImage(&loadedImage, newSize);
     image = loadedImage;
     modified = false;
     update();
     return true;
 }

 bool ScribbleArea::saveImage(const QString &fileName, const char *fileFormat)
 {
     QImage visibleImage = image;
     resizeImage(&visibleImage, size());

     if (visibleImage.save(fileName, fileFormat)) {
         modified = false;
         return true;
     } else {
         return false;
     }
 }

 void ScribbleArea::setPenColor(const QColor &newColor)
 {
     myPenColor = newColor;
 }

 void ScribbleArea::setPenWidth(int newWidth)
 {
     myPenWidth = newWidth;
 }

 void ScribbleArea::clearImage()
 {
     image.fill(qRgb(255, 255, 255));
     modified = true;
     update();
 }

 void ScribbleArea::mousePressEvent(QMouseEvent *event)
 {
     if (event->button() == Qt::LeftButton) {
         lastPoint = event->pos();
         scribbling = true;
     }
 }

 void ScribbleArea::mouseMoveEvent(QMouseEvent *event)
 {
     if ((event->buttons() & Qt::LeftButton) && scribbling)
         drawLineTo(event->pos());
 }

 void ScribbleArea::mouseReleaseEvent(QMouseEvent *event)
 {
     if (event->button() == Qt::LeftButton && scribbling) {
         drawLineTo(event->pos());
         scribbling = false;
     }
 }

 void ScribbleArea::paintEvent(QPaintEvent * /* event */)
 {
     QPainter painter(this);
     painter.drawImage(QPoint(0, 0), image);
 }

 void ScribbleArea::resizeEvent(QResizeEvent *event)
 {
     if (width() > image.width() || height() > image.height()) {
         int newWidth = qMax(width() + 128, image.width());
         int newHeight = qMax(height() + 128, image.height());
         resizeImage(&image, QSize(newWidth, newHeight));
         update();
     }
     QWidget::resizeEvent(event);
 }

 void ScribbleArea::drawLineTo(const QPoint &endPoint)
 {
     QPainter painter(&image);
     painter.setPen(QPen(myPenColor, myPenWidth, Qt::SolidLine, Qt::RoundCap,
                         Qt::RoundJoin));
     painter.drawLine(lastPoint, endPoint);
     modified = true;

     int rad = (myPenWidth / 2) + 2;
     update(QRect(lastPoint, endPoint).normalized()
                                      .adjusted(-rad, -rad, +rad, +rad));
     lastPoint = endPoint;
 }

 void ScribbleArea::resizeImage(QImage *image, const QSize &newSize)
 {
     if (image->size() == newSize)
         return;

     QImage newImage(newSize, QImage::Format_RGB32);
     newImage.fill(qRgb(255, 255, 255));
     QPainter painter(&newImage);
     painter.drawImage(QPoint(0, 0), *image);
     *image = newImage;
 }

 void ScribbleArea::print()
 {
 #ifndef QT_NO_PRINTER
     QPrinter printer(QPrinter::HighResolution);

     QPrintDialog *printDialog = new QPrintDialog(&printer, this);
     if (printDialog->exec() == QDialog::Accepted) {
         QPainter painter(&printer);
         QRect rect = painter.viewport();
         QSize size = image.size();
         size.scale(rect.size(), Qt::KeepAspectRatio);
         painter.setViewport(rect.x(), rect.y(), size.width(), size.height());
         painter.setWindow(image.rect());
         painter.drawImage(0, 0, image);
     }
 #endif // QT_NO_PRINTER
 }