--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/threads/mandelbrot/mandelbrotwidget.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,240 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include <math.h>
+
+#include "mandelbrotwidget.h"
+
+//! [0]
+const double DefaultCenterX = -0.637011f;
+const double DefaultCenterY = -0.0395159f;
+const double DefaultScale = 0.00403897f;
+
+const double ZoomInFactor = 0.8f;
+const double ZoomOutFactor = 1 / ZoomInFactor;
+const int ScrollStep = 20;
+//! [0]
+
+//! [1]
+MandelbrotWidget::MandelbrotWidget(QWidget *parent)
+ : QWidget(parent)
+{
+ centerX = DefaultCenterX;
+ centerY = DefaultCenterY;
+ pixmapScale = DefaultScale;
+ curScale = DefaultScale;
+
+ qRegisterMetaType<QImage>("QImage");
+ connect(&thread, SIGNAL(renderedImage(const QImage &, double)),
+ this, SLOT(updatePixmap(const QImage &, double)));
+
+ setWindowTitle(tr("Mandelbrot"));
+#ifndef QT_NO_CURSOR
+ setCursor(Qt::CrossCursor);
+#endif
+ resize(550, 400);
+}
+//! [1]
+
+//! [2]
+void MandelbrotWidget::paintEvent(QPaintEvent * /* event */)
+{
+ QPainter painter(this);
+ painter.fillRect(rect(), Qt::black);
+
+ if (pixmap.isNull()) {
+ painter.setPen(Qt::white);
+ painter.drawText(rect(), Qt::AlignCenter,
+ tr("Rendering initial image, please wait..."));
+//! [2] //! [3]
+ return;
+//! [3] //! [4]
+ }
+//! [4]
+
+//! [5]
+ if (curScale == pixmapScale) {
+//! [5] //! [6]
+ painter.drawPixmap(pixmapOffset, pixmap);
+//! [6] //! [7]
+ } else {
+//! [7] //! [8]
+ double scaleFactor = pixmapScale / curScale;
+ int newWidth = int(pixmap.width() * scaleFactor);
+ int newHeight = int(pixmap.height() * scaleFactor);
+ int newX = pixmapOffset.x() + (pixmap.width() - newWidth) / 2;
+ int newY = pixmapOffset.y() + (pixmap.height() - newHeight) / 2;
+
+ painter.save();
+ painter.translate(newX, newY);
+ painter.scale(scaleFactor, scaleFactor);
+ QRectF exposed = painter.matrix().inverted().mapRect(rect()).adjusted(-1, -1, 1, 1);
+ painter.drawPixmap(exposed, pixmap, exposed);
+ painter.restore();
+ }
+//! [8] //! [9]
+
+ QString text = tr("Use mouse wheel or the '+' and '-' keys to zoom. "
+ "Press and hold left mouse button to scroll.");
+ QFontMetrics metrics = painter.fontMetrics();
+ int textWidth = metrics.width(text);
+
+ painter.setPen(Qt::NoPen);
+ painter.setBrush(QColor(0, 0, 0, 127));
+ painter.drawRect((width() - textWidth) / 2 - 5, 0, textWidth + 10,
+ metrics.lineSpacing() + 5);
+ painter.setPen(Qt::white);
+ painter.drawText((width() - textWidth) / 2,
+ metrics.leading() + metrics.ascent(), text);
+}
+//! [9]
+
+//! [10]
+void MandelbrotWidget::resizeEvent(QResizeEvent * /* event */)
+{
+ thread.render(centerX, centerY, curScale, size());
+}
+//! [10]
+
+//! [11]
+void MandelbrotWidget::keyPressEvent(QKeyEvent *event)
+{
+ switch (event->key()) {
+ case Qt::Key_Plus:
+ zoom(ZoomInFactor);
+ break;
+ case Qt::Key_Minus:
+ zoom(ZoomOutFactor);
+ break;
+ case Qt::Key_Left:
+ scroll(-ScrollStep, 0);
+ break;
+ case Qt::Key_Right:
+ scroll(+ScrollStep, 0);
+ break;
+ case Qt::Key_Down:
+ scroll(0, -ScrollStep);
+ break;
+ case Qt::Key_Up:
+ scroll(0, +ScrollStep);
+ break;
+ default:
+ QWidget::keyPressEvent(event);
+ }
+}
+//! [11]
+
+//! [12]
+void MandelbrotWidget::wheelEvent(QWheelEvent *event)
+{
+ int numDegrees = event->delta() / 8;
+ double numSteps = numDegrees / 15.0f;
+ zoom(pow(ZoomInFactor, numSteps));
+}
+//! [12]
+
+//! [13]
+void MandelbrotWidget::mousePressEvent(QMouseEvent *event)
+{
+ if (event->button() == Qt::LeftButton)
+ lastDragPos = event->pos();
+}
+//! [13]
+
+//! [14]
+void MandelbrotWidget::mouseMoveEvent(QMouseEvent *event)
+{
+ if (event->buttons() & Qt::LeftButton) {
+ pixmapOffset += event->pos() - lastDragPos;
+ lastDragPos = event->pos();
+ update();
+ }
+}
+//! [14]
+
+//! [15]
+void MandelbrotWidget::mouseReleaseEvent(QMouseEvent *event)
+{
+ if (event->button() == Qt::LeftButton) {
+ pixmapOffset += event->pos() - lastDragPos;
+ lastDragPos = QPoint();
+
+ int deltaX = (width() - pixmap.width()) / 2 - pixmapOffset.x();
+ int deltaY = (height() - pixmap.height()) / 2 - pixmapOffset.y();
+ scroll(deltaX, deltaY);
+ }
+}
+//! [15]
+
+//! [16]
+void MandelbrotWidget::updatePixmap(const QImage &image, double scaleFactor)
+{
+ if (!lastDragPos.isNull())
+ return;
+
+ pixmap = QPixmap::fromImage(image);
+ pixmapOffset = QPoint();
+ lastDragPos = QPoint();
+ pixmapScale = scaleFactor;
+ update();
+}
+//! [16]
+
+//! [17]
+void MandelbrotWidget::zoom(double zoomFactor)
+{
+ curScale *= zoomFactor;
+ update();
+ thread.render(centerX, centerY, curScale, size());
+}
+//! [17]
+
+//! [18]
+void MandelbrotWidget::scroll(int deltaX, int deltaY)
+{
+ centerX += deltaX * curScale;
+ centerY += deltaY * curScale;
+ update();
+ thread.render(centerX, centerY, curScale, size());
+}
+//! [18]