summaryrefslogtreecommitdiffstats
path: root/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp')
-rw-r--r--examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp140
1 files changed, 65 insertions, 75 deletions
diff --git a/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp b/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp
index a1431db0d3..bbe694831d 100644
--- a/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp
+++ b/examples/corelib/threads/mandelbrot/mandelbrotwidget.cpp
@@ -1,68 +1,23 @@
-/****************************************************************************
-**
-** Copyright (C) 2021 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.
-** * 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 The Qt Company Ltd 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."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "mandelbrotwidget.h"
-#include <QPainter>
+#include <QGesture>
+#include <QGestureEvent>
#include <QKeyEvent>
+#include <QPainter>
#include <math.h>
//! [0]
-const double DefaultCenterX = -0.637011;
-const double DefaultCenterY = -0.0395159;
-const double DefaultScale = 0.00403897;
+constexpr double DefaultCenterX = -0.637011;
+constexpr double DefaultCenterY = -0.0395159;
+constexpr double DefaultScale = 0.00403897;
-const double ZoomInFactor = 0.8;
-const double ZoomOutFactor = 1 / ZoomInFactor;
-const int ScrollStep = 20;
+constexpr double ZoomInFactor = 0.8;
+constexpr double ZoomOutFactor = 1 / ZoomInFactor;
+constexpr int ScrollStep = 20;
//! [0]
//! [1]
@@ -73,8 +28,7 @@ MandelbrotWidget::MandelbrotWidget(QWidget *parent) :
pixmapScale(DefaultScale),
curScale(DefaultScale)
{
- help = tr("Use mouse wheel or the '+' and '-' keys to zoom. "
- "Press and hold left mouse button to scroll.");
+ help = tr("Zoom with mouse wheel, +/- keys or pinch. Scroll with arrow keys or by dragging.");
connect(&thread, &RenderThread::renderedImage,
this, &MandelbrotWidget::updatePixmap);
@@ -93,7 +47,8 @@ void MandelbrotWidget::paintEvent(QPaintEvent * /* event */)
if (pixmap.isNull()) {
painter.setPen(Qt::white);
- painter.drawText(rect(), Qt::AlignCenter, tr("Rendering initial image, please wait..."));
+ painter.drawText(rect(), Qt::AlignCenter|Qt::TextWordWrap,
+ tr("Rendering initial image, please wait..."));
//! [2] //! [3]
return;
//! [3] //! [4]
@@ -107,37 +62,51 @@ void MandelbrotWidget::paintEvent(QPaintEvent * /* event */)
//! [6] //! [7]
} else {
//! [7] //! [8]
- auto previewPixmap = qFuzzyCompare(pixmap.devicePixelRatio(), qreal(1))
+ const auto previewPixmap = qFuzzyCompare(pixmap.devicePixelRatio(), qreal(1))
? pixmap
: pixmap.scaled(pixmap.deviceIndependentSize().toSize(), Qt::KeepAspectRatio,
Qt::SmoothTransformation);
- double scaleFactor = pixmapScale / curScale;
- int newWidth = int(previewPixmap.width() * scaleFactor);
- int newHeight = int(previewPixmap.height() * scaleFactor);
- int newX = pixmapOffset.x() + (previewPixmap.width() - newWidth) / 2;
- int newY = pixmapOffset.y() + (previewPixmap.height() - newHeight) / 2;
+ const double scaleFactor = pixmapScale / curScale;
+ const int newWidth = int(previewPixmap.width() * scaleFactor);
+ const int newHeight = int(previewPixmap.height() * scaleFactor);
+ const int newX = pixmapOffset.x() + (previewPixmap.width() - newWidth) / 2;
+ const int newY = pixmapOffset.y() + (previewPixmap.height() - newHeight) / 2;
painter.save();
painter.translate(newX, newY);
painter.scale(scaleFactor, scaleFactor);
- QRectF exposed = painter.transform().inverted().mapRect(rect()).adjusted(-1, -1, 1, 1);
+ const QRectF exposed = painter.transform().inverted().mapRect(rect())
+ .adjusted(-1, -1, 1, 1);
painter.drawPixmap(exposed, previewPixmap, exposed);
painter.restore();
}
//! [8] //! [9]
- QString text = help;
- if (!info.isEmpty())
- text += ' ' + info;
- QFontMetrics metrics = painter.fontMetrics();
- int textWidth = metrics.horizontalAdvance(text);
+ const QFontMetrics metrics = painter.fontMetrics();
+ if (!info.isEmpty()){
+ const int infoWidth = metrics.horizontalAdvance(info);
+ const int infoHeight = (infoWidth/width() + 1) * (metrics.height() + 5);
+
+ painter.setPen(Qt::NoPen);
+ painter.setBrush(QColor(0, 0, 0, 127));
+ painter.drawRect((width() - infoWidth) / 2 - 5, 0, infoWidth + 10, infoHeight);
+
+ painter.setPen(Qt::white);
+ painter.drawText(rect(), Qt::AlignHCenter|Qt::AlignTop|Qt::TextWordWrap, info);
+ }
+
+ const int helpWidth = metrics.horizontalAdvance(help);
+ const int helpHeight = (helpWidth/width() + 1) * (metrics.height() + 5);
painter.setPen(Qt::NoPen);
painter.setBrush(QColor(0, 0, 0, 127));
- painter.drawRect((width() - textWidth) / 2 - 5, 0, textWidth + 10, metrics.lineSpacing() + 5);
+ painter.drawRect((width() - helpWidth) / 2 - 5, height()-helpHeight, helpWidth + 10,
+ helpHeight);
+
painter.setPen(Qt::white);
- painter.drawText((width() - textWidth) / 2, metrics.leading() + metrics.ascent(), text);
+ painter.drawText(rect(), Qt::AlignHCenter|Qt::AlignBottom|Qt::TextWordWrap, help);
+
}
//! [9]
@@ -217,8 +186,8 @@ void MandelbrotWidget::mouseReleaseEvent(QMouseEvent *event)
lastDragPos = QPoint();
const auto pixmapSize = pixmap.deviceIndependentSize().toSize();
- int deltaX = (width() - pixmapSize.width()) / 2 - pixmapOffset.x();
- int deltaY = (height() - pixmapSize.height()) / 2 - pixmapOffset.y();
+ const int deltaX = (width() - pixmapSize.width()) / 2 - pixmapOffset.x();
+ const int deltaY = (height() - pixmapSize.height()) / 2 - pixmapOffset.y();
scroll(deltaX, deltaY);
}
}
@@ -258,3 +227,24 @@ void MandelbrotWidget::scroll(int deltaX, int deltaY)
thread.render(centerX, centerY, curScale, size(), devicePixelRatio());
}
//! [18]
+
+//! [gesture1]
+#ifndef QT_NO_GESTURES
+bool MandelbrotWidget::gestureEvent(QGestureEvent *event)
+{
+ if (auto *pinch = static_cast<QPinchGesture *>(event->gesture(Qt::PinchGesture))) {
+ if (pinch->changeFlags().testFlag(QPinchGesture::ScaleFactorChanged))
+ zoom(1.0 / pinch->scaleFactor());
+ return true;
+ }
+ return false;
+}
+
+bool MandelbrotWidget::event(QEvent *event)
+{
+ if (event->type() == QEvent::Gesture)
+ return gestureEvent(static_cast<QGestureEvent*>(event));
+ return QWidget::event(event);
+}
+#endif
+//! [gesture1]