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/****************************************************************************
**
** Copyright (C) 2014 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.io
**
** This file is part of the Qt Charts module.
**
** Licensees holding valid commercial license for Qt may use this file in
** accordance with the Qt License Agreement provided with the Software
** or, alternatively, in accordance with the terms contained in a written
** agreement between you and Digia.
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.io
**
****************************************************************************/
/*!
\example qmloscilloscope
\title QML Oscilloscope
\ingroup qtcharts_examples
\image examples_qmloscilloscope.png
\brief The example shows how to implement application with strict performance requirements
using the Qt Charts QML API.
The oscilloscope application demonstrates how to use the Qt Charts QML API to implement an
application with strict performance requirements. The application uses generated data with
configurable characteristics to mimic a simple oscilloscope user interface. To find out the
actual screen refresh performance of the application, you can set QML_SHOW_FRAMERATE = 1 to
your run environment settings to get the framerate shown in the application output console.
To do so go to Projects - Run - Run environment in Qt Creator and select Add. Then you can
experiment with the different configurable options of the example application to find the
configuration that gives you the best performance in your environment.
Note: You can try if enabling OpenGL improves the performance with the following startup
parameter:
\code
-graphicssystem opengl
\endcode
The application window is shared by control and scope views:
\snippet qmloscilloscope/qml/qmloscilloscope/main.qml 1
\dots
\snippet qmloscilloscope/qml/qmloscilloscope/main.qml 2
ControlView implements the buttons used for configuring. ScopeView uses a ChartView to show
a chart with two line series:
\snippet qmloscilloscope/qml/qmloscilloscope/ScopeView.qml 1
\dots
The data of the line series is updated with a QML timer. In a real life application the
updating could be triggered with a signal from Qt C++ code.
\snippet qmloscilloscope/qml/qmloscilloscope/ScopeView.qml 2
The oscilloscope also allows you to switch the type of the series used for visualizing the
signal sources. This is implemented by dynamically destroying and creating series:
\snippet qmloscilloscope/qml/qmloscilloscope/ScopeView.qml 3
\note QML_SHOW_FRAMERATE environment variable doesn't work with Qt Quick 2.
From Qt 5.1.0 on, the QSG_RENDER_TIMING environment variable can be used
similarly to display rendering time.
*/
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