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+/*!
+\example painting/svggenerator
+\title SVG Generator Example
+The SVG Generator example shows how to add SVG file export to applications.
+\image svggenerator-example.png
+Scalable Vector Graphics (SVG) is an XML-based language for describing
+two-dimensional vector graphics. Qt provides classes for rendering and
+generating SVG drawings. This example allows the user to create a simple
+picture and save it to an SVG file.
+The example consists of two classes: \c Window and \c DisplayWidget.
+The \c Window class contains the application logic and constructs the user
+interface from a Qt Designer UI file as described in the
+\l{Using a Designer UI File in Your Application#The Multiple Inheritance Approach}{Qt Designer manual}.
+It also contains the code to write an SVG file.
+The \c DisplayWidget class performs all the work of painting a picture on
+screen. Since we want the SVG to resemble this picture as closely as
+possible, we make this code available to the \c Window class so that it can
+be used to generate SVG files.
+\section1 The DisplayWidget Class
+The \c DisplayWidget class displays a drawing consisting of a selection of
+elements chosen by the user. These are defined using \c Shape and
+\c Background enums that are included within the class definition:
+\snippet examples/painting/svggenerator/displaywidget.h DisplayWidget class definition
+Much of this class is used to configure the appearance of the drawing. The
+\c paintEvent() and \c paint() functions are most relevant to the purpose
+of this example, so we will describe these here and leave the reader to
+look at the source code for the example to see how shapes and colors are
+handled.
+We reimplement the QWidget::paintEvent() function to display the drawing
+on screen:
+\snippet examples/painting/svggenerator/displaywidget.cpp paint event
+Here, we only construct a QPainter object, begin painting on the device
+and set a render hint for improved output quality before calling the
+\c paint() function to perform the painting itself. When this returns,
+we close the painter and return.
+The \c paint() function is designed to be used for different painting
+tasks. In this example, we use it to draw on a \c DisplayWidget instance
+and on a QSvgGenerator object. We show how the painting is performed to
+demonstrate that there is nothing device-specific about the process:
+\snippet examples/painting/svggenerator/displaywidget.cpp paint function
+\section1 The Window Class
+The \c Window class represents the example's window, containing the user
+interface, which has been created using Qt Designer:
+\snippet examples/painting/svggenerator/window.h Window class definition
+As with the \c DisplayWidget class, we concentrate on the parts of the code
+which are concerned with painting and SVG generation. In the \c Window
+class, the \c saveSvg() function is called whenever the \gui{Save As...}
+button is clicked; this connection was defined in the \c{window.ui} file
+using Qt Designer.
+The start of the \c saveSvg() function performs the task of showing a file
+dialog so that the user can specify a SVG file to save the drawing to.
+\snippet examples/painting/svggenerator/window.cpp save SVG
+In the rest of the function, we set up the generator and configure it to
+generate output with the appropriate dimensions and write to the
+user-specified file. We paint on the QSvgGenerator object in the same way
+that we paint on a widget, calling the \c DisplayWidget::paint() function
+so that we use exactly the same code that we used to display the drawing.
+The generation process itself begins with the call to the painter's
+\l{QPainter::}{begin()} function and ends with call to its
+\l{QPainter::}{end()} function. The QSvgGenerator paint device relies on
+the explicit use of these functions to ensure that output is written to
+the file.
+\section1 Further Reading
+The \l{SVG Viewer Example} shows how to display SVG drawings in an
+application, and can be used to show the contents of SVG files created
+by this example.
+See the QtSvg module documentation for more information about SVG and Qt's
+SVG classes.
+*/