Reading and Writing Image Files

Scalable Vector Graphics (SVG) is a language for describing two-dimensional graphics and graphical applications in XML. SVG 1.1 is a W3C Recommendation and forms the core of the current SVG developments in Qt. SVG 1.2 is the specification currently being developed by the SVG Working Group, and it is available in draft form. The Mobile SVG Profiles (SVG Basic and SVG Tiny) are aimed at resource-limited devices and are part of the 3GPP platform for third generation mobile phones. You can read more about SVG at About SVG.

Qt supports the static features of SVG 1.2 Tiny. ECMA scripts and DOM manipulation are currently not supported.

SVG drawings can be rendered onto any QPaintDevice subclass. This approach gives developers the flexibility to experiment, in order to find the best solution for each application.

The easiest way to render SVG files is to construct a QSvgWidget and load an SVG file using one of the QSvgWidget::load() functions.

QSvgRenderer is the class responsible for rendering SVG files for QSvgWidget, and it can be used directly to provide SVG support for custom widgets. To load an SVG file, construct a QSvgRenderer with a file name or the contents of a file, or call QSvgRenderer::load() on an existing renderer. If the SVG file has been loaded successfully the QSvgRenderer::isValid() will return true.

Once you have loaded the SVG file successfully, you can render it with the QSvgRenderer::render() function. Note that this scheme allows you to render SVG files on all paint devices supported by Qt, including QWidget, QGLWidget, and QImage. See the SVG Viewer example for more details.