Controlling Cairo Features at Run Time

Foundation > Using Rogue Wave Views on X Window Systems > Using Cairo Features with Rogue Wave Views > Controlling Cairo Features at Run Time

It is possible to specify, through a resource or an environment variable. if you want Cairo to be used. The following table summarizes the possible values and the effect of each:

Cairo Resources
Resource (.ini file)	Environment Variable	Value
UseCairo	ILVUSECAIRO	needed: Cairo is used only when it is needed, for example, when transparency or anti-aliasing is required. This is the default. true: Cairo is used each time it is possible. false: Cairo is never used.

The IlvDisplay class also has a method to indicate whether your application is correctly set to draw using Cairo:

IlvDisplay::isCairoEnabled

Rogue Wave Views GDI+ integration does not support line drawing using gradients. In order for Cairo to use identical rendering to GDI+, the Cairo feature in Rogue Wave Views is set, by default, not to use gradients for line drawings. To force Rogue Wave Views to allow Cairo line drawings using gradients, you can set the following resource or environment variable:

Cairo Resource for line drawing with gradients

Resource (.ini file)	Environment Variable	Value
UseGradientLines	ILVUSEGRADIENTLINES	true: Allow the use of gradients to draw lines.

Version 6.0