Changes in GTK+ 3.22

The CSS parser has gotten a bit more selective in what it accepts as valid values for the font: shorthand. Following the CSS specification, at least a size and a family name are required now. If you want to change an individual facet of the font, like the weight, use the individual CSS properties: font-weight, font-size, font-family, etc.

The CSS parser now warns about some more constructs that are not according to the CSS spec, such as gradients with a single color stop. Instead, you can just use image(<color>).

The “ignore-hidden” property has not been working properly for a long time, and we've not documented it as broken and deprecated. The recommended alternative for reserving space of widgets that are not currently shown in the UI is to use a GtkStack (with some 'filler' widget, e.g. an empty GtkBox, in another page).

GtkScrolledWindow now respects the natural size of its child and passes it along. This may change the size distribution of layouts involving scrolled windows (they may take up more space than before). In most cases, setting suitable values for “max-content-width” and “max-content-height” will allow control over the size of the scrolled window.