GNOME Bugzilla – Bug 703253
Unable to specify CSS transition based on start and end state
Last modified: 2018-04-15 00:11:03 UTC
GTK+'s CSS theming doesn't provide a way to specify transitions according to beginning and end states. Instead, each style class can have a transition associated with it, and it is triggered whenever that style is applied. The problem is that, in order to use CSS transitions, we need to specify which transition should be used depending on the start and end point. For example: insensitive button > sensitive button : fast transition sensitive button > hovered button : slow transition insensitive button > hovered button : fast transition Without this specificity, it's not really possible to make use of CSS transitions. https://mail.gnome.org/archives/gtk-devel-list/2013-May/msg00043.html
It's worth checking with Lapo and Jakub about whether this bug is needed, since I think that they are using CSS transitions in Adwaita now.
Hi all - is this still a problem? Transitions can be applied to any property by any selector, so my guess is that the requested patterns can be done - though in reality the themes use 200 ms for transitions everywhere or near-as.
As announced a while ago, we are migrating to gitlab, and bugs that haven't seen activity in the last year or so will be not be migrated, but closed out in bugzilla. If this bug is still relevant to you, you can open a new issue describing the symptoms and how to reproduce it with gtk 3.22.x or master in gitlab: https://gitlab.gnome.org/GNOME/gtk/issues/new