Hi; On 12 November 2016 at 19:02, <zahlenm...@gmx.de> wrote: > I am struggling how to translate operators of the form > color = &style->light[GTK_STATE_PRELIGHT]; > into proper Gtk3. The documentation says: > "One notable difference is the reduction from fg/bg/text/base colors to > only foreground/background, in exchange the widget is able to render its > various elements with different CSS classes, which can be themed > independently."
Your issues with this task is that you're approaching it by thinking that only the syntax to style widgets has changed — whereas the whole rendering API has been changed, starting in GTK+ 3.x. You cannot query a color from the style and then draw with it, because GTK+ uses CSS to render, and CSS does not have "colors". You cannot query the state of the CSS style and then try to mimic a subset of it with your own rendering code. You cannot assume themes will support your widgets The styling machinery in GTK+ 3.x (and 4.x) is not like the one in GTK+ 2.x, where you could just define a few solid colors; it's a complex rendering API that influences sizing blending of different elements. They are conceptually different. > First question would be: What do the different colors stand for anyway? > What does light and dark mean when it comes to rendering? For example, I > am using the Arc Theme which does not provide .light or .dark classes > for different widgets. The whole theme provides a dark variant of itself; a theme variant is literally a separate theme, with a "-dark" suffix, that gets loaded automatically on application request. That's also why various themes are written using SASS and other CSS pre-processors. > But I also don't want to provide an > application-specific CSS file because the application should follow the > system theme. If you want a custom widget to render with the system theme then you'll need to use the gtk_render_* API and apply the same classes you wish to reuse, like "osd" or "dim-label" or "linked" or "suggested-action". If your application is using custom widgets, with custom rendering, though, you *will* have to provide application-specific CSS. You can try to integrate with common system themes, by creating different CSS fragments and loading them up depending on the theme name. > The second question would be how style properties fit into this as well. > Some colors are set explicitly via style properties, but those are also > deprecated. What would be the way to replace those? Style properties are replaced by CSS properties where appropriate. > I am looking for the recommended way/best practise of styling widgets, > not some hacks and workarounds. Can anybody help me? The overall best practices are: * do not style your widgets unless absolutely necessary; build composite widgets and let the system theme handle them for you * if you have custom widgets, always use the gtk_render_* API and the appropriate CSS classes to let GTK+ render them * if you have custom widgets and you wish to render them in specific ways then assign them an application-specific CSS class, and ship an application-specific CSS fragment * if you have custom widgets and you wish them to be rendered differently depending on the system theme, then you'll have to ship an application-specific CSS fragment for each theme you wish to support In short: if you want your application to look like the rest of the system UI, regardless of theme, then you'll have to use GTK widgets that themes can style generically; if you have custom widgetry, then you'll have to ship your own CSS fragments — possibly with support for multiple themes. Ciao, Emmanuele. -- https://www.bassi.io [@] ebassi [@gmail.com] _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
