GTK CSS properties

css.md

See https://git.gnome.org/browse/gtk+/tree/gtk/gtkcssstylepropertyimpl.c?h=gtk-3-8#n878 and https://git.gnome.org/browse/gtk+/tree/gtk/gtkcssstyleproperty.c?h=gtk-3-8#n272

Ani = Property can be animated Inh = Property inherits from parent widget

Property name	Type	Default	Ani	Inh	Notes
animation					Sets all animation-* properties except animation-play-state; specify iteration count first, then duration, then delay
animation-delay	array(time)	0	N	N
animation-direction	array(direction)	normal	N	N
animation-duration	array(time)	0	N	N
animation-fill-mode	array(fill)	none	N	N
animation-iteration-count	array(iteration count)	1	N	N
animation-name	array(string)	none	N	N
animation-play-state	play state	running	N	N
animation-timing-function	array(ease)	ease	N	N
background					Sets all background-* properties; separate size and position with "/"; clip and origin are set to the same value
background-clip	array(area)	border-box	N	N
background-color	color	black	Y	N
background-image	array(image)	none	Y	N
background-origin	array(area)	padding-box	N	N
background-position	array(position)	0 0	Y	N
background-repeat	array(repeat)	repeat repeat	N	N
background-size	array(background size)	auto auto	Y	N
border					Sets color, style, and width of all four sides at once; clears all border-image-* properties
border-bottom					Sets color, style, and width in any order
border-left					ditto
border-right					ditto
border-top					ditto
border-color					Sets all border-*-color properties
border-bottom-color	color	currentColor	Y	N
border-left-color	color	currentColor	Y	N
border-right-color	color	currentColor	Y	N
border-top-color	color	currentColor	Y	N
border-style					Sets all border-*-style properties
border-bottom-style	border style	none	N	N
border-left-style	border style	none	N	N
border-right-style	border style	none	N	N
border-top-style	border style	none	N	N
border-width					Sets all border-*-width properties
border-bottom-width	length	0	Y	N
border-left-width	length	0	Y	N
border-right-width	length	0	Y	N
border-top-width	length	0	Y	N
border-radius					Sets all border-*-radius properties (x-values ("/" y-values)?)
border-bottom-left-radius	corner	0 0	Y	N
border-bottom-right-radius	corner	0 0	Y	N
border-top-left-radius	corner	0 0	Y	N
border-top-right-radius	corner	0 0	Y	N
border-image					Sets all border-image-* properties; separate slice and width by "/"
border-image-repeat	repeat	stretch stretch	N	N
border-image-slice	border	100% 100% 100% 100%	N	N	"auto" not allowed
border-image-source	image	none	Y	N
border-image-width	border	1 1 1 1	N	N	"fill" not allowed
box-shadow	shadow	none	Y	N	Currently, only inset box shadows work
color	color	white	Y	Y
engine	string	none?	N	N	Theming engine
font					Parsed by pango_font_description_from_string(); sets all font-* properties
font-family	array	"Sans"	N	Y
font-size	length	medium	Y	Y
font-style	style	normal	N	Y
font-variant	variant	normal	N	Y
font-weight	weight	normal	N	Y
gtk-key-bindings	array(string)	none	N	N
icon-shadow	shadow	none	Y	Y
margin					Sets all margin-* properties
margin-bottom	length	0	Y	N
margin-left	length	0	Y	N
margin-right	length	0	Y	N
margin-top	length	0	Y	N
opacity	number	1	Y	N	Note that it is applied cumulatively to the opacity set by gtk_widget_set_opacity()! Also, the "animatable" is a lie.
outline-color	color	currentColor	N	N
outline-style	border style	none	N	N
outline-offset	length	0	N	N
outline-width	length	0	Y	N
padding					Sets all padding-* properties
padding-bottom	length	0	Y	N
padding-left	length	0	Y	N
padding-right	length	0	Y	N
padding-top	length	0	Y	N
text-shadow	shadow	none	Y	Y
transition					Sets all transition-* properties; specify duration before delay
transition-delay	array(time)	0	N	N
transition-duration	array(time)	0	N	N
transition-property	array(string)	"all"	N	N
transition-timing-function	array(ease)	ease	N	N

For the shorthand properties that set values on four sides at once, you can give from one to four values. The order is top, right, bottom, left. If right or bottom are not given, they are equal to top. If left is not given, it is equal to right (and therefore top if right is not given.)

Syntax of types of values

area:
  "border-box" | "padding-box" | "content-box"

array:
  value ("," value)*

background repeat:
  "none" | "repeat-x" | "repeat-y" | ("no-repeat" | "repeat" | "round" | "space"){1, 2}

background size:
  "cover" | "contain" | ("auto" | positive length or percentage){2}

border:
  "fill"? ("auto" | number){1,4} "fill"?

border repeat:
  ("stretch" | "repeat" | "round" | "space"){1, 2} | "none"

border style:
  "none" | "solid" | "inset" | "outset" | "hidden" | "dotted" | "dashed" | "double" | "groove" | "ridge"

color:
  "currentColor" | "transparent" | "@"defined-color | color-function | "#"(rgb | rrggbb) | named-color
color-function:
  rgba(0-255 or percentage, 0-255 or percentage, 0-255 or percentage, double)
  | rgb(0-255 or percentage, 0-255 or percentage, 0-255 or percentage)
  | lighter(color) => 1.3 * color
  | darker(color) => 0.7 * color
  | shade(color, double) => double * color
  | alpha(color, double)
  | mix(color, color, double)
  | -gtk-win32-color(name, int)
named-color:
  name understood by gdk_rgba_parse() (http://en.wikipedia.org/wiki/X11_color_names)

corner:
  (positive length or percentage){1,2}
  // refers to x and y; if only x given, then y = x

direction:
  "normal" | "reverse" | "alternate" | "alternate-reverse"

ease:
  "linear" | "ease-in-out" | "ease-in" | "ease-out" | "ease" | "step-start" | "step-end"
  | "steps" "(" unsigned-int ("," ("start" | "end"))? ")"
  | "cubic-bezier" "(" double 0-1 "," double 0-1 "," double 0-1 "," double 0-1 ")"

engine:
  "none" | string

fill:
  "none" | "forwards" | "backwards" | "both"

font size:
  "smaller" | "larger" | "xx-small" | "x-small" | "small" | "medium" | "large" | "x-large" | "xx-large"

font style:
  "normal" | "oblique" | "italic"

font variant:
  "normal" | "small-caps"

font weight:
  "100" | "200" | "300" | "normal" | "400" | "500" | "600" | "bold" | "700" | "800" | "900"
  // normal = 400, bold = 700

image:
  "none"
  | "url(" string ")"
  | "-gtk-gradient(" ("radial" ("," gradient-x gradient-y "," double){2} | "linear" ("," gradient-x gradient-y){2}) ("," ("from" "(" | "to" "(" | "color-stop" "(" double ",") string ")")+ ")"
  | "-gtk-win32-theme-part(" string "," int int ("," ("over" "(" int int "," double | "margins" "(" int{1,4} ) ")")+ ")"
  | ("linear-gradient(" | "repeating-linear-gradient(") (("to" any order(("top" | "bottom"), ("left" | "right")) | angle) ",")? (color (length | percentage)? ("," (color (length | percentage)?)*)? ")"
  | "cross-fade(" percentage? image ("," image)? ")"
  // if percentage is not given, then 50%. in future, should be able to specify colors as well
gradient-x:
  "left" | "right" | "center" | double
gradient-y:
  "top" | "bottom" | "center" | double

iteration count:
  "infinite" | number

play state:
  "running" | "paused"

position:
  ("left" | "right" | "top" | "bottom" | "center" | length | percentage){1, 2}
  // in such a combination that one horizontal and one vertical value are specified

shadows:
  "none" | array("inset"? number number positive-number? number? "inset"? color)
  // numbers: hoffset voffset radius=0.0 spread=0.0

Thanks legend