1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
# Theming
Since the widget toolkit is **GTK3** theming is done with **CSS**.
- [CSS tutorial](https://www.w3schools.com/css/)
- [GTK CSS Overview wiki](https://docs.gtk.org/gtk3/css-overview.html)
- [GTK CSS Properties Overview wiki](https://docs.gtk.org/gtk3/css-properties.html)
:::warning GTK is not the web
While most features are implemented in GTK,
you can't assume anything that works on the web will work with GTK.
Refer to the [GTK docs](https://docs.gtk.org/gtk3/css-overview.html)
to see what is available.
:::
So far every widget you made used your default GTK3 theme.
To make them more custom, you can apply stylesheets to them.
## From file at startup
You can pass a path to a file or css as a string in `App:start`
:::code-group
```lua [init.lua]
local inline_css = [[
window {
background-color: transparent;
}
]]
App:start({
css = inline_css,
css = "/path/to/style.css",
css = "./style.css",
})
```
:::
:::warning
When using relative paths, so for example `./style.css` keep in mind that they
will be relative to the current working directory.
:::
## Css Property on Widgets
```lua
Widget.Label({
css = "color: blue; padding: 1em;",
label = "hello"
})
```
:::info
The `css` property of a widget will not cascade to its children.
:::
## Apply Stylesheets at Runtime
You can apply additional styles at runtime.
```lua
App:apply_css("/path/to/file.css")
```
```lua
App:apply_css([[
window {
background-color: transparent;
}
]])
```
```lua
App:reset_css() -- reset if need
```
:::warning
`App:apply_css` will apply on top of other stylesheets applied before.
You can reset stylesheets with `App:reset_css`
or by passing `true` as a second parameter to `App:apply_css`.
:::
## Inspector
If you are not sure about the widget hierarchy or any CSS selector,
you can use the [GTK inspector](https://wiki.gnome.org/Projects/GTK/Inspector)
```sh
# to bring up the inspector run
astal --inspector
```
## Using SCSS
Gtk's CSS only supports a subset of what the web offers.
Most notably nested selectors are unsupported by Gtk, but this can be
workaround by using preprocessors like [SCSS](https://sass-lang.com/).
:::code-group
```sh [<i class="devicon-archlinux-plain"></i> Arch]
sudo pacman -Syu dart-sass
```
```sh [<i class="devicon-fedora-plain"></i> Fedora]
npm install -g sass # not packaged on Fedora
```
```sh [<i class="devicon-ubuntu-plain"></i> Ubuntu]
npm install -g sass # not packaged on Ubuntu
```
:::
:::code-group
```lua [init.lua]
local scss = "./style.scss"
local css = "/tmp/style.css"
astal.exec(string.format("sass %s %s", scss, css))
App:start({
css = css,
})
```
:::
|
