# Theming

A default theme from this repository can be copied to use as a base and edit,
for example:

```sh
    cp mirage/src/themes/Midnight.qpl \
       "${XDG_DATA_HOME:-$HOME/.local/share}/mirage/themes/MyTheme.qpl"
```

Or for Flatpak users:

```sh
    cp mirage/src/themes/Midnight.qpl \
       ~/.var/app/io.github.mirukana.mirage/data/mirage/themes/MyTheme.qpl
```

The `theme` property in [`settings.py`](CONFIG.md#settingspy) would need
to be set to `MyTheme.qpl` in this case.

Theme files are nested-by-indentations sections of properties and values.  
Properties are declared as `<type> <name>: <value>`.  
Values can be any JavaScript (ECMAScript 7) expressions.

Most of the properties are of type `color`.
Their values, if not just refering to another property,
can be expressed with a:

- [SVG/CSS color name](https://www.december.com/html/spec/colorsvg.html)
  string, e.g. `"blue"`
- Hexadecimal code string, e.g. `"#fff"` or `"#cc0000"`
- RGBA value, using the `Qt.rgba(0-1, 0-1, 0-1, 0-1)` function
- HSLA value, using the `Qt.hsla(0-1, 0-1, 0-1, 0-1)` function
- HSVA value, using the `Qt.hsva(0-1, 0-1, 0-1, 0-1)` function
- [HSLUV](https://www.hsluv.org/) value, using the
  `hsluv(0-360, 0-100, 0-100, 0-1)` function. This is the prefered method 
  used throughout the default theme files
  (why? see [this](https://www.hsluv.org/comparison/#rainbow-hsluv) and
  [that](https://www.boronine.com/2012/03/26/Color-Spaces-for-Human-Beings/#hsl-is-a-lemon))

If you just want to change the background picture,
or use a gradient/simple color instead, search for the `ui:` section in your
text editor.

When an in-use theme file is saved while the application is running, it 
will automatically be reloaded and changes will be seen immediatly.

You can manually trigger a reload by updating the file's last change timestamp,
e.g. with the `touch` command: 

```sh
touch ~/.config/mirage/settings.py
```

**Warnings**: 

- API currently unstable: theme properties are often renamed, added or deleted.
- The file format for themes will soon change
- The current file format forces all theme to have all properties
  defined, instead of being able to only specify the ones to override from the
  default theme.
