Add color theme config

* add option `theme` that allows for setting of a theme,
the default is `default`

* under `themes` the themes can be described as follows:

either:
```
themes:
  default:
    fg: [0,0,0]
    bg: [0,0,0]
    black: [0,0,0]
    red: [0,0,0]
    green: [0,0,0]
    yellow: [0,0,0]
    blue: [0,0,0]
    magenta: [0,0,0]
    cyan: [0,0,0]
    white: [0,0,0]
    orange: [0,0,0]
```
or
```
themes:
  default:
    fg: 0
    bg: 0
    black: 0
    red: 0
    green: 0
    yellow: 0
    blue: 0
    magenta: 0
    cyan: 0
    white: 0
    orange: 0
```

If the key is different from default, it needs to either be specified on
start with `options --theme [THEME]`, or in the configuration file under
theme: [THEME].

closes #390

1 files changed, 94 insertions, 0 deletions

diff --git a/zellij-utils/src/input/theme.rs b/zellij-utils/src/input/theme.rs
new file mode 100644
index 000000000..35bd3d87b
--- /dev/null
+++ b/zellij-utils/src/input/theme.rs
@@ -0,0 +1,94 @@
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+use super::options::Options;
+use zellij_tile::data::{Palette, PaletteColor};
+
+/// Intermediate deserialization of themes
+#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
+pub struct ThemesFromYaml(HashMap<String, Theme>);
+
+#[derive(Debug, Clone, PartialEq, Deserialize, Serialize)]
+struct Theme {
+    #[serde(flatten)]
+    palette: PaletteFromYaml,
+}
+
+/// Intermediate deserialization struct
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, Hash, Default)]
+pub struct PaletteFromYaml {
+    pub fg: PaletteColorFromYaml,
+    pub bg: PaletteColorFromYaml,
+    pub black: PaletteColorFromYaml,
+    pub red: PaletteColorFromYaml,
+    pub green: PaletteColorFromYaml,
+    pub yellow: PaletteColorFromYaml,
+    pub blue: PaletteColorFromYaml,
+    pub magenta: PaletteColorFromYaml,
+    pub cyan: PaletteColorFromYaml,
+    pub white: PaletteColorFromYaml,
+    pub orange: PaletteColorFromYaml,
+}
+
+/// Intermediate deserialization enum
+// This is here in order to make the untagged enum work
+#[derive(Clone, Copy, Debug, Serialize, Deserialize, PartialEq, Eq, Hash)]
+#[serde(untagged)]
+pub enum PaletteColorFromYaml {
+    Rgb((u8, u8, u8)),
+    EightBit(u8),
+}
+
+impl Default for PaletteColorFromYaml {
+    fn default() -> Self {
+        PaletteColorFromYaml::EightBit(0)
+    }
+}
+
+impl ThemesFromYaml {
+    pub fn theme_config(self, opts: &Options) -> Option<Palette> {
+        let mut from_yaml = self;
+        match &opts.theme {
+            Some(theme) => from_yaml.from_default_theme(theme.to_owned()),
+            None => from_yaml.from_default_theme("default".into()),
+        }
+    }
+
+    fn get_theme(&mut self, theme: String) -> Option<Theme> {
+        self.0.remove(&theme)
+    }
+
+    fn from_default_theme(&mut self, theme: String) -> Option<Palette> {
+        self.clone()
+            .get_theme(theme)
+            .map(|t| Palette::from(t.palette))
+    }
+}
+
+impl From<PaletteFromYaml> for Palette {
+    fn from(yaml: PaletteFromYaml) -> Self {
+        Palette {
+            fg: yaml.fg.into(),
+            bg: yaml.fg.into(),
+            black: yaml.black.into(),
+            red: yaml.red.into(),
+            green: yaml.green.into(),
+            yellow: yaml.yellow.into(),
+            blue: yaml.blue.into(),
+            magenta: yaml.magenta.into(),
+            cyan: yaml.cyan.into(),
+            white: yaml.white.into(),
+            orange: yaml.orange.into(),
+            ..Palette::default()
+        }
+    }
+}
+
+impl From<PaletteColorFromYaml> for PaletteColor {
+    fn from(yaml: PaletteColorFromYaml) -> Self {
+        match yaml {
+            PaletteColorFromYaml::Rgb(color) => PaletteColor::Rgb(color),
+            PaletteColorFromYaml::EightBit(color) => PaletteColor::EightBit(color),
+        }
+    }
+}