feat: Gesture configuration in shortcuts config

config/src/shortcuts/action.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use std::str::FromStr;
+
 use serde::{Deserialize, Serialize};
 
 /// An operation which may be bound to a keyboard shortcut.
@@ -180,7 +182,7 @@ pub enum System {
 }
 
 /// Defines the direction of an operation
-#[derive(Copy, Clone, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
+#[derive(Copy, Clone, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize, Hash)]
 pub enum Direction {
     Left,
     Right,
@@ -200,6 +202,31 @@ impl std::ops::Not for Direction {
     }
 }
 
+impl ToString for Direction {
+    fn to_string(&self) -> String {
+        match self {
+            Direction::Left => "Left".to_string(),
+            Direction::Right => "Right".to_string(),
+            Direction::Up => "Up".to_string(),
+            Direction::Down => "Down".to_string(),
+        }
+    }
+}
+
+impl FromStr for Direction {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "Down" => Ok(Self::Down),
+            "Up" => Ok(Self::Up),
+            "Left" => Ok(Self::Left),
+            "Right" => Ok(Self::Right),
+            _ => return Err(format!("String {} cannot be converted to direction.", s)),
+        }
+    }
+}
+
 /// Defines the direction to focus towards
 #[derive(Copy, Clone, Debug, Deserialize, Eq, Ord, PartialEq, PartialOrd, Serialize)]
 pub enum FocusDirection {

config/src/shortcuts/gesture.rs

@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: MPL-2.0
+use std::str::FromStr;
+
+use serde::{Deserialize, Serialize};
+
+use super::action::Direction;
+
+/// Description of a gesture that can be handled by the compositor
+#[serde_with::serde_as]
+#[derive(Clone, Debug, Deserialize, PartialEq, Eq, Serialize, Hash)]
+#[serde(deny_unknown_fields)]
+pub struct Gesture {
+    /// How many fingers are held down
+    pub fingers: u32,
+    pub direction: Direction,
+    // A custom description for a custom binding
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub description: Option<String>,
+}
+
+impl Gesture {
+    /// Creates a new gesture from a number of fingers and a direction
+    pub fn new(fingers: impl Into<u32>, direction: impl Into<Direction>) -> Gesture {
+        Gesture {
+            fingers: fingers.into(),
+            direction: direction.into(),
+            description: None,
+        }
+    }
+
+    /// Append the binding to an existing string
+    pub fn to_string_in_place(&self, string: &mut String) {
+        string.push_str(&format!(
+            "{} Finger {}",
+            self.fingers,
+            self.direction.to_string()
+        ));
+    }
+}
+
+impl ToString for Gesture {
+    fn to_string(&self) -> String {
+        let mut string = String::new();
+        self.to_string_in_place(&mut string);
+        string
+    }
+}
+
+impl FromStr for Gesture {
+    type Err = String;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        let mut value_iter = value.split("+");
+        let n = match value_iter.next() {
+            Some(val) => val,
+            None => {
+                return Err(format!("no value for the number of fingers"));
+            }
+        };
+        let fingers = match u32::from_str(n) {
+            Ok(a) => a,
+            Err(_) => {
+                return Err(format!("could not parse number of fingers"));
+            }
+        };
+
+        let n2 = match value_iter.next() {
+            Some(val) => val,
+            None => {
+                return Err(format!("could not parse direction"));
+            }
+        };
+
+        let direction = match Direction::from_str(n2) {
+            Ok(dir) => dir,
+            Err(e) => {
+                return Err(e);
+            }
+        };
+
+        if let Some(n3) = value_iter.next() {
+            return Err(format!("Extra data {} not expected", n3));
+        }
+
+        return Ok(Self {
+            fingers,
+            direction,
+            description: None,
+        });
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::shortcuts::action::Direction;
+
+    use super::Gesture;
+    use std::str::FromStr;
+
+    #[test]
+    fn binding_from_str() {
+        assert_eq!(
+            Gesture::from_str("3+Left"),
+            Ok(Gesture::new(
+                3 as u32,
+                Direction::Left
+            ))
+        );
+
+        assert_eq!(
+            Gesture::from_str("5+Up"),
+            Ok(Gesture::new(
+                5 as u32,
+                Direction::Up
+            ))
+        );
+
+        assert_ne!(
+            Gesture::from_str("4+Left+More+Info"),
+            Ok(Gesture::new(
+                4 as u32,
+                Direction::Left
+            ))
+        );
+    }
+}

config/src/shortcuts/mod.rs

@@ -5,10 +5,13 @@ pub use action::Action;
 
 pub mod modifier;
 
+use action::Direction;
 pub use modifier::{Modifier, Modifiers, ModifiersDef};
 
 mod binding;
+mod gesture;
 pub use binding::Binding;
+pub use gesture::Gesture;
 
 pub mod sym;
 
@@ -49,6 +52,31 @@ pub fn shortcuts(context: &cosmic_config::Config) -> Shortcuts {
     shortcuts
 }
 
+/// Get the current system gesture configuration
+///
+/// Merges user-defined custom gestures to the system default config
+pub fn gestures(context: &cosmic_config::Config) -> Gestures {
+    // Load gestures defined by the system.
+    let mut gestures = context
+        .get::<Gestures>("default_gestures")
+        .unwrap_or_else(|why| {
+            tracing::error!("shortcuts defaults config error: {why:?}");
+            Gestures::default()
+        });
+
+    // Load custom gestures defined by the user.
+    let custom_gestures = context
+        .get::<Gestures>("custom_gestures")
+        .unwrap_or_else(|why| {
+            tracing::error!("shortcuts custom config error: {why:?}");
+            Gestures::default()
+        });
+
+    // Combine while overriding system gestures.
+    gestures.0.extend(custom_gestures.0);
+    gestures
+}
+
 /// Get a map of system actions and their configured commands
 pub fn system_actions(context: &cosmic_config::Config) -> SystemActions {
     let mut config = SystemActions::default();
@@ -80,6 +108,8 @@ pub fn system_actions(context: &cosmic_config::Config) -> SystemActions {
 pub struct Config {
     pub defaults: Shortcuts,
     pub custom: Shortcuts,
+    pub default_gestures: Gestures,
+    pub custom_gestures: Gestures,
     pub system_actions: SystemActions,
 }
 
@@ -97,6 +127,18 @@ impl Config {
             .shortcut_for_action(action)
             .or_else(|| self.defaults.shortcut_for_action(action))
     }
+
+    pub fn gestures(&self) -> impl Iterator<Item = (&Gesture, &Action)> {
+        self.custom_gestures
+            .iter()
+            .chain(self.default_gestures.iter())
+    }
+
+    pub fn gesture_for_action(&self, action: &Action) -> Option<String> {
+        self.custom_gestures
+            .gesture_for_action(action)
+            .or_else(|| self.default_gestures.gesture_for_action(action))
+    }
 }
 
 /// A map of defined key [Binding]s and their triggerable [Action]s
@@ -172,3 +214,49 @@ pub enum State {
     Pressed,
     Released,
 }
+
+/// A map of defined [Gesture]s and their triggerable [Action]s
+#[derive(Clone, Debug, Default, PartialEq, Deserialize, Serialize)]
+#[serde(transparent)]
+pub struct Gestures(pub HashMap<Gesture, Action>);
+
+impl Gestures {
+    pub fn insert_default_gesture(
+        &mut self,
+        fingers: u32,
+        direction: Direction,
+        action: Action,
+    ) {
+        if !self.0.values().any(|a| a == &action) {
+            let pattern = Gesture {
+                description: None,
+                fingers,
+                direction,
+            };
+            if !self.0.contains_key(&pattern) {
+                self.0.insert(pattern, action.clone());
+            }
+        }
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = (&Gesture, &Action)> {
+        self.0.iter()
+    }
+
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = (&Gesture, &mut Action)> {
+        self.0.iter_mut()
+    }
+
+    pub fn gesture_for_action(&self, action: &Action) -> Option<String> {
+        self.gestures(action)
+            .next() // take the first one
+            .map(|gesture| gesture.to_string())
+    }
+
+    pub fn gestures<'a>(&'a self, action: &'a Action) -> impl Iterator<Item = &'a Gesture> {
+        self.0
+            .iter()
+            .filter(move |(_, a)| *a == action)
+            .map(|(b, _)| b)
+    }
+}