WIP

crates/settings2/src/keymap_file.rs

@@ -0,0 +1,163 @@
+use crate::{settings_store::parse_json_with_comments, SettingsAssets};
+use anyhow::{anyhow, Context, Result};
+use collections::BTreeMap;
+use gpui2::{AppContext, KeyBinding};
+use schemars::{
+    gen::{SchemaGenerator, SchemaSettings},
+    schema::{InstanceType, Schema, SchemaObject, SingleOrVec, SubschemaValidation},
+    JsonSchema,
+};
+use serde::Deserialize;
+use serde_json::Value;
+use util::{asset_str, ResultExt};
+
+#[derive(Debug, Deserialize, Default, Clone, JsonSchema)]
+#[serde(transparent)]
+pub struct KeymapFile(Vec<KeymapBlock>);
+
+#[derive(Debug, Deserialize, Default, Clone, JsonSchema)]
+pub struct KeymapBlock {
+    #[serde(default)]
+    context: Option<String>,
+    bindings: BTreeMap<String, KeymapAction>,
+}
+
+#[derive(Debug, Deserialize, Default, Clone)]
+#[serde(transparent)]
+pub struct KeymapAction(Value);
+
+impl JsonSchema for KeymapAction {
+    fn schema_name() -> String {
+        "KeymapAction".into()
+    }
+
+    fn json_schema(_: &mut SchemaGenerator) -> Schema {
+        Schema::Bool(true)
+    }
+}
+
+#[derive(Deserialize)]
+struct ActionWithData(Box<str>, Value);
+
+impl KeymapFile {
+    pub fn load_asset(asset_path: &str, cx: &mut AppContext) -> Result<()> {
+        let content = asset_str::<SettingsAssets>(asset_path);
+
+        Self::parse(content.as_ref())?.add_to_cx(cx)
+    }
+
+    pub fn parse(content: &str) -> Result<Self> {
+        parse_json_with_comments::<Self>(content)
+    }
+
+    pub fn add_to_cx(self, cx: &mut AppContext) -> Result<()> {
+        for KeymapBlock { context, bindings } in self.0 {
+            let bindings = bindings
+                .into_iter()
+                .filter_map(|(keystroke, action)| {
+                    let action = action.0;
+
+                    // This is a workaround for a limitation in serde: serde-rs/json#497
+                    // We want to deserialize the action data as a `RawValue` so that we can
+                    // deserialize the action itself dynamically directly from the JSON
+                    // string. But `RawValue` currently does not work inside of an untagged enum.
+                    match action {
+                        Value::Array(items) => {
+                            let Ok([name, data]): Result<[serde_json::Value; 2], _> =
+                                items.try_into()
+                            else {
+                                return Some(Err(anyhow!("Expected array of length 2")));
+                            };
+                            let serde_json::Value::String(name) = name else {
+                                return Some(Err(anyhow!(
+                                    "Expected first item in array to be a string."
+                                )));
+                            };
+                            cx.build_action(&name, Some(data))
+                        }
+                        Value::String(name) => cx.build_action(&name, None),
+                        Value::Null => Ok(no_action()),
+                        _ => {
+                            return Some(Err(anyhow!("Expected two-element array, got {action:?}")))
+                        }
+                    }
+                    .with_context(|| {
+                        format!(
+                            "invalid binding value for keystroke {keystroke}, context {context:?}"
+                        )
+                    })
+                    .log_err()
+                    .map(|action| KeyBinding::load(&keystroke, action, context.as_deref()))
+                })
+                .collect::<Result<Vec<_>>>()?;
+
+            cx.bind_keys(bindings);
+        }
+        Ok(())
+    }
+
+    pub fn generate_json_schema(action_names: &[&'static str]) -> serde_json::Value {
+        let mut root_schema = SchemaSettings::draft07()
+            .with(|settings| settings.option_add_null_type = false)
+            .into_generator()
+            .into_root_schema_for::<KeymapFile>();
+
+        let action_schema = Schema::Object(SchemaObject {
+            subschemas: Some(Box::new(SubschemaValidation {
+                one_of: Some(vec![
+                    Schema::Object(SchemaObject {
+                        instance_type: Some(SingleOrVec::Single(Box::new(InstanceType::String))),
+                        enum_values: Some(
+                            action_names
+                                .iter()
+                                .map(|name| Value::String(name.to_string()))
+                                .collect(),
+                        ),
+                        ..Default::default()
+                    }),
+                    Schema::Object(SchemaObject {
+                        instance_type: Some(SingleOrVec::Single(Box::new(InstanceType::Array))),
+                        ..Default::default()
+                    }),
+                    Schema::Object(SchemaObject {
+                        instance_type: Some(SingleOrVec::Single(Box::new(InstanceType::Null))),
+                        ..Default::default()
+                    }),
+                ]),
+                ..Default::default()
+            })),
+            ..Default::default()
+        });
+
+        root_schema
+            .definitions
+            .insert("KeymapAction".to_owned(), action_schema);
+
+        serde_json::to_value(root_schema).unwrap()
+    }
+}
+
+fn no_action() -> Box<dyn gpui2::Action> {
+    todo!()
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::KeymapFile;
+
+    #[test]
+    fn can_deserialize_keymap_with_trailing_comma() {
+        let json = indoc::indoc! {"[
+              // Standard macOS bindings
+              {
+                \"bindings\": {
+                  \"up\": \"menu::SelectPrev\",
+                },
+              },
+            ]
+                  "
+
+        };
+        KeymapFile::parse(json).unwrap();
+    }
+}