Support multiple modifier keys

Alfred supports combinations of keys as modifiers. This adds support
for `ctrl+shift` and similar combinations.

crates/cli/src/main.rs

@@ -58,7 +58,6 @@ fn init(manifest_dir: &Path, name: Option<OsString>) -> Result<()> {
 
     // Add workflow/<binary> to the gitignore file (if it exists)
     if let Ok(mut file) = fs::OpenOptions::new()
-        .write(true)
         .append(true)
         .open(manifest_dir.join(".gitignore"))
     {

examples/hello-alfred/src/main.rs

@@ -23,7 +23,10 @@ fn main() -> Result<(), Box<dyn Error>> {
         .large_type_text("this text will be displayed with ⌘L")
         .modifier(Modifier::new(Key::Command).subtitle("⌘ changes the subtitle"))
         .modifier(Modifier::new(Key::Option).arg("/path/to/modified.jpg"))
-        .modifier(Modifier::new(Key::Control).icon(Icon::with_image("/path/to/file.png")))
+        .modifier(
+            Modifier::new_multi([Key::Control, Key::Shift])
+                .icon(Icon::with_image("/path/to/file.png")),
+        )
         .modifier(Modifier::new(Key::Shift).valid(false))
         .quicklook_url("https://example.com")
         .action(value!({

src/lib.rs

@@ -85,6 +85,15 @@ pub enum Key {
     Function,
 }
 
+/// A keyboard modifier combination.
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
+#[serde(untagged)]
+enum Keys {
+    One(Key),
+    #[serde(serialize_with = "serialize_many_keys")]
+    Many(Vec<Key>),
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 enum IconInner {
     /// Load an image from a path.
@@ -146,7 +155,7 @@ struct Data {
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
 pub struct Modifier {
     /// The modifier key.
-    key: Key,
+    key: Keys,
 
     /// The modifier data.
     data: Data,
@@ -192,7 +201,7 @@ pub struct Item {
 
     /// Control how the modifier keys react.
     #[serde(rename = "mods", skip_serializing_if = "HashMap::is_empty")]
-    modifiers: HashMap<Key, Data>,
+    modifiers: HashMap<Keys, Data>,
 
     /// Defines the copied or large type text for this item.
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -228,6 +237,26 @@ pub struct Output {
 // Implementations
 ////////////////////////////////////////////////////////////////////////////////
 
+fn serialize_many_keys<S>(duration: &[Key], s: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    let mut out = String::with_capacity(5 * duration.len());
+    for (i, key) in duration.iter().enumerate() {
+        if i != 0 {
+            out.push('+');
+        }
+        out.push_str(match key {
+            Key::Command => "cmd",
+            Key::Option => "alt",
+            Key::Control => "ctrl",
+            Key::Shift => "shift",
+            Key::Function => "fn",
+        });
+    }
+    s.serialize_str(&out)
+}
+
 impl Serialize for Icon {
     fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
         match &self.0 {
@@ -322,7 +351,23 @@ impl Modifier {
     #[must_use]
     pub fn new(key: Key) -> Self {
         Self {
-            key,
+            key: Keys::One(key),
+            data: Data::default(),
+        }
+    }
+
+    /// Create a new modifier with multiple keys.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use powerpack::{Key, Modifier};
+    /// let m = Modifier::multi([Key::Command, Key::Option]);
+    /// ```
+    #[must_use]
+    pub fn new_multi(keys: impl IntoIterator<Item = Key>) -> Self {
+        Self {
+            key: Keys::Many(keys.into_iter().collect()),
             data: Data::default(),
         }
     }

tests/basic.rs

@@ -32,7 +32,10 @@ fn all() {
         .large_type_text("this text will be displayed with ⌘L")
         .modifier(Modifier::new(Key::Command).subtitle("⌘ changes the subtitle"))
         .modifier(Modifier::new(Key::Option).arg("/path/to/modified.jpg"))
-        .modifier(Modifier::new(Key::Control).icon(Icon::with_image("/path/to/file.png")))
+        .modifier(
+            Modifier::new_multi([Key::Control, Key::Shift])
+                .icon(Icon::with_image("/path/to/file.png")),
+        )
         .modifier(Modifier::new(Key::Shift).valid(false))
         .quicklook_url("https://example.com")
         .action(value!({

tests/testdata/all.golden

@@ -15,19 +15,19 @@
       "autocomplete": "to this",
       "type": "file:skipcheck",
       "mods": {
-        "cmd": {
-          "subtitle": "⌘ changes the subtitle"
-        },
         "alt": {
           "arg": "/path/to/modified.jpg"
         },
-        "ctrl": {
+        "ctrl+shift": {
           "icon": {
             "path": "/path/to/file.png"
           }
         },
         "shift": {
           "valid": false
+        },
+        "cmd": {
+          "subtitle": "⌘ changes the subtitle"
         }
       },
       "text": {