Initial public release of Warp.

Repo-Sync-Origin: warpdotdev/warp-internal@12af1d983b

app/src/terminal/meta_shortcuts.rs

@@ -0,0 +1,72 @@
+use warpui::keymap::Keystroke;
+
+/// Whether this keystroke should dispatch an action in Warp despite the
+/// [`warpui::event::Event::KeyDown::is_composing`] being true.
+///
+/// Generally, we ignore all `KeyDown` events if the `is_composing` field is true. However it's
+/// possible to have keybinding conflicts between terminal apps which use the meta key and MacOS
+/// "dead keys". Dead keys are used to add diacritical marks to other characters. They are
+/// triggered by ⌥ and another letter. On the US layout, the dead keys are ⌥e, ⌥u, ⌥i, ⌥n, and ⌥`.
+/// They are different for other layouts, e.g. the Croatian layout has ⌥k. Ideally, we could check
+/// if a specific keystroke is a dead key. AFAICT the OS doesn't expose this, and it would be too
+/// difficult to maintain a map of layouts to lists of dead keys. Therefore, this function just
+/// checks if the keystroke is meta + one letter.
+///
+/// https://support.apple.com/guide/mac-help/enter-characters-with-accent-marks-on-mac-mh27474/mac#mchl45cdda7f
+///
+/// This function is intended to be used when handling [`warpui::event::Event::KeyDown`] when its
+/// `is_composing` is true. Returning true _does not_ mean the keystroke is a dead key necessarily.
+/// Interpreting it that way would result in false-positives. Rather, it means the app may dispatch
+/// an action for the keystroke _despite_ the fact that `is_composing` is true.
+/// Note that this is only relevant with [`crate::settings::ExtraMetaKeys`] enabled.
+pub(super) fn handle_keystroke_despite_composing(keystroke: &Keystroke) -> bool {
+    // This conflict only occurs on MacOS.
+    if !cfg!(target_os = "macos") {
+        return false;
+    }
+    if keystroke.cmd || keystroke.ctrl || keystroke.shift || keystroke.alt || !keystroke.meta {
+        return false;
+    }
+    if keystroke.key.len() != 1 {
+        return false;
+    }
+    true
+}
+
+#[cfg(all(test, target_os = "macos"))]
+mod tests {
+    use std::error;
+
+    use super::*;
+
+    #[test]
+    fn test_handle_keystroke_despite_composing() -> Result<(), Box<dyn error::Error>> {
+        assert!(handle_keystroke_despite_composing(&Keystroke::parse(
+            "meta-i"
+        )?));
+        assert!(handle_keystroke_despite_composing(&Keystroke::parse(
+            "meta-u"
+        )?));
+        assert!(handle_keystroke_despite_composing(&Keystroke::parse(
+            "meta-`"
+        )?));
+        assert!(handle_keystroke_despite_composing(&Keystroke::parse(
+            "meta-n"
+        )?));
+        assert!(handle_keystroke_despite_composing(&Keystroke::parse(
+            "meta-e"
+        )?));
+
+        assert!(!handle_keystroke_despite_composing(&Keystroke::parse(
+            "alt-i"
+        )?));
+        assert!(!handle_keystroke_despite_composing(&Keystroke::parse(
+            "ctrl-i"
+        )?));
+        assert!(!handle_keystroke_despite_composing(&Keystroke::parse(
+            "meta-shift-I"
+        )?));
+
+        Ok(())
+    }
+}