Tab walks the edit-server and friend screens through their buttons

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

crates/horizon-client/src/multiplayer.rs

@@ -1676,10 +1676,12 @@ impl Screen {
     pub fn focused_box(&self, (w, _h): (f32, f32)) -> Option<[f32; 4]> {
         let y = match self {
             Self::Edit { focus: 0, .. } => 66.0,
-            Self::Edit { .. } => 106.0,
+            Self::Edit { focus: 1, .. } => 106.0,
+            Self::Edit { .. } => return None,
             Self::Direct { .. } => 116.0,
             Self::Friend { focus: 0, .. } => 64.0,
-            Self::Friend { .. } => 105.0,
+            Self::Friend { focus: 1, .. } => 105.0,
+            Self::Friend { .. } => return None,
             _ => return None,
         };
         Some([(w / 2.0).floor() - 100.0, y, 200.0, 20.0])
@@ -1691,11 +1693,20 @@ impl Screen {
                 address,
                 focus,
                 ..
-            } => Some(if *focus == 0 { name } else { address }),
+            } => match *focus {
+                0 => Some(name),
+                1 => Some(address),
+                // A button has the focus.
+                _ => None,
+            },
             Self::Direct { address } => Some(address),
             Self::Friend {
                 code, relay, focus, ..
-            } => Some(if *focus == 0 { code } else { relay }),
+            } => match *focus {
+                0 => Some(code),
+                1 => Some(relay),
+                _ => None,
+            },
             _ => None,
         }
     }
@@ -1776,9 +1787,31 @@ impl Screen {
             128
         }
     }
-    pub fn tab(&mut self) {
-        if let Self::Edit { focus, .. } | Self::Friend { focus, .. } = self {
-            *focus = (*focus + 1) % 2;
+    /// Tab (`reverse`: Shift+Tab) through the focus order of `ManageServerScreen`
+    /// and the friend screen: the text fields, then the enabled `buttons`, then
+    /// round to the first field. `button` is the focused button, if any; a field
+    /// has the focus (`focus` below 2) only while no button does.
+    pub fn tab_dir(&mut self, reverse: bool, buttons: &[u8], button: &mut Option<u8>) {
+        let (Self::Edit { focus, .. } | Self::Friend { focus, .. }) = self else {
+            return;
+        };
+        let stops = 2 + buttons.len();
+        let at = match *button {
+            Some(id) => buttons.iter().position(|&b| b == id).map(|i| 2 + i),
+            None => Some(usize::from(*focus).min(1)),
+        }
+        .unwrap_or(0);
+        let next = if reverse {
+            (at + stops - 1) % stops
+        } else {
+            (at + 1) % stops
+        };
+        if next < 2 {
+            *focus = next as u8;
+            *button = None;
+        } else {
+            *focus = 2;
+            *button = Some(buttons[next - 2]);
         }
     }
     /// Escape: back to the list, or out of it (true).

crates/horizon-client/src/title.rs

@@ -3168,6 +3168,14 @@ Would you like to enable the Narrator or visit the Accessibility Settings?",
             .map(|b| b.id);
         if hit.is_some() {
             self.focused_button = hit;
+        } else if matches!(
+            self.mode,
+            Mode::Multiplayer(
+                crate::multiplayer::Screen::Edit { .. } | crate::multiplayer::Screen::Friend { .. }
+            )
+        ) {
+            // A press on a text field takes the focus from the button.
+            self.focused_button = None;
         }
         if matches!(self.mode, Mode::CreateFlat { .. }) {
             self.flat_click(x, y, (w, h), hit);
@@ -3756,8 +3764,17 @@ Would you like to enable the Narrator or visit the Accessibility Settings?",
         if self.rules.get_mut().is_some() {
             return;
         }
-        if let Mode::Multiplayer(screen) = &mut self.mode {
-            screen.tab();
+        if matches!(self.mode, Mode::Multiplayer(_)) {
+            let (w, h) = size;
+            let enabled: Vec<u8> = self
+                .buttons(w, h)
+                .iter()
+                .filter(|b| b.enabled)
+                .map(|b| b.id)
+                .collect();
+            if let Mode::Multiplayer(screen) = &mut self.mode {
+                screen.tab_dir(reverse, &enabled, &mut self.focused_button);
+            }
             return;
         }
         let (w, h) = size;

crates/horizon-client/src/title/tests.rs

@@ -1152,6 +1152,53 @@ fn world_fields_edit_at_their_cursor() {
     assert_eq!(f.title.search, "world");
 }
 
+/// `ManageServerScreen`'s focus order: the name, the address, the Server
+/// Resource Packs button, Done, Cancel, then the name again.
+#[test]
+fn tab_walks_the_edit_server_screen_through_its_buttons() {
+    use crate::multiplayer::Screen;
+    let size = (854.0, 480.0);
+    let mut f = Fixture::new();
+    f.title.mode = Mode::Multiplayer(Screen::Edit {
+        index: None,
+        name: "Minecraft Server".into(),
+        address: "localhost".into(),
+        focus: 0,
+        packs: None,
+    });
+    let focus = |f: &Fixture| match &f.title.mode {
+        Mode::Multiplayer(Screen::Edit { focus, .. }) => (*focus, f.title.focused_button),
+        _ => panic!("edit"),
+    };
+    let mut seen = Vec::new();
+    for _ in 0..5 {
+        f.title.tab_dir(false, size);
+        seen.push(focus(&f));
+    }
+    // Address, then packs (60), Done (50), Cancel (51), and round to the name.
+    assert_eq!(
+        seen,
+        [
+            (1, None),
+            (2, Some(60)),
+            (2, Some(50)),
+            (2, Some(51)),
+            (0, None)
+        ]
+    );
+    // A button has the focus: typing goes nowhere.
+    f.title.tab_dir(true, size);
+    assert_eq!(focus(&f), (2, Some(51)));
+    f.title.type_text("x");
+    let Mode::Multiplayer(Screen::Edit { name, address, .. }) = &f.title.mode else {
+        panic!("edit");
+    };
+    assert_eq!(
+        (name.as_str(), address.as_str()),
+        ("Minecraft Server", "localhost")
+    );
+}
+
 #[test]
 fn server_fields_edit_at_their_cursor() {
     use winit::keyboard::KeyCode;
@@ -1179,8 +1226,8 @@ fn server_fields_edit_at_their_cursor() {
         panic!("add server");
     };
     assert_eq!(address, "Yhost");
-    // Tab moves to the name, which edits at its own cursor.
-    f.title.tab();
+    // Shift+Tab moves back to the name, which edits at its own cursor.
+    f.title.tab_dir(true, (854.0, 480.0));
     f.title.field_key(KeyCode::ArrowLeft, false, false);
     f.title.type_text("X");
     let Mode::Multiplayer(crate::multiplayer::Screen::Edit { name, .. }) = &f.title.mode else {