Small improvements for directional navigation (#17395)

# Objective

While working on more complex directional navigation work, I noticed a
few small things.

## Solution

Rather than stick them in a bigger PR, split them out now.

- Include more useful information when responding to
`DirectionalNavigationError`.
- Use the less controversial `Click` events (rather than `Pressed`) in
the example
- Implement add_looping_edges in terms of `add_edges`. Thanks @rparrett
for the idea.

## Testing

Ran the `directional_navigation` example and things still work.

crates/bevy_input_focus/src/directional_navigation.rs

@@ -186,10 +186,11 @@ impl DirectionalNavigationMap {
     ///
     /// This is useful for creating a circular navigation path between a set of entities, such as a menu.
     pub fn add_looping_edges(&mut self, entities: &[Entity], direction: CompassOctant) {
-        for i in 0..entities.len() {
-            let a = entities[i];
-            let b = entities[(i + 1) % entities.len()];
-            self.add_symmetrical_edge(a, b, direction);
+        self.add_edges(entities, direction);
+        if let Some((first_entity, rest)) = entities.split_first() {
+            if let Some(last_entity) = rest.last() {
+                self.add_symmetrical_edge(*last_entity, *first_entity, direction);
+            }
         }
     }
 
@@ -227,14 +228,17 @@ impl DirectionalNavigation<'_> {
     /// If the result was `Ok`, the [`InputFocus`] resource is updated to the new focus as part of this method call.
     pub fn navigate(
         &mut self,
-        octant: CompassOctant,
+        direction: CompassOctant,
     ) -> Result<Entity, DirectionalNavigationError> {
         if let Some(current_focus) = self.focus.0 {
-            if let Some(new_focus) = self.map.get_neighbor(current_focus, octant) {
+            if let Some(new_focus) = self.map.get_neighbor(current_focus, direction) {
                 self.focus.set(new_focus);
                 Ok(new_focus)
             } else {
-                Err(DirectionalNavigationError::NoNeighborInDirection)
+                Err(DirectionalNavigationError::NoNeighborInDirection {
+                    current_focus,
+                    direction,
+                })
             }
         } else {
             Err(DirectionalNavigationError::NoFocus)
@@ -249,8 +253,13 @@ pub enum DirectionalNavigationError {
     #[error("No focusable entity is currently set.")]
     NoFocus,
     /// No neighbor in the requested direction.
-    #[error("No neighbor in the requested direction.")]
-    NoNeighborInDirection,
+    #[error("No neighbor from {current_focus} in the {direction:?} direction.")]
+    NoNeighborInDirection {
+        /// The entity that was the focus when the error occurred.
+        current_focus: Entity,
+        /// The direction in which the navigation was attempted.
+        direction: CompassOctant,
+    },
 }
 
 #[cfg(test)]

examples/ui/directional_navigation.rs

@@ -5,6 +5,8 @@
 //!
 //! In this example, we will set up a simple UI with a grid of buttons that can be navigated using the arrow keys or gamepad input.
 
+use std::time::Duration;
+
 use bevy::{
     input_focus::{
         directional_navigation::{
@@ -65,9 +67,7 @@ const FOCUSED_BORDER: Srgba = bevy::color::palettes::tailwind::BLUE_50;
 // In a real project, each button would also have its own unique behavior,
 // to capture the actual intent of the user
 fn universal_button_click_behavior(
-    // We're using an on-mouse-down trigger to improve responsiveness;
-    // Clicked is better when you want roll-off cancellation
-    mut trigger: Trigger<Pointer<Pressed>>,
+    mut trigger: Trigger<Pointer<Click>>,
     mut button_query: Query<(&mut BackgroundColor, &mut ResetTimer)>,
 ) {
     let button_entity = trigger.target();
@@ -368,7 +368,7 @@ fn highlight_focused_element(
     }
 }
 
-// By sending a Pointer<Pressed> trigger rather than directly handling button-like interactions,
+// By sending a Pointer<Click> trigger rather than directly handling button-like interactions,
 // we can unify our handling of pointer and keyboard/gamepad interactions
 fn interact_with_focused_button(
     action_state: Res<ActionState>,
@@ -381,7 +381,7 @@ fn interact_with_focused_button(
     {
         if let Some(focused_entity) = input_focus.0 {
             commands.trigger_targets(
-                Pointer::<Pressed> {
+                Pointer::<Click> {
                     target: focused_entity,
                     // We're pretending that we're a mouse
                     pointer_id: PointerId::Mouse,
@@ -395,7 +395,7 @@ fn interact_with_focused_button(
                         ),
                         position: Vec2::ZERO,
                     },
-                    event: Pressed {
+                    event: Click {
                         button: PointerButton::Primary,
                         // This field isn't used, so we're just setting it to a placeholder value
                         hit: HitData {
@@ -404,6 +404,7 @@ fn interact_with_focused_button(
                             position: None,
                             normal: None,
                         },
+                        duration: Duration::from_secs_f32(0.1),
                     },
                 },
                 focused_entity,