Derive Reflect + FromReflect for input types (bevyengine#6232)

# Objective

Adds support for reflecting many more of the input types. This allows those types to be used via scripting, `bevy-inspector-egui`, etc. These types are registered by the `InputPlugin` so that they're automatically available to anyone who wants to use them 

Closes bevyengine#6223 

## Solution

Many types now have `#[derive(Reflect, FromReflect)]` added to them in `bevy_input`. Additionally, `#[reflect(traits...)]` has been added for applicable traits to the types.

This PR does not add reflection support for types which have private fields. Notably, `Touch` and `Touches` don't implement `Reflect`/`FromReflect`.

This adds the "glam" feature to the `bevy_reflect` dependency for package `bevy_input`. Since `bevy_input` transitively depends on `glam` already, all this brings in are the reflection `impl`s.

## Migration Guide

- `Input<T>` now implements `Reflect` via `#[reflect]` instead of `#[reflect_value]`. This means it now exposes its private fields via the `Reflect` trait rather than being treated as a value type. For code that relies on the `Input<T>` struct being treated as a value type by reflection, it is still possible to wrap the `Input<T>` type with a wrapper struct and apply `#[reflect_value]` to it.
  - As a reminder, private fields exposed via reflection are not subject to any stability guarantees.
---

## Changelog

Added
- Implemented `Reflect` + `FromReflect` for many input-related types. These types are automatically registered when adding the `InputPlugin`.

crates/bevy_input/Cargo.toml

@@ -18,7 +18,7 @@ bevy_app = { path = "../bevy_app", version = "0.9.0-dev" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.9.0-dev" }
 bevy_math = { path = "../bevy_math", version = "0.9.0-dev" }
 bevy_utils = { path = "../bevy_utils", version = "0.9.0-dev" }
-bevy_reflect = { path = "../bevy_reflect", version = "0.9.0-dev" }
+bevy_reflect = { path = "../bevy_reflect", version = "0.9.0-dev", features = ["glam"] }
 
 # other
 serde = { version = "1", features = ["derive"], optional = true }

crates/bevy_input/src/gamepad.rs

@@ -1,6 +1,7 @@
 use crate::{Axis, Input};
 use bevy_ecs::event::{EventReader, EventWriter};
 use bevy_ecs::system::{Res, ResMut, Resource};
+use bevy_reflect::{std_traits::ReflectDefault, FromReflect, Reflect};
 use bevy_utils::{tracing::info, HashMap};
 use thiserror::Error;
 
@@ -53,6 +54,9 @@ pub enum ButtonSettingsError {
     },
 }
 
+#[cfg(feature = "serialize")]
+use bevy_reflect::{ReflectDeserialize, ReflectSerialize};
+
 /// A gamepad with an associated `ID`.
 ///
 /// ## Usage
@@ -64,8 +68,13 @@ pub enum ButtonSettingsError {
 /// ## Note
 ///
 /// The `ID` of a gamepad is fixed until the gamepad disconnects or the app is restarted.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct Gamepad {
     /// The `ID` of the gamepad.
     pub id: usize,
@@ -79,8 +88,13 @@ impl Gamepad {
 }
 
 /// Metadata associated with a `Gamepad`.
-#[derive(Debug, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Clone, PartialEq, Eq, Reflect, FromReflect)]
+#[reflect(Debug, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct GamepadInfo {
     pub name: String,
 }
@@ -129,8 +143,13 @@ impl Gamepads {
 }
 
 /// The data contained in a [`GamepadEvent`] or [`GamepadEventRaw`].
-#[derive(Debug, Clone, PartialEq)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Clone, PartialEq, Reflect, FromReflect)]
+#[reflect(Debug, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub enum GamepadEventType {
     /// A [`Gamepad`] has been connected.
     Connected(GamepadInfo),
@@ -162,8 +181,13 @@ pub enum GamepadEventType {
 /// [`Axis<GamepadAxis>`], and [`Axis<GamepadButton>`] resources won't be updated correctly.
 ///
 /// An example for gamepad input mocking can be seen in the documentation of the [`GamepadEventRaw`].
-#[derive(Debug, Clone, PartialEq)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Clone, PartialEq, Reflect, FromReflect)]
+#[reflect(Debug, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct GamepadEvent {
     /// The gamepad this event corresponds to.
     pub gamepad: Gamepad,
@@ -266,8 +290,13 @@ impl GamepadEvent {
 /// #
 /// # bevy_ecs::system::assert_is_system(change_resource_on_gamepad_button_press);
 /// ```
-#[derive(Debug, Clone, PartialEq)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Clone, PartialEq, Reflect, FromReflect)]
+#[reflect(Debug, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct GamepadEventRaw {
     /// The gamepad this event corresponds to.
     pub gamepad: Gamepad,
@@ -293,8 +322,13 @@ impl GamepadEventRaw {
 /// [`GamepadEventType::ButtonChanged`]. It is also used in the [`GamepadButton`]
 /// which in turn is used to create the [`Input<GamepadButton>`] or
 /// [`Axis<GamepadButton>`] `bevy` resources.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub enum GamepadButtonType {
     /// The bottom action button of the action pad (i.e. PS: Cross, Xbox: A).
     South,
@@ -353,8 +387,13 @@ pub enum GamepadButtonType {
 /// ## Updating
 ///
 /// The resources are updated inside of the [`gamepad_event_system`].
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct GamepadButton {
     /// The gamepad on which the button is located on.
     pub gamepad: Gamepad,
@@ -390,8 +429,13 @@ impl GamepadButton {
 /// This is used to determine which axis has changed its value when receiving a
 /// [`GamepadEventType::AxisChanged`]. It is also used in the [`GamepadAxis`]
 /// which in turn is used to create the [`Axis<GamepadAxis>`] `bevy` resource.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub enum GamepadAxisType {
     /// The horizontal value of the left stick.
     LeftStickX,
@@ -421,8 +465,13 @@ pub enum GamepadAxisType {
 /// ## Updating
 ///
 /// The resource is updated inside of the [`gamepad_event_system`].
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct GamepadAxis {
     /// The gamepad on which the axis is located on.
     pub gamepad: Gamepad,
@@ -460,7 +509,8 @@ impl GamepadAxis {
 ///
 /// The [`GamepadSettings`] are used inside of the [`gamepad_event_system`], but are never written to
 /// inside of `bevy`. To modify these settings, mutate the corresponding resource.
-#[derive(Resource, Default, Debug)]
+#[derive(Resource, Default, Debug, Reflect, FromReflect)]
+#[reflect(Debug, Default)]
 pub struct GamepadSettings {
     /// The default button settings.
     pub default_button_settings: ButtonSettings,
@@ -542,7 +592,8 @@ impl GamepadSettings {
 /// value is surpassed and released if the `release_threshold` value is undercut.
 ///
 /// Allowed values: `0.0 <= ``release_threshold`` <= ``press_threshold`` <= 1.0`
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Reflect, FromReflect)]
+#[reflect(Debug, Default)]
 pub struct ButtonSettings {
     press_threshold: f32,
     release_threshold: f32,
@@ -701,7 +752,8 @@ impl ButtonSettings {
 /// Otherwise, values will not be rounded.
 ///
 /// The valid range is `[-1.0, 1.0]`.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Reflect, FromReflect)]
+#[reflect(Debug, Default)]
 pub struct AxisSettings {
     /// Values that are higher than `livezone_upperbound` will be rounded up to -1.0.
     livezone_upperbound: f32,
@@ -1015,7 +1067,8 @@ impl AxisSettings {
 /// ## Updating
 ///
 /// The current value of a button is received through the [`GamepadEvent`]s or [`GamepadEventRaw`]s.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Reflect, FromReflect)]
+#[reflect(Debug, Default)]
 pub struct ButtonAxisSettings {
     /// The high value at which to apply rounding.
     pub high: f32,

crates/bevy_input/src/input.rs

@@ -1,5 +1,5 @@
 use bevy_ecs::system::Resource;
-use bevy_reflect::Reflect;
+use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 use bevy_utils::HashSet;
 use std::hash::Hash;
 
@@ -35,7 +35,7 @@ use bevy_ecs::schedule::State;
 /// * Call the [`Input::release`] method for each release event.
 /// * Call the [`Input::clear`] method at each frame start, before processing events.
 #[derive(Debug, Clone, Resource, Reflect)]
-#[reflect_value]
+#[reflect(Default)]
 pub struct Input<T: Copy + Eq + Hash + Send + Sync + 'static> {
     /// A collection of every button that is currently being pressed.
     pressed: HashSet<T>,

crates/bevy_input/src/keyboard.rs

@@ -2,6 +2,9 @@ use crate::{ButtonState, Input};
 use bevy_ecs::{event::EventReader, system::ResMut};
 use bevy_reflect::{FromReflect, Reflect};
 
+#[cfg(feature = "serialize")]
+use bevy_reflect::{ReflectDeserialize, ReflectSerialize};
+
 /// A keyboard input event.
 ///
 /// This event is the translated version of the `WindowEvent::KeyboardInput` from the `winit` crate.
@@ -11,8 +14,13 @@ use bevy_reflect::{FromReflect, Reflect};
 ///
 /// The event is consumed inside of the [`keyboard_input_system`](crate::keyboard::keyboard_input_system)
 /// to update the [`Input<KeyCode>`](crate::Input<KeyCode>) resource.
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Reflect, FromReflect)]
+#[reflect(Debug, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct KeyboardInput {
     /// The scan code of the key.
     pub scan_code: u32,
@@ -62,9 +70,13 @@ pub fn keyboard_input_system(
 /// ## Updating
 ///
 /// The resource is updated inside of the [`keyboard_input_system`](crate::keyboard::keyboard_input_system).
-#[derive(Reflect, FromReflect, Debug, Hash, Ord, PartialOrd, PartialEq, Eq, Clone, Copy)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
-#[reflect(Hash, PartialEq)]
+#[derive(Debug, Hash, Ord, PartialOrd, PartialEq, Eq, Clone, Copy, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 #[repr(u32)]
 pub enum KeyCode {
     /// The `1` key over the letters.
@@ -425,7 +437,11 @@ pub enum KeyCode {
 /// ## Updating
 ///
 /// The resource is updated inside of the [`keyboard_input_system`](crate::keyboard::keyboard_input_system).
-#[derive(Reflect, FromReflect, Debug, Hash, Ord, PartialOrd, PartialEq, Eq, Clone, Copy)]
-#[reflect(Hash, PartialEq)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Hash, Ord, PartialOrd, PartialEq, Eq, Clone, Copy, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub struct ScanCode(pub u32);

crates/bevy_input/src/lib.rs

@@ -6,7 +6,6 @@ pub mod mouse;
 pub mod touch;
 
 pub use axis::*;
-use bevy_ecs::schedule::{IntoSystemDescriptor, SystemLabel};
 pub use input::*;
 
 pub mod prelude {
@@ -24,16 +23,24 @@ pub mod prelude {
 }
 
 use bevy_app::prelude::*;
+use bevy_ecs::schedule::{IntoSystemDescriptor, SystemLabel};
+use bevy_reflect::{FromReflect, Reflect};
 use keyboard::{keyboard_input_system, KeyCode, KeyboardInput, ScanCode};
-use mouse::{mouse_button_input_system, MouseButton, MouseButtonInput, MouseMotion, MouseWheel};
-use prelude::Gamepads;
-use touch::{touch_screen_input_system, TouchInput, Touches};
+use mouse::{
+    mouse_button_input_system, MouseButton, MouseButtonInput, MouseMotion, MouseScrollUnit,
+    MouseWheel,
+};
+use touch::{touch_screen_input_system, ForceTouch, TouchInput, TouchPhase, Touches};
 
 use gamepad::{
-    gamepad_connection_system, gamepad_event_system, GamepadAxis, GamepadButton, GamepadEvent,
-    GamepadEventRaw, GamepadSettings,
+    gamepad_connection_system, gamepad_event_system, AxisSettings, ButtonAxisSettings,
+    ButtonSettings, Gamepad, GamepadAxis, GamepadAxisType, GamepadButton, GamepadButtonType,
+    GamepadEvent, GamepadEventRaw, GamepadEventType, GamepadSettings, Gamepads,
 };
 
+#[cfg(feature = "serialize")]
+use bevy_reflect::{ReflectDeserialize, ReflectSerialize};
+
 /// Adds keyboard and mouse input to an App
 #[derive(Default)]
 pub struct InputPlugin;
@@ -84,12 +91,51 @@ impl Plugin for InputPlugin {
                 CoreStage::PreUpdate,
                 touch_screen_input_system.label(InputSystem),
             );
+
+        // Register common types
+        app.register_type::<ButtonState>();
+
+        // Register keyboard types
+        app.register_type::<KeyboardInput>()
+            .register_type::<KeyCode>()
+            .register_type::<ScanCode>();
+
+        // Register mouse types
+        app.register_type::<MouseButtonInput>()
+            .register_type::<MouseButton>()
+            .register_type::<MouseMotion>()
+            .register_type::<MouseScrollUnit>()
+            .register_type::<MouseWheel>();
+
+        // Register touch types
+        app.register_type::<TouchInput>()
+            .register_type::<ForceTouch>()
+            .register_type::<TouchPhase>();
+
+        // Register gamepad types
+        app.register_type::<Gamepad>()
+            .register_type::<GamepadEventType>()
+            .register_type::<GamepadEvent>()
+            .register_type::<GamepadEventRaw>()
+            .register_type::<GamepadButtonType>()
+            .register_type::<GamepadButton>()
+            .register_type::<GamepadAxisType>()
+            .register_type::<GamepadAxis>()
+            .register_type::<GamepadSettings>()
+            .register_type::<ButtonSettings>()
+            .register_type::<AxisSettings>()
+            .register_type::<ButtonAxisSettings>();
     }
 }
 
 /// The current "press" state of an element
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
-#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Reflect, FromReflect)]
+#[reflect(Debug, Hash, PartialEq)]
+#[cfg_attr(
+    feature = "serialize",
+    derive(serde::Serialize, serde::Deserialize),
+    reflect(Serialize, Deserialize)
+)]
 pub enum ButtonState {
     Pressed,
     Released,