Deprecate ReceivedCharacter (#12868)

# Objective

- Partially resolves #12639.

## Solution

- Deprecate `ReceivedCharacter`.
- Replace `ReceivedCharacter` with `KeyboardInput` in the relevant
examples.

## Migration Guide

- `ReceivedCharacter` is now deprecated, use `KeyboardInput` instead.

- Before:
  ```rust
  fn listen_characters(events: EventReader<ReceivedCharacter>) {
    for event in events.read() {
      info!("{}", event.char);
    }
  }
  ```
  
  After:
  ```rust
  fn listen_characters(events: EventReader<KeyboardInput>) {
    for event in events.read() {
      // Only check for characters when the key is pressed.
      if event.state == ButtonState::Released {
        continue;
      }
// Note that some keys such as `Space` and `Tab` won't be detected as
before.
      // Instead, check for them with `Key::Space` and `Key::Tab`.
      if let Key::Character(character) = &event.logical_key {
        info!("{}", character);
      }
    }
  }
  ```

---------

Co-authored-by: Mike <mike.hsu@gmail.com>

crates/bevy_window/src/event.rs

@@ -1,3 +1,4 @@
+#![allow(deprecated)]
 use std::path::PathBuf;
 
 use bevy_ecs::entity::Entity;
@@ -171,6 +172,7 @@ pub struct CursorLeft {
 }
 
 /// An event that is sent whenever a window receives a character from the OS or underlying system.
+#[deprecated(since = "0.14.0", note = "Use `KeyboardInput` instead.")]
 #[derive(Event, Debug, Clone, PartialEq, Eq, Reflect)]
 #[reflect(Debug, PartialEq)]
 #[cfg_attr(

crates/bevy_window/src/lib.rs

@@ -28,6 +28,7 @@ pub use window::*;
 
 #[allow(missing_docs)]
 pub mod prelude {
+    #[allow(deprecated)]
     #[doc(hidden)]
     pub use crate::{
         CursorEntered, CursorIcon, CursorLeft, CursorMoved, FileDragAndDrop, Ime, MonitorSelection,
@@ -85,6 +86,7 @@ pub struct WindowPlugin {
 impl Plugin for WindowPlugin {
     fn build(&self, app: &mut App) {
         // User convenience events
+        #[allow(deprecated)]
         app.add_event::<WindowResized>()
             .add_event::<WindowCreated>()
             .add_event::<WindowClosed>()
@@ -132,6 +134,7 @@ impl Plugin for WindowPlugin {
         }
 
         // Register event types
+        #[allow(deprecated)]
         app.register_type::<WindowResized>()
             .register_type::<RequestRedraw>()
             .register_type::<WindowCreated>()

crates/bevy_winit/src/lib.rs

@@ -43,6 +43,7 @@ use bevy_math::{ivec2, DVec2, Vec2};
 #[cfg(not(target_arch = "wasm32"))]
 use bevy_tasks::tick_global_task_pools_on_main_thread;
 use bevy_utils::tracing::{error, trace, warn};
+#[allow(deprecated)]
 use bevy_window::{
     exit_on_all_closed, ApplicationLifetime, CursorEntered, CursorLeft, CursorMoved,
     FileDragAndDrop, Ime, ReceivedCharacter, RequestRedraw, Window,
@@ -474,6 +475,7 @@ fn handle_winit_event(
                     if event.state.is_pressed() {
                         if let Some(char) = &event.text {
                             let char = char.clone();
+                            #[allow(deprecated)]
                             winit_events.send(ReceivedCharacter { window, char });
                         }
                     }

crates/bevy_winit/src/winit_event.rs

@@ -1,3 +1,4 @@
+#![allow(deprecated)]
 #![allow(missing_docs)]
 
 use bevy_app::App;

examples/input/char_input_events.rs

@@ -1,6 +1,12 @@
 //! Prints out all chars as they are inputted.
 
-use bevy::prelude::*;
+use bevy::{
+    input::{
+        keyboard::{Key, KeyboardInput},
+        ButtonState,
+    },
+    prelude::*,
+};
 
 fn main() {
     App::new()
@@ -10,8 +16,14 @@ fn main() {
 }
 
 /// This system prints out all char events as they come in
-fn print_char_event_system(mut char_input_events: EventReader<ReceivedCharacter>) {
+fn print_char_event_system(mut char_input_events: EventReader<KeyboardInput>) {
     for event in char_input_events.read() {
-        info!("{:?}: '{}'", event, event.char);
+        // Only check for characters when the key is pressed
+        if event.state == ButtonState::Released {
+            continue;
+        }
+        if let Key::Character(character) = &event.logical_key {
+            info!("{:?}: '{}'", event, character);
+        }
     }
 }

examples/input/text_input.rs

@@ -6,7 +6,13 @@
 
 use std::mem;
 
-use bevy::{input::keyboard::KeyboardInput, prelude::*};
+use bevy::{
+    input::{
+        keyboard::{Key, KeyboardInput},
+        ButtonState,
+    },
+    prelude::*,
+};
 
 fn main() {
     App::new()
@@ -17,7 +23,6 @@ fn main() {
             (
                 toggle_ime,
                 listen_ime_events,
-                listen_received_character_events,
                 listen_keyboard_input_events,
                 bubbling_text,
             ),
@@ -163,25 +168,19 @@ fn listen_ime_events(
     }
 }
 
-fn listen_received_character_events(
-    mut events: EventReader<ReceivedCharacter>,
-    mut edit_text: Query<&mut Text, (Without<Node>, Without<Bubble>)>,
-) {
-    for event in events.read() {
-        edit_text.single_mut().sections[0]
-            .value
-            .push_str(&event.char);
-    }
-}
-
 fn listen_keyboard_input_events(
     mut commands: Commands,
     mut events: EventReader<KeyboardInput>,
     mut edit_text: Query<&mut Text, (Without<Node>, Without<Bubble>)>,
 ) {
     for event in events.read() {
-        match event.key_code {
-            KeyCode::Enter => {
+        // Only trigger changes when the key is first pressed.
+        if event.state == ButtonState::Released {
+            continue;
+        }
+
+        match &event.logical_key {
+            Key::Enter => {
                 let mut text = edit_text.single_mut();
                 if text.sections[0].value.is_empty() {
                     continue;
@@ -198,9 +197,15 @@ fn listen_keyboard_input_events(
                     },
                 ));
             }
-            KeyCode::Backspace => {
+            Key::Space => {
+                edit_text.single_mut().sections[0].value.push(' ');
+            }
+            Key::Backspace => {
                 edit_text.single_mut().sections[0].value.pop();
             }
+            Key::Character(character) => {
+                edit_text.single_mut().sections[0].value.push_str(character);
+            }
             _ => continue,
         }
     }