Rename ElementState to ButtonState (bevyengine#4314)

# Objective

- Part of the splitting process of bevyengine#3692.

## Solution

- Rename `ElementState` to `ButtonState`

## Reasons

- The old name was too generic.
- If something can be pressed it is automatically button-like (thanks to @alice-i-cecile for bringing it up in bevyengine#3692).
- The reason it is called `ElementState` is because that's how `winit` calls it.
- It is used to define if a keyboard or mouse **button** is pressed or not.
- Discussion in bevyengine#3692.

## Changelog

### Changed

- The `ElementState` type received a rename and is now called `ButtonState`.

## Migration Guide

- The `ElementState` type received a rename and is now called `ButtonState`. To migrate you just have to change every occurrence of `ElementState` to `ButtonState`.

Co-authored-by: KDecay <KDecayMusic@protonmail.com>

crates/bevy_input/src/keyboard.rs

@@ -1,4 +1,4 @@
-use crate::{ElementState, Input};
+use crate::{ButtonState, Input};
 use bevy_ecs::event::EventReader;
 use bevy_ecs::system::ResMut;
 
@@ -7,7 +7,7 @@ use bevy_ecs::system::ResMut;
 pub struct KeyboardInput {
     pub scan_code: u32,
     pub key_code: Option<KeyCode>,
-    pub state: ElementState,
+    pub state: ButtonState,
 }
 
 /// Updates the `Input<KeyCode>` resource with the latest `KeyboardInput` events
@@ -24,8 +24,8 @@ pub fn keyboard_input_system(
         } = event
         {
             match state {
-                ElementState::Pressed => keyboard_input.press(*key_code),
-                ElementState::Released => keyboard_input.release(*key_code),
+                ButtonState::Pressed => keyboard_input.press(*key_code),
+                ButtonState::Released => keyboard_input.release(*key_code),
             }
         }
     }

crates/bevy_input/src/lib.rs

@@ -90,13 +90,13 @@ impl Plugin for InputPlugin {
 /// The current "press" state of an element
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 #[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
-pub enum ElementState {
+pub enum ButtonState {
     Pressed,
     Released,
 }
 
-impl ElementState {
+impl ButtonState {
     pub fn is_pressed(&self) -> bool {
-        matches!(self, ElementState::Pressed)
+        matches!(self, ButtonState::Pressed)
     }
 }

crates/bevy_input/src/mouse.rs

@@ -1,12 +1,12 @@
-use crate::{ElementState, Input};
+use crate::{ButtonState, Input};
 use bevy_ecs::{event::EventReader, system::ResMut};
 use bevy_math::Vec2;
 
 /// A mouse button input event
 #[derive(Debug, Clone)]
 pub struct MouseButtonInput {
     pub button: MouseButton,
-    pub state: ElementState,
+    pub state: ButtonState,
 }
 
 /// A button on a mouse device
@@ -49,8 +49,8 @@ pub fn mouse_button_input_system(
     mouse_button_input.clear();
     for event in mouse_button_input_events.iter() {
         match event.state {
-            ElementState::Pressed => mouse_button_input.press(event.button),
-            ElementState::Released => mouse_button_input.release(event.button),
+            ButtonState::Pressed => mouse_button_input.press(event.button),
+            ButtonState::Released => mouse_button_input.release(event.button),
         }
     }
 }

crates/bevy_input/src/system.rs

@@ -1,4 +1,4 @@
-use crate::{ElementState, KeyCode, KeyboardInput};
+use crate::{ButtonState, KeyCode, KeyboardInput};
 use bevy_app::AppExit;
 use bevy_ecs::prelude::{EventReader, EventWriter};
 
@@ -14,7 +14,7 @@ pub fn exit_on_esc_system(
 ) {
     for event in keyboard_input_events.iter() {
         if let Some(key_code) = event.key_code {
-            if event.state == ElementState::Pressed && key_code == KeyCode::Escape {
+            if event.state == ButtonState::Pressed && key_code == KeyCode::Escape {
                 app_exit_events.send_default();
             }
         }

crates/bevy_winit/src/converters.rs

@@ -2,7 +2,7 @@ use bevy_input::{
     keyboard::{KeyCode, KeyboardInput},
     mouse::MouseButton,
     touch::{ForceTouch, TouchInput, TouchPhase},
-    ElementState,
+    ButtonState,
 };
 use bevy_math::Vec2;
 use bevy_window::CursorIcon;
@@ -15,10 +15,10 @@ pub fn convert_keyboard_input(keyboard_input: &winit::event::KeyboardInput) -> K
     }
 }
 
-pub fn convert_element_state(element_state: winit::event::ElementState) -> ElementState {
+pub fn convert_element_state(element_state: winit::event::ElementState) -> ButtonState {
     match element_state {
-        winit::event::ElementState::Pressed => ElementState::Pressed,
-        winit::event::ElementState::Released => ElementState::Released,
+        winit::event::ElementState::Pressed => ButtonState::Pressed,
+        winit::event::ElementState::Released => ButtonState::Released,
     }
 }