Major overhaul of input and communication systems

* Add input manager

* WIP lifetime hell

* Hell yeah, dark lifetime magic

* Replace events with actions in tools

* Fix borrow in GlobalEventHandler

* Fix typo in response-handler

* Distribute dispatch structure

* Add translation from events to actions

* Port default key actions to input_mapper

* Split actions macro

* Add handling for Ambiguous Mouse events

* Fix warnings and clippy lints

* Add actions macro

* WIP rework

* Add AsMessage macro

* Add implementation for derived enums

* Add macro implementation for top level message

* Add #[child] attribute to indicate derivation

* Replace some mentions of Actions and Responses with Message

* It compiles !!!

* Add functionality to some message handlers

* Add document rendering

* ICE

* Rework the previous code while keeping basic functionality

* Reduce parent-top-level macro args to only two

* Add workaround for ICE

* Fix cyclic reference in document.rs

* Make derive_transitive_child a bit more powerful

This addresses the todo that was left,
enabling arbitrary expressions to be passed as the last
parameter of a #[parent] attribute

* Adapt frontend message format

* Make responses use VecDeque

Our responses are a queue so we should use a queue type for them

* Move traits to sensible location

* Are we rectangle yet?

* Simplify, improve & document `derive_discriminant`

* Change `child` to `sub_discriminant`

This only applies to `ToDiscriminant`.
Code using `#[impl_message]` continues to work.

* Add docs for `derive_transitive_child`

* Finish docs and improve macros

The improvements are that impl_message now uses trait
resolution to obtain the parent's discriminant
and that derive_as_message now allows for non-unit
variants (which we don't use but it's nice to have,
just in case)

* Remove logging call

* Move files around and cleanup structure

* Fix proc macro doc tests

* Improve actions_fn!() macro

* Add ellipse tool

* Pass populated actions list to the input mapper

* Add KeyState bitvector

* Merge mouse buttons into "keyboard"

* Add macro for initialization of key mapper table

* Add syntactic sugar for the macro

* Implement mapping function

* Translate the remaining tools

* Fix shape tool

* Add keybindings for line and pen tool

* Fix modifiers

* Cleanup

* Add doc comments for the actions macro

* Fix formatting

* Rename MouseMove to PointerMove

* Add keybinds for tools

* Apply review suggestions

* Rename KeyMappings -> KeyMappingEntries

* Apply review changes

Co-authored-by: T0mstone <realt0mstone@gmail.com>
Co-authored-by: Paul Kupper <kupper.pa@gmail.com>

core/editor/src/input/input_mapper.rs

@@ -0,0 +1,191 @@
+use crate::message_prelude::*;
+use crate::tool::ToolType;
+
+use super::{
+	keyboard::{Key, KeyStates, NUMBER_OF_KEYS},
+	InputPreprocessor,
+};
+
+#[impl_message(Message, InputMapper)]
+#[derive(PartialEq, Clone, Debug)]
+pub enum InputMapperMessage {
+	PointerMove,
+	KeyUp(Key),
+	KeyDown(Key),
+}
+
+#[derive(PartialEq, Clone, Debug)]
+struct MappingEntry {
+	trigger: InputMapperMessage,
+	modifiers: KeyStates,
+	action: Message,
+}
+
+#[derive(Debug, Clone, Default)]
+struct KeyMappingEntries(Vec<MappingEntry>);
+
+impl KeyMappingEntries {
+	fn match_mapping(&self, keys: &KeyStates, actions: ActionList) -> Option<Message> {
+		for entry in self.0.iter() {
+			let all_required_modifiers_pressed = ((*keys & entry.modifiers) ^ entry.modifiers).is_empty();
+			if all_required_modifiers_pressed && actions.iter().flatten().any(|action| entry.action.to_discriminant() == *action) {
+				return Some(entry.action.clone());
+			}
+		}
+		None
+	}
+	fn push(&mut self, entry: MappingEntry) {
+		self.0.push(entry)
+	}
+}
+
+#[derive(Debug, Clone)]
+struct Mapping {
+	up: [KeyMappingEntries; NUMBER_OF_KEYS],
+	down: [KeyMappingEntries; NUMBER_OF_KEYS],
+	pointer_move: KeyMappingEntries,
+}
+
+macro_rules! modifiers {
+	($($m:ident),*) => {{
+		#[allow(unused_mut)]
+		let mut state = KeyStates::new();
+		$(
+			state.set(Key::$m as usize);
+		),*
+		state
+	}};
+}
+macro_rules! entry {
+	{action=$action:expr, key_down=$key:ident $(, modifiers=[$($m:ident),* $(,)?])?} => {{
+		entry!{action=$action, message=InputMapperMessage::KeyDown(Key::$key) $(, modifiers=[$($m),*])?}
+	}};
+	{action=$action:expr, key_up=$key:ident $(, modifiers=[$($m:ident),* $(,)?])?} => {{
+		entry!{action=$action, message=InputMapperMessage::KeyUp(Key::$key) $(, modifiers=[$($m),* ])?}
+	}};
+	{action=$action:expr, message=$message:expr $(, modifiers=[$($m:ident),* $(,)?])?} => {{
+		MappingEntry {trigger: $message, modifiers: modifiers!($($($m),*)?), action: $action.into()}
+	}};
+}
+macro_rules! mapping {
+	//[$(<action=$action:expr; message=$key:expr; $(modifiers=[$($m:ident),* $(,)?];)?>)*] => {{
+	[$($entry:expr),* $(,)?] => {{
+		let mut up: [KeyMappingEntries; NUMBER_OF_KEYS] = Default::default();
+		let mut down: [KeyMappingEntries; NUMBER_OF_KEYS] = Default::default();
+		let mut pointer_move: KeyMappingEntries = Default::default();
+		$(
+			let arr = match $entry.trigger {
+				InputMapperMessage::KeyDown(key) => &mut down[key as usize],
+				InputMapperMessage::KeyUp(key) => &mut up[key as usize],
+				InputMapperMessage::PointerMove => &mut pointer_move,
+			};
+			arr.push($entry);
+		)*
+		(up, down, pointer_move)
+	}};
+}
+
+impl Default for Mapping {
+	fn default() -> Self {
+		let (up, down, pointer_move) = mapping![
+			// Rectangle
+			entry! {action=RectangleMessage::Center, key_down=KeyAlt},
+			entry! {action=RectangleMessage::UnCenter, key_up=KeyAlt},
+			entry! {action=RectangleMessage::MouseMove, message=InputMapperMessage::PointerMove},
+			entry! {action=RectangleMessage::DragStart, key_down=Lmb},
+			entry! {action=RectangleMessage::DragStop, key_up=Lmb},
+			entry! {action=RectangleMessage::Abort, key_down=Rmb},
+			entry! {action=RectangleMessage::Abort, key_down=KeyEscape},
+			entry! {action=RectangleMessage::LockAspectRatio, key_down=KeyShift},
+			entry! {action=RectangleMessage::UnlockAspectRatio, key_up=KeyShift},
+			entry! {action=RectangleMessage::LockAspectRatio, key_down=KeyCaps},
+			entry! {action=RectangleMessage::UnlockAspectRatio, key_up=KeyCaps},
+			// Ellipse
+			entry! {action=EllipseMessage::Center, key_down=KeyAlt},
+			entry! {action=EllipseMessage::UnCenter, key_up=KeyAlt},
+			entry! {action=EllipseMessage::MouseMove, message=InputMapperMessage::PointerMove},
+			entry! {action=EllipseMessage::DragStart, key_down=Lmb},
+			entry! {action=EllipseMessage::DragStop, key_up=Lmb},
+			entry! {action=EllipseMessage::Abort, key_down=Rmb},
+			entry! {action=EllipseMessage::Abort, key_down=KeyEscape},
+			entry! {action=EllipseMessage::LockAspectRatio, key_down=KeyShift},
+			entry! {action=EllipseMessage::UnlockAspectRatio, key_up=KeyShift},
+			entry! {action=EllipseMessage::LockAspectRatio, key_down=KeyCaps},
+			entry! {action=EllipseMessage::UnlockAspectRatio, key_up=KeyCaps},
+			// Shape
+			entry! {action=ShapeMessage::Center, key_down=KeyAlt},
+			entry! {action=ShapeMessage::UnCenter, key_up=KeyAlt},
+			entry! {action=ShapeMessage::MouseMove, message=InputMapperMessage::PointerMove},
+			entry! {action=ShapeMessage::DragStart, key_down=Lmb},
+			entry! {action=ShapeMessage::DragStop, key_up=Lmb},
+			entry! {action=ShapeMessage::Abort, key_down=Rmb},
+			entry! {action=ShapeMessage::Abort, key_down=KeyEscape},
+			entry! {action=ShapeMessage::LockAspectRatio, key_down=KeyShift},
+			entry! {action=ShapeMessage::UnlockAspectRatio, key_up=KeyShift},
+			entry! {action=ShapeMessage::LockAspectRatio, key_down=KeyCaps},
+			entry! {action=ShapeMessage::UnlockAspectRatio, key_up=KeyCaps},
+			// Line
+			entry! {action=LineMessage::Center, key_down=KeyAlt},
+			entry! {action=LineMessage::UnCenter, key_up=KeyAlt},
+			entry! {action=LineMessage::MouseMove, message=InputMapperMessage::PointerMove},
+			entry! {action=LineMessage::DragStart, key_down=Lmb},
+			entry! {action=LineMessage::DragStop, key_up=Lmb},
+			entry! {action=LineMessage::Abort, key_down=Rmb},
+			entry! {action=LineMessage::Abort, key_down=KeyEscape},
+			entry! {action=LineMessage::LockAngle, key_down=KeyControl},
+			entry! {action=LineMessage::UnlockAngle, key_up=KeyControl},
+			entry! {action=LineMessage::SnapToAngle, key_down=KeyShift},
+			entry! {action=LineMessage::UnSnapToAngle, key_up=KeyShift},
+			entry! {action=LineMessage::SnapToAngle, key_down=KeyCaps},
+			entry! {action=LineMessage::UnSnapToAngle, key_up=KeyCaps},
+			// Pen
+			entry! {action=PenMessage::MouseMove, message=InputMapperMessage::PointerMove},
+			entry! {action=PenMessage::DragStart, key_down=Lmb},
+			entry! {action=PenMessage::DragStop, key_up=Lmb},
+			entry! {action=PenMessage::Confirm, key_down=Rmb},
+			entry! {action=PenMessage::Confirm, key_down=KeyEscape},
+			entry! {action=PenMessage::Confirm, key_down=KeyEnter},
+			// Document Actions
+			entry! {action=DocumentMessage::Undo, key_down=KeyZ, modifiers=[KeyControl]},
+			// Tool Actions
+			entry! {action=ToolMessage::SelectTool(ToolType::Rectangle), key_down=KeyM},
+			entry! {action=ToolMessage::SelectTool(ToolType::Ellipse), key_down=KeyE},
+			entry! {action=ToolMessage::SelectTool(ToolType::Select), key_down=KeyV},
+			entry! {action=ToolMessage::SelectTool(ToolType::Line), key_down=KeyL},
+			entry! {action=ToolMessage::SelectTool(ToolType::Shape), key_down=KeyY},
+			entry! {action=ToolMessage::SwapColors, key_down=KeyX, modifiers=[KeyShift]},
+			// Global Actions
+			entry! {action=GlobalMessage::LogInfo, key_down=Key1},
+			entry! {action=GlobalMessage::LogDebug, key_down=Key2},
+			entry! {action=GlobalMessage::LogTrace, key_down=Key3},
+		];
+		Self { up, down, pointer_move }
+	}
+}
+
+impl Mapping {
+	fn match_message(&self, message: InputMapperMessage, keys: &KeyStates, actions: ActionList) -> Option<Message> {
+		use InputMapperMessage::*;
+		let list = match message {
+			KeyDown(key) => &self.down[key as usize],
+			KeyUp(key) => &self.up[key as usize],
+			PointerMove => &self.pointer_move,
+		};
+		list.match_mapping(keys, actions)
+	}
+}
+
+#[derive(Debug, Default)]
+pub struct InputMapper {
+	mapping: Mapping,
+}
+
+impl MessageHandler<InputMapperMessage, (&InputPreprocessor, ActionList)> for InputMapper {
+	fn process_action(&mut self, message: InputMapperMessage, data: (&InputPreprocessor, ActionList), responses: &mut VecDeque<Message>) {
+		let (input, actions) = data;
+		if let Some(message) = self.mapping.match_message(message, &input.keyboard, actions) {
+			responses.push_back(message);
+		}
+	}
+	advertise_actions!();
+}

core/editor/src/input/input_preprocessor.rs

@@ -0,0 +1,74 @@
+use super::keyboard::{Key, KeyStates};
+use super::mouse::{MouseKeys, MouseState, ViewportPosition};
+use crate::message_prelude::*;
+
+#[doc(inline)]
+pub use document_core::DocumentResponse;
+
+#[impl_message(Message, InputPreprocessor)]
+#[derive(PartialEq, Clone, Debug)]
+pub enum InputPreprocessorMessage {
+	MouseDown(MouseState),
+	MouseUp(MouseState),
+	MouseMove(ViewportPosition),
+	KeyUp(Key),
+	KeyDown(Key),
+}
+
+#[derive(Debug, Default)]
+pub struct InputPreprocessor {
+	pub keyboard: KeyStates,
+	pub mouse: MouseState,
+}
+
+enum KeyPosition {
+	Pressed,
+	Released,
+}
+
+impl MessageHandler<InputPreprocessorMessage, ()> for InputPreprocessor {
+	fn process_action(&mut self, message: InputPreprocessorMessage, _data: (), responses: &mut VecDeque<Message>) {
+		let response = match message {
+			InputPreprocessorMessage::MouseMove(pos) => {
+				self.mouse.position = pos;
+				InputMapperMessage::PointerMove.into()
+			}
+			InputPreprocessorMessage::MouseDown(state) => self.translate_mouse_event(state, KeyPosition::Pressed),
+			InputPreprocessorMessage::MouseUp(state) => self.translate_mouse_event(state, KeyPosition::Released),
+			InputPreprocessorMessage::KeyDown(key) => {
+				self.keyboard.set(key as usize);
+				InputMapperMessage::KeyDown(key).into()
+			}
+			InputPreprocessorMessage::KeyUp(key) => {
+				self.keyboard.unset(key as usize);
+				InputMapperMessage::KeyUp(key).into()
+			}
+		};
+		responses.push_back(response)
+	}
+	// clean user input and if possible reconstruct it
+	// store the changes in the keyboard if it is a key event
+	// transform canvas coordinates to document coordinates
+	advertise_actions!();
+}
+
+impl InputPreprocessor {
+	fn translate_mouse_event(&mut self, new_state: MouseState, position: KeyPosition) -> Message {
+		// Calculate the difference between the two key states (binary xor)
+		let diff = self.mouse.mouse_keys ^ new_state.mouse_keys;
+		self.mouse = new_state;
+		let key = match diff {
+			MouseKeys::LEFT => Key::Lmb,
+			MouseKeys::RIGHT => Key::Rmb,
+			MouseKeys::MIDDLE => Key::Mmb,
+			_ => {
+				log::warn!("The number of buttons modified at the same time was not equal to 1. Modification: {:#010b}", diff);
+				Key::UnknownKey
+			}
+		};
+		match position {
+			KeyPosition::Pressed => InputMapperMessage::KeyDown(key).into(),
+			KeyPosition::Released => InputMapperMessage::KeyUp(key).into(),
+		}
+	}
+}

core/editor/src/input/keyboard.rs

@@ -0,0 +1,143 @@
+pub const NUMBER_OF_KEYS: usize = Key::NumKeys as usize;
+// Edit this to specify the storage type used
+// TODO: Increase size of type
+pub type StorageType = u8;
+const STORAGE_SIZE: u32 = std::mem::size_of::<usize>() as u32 * 8 + 2 - std::mem::size_of::<StorageType>().leading_zeros();
+const STORAGE_SIZE_BITS: usize = 1 << STORAGE_SIZE;
+const KEY_MASK_STORAGE_LENGTH: usize = (NUMBER_OF_KEYS + STORAGE_SIZE_BITS - 1) >> STORAGE_SIZE;
+pub type KeyStates = BitVector<KEY_MASK_STORAGE_LENGTH>;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum Key {
+	UnknownKey,
+	// MouseKeys
+	Lmb,
+	Rmb,
+	Mmb,
+
+	// Keyboard keys
+	KeyR,
+	KeyM,
+	KeyE,
+	KeyL,
+	KeyP,
+	KeyV,
+	KeyX,
+	KeyZ,
+	KeyY,
+	KeyEnter,
+	Key0,
+	Key1,
+	Key2,
+	Key3,
+	Key4,
+	Key5,
+	Key6,
+	Key7,
+	Key8,
+	Key9,
+	KeyShift,
+	KeyCaps,
+	KeyControl,
+	KeyAlt,
+	KeyEscape,
+
+	// This has to be the last element in the enum.
+	NumKeys,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct BitVector<const LENGTH: usize>([StorageType; LENGTH]);
+
+use std::{
+	fmt::{Display, Formatter},
+	ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign},
+	usize,
+};
+
+impl<const LENGTH: usize> BitVector<LENGTH> {
+	#[inline]
+	fn convert_index(bitvector_index: usize) -> (usize, StorageType) {
+		let bit = 1 << (bitvector_index & (STORAGE_SIZE_BITS as StorageType - 1) as usize);
+		let offset = bitvector_index >> STORAGE_SIZE;
+		(offset, bit)
+	}
+	pub const fn new() -> Self {
+		Self([0; LENGTH])
+	}
+	pub fn set(&mut self, bitvector_index: usize) {
+		let (offset, bit) = Self::convert_index(bitvector_index);
+		self.0[offset] |= bit;
+	}
+	pub fn unset(&mut self, bitvector_index: usize) {
+		let (offset, bit) = Self::convert_index(bitvector_index);
+		self.0[offset] &= !bit;
+	}
+	pub fn toggle(&mut self, bitvector_index: usize) {
+		let (offset, bit) = Self::convert_index(bitvector_index);
+		self.0[offset] ^= bit;
+	}
+	pub fn is_empty(&self) -> bool {
+		let mut result = 0;
+		for storage in self.0.iter() {
+			result |= storage;
+		}
+		result == 0
+	}
+}
+
+impl<const LENGTH: usize> Default for BitVector<LENGTH> {
+	fn default() -> Self {
+		Self::new()
+	}
+}
+
+impl<const LENGTH: usize> Display for BitVector<LENGTH> {
+	fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+		for storage in self.0.iter().rev() {
+			write!(f, "{:0width$b}", storage, width = STORAGE_SIZE_BITS)?;
+		}
+		Ok(())
+	}
+}
+
+macro_rules! bit_ops {
+	($(($op:ident, $func:ident)),* $(,)?) => {
+		$(
+			impl<const LENGTH: usize> $op for BitVector<LENGTH> {
+				type Output = Self;
+				fn $func(self, right: Self) -> Self::Output {
+					let mut result = Self::new();
+					for ((left, right), new) in self.0.iter().zip(right.0.iter()).zip(result.0.iter_mut()) {
+						*new = $op::$func(left, right);
+					}
+					result
+				}
+			}
+			impl<const LENGTH: usize> $op for &BitVector<LENGTH> {
+				type Output = BitVector<LENGTH>;
+				fn $func(self, right: Self) -> Self::Output {
+					let mut result = BitVector::<LENGTH>::new();
+					for ((left, right), new) in self.0.iter().zip(right.0.iter()).zip(result.0.iter_mut()) {
+						*new = $op::$func(left, right);
+					}
+					result
+				}
+			}
+		)*
+	};
+}
+macro_rules! bit_ops_assign {
+	($(($op:ident, $func:ident)),* $(,)?) => {
+		$(impl<const LENGTH: usize> $op for BitVector<LENGTH> {
+			fn $func(&mut self, right: Self)  {
+				for (left, right) in self.0.iter_mut().zip(right.0.iter()) {
+					$op::$func(left, right);
+				}
+			}
+		})*
+	};
+}
+
+bit_ops!((BitAnd, bitand), (BitOr, bitor), (BitXor, bitxor));
+bit_ops_assign!((BitAndAssign, bitand_assign), (BitOrAssign, bitor_assign), (BitXorAssign, bitxor_assign));

core/editor/src/input/mod.rs

@@ -0,0 +1,9 @@
+pub mod input_mapper;
+pub mod input_preprocessor;
+pub mod keyboard;
+pub mod mouse;
+
+pub use {
+	input_mapper::{InputMapper, InputMapperMessage, InputMapperMessageDiscriminant},
+	input_preprocessor::{InputPreprocessor, InputPreprocessorMessage, InputPreprocessorMessageDiscriminant},
+};

core/editor/src/input/mouse.rs

@@ -0,0 +1,48 @@
+use bitflags::bitflags;
+
+// origin is top left
+#[derive(Debug, Copy, Clone, Default, Eq, PartialEq)]
+pub struct ViewportPosition {
+	pub x: u32,
+	pub y: u32,
+}
+
+impl ViewportPosition {
+	pub fn distance(&self, other: &Self) -> f64 {
+		let x_diff = other.x as i64 - self.x as i64;
+		let y_diff = other.y as i64 - self.y as i64;
+		f64::sqrt((x_diff * x_diff + y_diff * y_diff) as f64)
+	}
+}
+
+#[derive(Debug, Copy, Clone, Default, Eq, PartialEq)]
+pub struct MouseState {
+	pub position: ViewportPosition,
+	pub mouse_keys: MouseKeys,
+}
+
+impl MouseState {
+	pub fn new() -> MouseState {
+		Self::default()
+	}
+
+	pub fn from_pos(x: u32, y: u32) -> MouseState {
+		MouseState {
+			position: ViewportPosition { x, y },
+			mouse_keys: MouseKeys::default(),
+		}
+	}
+	pub fn from_u8_pos(keys: u8, position: ViewportPosition) -> Self {
+		let mouse_keys = MouseKeys::from_bits(keys).expect("invalid modifier keys");
+		Self { position, mouse_keys }
+	}
+}
+bitflags! {
+	#[derive(Default)]
+	#[repr(transparent)]
+	pub struct MouseKeys: u8 {
+		const LEFT   = 0b0000_0001;
+		const RIGHT  = 0b0000_0010;
+		const MIDDLE = 0b0000_0100;
+	}
+}