Add command and query modules

canvas/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+orfail = { version = "1.1.0", features = ["serde"] }
 pati = { version = "0.2", path = "../pati/" }
 serde = { version = "1.0.188", features = ["derive"] }
 serde_json = "1.0.107"

canvas/src/canvas.rs

@@ -1,2 +1,64 @@
-#[derive(Debug)]
-pub struct Canvas {}
+use crate::{
+    command::CanvasCommand,
+    query::{CanvasQuery, CanvasQueryValue},
+};
+use orfail::OrFail;
+use pati::{Color, Image, Point};
+
+#[derive(Debug, Default)]
+pub struct Canvas {
+    image: Image,
+    cursor: Point,
+    camera: Point,
+    brush_color: Color,
+    background_color: Color,
+}
+
+impl Canvas {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn image(&self) -> &Image {
+        &self.image
+    }
+
+    pub fn cursor(&self) -> Point {
+        self.cursor
+    }
+
+    pub fn camera(&self) -> Point {
+        self.camera
+    }
+
+    pub fn brush_color(&self) -> Color {
+        self.brush_color
+    }
+
+    pub fn background_color(&self) -> Color {
+        self.background_color
+    }
+
+    pub fn query(&self, query: &CanvasQuery) -> CanvasQueryValue {
+        match query {
+            CanvasQuery::Cursor => CanvasQueryValue::Cursor(self.cursor),
+            CanvasQuery::Camera => CanvasQueryValue::Camera(self.camera),
+            CanvasQuery::BrushColor => CanvasQueryValue::BrushColor(self.brush_color),
+            CanvasQuery::BackgroundColor => {
+                CanvasQueryValue::BackgroundColor(self.background_color)
+            }
+        }
+    }
+
+    pub fn command(&mut self, command: &CanvasCommand) -> orfail::Result<()> {
+        match command {
+            CanvasCommand::Move(c) => self.handle_move(*c).or_fail()?,
+        }
+        Ok(())
+    }
+
+    fn handle_move(&mut self, delta: Point) -> orfail::Result<()> {
+        self.cursor = self.cursor + delta;
+        Ok(())
+    }
+}

canvas/src/command.rs

@@ -1,7 +1,8 @@
+use pati::Point;
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 pub enum CanvasCommand {
-    //
+    Move(Point),
 }

canvas/src/lib.rs

@@ -1,5 +1,6 @@
+pub mod command;
+pub mod query;
+
 mod canvas;
-mod command;
 
 pub use canvas::Canvas;
-pub use command::CanvasCommand;

canvas/src/query.rs

@@ -0,0 +1,20 @@
+use pati::{Color, Point};
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum CanvasQuery {
+    Cursor,
+    Camera,
+    BrushColor,
+    BackgroundColor,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum CanvasQueryValue {
+    Cursor(Point),
+    Camera(Point),
+    BrushColor(Color),
+    BackgroundColor(Color),
+}