Start implementing Canvas backend

- Implement first POC Drawing type

- Start documenting process

- Update dependencies

- Formatting

.github/workflows/ci.yml

@@ -223,7 +223,7 @@ jobs:
 
       - name: Publish site
         if: github.event_name != 'pull_request' && github.ref == 'refs/heads/main'
-        uses: peaceiris/actions-gh-pages@v3.9.3
+        uses: peaceiris/actions-gh-pages@v4.0.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: docs/target/docs/site

build.sbt

@@ -263,7 +263,11 @@ lazy val svg = crossProject(JSPlatform, JVMPlatform)
 
 lazy val canvas = project
   .in(file("canvas"))
-  .settings(commonSettings, moduleName := "doode-canvas")
+  .settings(
+    commonSettings,
+    libraryDependencies += Dependencies.scalajsDom.value,
+    moduleName := "doode-canvas"
+  )
   .dependsOn(core.js)
   .enablePlugins(ScalaJSPlugin)
 

canvas/src/main/scala/doodle/canvas/algebra/Drawing.scala

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2015 Creative Scala
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package doodle.canvas.algebra
+
+import org.scalajs.dom.CanvasRenderingContext2D
+
+/** A canvas `Drawing` is a function that, when applied, produces a value of
+  * type `A` and has the side-effect of drawing on the canvas.
+  */
+opaque type Drawing[A] = Function[CanvasRenderingContext2D, A]
+object Drawing {
+  def apply[A](f: CanvasRenderingContext2D => A): Drawing[A] = f
+}

docs/src/pages/README.md

@@ -20,6 +20,7 @@ See the ScalaDoc @:api(doodle.index) for API documentation.
 ## Community
 
 Join the [Creative Scala Discord][discord].
+
 [discord]: https://discord.gg/rRhcFbJxVG
 
 

docs/src/pages/development/backend.md

@@ -0,0 +1,8 @@
+# Implementing a Backend
+
+This is a quick guide to implementing a backend. It assume familiarity with the major [concepts](../concepts/README.md) of Doodle.
+
+
+## Drawing Type
+
+Deciding on the `Drawing` type is the first step in implementing a backend. It must have the shape `Drawing[A]`, where `A` is the value produced when drawing the drawing.

docs/src/pages/development/directory.conf

@@ -0,0 +1,4 @@
+laika.navigationOrder = [
+  README.md
+  backend.md
+]

project/Dependencies.scala

@@ -10,6 +10,7 @@ object Dependencies {
   val fs2Version = "3.10.0"
 
   val scalatagsVersion = "0.12.0"
+  val scalajsDomVersion = "2.2.0"
 
   val batikVersion = "1.17"
 
@@ -25,6 +26,7 @@ object Dependencies {
   val fs2 = Def.setting("co.fs2" %%% "fs2-core" % fs2Version)
 
   val scalatags = Def.setting("com.lihaoyi" %%% "scalatags" % scalatagsVersion)
+  val scalajsDom = Def.setting("org.scala-js" %%% "scalajs-dom" % scalajsDomVersion)
 
   val batik =
     Def.setting("org.apache.xmlgraphics" % "batik-transcoder" % batikVersion)

project/plugins.sbt

@@ -3,5 +3,5 @@ addSbtPlugin("com.timushev.sbt" % "sbt-updates" % "0.6.4")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")
 addSbtPlugin("com.github.sbt" % "sbt-unidoc" % "0.5.0")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.12.0")
-addSbtPlugin("org.typelevel" % "sbt-typelevel" % "0.6.7")
-addSbtPlugin("org.typelevel" % "sbt-typelevel-site" % "0.6.7")
+addSbtPlugin("org.typelevel" % "sbt-typelevel" % "0.7.1")
+addSbtPlugin("org.typelevel" % "sbt-typelevel-site" % "0.7.1")