Switch to using Artifacts for assets/

Makes `AbstractPlotting` more amenable to inclusion in a relocated
system image where the original source directories may not exist
anymore.

.gitignore

@@ -12,5 +12,6 @@ phases.0001_print.jpg
 **/._*
 Manifest.toml
 !docs/Manifest.toml
+/build
 
 \.DS_Store

Artifacts.toml

@@ -0,0 +1,6 @@
+[assets]
+git-tree-sha1 = "a74800f299f6bdade309e459b999442f303aa64d"
+
+    [[assets.download]]
+    sha256 = "7ccfd273ff2ac996059d9019ff317202bdc69aef394fe450be557df9aae81733"
+    url = "https://github.com/JuliaPlots/AbstractPlotting.jl/releases/download/assets-0.1.0/assets-0.1.0.tar.gz"

Project.toml

@@ -5,6 +5,7 @@ version = "0.18.2"
 
 [deps]
 Animations = "27a7e980-b3e6-11e9-2bcd-0b925532e340"
+Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
 ColorBrewer = "a2cac450-b92f-5266-8821-25eda20663c8"
 ColorSchemes = "35d6a980-a343-548e-a6ea-1d62b119f2f4"
 ColorTypes = "3da002f7-5984-5a60-b8a6-cbb66c0b333f"

artifacts.jl

@@ -0,0 +1,33 @@
+# Artifact generator for the assets directory.
+
+using Pkg.Artifacts
+using URIs
+
+version = v"0.1.0"
+host = "https://github.com/JuliaPlots/AbstractPlotting.jl/releases/download"
+
+build_path = joinpath(@__DIR__, "build")
+
+ispath(build_path) && rm(build_path, force=true, recursive=true)
+mkpath(build_path)
+
+product_hash = create_artifact() do artifact_dir
+    cp(joinpath(@__DIR__, "assets"), artifact_dir; force = true)
+end
+
+archive_filename = "assets-$version.tar.gz"
+artifact_toml = joinpath(@__DIR__, "Artifacts.toml")
+download_hash = archive_artifact(product_hash, joinpath(build_path, archive_filename))
+
+bind_artifact!(
+    artifact_toml,
+    "assets",
+    product_hash,
+    force = true,
+    download_info = Tuple[
+        (
+            "$host/assets-$(escapeuri(string(version)))/$archive_filename",
+            download_hash,
+        ),
+    ],
+)

src/AbstractPlotting.jl

@@ -1,5 +1,6 @@
 module AbstractPlotting
 
+using Artifacts
 using Random
 using FFMPEG # get FFMPEG on any system!
 using Observables, GeometryBasics, IntervalSets, PlotUtils
@@ -242,7 +243,7 @@ export cgrad, available_gradients, showgradients
 
 export Pattern
 
-assetpath(files...) = normpath(joinpath(@__DIR__, "..", "assets", files...))
+assetpath(files...) = normpath(joinpath(artifact"assets", files...))
 
 export assetpath
 # default icon for Makie

src/conversions.jl

@@ -915,7 +915,7 @@ function convert_attribute(x::Union{Symbol, String}, k::key"font")
             end
         end
 
-        fontpath = joinpath(@__DIR__, "..", "assets", "fonts")
+        fontpath = assetpath("fonts")
         font = FreeTypeAbstraction.findfont(str; additional_fonts=fontpath)
         if font === nothing
             @warn("Could not find font $str, using Dejavu Sans")