Make GTK dependency optional. (#1241)

Author: luleyleo

CHANGELOG.md

@@ -87,6 +87,7 @@ You can find its changes [documented below](#060---2020-06-01).
 - Switch widget: Toggle animation being window refresh rate dependent ([#1145] by [@ForLoveOfCats])
 - Multi-click on Windows, partial fix for #859 ([#1157] by [@raphlinus])
 - Windows: fix crash on resize from incompatible resources ([#1191 by [@raphlinus]])
+- GTK: Related dependencies are now optional, facilitating a pure X11 build. ([#1241] by [@finnerale])
 
 ### Visual
 
@@ -459,6 +460,7 @@ Last release without a changelog :(
 [#1231]: https://github.com/linebender/druid/pull/1231
 [#1220]: https://github.com/linebender/druid/pull/1220
 [#1238]: https://github.com/linebender/druid/pull/1238
+[#1241]: https://github.com/linebender/druid/pull/1241
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.6.0...master
 [0.6.0]: https://github.com/linebender/druid/compare/v0.5.0...v0.6.0

druid-shell/Cargo.toml

@@ -15,6 +15,8 @@ default-target = "x86_64-pc-windows-msvc"
 
 [features]
 x11 = ["x11rb", "nix", "cairo-sys-rs"]
+gtk = ["gio", "gdk", "gdk-sys", "glib", "glib-sys", "gtk-sys", "gtk-rs"]
+default = ["gtk"]
 
 [dependencies]
 # NOTE: When changing the piet or kurbo versions, ensure that
@@ -30,19 +32,6 @@ instant = { version = "0.1.6", features = ["wasm-bindgen"] }
 anyhow = "1.0.32"
 keyboard-types = { version = "0.5.0", default_features = false }
 
-# Optional dependencies
-cairo-rs = { version = "0.9.1", default_features = false, optional = true }
-cairo-sys-rs = { version = "0.10.0", default_features = false, optional = true }
-gio = { version = "0.9.1", optional = true }
-gdk = { version = "0.13.2", optional = true }
-gdk-sys = { version = "0.10.0", optional = true }
-gtk = { version = "0.9.2", optional = true }
-glib = { version = "0.10.1", optional = true }
-glib-sys = { version = "0.10.0", optional = true }
-gtk-sys = { version = "0.10.0", optional = true }
-nix = { version = "0.18.0", optional = true }
-x11rb = { version = "0.6.0", features = ["allow-unsafe-code", "present", "randr", "xfixes"], optional = true }
-
 [target.'cfg(target_os="windows")'.dependencies]
 wio = "0.2.2"
 
@@ -58,17 +47,22 @@ objc = "0.2.7"
 core-graphics = "0.22.0"
 foreign-types = "0.3.2"
 bitflags = "1.2.1"
+cairo-rs = { version = "0.9.1", default_features = false, optional = true }
 
-# TODO(x11/dependencies): only use feature "xcb" if using X11
 [target.'cfg(target_os="linux")'.dependencies]
+# TODO(x11/dependencies): only use feature "xcb" if using X11
 cairo-rs = { version = "0.9.1", default_features = false, features = ["xcb"] }
-gio = "0.9.1"
-gdk = "0.13.2"
-gdk-sys = "0.10.0"
-glib = "0.10.1"
-glib-sys = "0.10.0"
-gtk-sys = "0.10.0"
-gtk = { version = "0.9.2", features = ["v3_22"] }
+cairo-sys-rs = { version = "0.10.0", default_features = false, optional = true }
+gio = { version = "0.9.1", optional = true }
+gdk = { version = "0.13.2", optional = true }
+gdk-sys = { version = "0.10.0", optional = true }
+# `gtk` gets renamed to `gtk-rs` so that we can use `gtk` as the feature name.
+gtk-rs = { version = "0.9.2", features = ["v3_22"], package = "gtk", optional = true }
+glib = { version = "0.10.1", optional = true }
+glib-sys = { version = "0.10.0", optional = true }
+gtk-sys = { version = "0.10.0", optional = true }
+nix = { version = "0.18.0", optional = true }
+x11rb = { version = "0.6.0", features = ["allow-unsafe-code", "present", "randr", "xfixes"], optional = true }
 
 [target.'cfg(target_arch="wasm32")'.dependencies]
 wasm-bindgen = "0.2.67"

druid-shell/src/lib.rs

@@ -30,6 +30,12 @@
 #![allow(clippy::new_without_default)]
 #![deny(clippy::trivially_copy_pass_by_ref)]
 
+// Rename `gtk_rs` back to `gtk`.
+// This allows us to use `gtk` as the feature name.
+// The `target_os` requirement is there to exclude anything `wasm` like.
+#[cfg(all(target_os = "linux", feature = "gtk"))]
+extern crate gtk_rs as gtk;
+
 pub use kurbo;
 pub use piet_common as piet;
 

druid/Cargo.toml

@@ -21,10 +21,12 @@ default-target = "x86_64-pc-windows-msvc"
 
 [features]
 x11 = ["druid-shell/x11"]
+gtk = ["druid-shell/gtk"]
 svg = ["usvg", "harfbuzz-sys"]
+default = ["gtk"]
 
 [dependencies]
-druid-shell = { version = "0.6.0", path = "../druid-shell" }
+druid-shell = { version = "0.6.0", default-features = false, path = "../druid-shell" }
 druid-derive = { version = "0.3.1", path = "../druid-derive" }
 
 log = "0.4.11"