X11 implementation of druid-shell (#599)

* Skeleton X11 backend; everything is unimplemented!()

* Compiles and runs, but does nothing.

* Huge hacks to try to get X11 window painting working

* It draws stuff!

* Schedule redraws by sleeping (TODO: fix later)

* Make menu functions no-ops so the 'shello' example doesn't crash

* Make TODOs easier to grep

* Knock out a bunch of the easier 'initial_pr' TODOs

* implement WindowHandle::close and WindowHandle::bring_to_front_and_focus

* Run github workflows for druid_shell_x11 branch; fix workflow errors

* keycodes

* mouse down

* review updates

* Quick cleanup of X11 platform code before PR

* [ci] Run x11 backend in ci

This also includes some general ci tweaks to make things a bit
more sensible, optimistically.

* Post merge fixes

* s/use_x11/x11

* Fix X11 hackery in examples

* Update copyright year in druid-shell/src/platform/x11 files

* Delete runloop.rs

* Turn all unimplemented!() calls into log::warn!() calls

* Return unknown keycode directly instead of using unreachable!()

* Update visibility on XWindow to pub(crate) instead of pub

* Fix clippy warnings for X11 implementation

* Small PR review cleanups

* update README with X11 info

* Re-create X11 piet context every redraw

* Communicate window size back to Druid

* handle mouse_up and mouse_move

* Make X11 window respond to window resize events.

* Flush XCB event queue when requesting redraw

* Code review fixes

Co-authored-by: Per Lindgren <[email protected]>
Co-authored-by: Per <Per Lindgren>
Co-authored-by: Colin Rofls <[email protected]>

Author: 3 people

.github/workflows/ci.yml

@@ -78,40 +78,47 @@ jobs:
           profile: minimal
           override: true
 
-      - name: cargo clippy (no-svg)
+      - name: cargo clippy (druid)
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --all -- -D warnings
-        if: contains(matrix.os, 'ubuntu') != true
+          args: --manifest-path=druid/Cargo.toml --features=svg,image -- -D warnings
 
-      - name: cargo clippy (svg)
+      - name: cargo clippy (druid-shell)
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --all --all-features -- -D warnings
-        if: contains(matrix.os, 'ubuntu')
+          args: --manifest-path=druid-shell/Cargo.toml -- -D warnings
 
+      - name: cargo clippy (druid-derive)
+        uses: actions-rs/cargo@v1
+        with:
+          command: clippy
+          args: --manifest-path=druid-derive/Cargo.toml -- -D warnings
 
-      - name: cargo test --all
+      - name: cargo test (druid)
         uses: actions-rs/cargo@v1
         with:
           command: test
-          args: --all
-        if: contains(matrix.os, 'ubuntu') != true
+          args: --manifest-path=druid/Cargo.toml --features=svg,image
 
-      - name: cargo test --all --all-features
+      - name: cargo test (druid-shell)
         uses: actions-rs/cargo@v1
         with:
           command: test
-          args: --all --all-features
-        if: contains(matrix.os, 'ubuntu')
+          args: --manifest-path=druid-shell/Cargo.toml
+
+      - name: cargo test (druid-derive)
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --manifest-path=druid-shell/Cargo.toml
 
       - name: Run rustc -D warnings in druid/
         uses: actions-rs/cargo@v1
         with:
           command: rustc
-          args: --manifest-path=druid/Cargo.toml -- -D warnings
+          args: --manifest-path=druid/Cargo.toml --features=svg,image -- -D warnings
 
       - name: Run rustc -d warnings in druid/druid-shell
         uses: actions-rs/cargo@v1
@@ -188,3 +195,47 @@ jobs:
         with:
           command: doc
           args: --document-private-items
+
+  # by default on linux we test gtk; to test x11 we need a separate job.
+  test-stable-x11:
+    runs-on: ubuntu-latest
+    name: cargo test stable (x11)
+    steps:
+      - uses: actions/checkout@v1
+
+      - name: install deps
+        run: |
+          sudo apt update
+          sudo apt install libx11-dev libgtk-3-dev
+
+      - name: install stable toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          components: clippy
+          profile: minimal
+          override: true
+
+      - name: cargo clippy (x11)
+        uses: actions-rs/cargo@v1
+        with:
+          command: clippy
+          args: --manifest-path=druid-shell/Cargo.toml --features=x11 -- -D warnings
+
+      - name: cargo test druid-shell
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --manifest-path=druid-shell/Cargo.toml --features=x11
+
+      - name: cargo test druid
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --manifest-path=druid/Cargo.toml --features=x11
+
+      - name: Run rustc -d warnings in druid/druid-shell
+        uses: actions-rs/cargo@v1
+        with:
+          command: rustc
+          args: --manifest-path=druid-shell/Cargo.toml  --features=x11 -- -D warnings

Cargo.lock

@@ -246,6 +246,10 @@ should be sufficient. Removing this dependency is on the roadmap.
 On Linux, druid requires gtk+3; see [gtk-rs dependencies] for installation
 instructions.
 
+Alternatively, there is an X11 backend available, although it is currently
+[missing quite a few features](https://github.com/xi-editor/druid/issues/475).
+You can try it out with `--features=x11`.
+
 ## Alternatives
 
 Druid is only one of many ongoing [Rust-native GUI experiments]. To mention a

README.md

@@ -11,6 +11,7 @@ edition = "2018"
 
 [features]
 use_gtk = ["gtk", "gtk-sys", "gio", "gdk", "gdk-sys", "glib", "glib-sys", "cairo-rs"]
+x11 = ["xcb", "cairo-sys-rs"]
 
 [package.metadata.docs.rs]
 default-target = "x86_64-pc-windows-msvc"
@@ -25,13 +26,15 @@ cfg-if = "0.1.10"
 kurbo = "0.5.11"
 
 cairo-rs = {  version = "0.8.1", default_features = false, optional = true }
+cairo-sys-rs = { version = "0.9.2", default_features = false, optional = true }
 gio = { version = "0.8.1", optional = true }
 gdk = { version = "0.12.1", optional = true }
 gdk-sys = { version = "0.9.0", optional = true }
 gtk = { version = "0.8.1", optional = true }
 glib = { version = "0.9.3", optional = true }
 glib-sys = { version = "0.9.0", optional = true }
 gtk-sys = { version = "0.9.0", optional = true }
+xcb = { version = "0.9.0", features = ["thread", "xlib_xcb", "randr"], optional = true }
 
 [target.'cfg(target_os="windows")'.dependencies]
 wio = "0.2"
@@ -45,8 +48,9 @@ cocoa = "0.20.0"
 objc = "0.2.5"
 cairo-rs = { version = "0.8.1", default_features = false }
 
+# TODO(x11/dependencies): only use feature "xcb" if using XCB
 [target.'cfg(target_os="linux")'.dependencies]
-cairo-rs = {  version = "0.8.1", default_features = false }
+cairo-rs = {  version = "0.8.1", default_features = false, features = ["xcb"] }
 gio = "0.8.1"
 gdk = "0.12.1"
 gdk-sys = "0.9.0"

druid-shell/Cargo.toml

@@ -121,5 +121,6 @@ fn main() {
 
     let window = builder.build().unwrap();
     window.show();
+
     app.run();
 }

druid-shell/examples/perftest.rs

@@ -67,6 +67,7 @@ impl WinHandler for HelloState {
         let deadline = std::time::Instant::now() + std::time::Duration::from_millis(500);
         let id = self.handle.request_timer(deadline);
         println!("keydown: {:?}, timer id = {:?}", event, id);
+
         false
     }
 
@@ -133,8 +134,9 @@ fn main() {
     builder.set_handler(Box::new(HelloState::default()));
     builder.set_title("Hello example");
     builder.set_menu(menubar);
-    let window = builder.build().unwrap();
 
+    let window = builder.build().unwrap();
     window.show();
+
     app.run();
 }

druid-shell/examples/shello.rs

@@ -21,6 +21,7 @@ use std::sync::atomic::{AtomicU64, Ordering};
 /// Strip the access keys from the menu string.
 ///
 /// Changes "E&xit" to "Exit". Actual ampersands are escaped as "&&".
+#[cfg(not(feature = "x11"))]
 #[cfg(any(target_os = "macos", target_os = "linux"))]
 pub fn strip_access_key(raw_menu_text: &str) -> String {
     let mut saw_ampersand = false;

druid-shell/src/common_util.rs

@@ -23,6 +23,7 @@ pub struct FileInfo {
 }
 
 /// Type of file dialog.
+#[cfg(not(feature = "x11"))]
 pub enum FileDialogType {
     /// File open dialog.
     Open,

druid-shell/src/dialog.rs

@@ -36,6 +36,10 @@ extern crate objc;
 #[macro_use]
 extern crate lazy_static;
 
+#[cfg(all(target_os = "linux", feature = "x11"))]
+#[macro_use]
+extern crate lazy_static;
+
 mod application;
 mod clipboard;
 mod common_util;

druid-shell/src/lib.rs

@@ -21,6 +21,9 @@ cfg_if::cfg_if! {
     } else if #[cfg(all(target_os = "macos", not(feature = "use_gtk")))] {
         mod mac;
         pub use mac::*;
+    } else if #[cfg(all(feature = "x11", target_os = "linux"))] {
+        mod x11;
+        pub use x11::*;
     } else if #[cfg(any(feature = "use_gtk", target_os = "linux"))] {
         mod gtk;
         pub use self::gtk::*;