Add experimental screen_reader feature

Part of https://github.com/emilk/egui/issues/167

Cargo.lock

@@ -66,6 +66,15 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "000444226fcff248f2bc4c7625be32c63caccfecc2723a2b9f78a7487a49c407"
 
+[[package]]
+name = "ansi_term"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+dependencies = [
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "atomic_refcell"
 version = "0.1.6"
@@ -119,6 +128,29 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "bindgen"
+version = "0.57.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd4865004a46a0aafb2a0a5eb19d3c9fc46ee5f063a6cfc605c69ac9ecf5263d"
+dependencies = [
+ "bitflags",
+ "cexpr",
+ "clang-sys",
+ "clap",
+ "env_logger",
+ "lazy_static",
+ "lazycell",
+ "log",
+ "peeking_take_while",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "rustc-hash",
+ "shlex",
+ "which",
+]
+
 [[package]]
 name = "bit-set"
 version = "0.5.2"
@@ -176,6 +208,12 @@ version = "1.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
 
+[[package]]
+name = "bytes"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b700ce4376041dcd0a327fd0097c41095743c4c8af8887265942faf1100bd040"
+
 [[package]]
 name = "calloop"
 version = "0.6.5"
@@ -201,6 +239,21 @@ version = "1.0.67"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
 
+[[package]]
+name = "cesu8"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d43a04d8753f35258c91f8ec639f792891f748a1edbd759cf1dcea3382ad83c"
+
+[[package]]
+name = "cexpr"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4aedb84272dbe89af497cf81375129abda4fc0a9e7c5d317498c15cc30c0d27"
+dependencies = [
+ "nom 5.1.2",
+]
+
 [[package]]
 name = "cfg-if"
 version = "0.1.10"
@@ -241,15 +294,30 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fff857943da45f546682664a79488be82e69e43c1a7a2307679ab9afb3a66d2e"
 
+[[package]]
+name = "clang-sys"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f54d78e30b388d4815220c8dd03fea5656b6c6d32adb59e89061552a102f8da1"
+dependencies = [
+ "glob",
+ "libc",
+ "libloading 0.7.0",
+]
+
 [[package]]
 name = "clap"
 version = "2.33.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37e58ac78573c40708d45522f0d80fa2f01cc4f9b4e2bf749807255454312002"
 dependencies = [
+ "ansi_term",
+ "atty",
  "bitflags",
+ "strsim 0.8.0",
  "textwrap",
  "unicode-width",
+ "vec_map",
 ]
 
 [[package]]
@@ -327,6 +395,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
 
+[[package]]
+name = "combine"
+version = "4.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc4369b5e4c0cddf64ad8981c0111e7df4f7078f4d6ba98fb31f2e17c4c57b7e"
+dependencies = [
+ "bytes",
+ "memchr",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.7.0"
@@ -541,7 +619,7 @@ dependencies = [
  "ident_case",
  "proc-macro2",
  "quote",
- "strsim",
+ "strsim 0.9.3",
  "syn",
 ]
 
@@ -628,6 +706,33 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ea835d29036a4087793836fa931b08837ad5e957da9e23886b29586fb9b6650"
 
+[[package]]
+name = "dyn-clonable"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e9232f0e607a262ceb9bd5141a3dfb3e4db6994b31989bbfd845878cba59fd4"
+dependencies = [
+ "dyn-clonable-impl",
+ "dyn-clone",
+]
+
+[[package]]
+name = "dyn-clonable-impl"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "558e40ea573c374cf53507fd240b7ee2f5477df7cfebdb97323ec61c719399c5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "dyn-clone"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee2626afccd7561a06cf1367e2950c4718ea04565e20fb5029b6c7d8ad09abcf"
+
 [[package]]
 name = "eframe"
 version = "0.10.0"
@@ -678,6 +783,7 @@ dependencies = [
  "glium",
  "serde",
  "serde_json",
+ "tts",
  "ureq",
  "webbrowser",
 ]
@@ -691,6 +797,7 @@ dependencies = [
  "js-sys",
  "serde",
  "serde_json",
+ "tts",
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
@@ -709,6 +816,19 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "env_logger"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17392a012ea30ef05a610aa97dfb49496e71c9f676b27879922ea5bdf60d9d3f"
+dependencies = [
+ "atty",
+ "humantime",
+ "log",
+ "regex",
+ "termcolor",
+]
+
 [[package]]
 name = "epaint"
 version = "0.10.0"
@@ -799,6 +919,12 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 
+[[package]]
+name = "gcc"
+version = "0.3.55"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f5f3913fa0bfe7ee1fd8248b6b9f42a5af4b9d65ec2dd2c3c26132b950ecfc2"
+
 [[package]]
 name = "getrandom"
 version = "0.2.2"
@@ -843,6 +969,12 @@ dependencies = [
  "takeable-option",
 ]
 
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+
 [[package]]
 name = "glutin"
 version = "0.26.0"
@@ -936,6 +1068,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "humantime"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
 [[package]]
 name = "ident_case"
 version = "1.0.1"
@@ -1021,6 +1159,20 @@ version = "0.4.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 
+[[package]]
+name = "jni"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24967112a1e4301ca5342ea339763613a37592b8a6ce6cf2e4494537c7a42faf"
+dependencies = [
+ "cesu8",
+ "combine",
+ "jni-sys",
+ "log",
+ "thiserror",
+ "walkdir",
+]
+
 [[package]]
 name = "jni-sys"
 version = "0.3.0"
@@ -1316,6 +1468,16 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "nom"
+version = "5.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffb4262d26ed83a1c0a33a38fe2bb15797329c85770da05e6b828ddb782627af"
+dependencies = [
+ "memchr",
+ "version_check",
+]
+
 [[package]]
 name = "nom"
 version = "6.1.2"
@@ -1489,6 +1651,12 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "peeking_take_while"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -1683,6 +1851,12 @@ version = "0.1.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e3bad0ee36814ca07d7968269dd4b7ec89ec2da10c4bb613928d3077083c232"
 
+[[package]]
+name = "rustc-hash"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
+
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -1814,6 +1988,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "sha1"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2579985fda508104f7587689507983eadd6a6e84dd35d6d115361f530916fa0d"
+
 [[package]]
 name = "shared_library"
 version = "0.1.9"
@@ -1824,6 +2004,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "shlex"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fdf1b9db47230893d76faad238fd6097fd6d6a9245cd7a4d90dbd639536bbd2"
+
 [[package]]
 name = "slab"
 version = "0.4.2"
@@ -1855,12 +2041,38 @@ dependencies = [
  "wayland-protocols",
 ]
 
+[[package]]
+name = "speech-dispatcher"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "076efad2c03a1c5cc41eaa82c30770130e014f6544769edea79e096a2f134412"
+dependencies = [
+ "lazy_static",
+ "speech-dispatcher-sys",
+]
+
+[[package]]
+name = "speech-dispatcher-sys"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b662a91fe7e39d3d11edcf0297c717a8c05683a6c6445df9aba83b034b2b2db5"
+dependencies = [
+ "bindgen",
+ "gcc",
+]
+
 [[package]]
 name = "spin"
 version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 
+[[package]]
+name = "strsim"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
+
 [[package]]
 name = "strsim"
 version = "0.9.3"
@@ -1906,6 +2118,15 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "36ae8932fcfea38b7d3883ae2ab357b0d57a02caaa18ebb4f5ece08beaec4aa0"
 
+[[package]]
+name = "termcolor"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dfed899f0eb03f32ee8c6a0aabdb8a7949659e3466561fc0adf54e26d88c5f4"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "textwrap"
 version = "0.11.0"
@@ -1994,6 +2215,37 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3e5d7cd7ab3e47dda6e56542f4bbf3824c15234958c6e1bd6aaa347e93499fdc"
 
+[[package]]
+name = "tts"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "592f268a2431704677a2cfa2d712dd0518b99bd1630f5977423e76db1cc826d2"
+dependencies = [
+ "cocoa-foundation",
+ "dyn-clonable",
+ "jni",
+ "lazy_static",
+ "libc",
+ "log",
+ "ndk-glue",
+ "objc",
+ "speech-dispatcher",
+ "thiserror",
+ "tts_winrt_bindings",
+ "wasm-bindgen",
+ "web-sys",
+ "winrt",
+]
+
+[[package]]
+name = "tts_winrt_bindings"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0cf13b200c067076f7a6001b3eac9a97d4fa0a322b10a2f958fd1176a1e1461"
+dependencies = [
+ "winrt",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.4"
@@ -2058,6 +2310,12 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
 [[package]]
 name = "version_check"
 version = "0.9.2"
@@ -2270,6 +2528,15 @@ dependencies = [
  "webpki",
 ]
 
+[[package]]
+name = "which"
+version = "3.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d011071ae14a2f6671d0b74080ae0cd8ebf3a6f8c9589a2cd45f23126fe29724"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "widestring"
 version = "0.4.3"
@@ -2350,6 +2617,53 @@ dependencies = [
  "x11-dl",
 ]
 
+[[package]]
+name = "winrt"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "daf62b1e56a9efd6caec59a053450dd9fe5bc3d0dc28a27d3054b85b68db95a4"
+dependencies = [
+ "sha1",
+ "winrt_macros",
+]
+
+[[package]]
+name = "winrt_gen"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497492d5f30d47cb397c3d5bee37700996822311062a3a609493523ad3bb9ae"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "serde_json",
+ "sha1",
+ "syn",
+ "winrt_gen_macros",
+]
+
+[[package]]
+name = "winrt_gen_macros"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85cd78ebb3f0f35f3d9b7f3272b7afac1904cc3e3f636a0a6e5877d72c78b7d8"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "winrt_macros"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d88594f878eee84909a5d20cad8bfef8587f9e1473ce81b74fbbd4b12748d662"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "winrt_gen",
+]
+
 [[package]]
 name = "ws2_32-sys"
 version = "0.2.1"
@@ -2397,7 +2711,7 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3a9a231574ae78801646617cefd13bfe94be907c0e4fa979cfd8b770aa3c5d08"
 dependencies = [
- "nom",
+ "nom 6.1.2",
 ]
 
 [[package]]

build_demo_web.sh

@@ -13,7 +13,17 @@ rm -f docs/${CRATE_NAME}_bg.wasm
 
 echo "Building rust…"
 BUILD=release
-cargo build --release --all-features -p ${CRATE_NAME} --lib --target wasm32-unknown-unknown
+FEATURES="http,persistence" # screen_reader is experimental
+# FEATURES="http,persistence,screen_reader" # screen_reader is experimental
+
+(
+  cd egui_demo_app && cargo build \
+    -p ${CRATE_NAME} \
+    --release \
+    --lib \
+    --target wasm32-unknown-unknown \
+    --features ${FEATURES}
+)
 
 echo "Generating JS bindings for wasm…"
 TARGET_NAME="${CRATE_NAME}.wasm"

eframe/Cargo.toml

@@ -30,4 +30,5 @@ egui_web = { version = "0.10.0", path = "../egui_web" }
 default = []
 http = ["egui_glium/http", "egui_web/http"]
 persistence = ["epi/persistence", "egui_glium/persistence", "egui_web/persistence"]
+screen_reader = ["egui_glium/screen_reader", "egui_web/screen_reader"] # experimental
 time = ["egui_glium/time"] # for seconds_since_midnight

egui/src/data/output.rs

@@ -31,6 +31,19 @@ impl Output {
     pub fn open_url(&mut self, url: impl Into<String>) {
         self.open_url = Some(OpenUrl::same_tab(url))
     }
+
+    /// This can be used by a text-to-speech system to describe the events (if any).
+    pub fn events_description(&self) -> String {
+        // only describe last event:
+        for event in self.events.iter().rev() {
+            match event {
+                OutputEvent::WidgetEvent(WidgetEvent::Focus, widget_info) => {
+                    return widget_info.description();
+                }
+            }
+        }
+        Default::default()
+    }
 }
 
 #[derive(Clone, PartialEq)]
@@ -202,6 +215,63 @@ impl WidgetInfo {
             ..Self::new(WidgetType::TextEdit)
         }
     }
+
+    /// This can be used by a text-to-speech system to describe the widget.
+    pub fn description(&self) -> String {
+        let Self {
+            typ,
+            label,
+            edit_text,
+            selected,
+            value,
+        } = self;
+
+        // TODO: localization
+        let widget_name = match typ {
+            WidgetType::Label => "",
+            WidgetType::Hyperlink => "link",
+            WidgetType::TextEdit => "text edit",
+            WidgetType::Button => "button",
+            WidgetType::Checkbox => "checkbox",
+            WidgetType::RadioButton => "radio",
+            WidgetType::SelectableLabel => "selectable",
+            WidgetType::ComboBox => "combo",
+            WidgetType::Slider => "slider",
+            WidgetType::DragValue => "drag value",
+            WidgetType::ColorButton => "color button",
+            WidgetType::ImageButton => "image button",
+            WidgetType::CollapsingHeader => "collapsing header",
+            WidgetType::Other => "",
+        };
+
+        let mut description = widget_name.to_owned();
+
+        if let Some(selected) = selected {
+            if *typ == WidgetType::Checkbox {
+                description += " ";
+                description += if *selected { "checked" } else { "unchecked" };
+            } else {
+                description += if *selected { "selected" } else { "" };
+            };
+        }
+
+        if let Some(label) = label {
+            description += " ";
+            description += label;
+        }
+
+        if let Some(edit_text) = edit_text {
+            description += " ";
+            description += edit_text;
+        }
+
+        if let Some(value) = value {
+            description += " ";
+            description += &value.to_string();
+        }
+
+        description.trim().to_owned()
+    }
 }
 
 /// The different types of built-in widgets in egui

egui_demo_app/Cargo.toml

@@ -17,4 +17,5 @@ egui_demo_lib = { version = "0.10.0", path = "../egui_demo_lib" }
 default = ["persistence"]
 http = ["eframe/http", "egui_demo_lib/http"]
 persistence = ["eframe/persistence", "egui_demo_lib/persistence"]
+screen_reader = ["eframe/screen_reader"] # experimental
 syntect = ["egui_demo_lib/syntect"]

egui_glium/Cargo.toml

@@ -31,6 +31,9 @@ directories-next = { version = "2", optional = true }
 serde = { version = "1", optional = true }
 serde_json = { version = "1", optional = true }
 
+# feature screen_reader
+tts = { version = "0.14", optional = true }
+
 # feature "time"
 chrono = { version = "0.4", optional = true }
 
@@ -46,3 +49,4 @@ persistence = [
     "serde",
 ]
 time = ["chrono"] # for seconds_since_midnight
+screen_reader = ["tts"] # experimental

egui_glium/src/backend.rs

@@ -180,6 +180,8 @@ pub fn run(mut app: Box<dyn epi::App>) -> ! {
     #[cfg(feature = "http")]
     let http = std::sync::Arc::new(crate::http::GliumHttp {});
 
+    let mut screen_reader = crate::screen_reader::ScreenReader::default();
+
     if app.warm_up_enabled() {
         // let warm_up_start = Instant::now();
         input_state.raw.time = Some(0.0);
@@ -273,6 +275,7 @@ pub fn run(mut app: Box<dyn epi::App>) -> ! {
                 };
             }
 
+            screen_reader.speak(&egui_output.events_description());
             handle_output(egui_output, &display, clipboard.as_mut());
 
             #[cfg(feature = "persistence")]

egui_glium/src/lib.rs

@@ -15,6 +15,7 @@ pub mod http;
 mod painter;
 #[cfg(feature = "persistence")]
 pub mod persistence;
+pub mod screen_reader;
 pub mod window_settings;
 
 pub use backend::*;

egui_glium/src/screen_reader.rs

@@ -0,0 +1,44 @@
+pub struct ScreenReader {
+    #[cfg(feature = "screen_reader")]
+    tts: Option<tts::TTS>,
+}
+
+#[cfg(not(feature = "screen_reader"))]
+impl Default for ScreenReader {
+    fn default() -> Self {
+        Self {}
+    }
+}
+
+#[cfg(feature = "screen_reader")]
+impl Default for ScreenReader {
+    fn default() -> Self {
+        let tts = match tts::TTS::default() {
+            Ok(screen_reader) => {
+                eprintln!("Initialized screen reader.");
+                Some(screen_reader)
+            }
+            Err(err) => {
+                eprintln!("Failed to load screen reader: {}", err);
+                None
+            }
+        };
+        Self { tts }
+    }
+}
+
+impl ScreenReader {
+    #[cfg(not(feature = "screen_reader"))]
+    pub fn speak(&mut self, _text: &str) {}
+
+    #[cfg(feature = "screen_reader")]
+    pub fn speak(&mut self, text: &str) {
+        if let Some(tts) = &mut self.tts {
+            eprintln!("Speaking: {:?}", text);
+            let interrupt = true;
+            if let Err(err) = tts.speak(text, interrupt) {
+                eprintln!("Failed to read: {}", err);
+            }
+        }
+    }
+}

egui_web/Cargo.toml

@@ -25,6 +25,7 @@ epi = { version = "0.10.0", path = "../epi" }
 js-sys = "0.3"
 serde = { version = "1", optional = true }
 serde_json = { version = "1", optional = true }
+tts = { version = "0.14", optional = true } # feature screen_reader
 wasm-bindgen = "0.2"
 wasm-bindgen-futures = "0.4"
 
@@ -39,6 +40,7 @@ http = [
   "web-sys/Response",
 ]
 persistence = ["serde", "serde_json"]
+screen_reader = ["tts"] # experimental
 
 [dependencies.web-sys]
 version = "0.3"

egui_web/src/backend.rs

@@ -135,6 +135,7 @@ pub struct AppRunner {
     pub(crate) needs_repaint: std::sync::Arc<NeedRepaint>,
     storage: LocalStorage,
     last_save_time: f64,
+    screen_reader: crate::screen_reader::ScreenReader,
     #[cfg(feature = "http")]
     http: Arc<http::WebHttp>,
 }
@@ -152,6 +153,7 @@ impl AppRunner {
             needs_repaint: Default::default(),
             storage,
             last_save_time: now_sec(),
+            screen_reader: Default::default(),
             #[cfg(feature = "http")]
             http: Arc::new(http::WebHttp {}),
         })
@@ -217,6 +219,7 @@ impl AppRunner {
         let egui_ctx = &self.web_backend.ctx;
         self.app.update(egui_ctx, &mut frame);
         let (egui_output, clipped_meshes) = self.web_backend.end_frame()?;
+        self.screen_reader.speak(&egui_output.events_description());
         handle_output(&egui_output);
 
         {

egui_web/src/lib.rs

@@ -12,6 +12,7 @@ pub mod backend;
 #[cfg(feature = "http")]
 pub mod http;
 mod painter;
+pub mod screen_reader;
 pub mod webgl1;
 pub mod webgl2;
 

egui_web/src/screen_reader.rs

@@ -0,0 +1,47 @@
+pub struct ScreenReader {
+    #[cfg(feature = "screen_reader")]
+    tts: Option<tts::TTS>,
+}
+
+#[cfg(not(feature = "screen_reader"))]
+impl Default for ScreenReader {
+    fn default() -> Self {
+        Self {}
+    }
+}
+
+#[cfg(feature = "screen_reader")]
+impl Default for ScreenReader {
+    fn default() -> Self {
+        let tts = match tts::TTS::default() {
+            Ok(screen_reader) => {
+                crate::console_log("Initialized screen reader.");
+                Some(screen_reader)
+            }
+            Err(err) => {
+                crate::console_warn(format!("Failed to load screen reader: {}", err));
+                None
+            }
+        };
+        Self { tts }
+    }
+}
+
+impl ScreenReader {
+    #[cfg(not(feature = "screen_reader"))]
+    pub fn speak(&mut self, _text: &str) {}
+
+    #[cfg(feature = "screen_reader")]
+    pub fn speak(&mut self, text: &str) {
+        if text.is_empty() {
+            return;
+        }
+        if let Some(tts) = &mut self.tts {
+            crate::console_log(format!("Speaking: {:?}", text));
+            let interrupt = true;
+            if let Err(err) = tts.speak(text, interrupt) {
+                crate::console_warn(format!("Failed to read: {}", err));
+            }
+        }
+    }
+}