chore: add emoji fallback font support for web

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Desktop: audio playback failed with *Failed to play audio* on every record,
   because the JDK cannot decode the `.m4a` (AAC) recordings on its own.
+- add emoji fallback for web
 
 ## [1.0.0-alpha02] - 2026-08-04
 

README.md

@@ -107,6 +107,10 @@ runs with crash reporting disabled until you configure it. See
 
 ## License
 
+The web build bundles a subset of [Noto Color Emoji](https://github.com/googlefonts/noto-emoji),
+licensed under the SIL Open Font License 1.1
+([data/resources/licenses/NotoColorEmoji-OFL.txt](./data/resources/licenses/NotoColorEmoji-OFL.txt)).
+
 This project is licensed under the Apache License 2.0. See the [LICENSE](LICENSE) file for details.
 
 ```

data/resources/licenses/NotoColorEmoji-OFL.txt

@@ -0,0 +1,92 @@
+This Font Software is licensed under the SIL Open Font License,
+Version 1.1.
+
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font
+creation efforts of academic and linguistic communities, and to
+provide a free and open framework in which fonts may be shared and
+improved in partnership with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply to
+any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software
+components as distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to,
+deleting, or substituting -- in part or in whole -- any of the
+components of the Original Version, by changing formats or by porting
+the Font Software to a new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed,
+modify, redistribute, and sell modified and unmodified copies of the
+Font Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components, in
+Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the
+corresponding Copyright Holder. This restriction only applies to the
+primary font name as presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created using
+the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

shared/src/androidMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.android.kt

@@ -0,0 +1,7 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/** No-op: Android supplies the system emoji font. */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() = Unit

shared/src/commonMain/kotlin/bzh/ajaury/chombev/App.kt

@@ -27,6 +27,7 @@ import bzh.ajaury.chombev.onboarding.ui.viewmodel.OnboardingViewModel
 import bzh.ajaury.chombev.player.ui.PlayerScreen
 import bzh.ajaury.chombev.records.ui.RecordsScreen
 import bzh.ajaury.chombev.theme.ChomBevTheme
+import bzh.ajaury.chombev.theme.RegisterEmojiFallbackFont
 import bzh.ajaury.chombev.web.model.WebPage
 import bzh.ajaury.chombev.web.ui.WebViewScreen
 import org.koin.compose.KoinApplication
@@ -53,6 +54,8 @@ fun App() {
         val darkTheme = isSystemInDarkTheme()
 
         ChomBevTheme(darkTheme = darkTheme) {
+            RegisterEmojiFallbackFont()
+
             val onboardingViewModel: OnboardingViewModel = koinViewModel()
             val onboardingUiState by onboardingViewModel.uiState.collectAsStateWithLifecycle()
 

shared/src/commonMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.kt

@@ -0,0 +1,15 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/**
+ * Makes colour emoji renderable on platforms whose font manager has no emoji font of its own.
+ *
+ * Android, iOS and Desktop resolve emoji through the system fonts, so their implementations do
+ * nothing. Only the web needs a bundled font: Skia runs in the browser without any system font
+ * manager, and the default font baked into skiko has no emoji glyphs — they come out as tofu boxes.
+ *
+ * Emits nothing; call it once, high in the composition.
+ */
+@Composable
+internal expect fun RegisterEmojiFallbackFont()

shared/src/iosMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.ios.kt

@@ -0,0 +1,7 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/** No-op: iOS supplies Apple Color Emoji. */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() = Unit

shared/src/jvmMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.jvm.kt

@@ -0,0 +1,7 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+
+/** No-op: The desktop JVM resolves emoji through the system font manager. */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() = Unit

shared/src/webMain/kotlin/bzh/ajaury/chombev/theme/EmojiFallbackFont.web.kt

@@ -0,0 +1,34 @@
+package bzh.ajaury.chombev.theme
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.ui.platform.LocalFontFamilyResolver
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.platform.Font
+import bzh.ajaury.chombev.resources.generated.resources.Res
+import bzh.ajaury.chombev.resources.generated.resources.noto_color_emoji
+import org.jetbrains.compose.resources.getFontResourceBytes
+import org.jetbrains.compose.resources.rememberResourceEnvironment
+
+private const val EMOJI_FONT_IDENTITY = "NotoColorEmoji"
+
+/**
+ * Loads the bundled Noto Color Emoji subset and hands it to the font resolver.
+ *
+ * Resolving a font is what registers its typeface with Skia's fallback provider — Compose builds
+ * its [org.jetbrains.skia.paragraph.FontCollection] on a `FontMgrWithFallback` fed by every font
+ * the app has loaded — so a single [androidx.compose.ui.text.font.FontFamily.Resolver.preload] is
+ * enough for emoji to appear in any `Text`, without touching the screens that display them.
+ */
+@Composable
+internal actual fun RegisterEmojiFallbackFont() {
+    val resourceEnvironment = rememberResourceEnvironment()
+    val fontFamilyResolver = LocalFontFamilyResolver.current
+
+    LaunchedEffect(resourceEnvironment, fontFamilyResolver) {
+        val fontBytes = getFontResourceBytes(resourceEnvironment, Res.font.noto_color_emoji)
+        fontFamilyResolver.preload(
+            FontFamily(Font(identity = EMOJI_FONT_IDENTITY, data = fontBytes)),
+        )
+    }
+}