Can't use TextMeasurer in application scope (LocalFontFamilyResolver / LocalLayoutDirection not present)

[kirill-grouchnikov]

Desktop version 1.4.0 on macOS

Run this:

@OptIn(ExperimentalTextApi::class)
fun main() = application {
    val textMeasurer = rememberTextMeasurer()
    Window(onCloseRequest = ::exitApplication) {
    }
}

And it crashes with

Exception in thread "main" java.lang.IllegalStateException: CompositionLocal LocalFontFamilyResolver not present
	at androidx.compose.ui.platform.CompositionLocalsKt.noLocalProvidedFor(CompositionLocals.kt:219)
	at androidx.compose.ui.platform.CompositionLocalsKt.access$noLocalProvidedFor(CompositionLocals.kt:1)
	at androidx.compose.ui.platform.CompositionLocalsKt$LocalFontFamilyResolver$1.invoke(CompositionLocals.kt:110)
	at androidx.compose.ui.platform.CompositionLocalsKt$LocalFontFamilyResolver$1.invoke(CompositionLocals.kt:109)
	at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
	at androidx.compose.runtime.LazyValueHolder.getCurrent(ValueHolders.kt:29)
	at androidx.compose.runtime.LazyValueHolder.getValue(ValueHolders.kt:31)
	at androidx.compose.runtime.ComposerImpl.resolveCompositionLocal(Composer.kt:2070)
	at androidx.compose.runtime.ComposerImpl.consume(Composer.kt:2038)
	at androidx.compose.ui.text.TextMeasurerHelperKt.rememberTextMeasurer(TextMeasurerHelper.kt:53)
	at org.pushingpixels.aurora.demo.ComposableSingletons$MainKt$lambda-2$1.invoke(main.kt:10)
	at org.pushingpixels.aurora.demo.ComposableSingletons$MainKt$lambda-2$1.invoke(main.kt:9)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:116)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
	at androidx.compose.ui.window.Application_desktopKt$application$1$1.invoke(Application.desktop.kt:115)
	at androidx.compose.ui.window.Application_desktopKt$application$1$1.invoke(Application.desktop.kt:114)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:116)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
	at androidx.compose.ui.window.Application_desktopKt$awaitApplication$2$1$2$1$1.invoke(Application.desktop.kt:226)
	at androidx.compose.ui.window.Application_desktopKt$awaitApplication$2$1$2$1$1.invoke(Application.desktop.kt:225)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
	at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
	at androidx.compose.ui.window.Application_desktopKt$awaitApplication$2$1$2$1.invoke(Application.desktop.kt:221)
	at androidx.compose.ui.window.Application_desktopKt$awaitApplication$2$1$2$1.invoke(Application.desktop.kt:219)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:107)
	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:34)
	at androidx.compose.runtime.ActualJvm_jvmKt.invokeComposable(ActualJvm.jvm.kt:37)
	at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:3353)
	at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:3343)
	at androidx.compose.runtime.SnapshotStateKt__DerivedStateKt.observeDerivedStateRecalculations(DerivedState.kt:341)
	at androidx.compose.runtime.SnapshotStateKt.observeDerivedStateRecalculations(Unknown Source)
	at androidx.compose.runtime.ComposerImpl.doCompose(Composer.kt:3343)
	at androidx.compose.runtime.ComposerImpl.composeContent$runtime(Composer.kt:3278)
	at androidx.compose.runtime.CompositionImpl.composeContent(Composition.kt:587)
	at androidx.compose.runtime.Recomposer.composeInitial$runtime(Recomposer.kt:966)
	at androidx.compose.runtime.CompositionImpl.setContent(Composition.kt:519)
	at androidx.compose.ui.window.Application_desktopKt$awaitApplication$2$1$2.invokeSuspend(Application.desktop.kt:219)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Why is LocalFontFamilyResolver.current crashing in the application scope? And the same for LocalLayoutDirection.current

[m-sasha]

Indeed we're currently providing all the common composition locals only inside the window scope.

[m-sasha]

I'm not sure whether this should be considered a bug or a feature request.

[kirill-grouchnikov]

Another example where this is needed outside of the window scope.

The recently added functions in TextPainter to draw text in a multiplatform way require either TextMeasurer or TextLayoutResult. The later needs FontFamily.Resolver to be created. So in both cases, in order to use DrawScope.drawText we need these common composition locals to be available.

A common example of using DrawScope.drawText outside of the window scope would be to dynamically create things like icons and overlay them with text elements (or dynamically generate icons or images with text elements) for subsequent use as icons on buttons or somewhere else.

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.