Trying to delete a word via Ctrl+Backspace in an empty TextField causes an exception

[silenium-dev]

I've built a minimal example: https://github.com/silenium-dev/bug-report-example

I'll try to fix it myself and submit a pull request.

Stacktrace:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: offset(-1) is out of bounds [0, 0]
	at androidx.compose.ui.text.MultiParagraph.requireIndexInRangeInclusiveEnd(MultiParagraph.kt:755)
	at androidx.compose.ui.text.MultiParagraph.getWordBoundary--jx7JFs(MultiParagraph.kt:589)
	at androidx.compose.ui.text.TextLayoutResult.getWordBoundary--jx7JFs(TextLayoutResult.kt:518)
	at androidx.compose.foundation.text.selection.BaseTextPreparedSelection.getPrevWordOffset(TextPreparedSelection.kt:278)
	at androidx.compose.foundation.text.selection.BaseTextPreparedSelection.getPrevWordOffset$default(TextPreparedSelection.kt:272)
	at androidx.compose.foundation.text.selection.BaseTextPreparedSelection.getPreviousWordOffset(TextPreparedSelection.kt:198)
	at androidx.compose.foundation.text.TextFieldKeyInput$process$2$5.invoke(TextFieldKeyInput.kt:148)
	at androidx.compose.foundation.text.TextFieldKeyInput$process$2$5.invoke(TextFieldKeyInput.kt:147)
	at androidx.compose.foundation.text.selection.TextFieldPreparedSelection.deleteIfSelectedOr(TextPreparedSelection.kt:397)
	at androidx.compose.foundation.text.TextFieldKeyInput$process$2.invoke(TextFieldKeyInput.kt:147)
	at androidx.compose.foundation.text.TextFieldKeyInput$process$2.invoke(TextFieldKeyInput.kt:103)
	at androidx.compose.foundation.text.TextFieldKeyInput.commandExecutionContext(TextFieldKeyInput.kt:223)
	at androidx.compose.foundation.text.TextFieldKeyInput.process-ZmokQxo(TextFieldKeyInput.kt:103)
	at androidx.compose.foundation.text.TextFieldKeyInputKt$textFieldKeyInput$2$1.invoke-ZmokQxo(TextFieldKeyInput.kt:255)
	at androidx.compose.foundation.text.TextFieldKeyInputKt$textFieldKeyInput$2$1.invoke(TextFieldKeyInput.kt:255)
	at androidx.compose.ui.input.key.KeyInputModifier.propagateKeyEvent-ZmokQxo(KeyInputModifier.kt:124)
	at androidx.compose.ui.input.key.KeyInputModifier.processKeyInput-ZmokQxo(KeyInputModifier.kt:103)
	at androidx.compose.ui.platform.SkiaBasedOwner.sendKeyEvent-ZmokQxo(SkiaBasedOwner.skiko.kt:231)
	at androidx.compose.ui.ComposeScene.sendKeyEvent-ZmokQxo(ComposeScene.skiko.kt:572)
	at androidx.compose.ui.awt.ComposeLayer$onKeyEvent$1.invoke(ComposeLayer.desktop.kt:410)
	at androidx.compose.ui.awt.ComposeLayer$onKeyEvent$1.invoke(ComposeLayer.desktop.kt:406)
	at androidx.compose.ui.awt.ComposeLayer.catchExceptions(ComposeLayer.desktop.kt:109)
	at androidx.compose.ui.awt.ComposeLayer.onKeyEvent(ComposeLayer.desktop.kt:406)
	at androidx.compose.ui.awt.ComposeLayer.access$onKeyEvent(ComposeLayer.desktop.kt:87)
	at androidx.compose.ui.awt.ComposeLayer$7.keyPressed(ComposeLayer.desktop.kt:385)
	at java.desktop/java.awt.Component.processKeyEvent(Component.java:6584)
	at java.desktop/java.awt.Component.processEvent(Component.java:6403)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5001)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4833)
	at java.desktop/java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1952)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:883)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:1150)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:1020)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:848)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4882)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2324)
	at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2780)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4833)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:722)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:716)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:97)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:746)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:744)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:743)
	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)

[igordmn]

Thanks!

Reproduced in Compose 1.2.1, doesn't reproduce in 1.1.1, Windows/macOS

A minimal reproducer:

import androidx.compose.material.TextField
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.window.singleWindowApplication

fun main() = singleWindowApplication {
    var text by remember { mutableStateOf("") }
    TextField(text, onValueChange = { text = it })
}

1. Focus on the text field
2. Press Ctrl+Backspace (this combination removes whole words)

After the fix we should write tests for word removal behavior

[silenium-dev]

I've looked into this issue, and it seems to be a small fix.
The method BaseTextPreparedSelection.charOffset() limits the offset upwards by the text length, but not downwards.

Current code:

// frameworks/support/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/TextPreparedSelection.kt:345
private fun charOffset(offset: Int) =
    offset.coerceAtMost(text.length - 1)

I'm not able to test this as I don't have the necessary development environment setup (Any link or guide would be appreciated, I'd like to contribute more), but the fix should be:

private fun charOffset(offset: Int) =
        offset.coerceIn(0, text.length - 1)

[eymar]

@silenium-dev We don't have a full-fledged Contribution guide yet, but you here's how we setup the project: https://github.com/JetBrains/compose-jb/blob/master/compose/README.md (note: it differs from the upstream aosp repo setup)

For contributions to common code (either to the fork https://github.com/Jetbrains/androidx, or aosp) it's required to sign the CLA https://android-review.googlesource.com/settings/new-agreement so your contribution can be further upstreamed, or you may want to submit it directly to the upstream repo right away (skipping the JB fork repo - different project setup) - https://source.android.com/docs/setup/contribute/submit-patches.

[asapha]

There's an existing issue on Google's issue tracker by the way.

[eymar]

merged the fixed into JB fork for now. It has to be upstreamed.