Add a version of Modifier.composed that accepts a key as well to determine equality [205851704]

Fixed

Feature Request

Status Update

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Description

je...@google.com

created issue #1

Nov 10, 2021 06:07PM

Currently, Modifier.composed { /*code*/ } != Modifier.composed { /*same code*/ }, which can lead to unexpected results in some cases.

For example, Modifier.testTag("tag") is inferred to be static, but Modifier.testTag("tag") != Modifier.testTag("tag"), which will make a difference when Live Literals is enabled.

To fix this, we need to implement ComposedModifier.equals(), which is not possible because we can't meaningfully compare lambdas with each other. As an alternative, we can add a version of composed that accepts a key to base equality on.

Simplified, something like this:

private class ComposedModifier(
    val key: String?,
    val factory: @Composable Modifier.() -> Modifier
) : Modifier.Element {
    override fun equals(other: Any?): Boolean {
        return key != null && (other as? ComposedModifier).key == key
    }
}

Comments

je...@google.com <je...@google.com> #2Nov 10, 2021 06:09PM

First of all thanks for this detailed issue.

This issue had been investigated thoroughly when it was first reported internally. The surprising detail in this report is that the issue is not reproducible before 1.7. I will look into this.

The main problem with POBox is the fact that it is deprecated. Since 2021 Sony has been shipping new Xperia devices with Gboard pre-installed. Although we are aware that there is still a considerable amount of users still using POBox, the described behavior is caused by POBox's noncompliant behavior with InputConnection and InputMethodManager documentation. However, this is understandable since TextView implementation was also not respecting the behavior that is expected from Editors.

Ultimately we have decided to enforce the documented behavior with specifically regards to when editors should call InputMethodManager.updateSelection. Also, although unconfirmed, there were traces of possible custom code being included in Sony OEM images that changed how InputMethodManager was notified from TextView. If POBox also depended on something like this, it would be impossible for Compose code to replicate the same unknown behavior.

po...@google.com <po...@google.com> Nov 12, 2021 10:59AM

Assigned to ad...@google.com.

ad...@google.com <ad...@google.com> Nov 12, 2021 10:48PM

Accepted by ad...@google.com.

ap...@google.com <ap...@google.com> #3Nov 15, 2021 08:34PM

Marked as fixed.

If the investigation takes time, would it be possible to revert the surrounding implementation to 1.6.x equivalent?

Or is that option not available?

Even if the root cause is POBox, from the perspective of the app's customers, it looks like an app bug, so this issue is a blocker against updating Jetpack Compose.

Issue 205851704

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Issue summary

Comments

je...@google.com <je...@google.com> #2Nov 10, 2021 06:09PM

po...@google.com <po...@google.com> Nov 12, 2021 10:59AM

ad...@google.com <ad...@google.com> Nov 12, 2021 10:48PM

ap...@google.com <ap...@google.com> #3Nov 15, 2021 08:34PM

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