BackHandler under NavHost stops intercepting back presses on Activity restart [182284739]

Fixed

Bug

Status Update

No update yet.

Description

pa...@gmail.com

created issue #1

Mar 10, 2021 09:32AM

Jetpack Compose release version: 1.0.0-beta01

Android Studio Build: #AI-203.7148.57.2031.7185775, built on March 5, 2021

Steps to Reproduce:

Select "Proceed" button (navigating to Second screen).
Press system back button (navigating to Third screen).
Press system back button (navigating back to First screen, without interception).
Lock/unlock screen to restart Activity.
Press system back button (navigating to First screen instead of Third screen - interception stops working).

Code to reproduce the issue (from attached sample project):

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MaterialTheme {
                Surface(Modifier.fillMaxSize()) {
                    SampleApp()
                }
            }
        }
    }
}

@Composable
fun SampleApp() {
    val navController = rememberNavController()
    val navigateTo: (String) -> Unit = { route -> navController.navigate(route) }
    NavHost(navController, "first") {
        composable("first") { FirstScreen(onClick = { navigateTo("second") }) }
        composable("second") { SecondScreen(onBack = { navigateTo("third") }) }
        composable("third") { ThirdScreen() }
    }
}

@Composable
fun FirstScreen(onClick: () -> Unit) {
    Column {
        Text("First screen")
        Button(onClick) { Text("Proceed") }
    }
}

@Composable
fun SecondScreen(onBack: () -> Unit) {
    BackHandler {
        onBack()
        println("System back intercepted")
    }
    Text("Second screen")
}

@Composable
fun ThirdScreen() {
    Text("Third screen")
}

BackHandlerIssue.zip

30 MB

Download

Comments

cl...@google.com <cl...@google.com> Mar 10, 2021 10:26AM

Assigned to jb...@google.com.

pa...@gmail.com <pa...@gmail.com> #2Mar 10, 2021 09:27PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit c60f33e229e31ab328ef6b59dab63b264954831c
Author: Alexandre Elias <aelias@google.com>
Date: Fri Jul 10 16:23:09 2020

Semantics no-op cleanups

Partly in response to lmr's broad code review, I did a pass of
superficial API/implementation cleanup. The main changes are:

- I changed each Boolean SemanticsProperty where false is equivalent to
not being present to take "Unit" instead. This is conceptually
clearer: it avoids questions like "can I cancel out a semantics from a
merged child by setting it to false?" Because "property = Unit" looks
weird, I also changed the style of these to "property()".

- I moved the Semantics id generator closer to where it's used, in
SemanticsModifierCore. I made it internal and an AtomicInt.
(Note that integer ids are heavily used in the Android
AccessibilityNodeInfo APIs so I can't simply remove them entirely.)

- I deleted dead code. Some examples include SemanticsHintOverrides,
a public API not connected to anything, and SemanticsPropertyKey
merge() open method which is never called. (In both cases I have
a different plan in mind for accessibility.)

Fixes: 145951226
Fixes: 145955412
Test: existing tests
Relnote: "Single-value semantics properties now use a calling style.
For example, 'semantics { hidden = true }' is now written as:
'semantics { hidden() }'."

Change-Id: Ic1afd12ea22c926babc9662f1804d80b33aa0cfc

M ui/integration-tests/benchmark/src/androidTest/java/androidx/ui/benchmark/test/LayoutNodeModifierBenchmark.kt
M ui/ui-core/api/0.1.0-dev15.txt
M ui/ui-core/api/current.txt
M ui/ui-core/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-core/api/public_plus_experimental_current.txt
M ui/ui-core/api/restricted_0.1.0-dev15.txt
M ui/ui-core/api/restricted_current.txt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/graphics/vector/VectorTest.kt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/semantics/SemanticsTests.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidActuals.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeView.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeViewAccessibilityDelegateCompat.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidPopup.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/Expect.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsConfiguration.kt
D ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsHintOverrides.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsModifier.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsNode.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsOwner.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsWrapper.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/semantics/SemanticsProperties.kt
M ui/ui-foundation/api/0.1.0-dev15.txt
M ui/ui-foundation/api/current.txt
M ui/ui-foundation/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-foundation/api/public_plus_experimental_current.txt
M ui/ui-foundation/api/restricted_0.1.0-dev15.txt
M ui/ui-foundation/api/restricted_current.txt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Clickable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Dialog.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Scroller.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Selectable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Toggleable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/semantics/FoundationSemanticsProperties.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ButtonTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CardTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CheckboxScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/RadioButtonScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ScaffoldTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SnackbarTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SurfaceTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ripple/RippleIndicationTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/textfield/TextFieldScreenshotTest.kt
M ui/ui-material/src/main/java/androidx/ui/material/AppBar.kt
M ui/ui-material/src/main/java/androidx/ui/material/TextFieldImpl.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/AssertsTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/CallSemanticsActionTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ErrorMessagesTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/FindersTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/PrintToStringTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ScrollToTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/TextActionsTest.kt
M ui/ui-test/src/main/java/androidx/ui/test/Actions.kt
M ui/ui-test/src/main/java/androidx/ui/test/Filters.kt
M ui/ui-text/api/0.1.0-dev15.txt
M ui/ui-text/api/current.txt
M ui/ui-text/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-text/api/public_plus_experimental_current.txt
M ui/ui-text/api/restricted_0.1.0-dev15.txt
M ui/ui-text/api/restricted_current.txt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/CoreTextField.kt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/TextSemanticsProperties.kt

https://android-review.googlesource.com/1360099

ap...@google.com <ap...@google.com> #3Mar 23, 2021 04:23PM

Project: platform/frameworks/support
Branch: androidx-main

commit e465976de8f05f0d1db49b4e2887c9f3cd4beab5
Author: Jeremy Woods <jbwoods@google.com>
Date: Wed Mar 17 17:07:42 2021

Add OnBackPressedDispatcher observer before NavController observer

If you add a OnBackPressed callback with the NavBackStackEntry as the
lifecycle owner, if the Activity Lifecycle is STOPPED and STARTED again, the navController callback and NavBackStackEntry callback are readded to the Activity Lifecycle in the wrong order. This means that the new callback will not properly intercept onBackPressed() calls from the system, they will instead be intercepted by NavController.

If an OnBackPressedDispatcher is set, we should remove and readd the
NavController observer after we add the callback to the dispatcher.

RelNote: "OnBackPressedCallbacks added to a dispatcher with the
NavBackStackEntry as the LifecycleOwner now properly intercept back
after the Activity Lifecycle is STOPPED, then STARTED"
Test: NavControllerTest
Bug: 182284739

Change-Id: I6acf78848546160eaea7ed700ef8875664a125d0

M navigation/navigation-runtime/src/androidTest/java/androidx/navigation/NavControllerTest.kt
M navigation/navigation-runtime/src/main/java/androidx/navigation/NavController.kt

https://android-review.googlesource.com/1643646

jb...@google.com <jb...@google.com> #4Mar 29, 2021 03:48PM

Status: Assigned (reopened)

This has been fixed internally and will be part of the Navigation 2.3.5 release (via 2.4.0-alpha01).

ap...@google.com <ap...@google.com> #5Mar 29, 2021 07:10PM

Project: platform/frameworks/support
Branch: androidx-main

commit f231e0f384f9fd2e7a078bfcbeb7768c82c617b1
Author: Jeremy Woods <jbwoods@google.com>
Date: Wed Mar 17 17:40:05 2021

Add BackHandler callback with a LifecycleOwner

We need to ensure that the callback from BackHandler remains in the
proper position in the event of Lifecycle changes.

RelNote: "The BackHandler will now properly intercept back presses in
the event that the Activity is STOPPED, then STARTED again, and other
callbacks were added with a LifecycleOwner."
Test: BackHandlerTest
Bug: 182284739

Change-Id: I71de6184ba73f56b34de9dcddaf138d98c46417f

M activity/activity-compose/build.gradle
M activity/activity-compose/src/androidTest/java/androidx/activity/compose/BackHandlerTest.kt
M activity/activity-compose/src/main/java/androidx/activity/compose/BackHandler.kt

https://android-review.googlesource.com/1644062

jb...@google.com <jb...@google.com> #6Mar 29, 2021 08:06PM

Marked as fixed.

This has been addressed internally and will be available when using both the Activity 1.3.0-alpha06 and Navigation 2.3.5 releases.

ap...@google.com <ap...@google.com> #7Mar 31, 2021 11:14PM

Project: platform/frameworks/support
Branch: androidx-main

commit d1d6f89ba90be8e7fba193570b427f52ec98f57a
Author: Jeremy Woods <jbwoods@google.com>
Date: Wed Mar 31 09:40:42 2021

Make nav compose depend on Navigation 2.3.5

Upgrading to the latest Navigation version to take advantage of fixed
bugs, (particularly around OnBackPressedDispatcher and lifecycles

b/182284739

).

RelNote: "Navigation-compose now depends on Navigation version `2.3.5`"
Test: ./gradlew bOS
Change-Id: I7e63b32c93deaee60b1d5e132d3fa255c3ba85e2

M navigation/navigation-compose/build.gradle

https://android-review.googlesource.com/1660640

mc...@gmail.com <mc...@gmail.com> #8Apr 20, 2022 04:12PM

does not work for me on '2.4.2'

val navController: NavHostController = rememberNavController()
HomeNavHost(navController = navController)

BackHandler(true) {
// code doesnt get called here
}

ri...@gmail.com <ri...@gmail.com> #9Jan 5, 2023 05:08AM

I got similar issue, after I run launcher (exp: select document), BackHandler no longer triggers

BackHandler{
action.onBack()
}

ri...@gmail.com <ri...@gmail.com> #10Jan 5, 2023 09:02AM

to solve BackHandler no longer triggers after i run launcher, i am using this

@Composable
fun BaseBackHandler(onBackHandler: () -> Unit = {}) {
var refreshBackHandler by rememberSaveable { mutableStateOf(false) }
OnLifecycleEvent { _, event ->
when (event) {
Lifecycle.Event.ON_PAUSE -> {
refreshBackHandler = false
}
Lifecycle.Event.ON_RESUME -> {
refreshBackHandler = true
}
else -> {}
}
}
if (refreshBackHandler) {
BackHandler {
onBackHandler()
}
}
}

sb...@doximity.com <sb...@doximity.com> #11Mar 27, 2023 09:50PM

Is there a way to re-open this issue? Still experiencing this on latest version of the navigation library.

Message last modified on Mar 27, 2023 09:51PM

il...@google.com <il...@google.com> #12Mar 27, 2023 10:19PM

Re comment#11 - you can file a new issue with a sample project that reproduces your issue.

[Deleted User] <[Deleted User]> #13Apr 21, 2023 07:00PM

I opened a new bug as requested by comment#12: https://issuetracker.google.com/issues/279118447

Message last modified on Apr 21, 2023 07:00PM