OnDestinationChangedListener won't get called if it navigates somewhere in response to current destination. [190228815]

Fixed

Bug

Status Update

No update yet.

Description

sh...@google.com

created issue #1

Jun 4, 2021 10:40PM

Component used: Navigation Version used: 2.3.5 Devices/Android versions reproduced on: Irrelevant ;)

Repro steps:

In a OnDestinationChangedListener, set things up so that if the new destination is A, nav to B.
Set the current destination to A.
Add the OnDestinationChangedListener to the NavController.

Expected Result: OnDestinationChangedListener receives callback when it is set, and then receives a callback when it causes navigation to B.

Actual Result: OnDestinationChangedListener receives callback when it is set, and then DOES NOT receive a callback when it causes navigation to B.

After the OnDestinationChangedListener is set, this sort of reentrant call works as would be expected, but when getting the callback after having set the OnDestinationChangedListener, it does not.

I think this simply requires swapping

mOnDestinationChangedListeners.add(listener);

and

if (!mBackStack.isEmpty()) {
            NavBackStackEntry backStackEntry = mBackStack.peekLast();
            listener.onDestinationChanged(this, backStackEntry.getDestination(),
                    backStackEntry.getArguments());
        }

in NavController.java. :)

Comments

il...@google.com <il...@google.com> #2Jun 4, 2021 10:57PM

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

il...@google.com <il...@google.com> Jun 8, 2021 07:26PM

Assigned to il...@google.com.

il...@google.com <il...@google.com> Jun 9, 2021 12:00AM

Accepted by il...@google.com.

ap...@google.com <ap...@google.com> #3Jun 9, 2021 03:05AM

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

commit d4cb8c02c2b72efc8d181c68910775525108bc0c
Author: Ian Lake <ilake@google.com>
Date: Tue Jun 08 16:54:55 2021

Ensure that re-entrant listeners receive all updates

If an OnDestinationChangedListener calls navigate()
the first time it is triggered with the current
state, it should receive a second callback with the
destination it navigated to, ensuring that it always
has the most up to date destination and arguments.

Test: new NavControllerTest test passes
BUG: 190228815
Relnote: "An `OnDestinationChangedListener` that calls
`navigate()` the first time it receives a callback now
properly get a second callback with the destination it
navigated to."

Change-Id: Ie5f9e0f8dec404775c99a0e90c1cde8a9e059550

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/1730676

il...@google.com <il...@google.com> #4Jun 9, 2021 03:42AM

Marked as fixed.

This has been fixed internally and will be available in Navigation 2.4.0-alpha03.

sh...@google.com <sh...@google.com> #5Jun 11, 2021 05:07PM

Ah, thanks for fixing this Ian!

I meant to let you know that I will look into the other strategies you suggested. In case you are still interested, we show an identity verification screen given various conditions so we may navigate to it (and then back to where the user was previous to us navigating to it) often. One place where we check to see if it is needed is in an OnDestinationChanged callback. Also in that callback we do some other stuff like some analytics tracking and some other ui decoration stuff for certain screens. Given the current behavior we had to do some special stuff, but with your bug fix our code can be simplified!

Thanks so much!

Issue 190228815