IssueTracker

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

commit f27971d31a5947e0d0d38d40b99c96d3a76e2188
Author: Adam Powell <adamp@google.com>
Date:   Fri Jan 10 13:25:52 2020

    Integrate native fling spline into Compose UI
   
    Extract the native Android fling spline from android.widget.Scroller
    and move it into Compose UI foundation in such a way that it can be
    driven via an external time source.
   
    Future work will delegate to a similarly factored version of this
    in AOSP frameworks/base for a future platform release for forward
    compatibility with any future platform behavior changes.
   
    Thanks to the nature of the source material, testing this port for
    correct behavior will necessarily involve an instrumentation test and
    comparing values over "real" time with the output of
    android.widget.Scroller.
   
    This commit also starts spreading a new-ish pattern of @Composable
    factory functions that read default or configuration-specific values
    from the composition. An interesting outcome of this is that the result
    of such a factory may not be the content of a `remember {}` block - the
    `remember` body is not itself `@Composable`. In order to preserve
    expected object instance behavior as well as a reasonably usable caller
    experience this means that such factories must internally `remember`
    as needed.
   
    This might be for the best. When this pattern is used for complex
    hoisted state objects that require composition-based construction, it
    removes the need for an explicit `remember {}` on behalf of the caller
    and the right thing happens with simpler calling code. On the other
    hand, this may end up being confusing for developers who may not easily
    recognize when something needs to be `remember`ed.
   
    Current builds of the Android Studio plugin highlight composable calls
    in bright green and once an outstanding plugin bug is fixed, attempting
    to memo the result of one will be a compiler error. This might be
    enough. If not, we should explore other tooling (lint?) or conventions
    (`rememberFoo` for such factories?) to help aid in understanding
    and discoverability.
   
    Relnote: Scrollers now exhibit native Android fling motion behavior.
   
    Bug: 147493715
    Test: existing; manual
   
    Change-Id: I922af68261f3f1e81538a98a7575603e531fc035

M       ui/integration-tests/test/src/main/java/androidx/ui/integration/test/foundation/NestedScrollerTestCase.kt
M       ui/integration-tests/test/src/main/java/androidx/ui/integration/test/foundation/ScrollerTestCase.kt
M       ui/ui-foundation/api/0.1.0-dev04.txt
M       ui/ui-foundation/api/current.txt
M       ui/ui-foundation/api/public_plus_experimental_0.1.0-dev04.txt
M       ui/ui-foundation/api/public_plus_experimental_current.txt
M       ui/ui-foundation/api/restricted_0.1.0-dev04.txt
M       ui/ui-foundation/api/restricted_current.txt
M       ui/ui-foundation/integration-tests/samples/src/main/java/androidx/ui/foundation/samples/ScrollerSamples.kt
M       ui/ui-foundation/src/androidTest/java/androidx/ui/foundation/ScrollerTest.kt
M       ui/ui-foundation/src/main/java/androidx/ui/foundation/Scroller.kt
A       ui/ui-foundation/src/main/java/androidx/ui/foundation/animation/AndroidFlingCalculator.kt
A       ui/ui-foundation/src/main/java/androidx/ui/foundation/animation/AndroidFlingDecayAnimation.kt
A       ui/ui-foundation/src/main/java/androidx/ui/foundation/animation/AndroidFlingSpline.kt
M       ui/ui-foundation/src/main/java/androidx/ui/foundation/animation/FlingConfig.kt
M       ui/ui-material/integration-tests/material-demos/src/main/java/androidx/ui/material/demos/DynamicThemeActivity.kt
M       ui/ui-material/src/main/java/androidx/ui/material/Tab.kt

https://android-review.googlesource.com/1206049