TextView Carousel 在滚动时隐藏文本的最后一部分

Question

我正在尝试使用 TextView 实现轮播，但我遇到了一个奇怪的故障。当向左滚动TextView时，文本的最后一个字消失，不管多长，滚动时文本的最后一个字appear/disappear，滚动结束后消失。如果 TextView 中只有一个单词，最后一个字符会消失。

这里是例子：

main_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.main.MainFragment">

    <androidx.constraintlayout.motion.widget.MotionLayout
        android:id="@+id/motion_carousel"
        android:layout_width="0dp"
        android:layout_height="100dp"
        app:layoutDescription="@xml/carousel_scene"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:visibility="visible">

        <TextView
            android:id="@+id/text_title_0"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            android:background="#000"
            android:padding="18dp"
            android:textColor="#fff"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@+id/text_title_1"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="Text 0 disappear" />

        <TextView
            android:id="@+id/text_title_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            android:background="#000"
            android:padding="18dp"
            android:textColor="#fff"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@+id/text_title_2"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="Text 1 disappear" />

        <TextView
            android:id="@+id/text_title_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="#000"
            android:padding="18dp"
            android:textColor="#fff"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.5"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="Text 2 disappear" />

        <TextView
            android:id="@+id/text_title_3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            android:background="#000"
            android:padding="18dp"
            android:textColor="#fff"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toEndOf="@+id/text_title_2"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="Text 3 disappear" />

        <TextView
            android:id="@+id/text_title_4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            android:background="#000"
            android:padding="18dp"
            android:textColor="#fff"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toEndOf="@+id/text_title_3"
            app:layout_constraintTop_toTopOf="parent"
            tools:text="Text 4 disappear" />

        <androidx.constraintlayout.helper.widget.Carousel
            android:id="@+id/carousel_scene_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:carousel_backwardTransition="@+id/backward"
            app:carousel_firstView="@+id/text_title_2"
            app:carousel_forwardTransition="@+id/forward"
            app:carousel_nextState="@+id/next"
            app:carousel_previousState="@+id/previous"
            app:constraint_referenced_ids="text_title_0,text_title_1,text_title_2,text_title_3,text_title_4" />

    </androidx.constraintlayout.motion.widget.MotionLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

carousel_scene.xml

<?xml version="1.0" encoding="utf-8"?>
<MotionScene xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:motion="http://schemas.android.com/apk/res-auto"
    motion:defaultDuration="5000">

    <Transition
        android:id="@+id/forward"
        motion:constraintSetEnd="@+id/next"
        motion:constraintSetStart="@id/start"
        motion:duration="100">
        <OnSwipe
            motion:dragDirection="dragLeft"
            motion:maxAcceleration="20"
            motion:onTouchUp="decelerateAndComplete"
            motion:touchAnchorSide="left" />
    </Transition>

    <Transition
        android:id="@+id/backward"
        motion:constraintSetEnd="@+id/previous"
        motion:constraintSetStart="@+id/start"
        motion:duration="100">
        <OnSwipe
            motion:dragDirection="dragRight"
            motion:maxAcceleration="20"
            motion:onTouchUp="decelerateAndComplete"
            motion:touchAnchorSide="right" />

    </Transition>

    <ConstraintSet android:id="@+id/previous">

        <Constraint
            android:id="@+id/text_title_0"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintEnd_toStartOf="@id/text_title_1"
            motion:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@+id/text_title_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@+id/text_title_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintStart_toEndOf="@id/text_title_1"
            motion:layout_constraintTop_toTopOf="parent" />

    </ConstraintSet>

    <ConstraintSet android:id="@+id/start">

        <Constraint
            android:id="@+id/text_title_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintEnd_toStartOf="@id/text_title_2"
            motion:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@+id/text_title_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintHorizontal_bias="0.5"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@+id/text_title_3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintStart_toEndOf="@id/text_title_2"
            motion:layout_constraintTop_toTopOf="parent" />

    </ConstraintSet>

    <ConstraintSet android:id="@+id/next">

        <Constraint
            android:id="@+id/text_title_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintEnd_toStartOf="@id/text_title_3"
            motion:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@+id/text_title_3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            android:layout_marginEnd="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintEnd_toEndOf="parent"
            motion:layout_constraintStart_toStartOf="parent"
            motion:layout_constraintTop_toTopOf="parent" />

        <Constraint
            android:id="@+id/text_title_4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/carousel_names_horizontal_margin"
            motion:layout_constraintBottom_toBottomOf="parent"
            motion:layout_constraintStart_toEndOf="@id/text_title_3"
            motion:layout_constraintTop_toTopOf="parent" />

    </ConstraintSet>
</MotionScene>

MainFragment.kt

class MainFragment : Fragment() {

    companion object {
        fun newInstance() = MainFragment()
    }

    private lateinit var viewModel: MainViewModel
    private lateinit var binding: MainFragmentBinding

    private val nameList = mutableListOf<String>()

    init {

        for (i in 0..7){
            nameList.add("Text ${i} disappear")
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        binding = MainFragmentBinding.inflate(inflater, container, false)

        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.carouselSceneTitle.setAdapter(object : Carousel.Adapter {
            override fun count(): Int {
                return nameList.size
            }

            override fun populate(view: View, index: Int) {
                (view as TextView).apply {
                    text = nameList[index]
                }
            }

            override fun onNewItem(index: Int) {
            }
        })
    }
}

Answer 1

刚刚意识到在文本后添加一个空 space 可以解决问题，但它更像是一种变通方法，而不是正确的解决方案。

override fun populate(view: View, index: Int) {
    (view as TextView).apply {
        text = " " + nameList[index] + " "
    }
}

TextView Carousel 在滚动时隐藏文本的最后一部分

TextView Carousel hide last part of text when scrolling

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