android - MotionLayout中的TextView在大小动画上闪烁

Question

我目前正在尝试使用 MotionLayout 创建工具栏动画。一切正常，除了以约束为中心并用高度和宽度“wrap_content”定义的 TextView 在 TextView 的大小增加时部分闪烁。如果我将 TextView 向左对齐，一切都会按预期工作。这是一个已知的错误还是您知道我该如何解决这个问题？

布局

<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/motionLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FF0000"
    android:fitsSystemWindows="false">

<com.google.android.material.appbar.AppBarLayout
        android:id="@+id/app_bar"
        android:layout_width="match_parent"
        android:layout_height="250dp"
        android:theme="@style/AppTheme.AppBarOverlay">

    <com.example.motionlayout.CollapsibleToolbar
            android:id="@+id/constraintToolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:minHeight="56dp"
            app:layoutDescription="@xml/scene_11_header"
            app:layout_scrollFlags="scroll|enterAlways|snap|exitUntilCollapsed">

        <de.hdodenhof.circleimageview.CircleImageView
                android:id="@+id/icon"
                android:layout_width="wrap_content"
                android:layout_height="64dp"
                android:src="@drawable/maxmustermann" />

        <TextView
                android:id="@+id/name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Marco Schlosser"
                android:textColor="#FFFFFF"/>

        <ImageView
                android:id="@+id/ivMail"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:srcCompat="@drawable/ic_mail" />

        <ImageView
                android:id="@+id/ivPhone"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:srcCompat="@drawable/ic_phone" />

        <ImageView
                android:id="@+id/ivInfo"
                android:layout_width="24dp"
                android:layout_height="24dp"
                app:srcCompat="@drawable/ic_info_button" />


    </com.example.motionlayout.CollapsibleToolbar>

</com.google.android.material.appbar.AppBarLayout>

<include layout="@layout/content_scrolling" />

场景

<Transition
        app:constraintSetEnd="@id/end"
        app:constraintSetStart="@id/start"
        app:duration="1000"
        app:motionInterpolator="linear">

    <KeyFrameSet>
        <KeyPosition
                app:framePosition="30"
                app:keyPositionType="deltaRelative"
                app:motionTarget="@id/icon"
                app:percentX="0.9"
                app:percentY="0.1" />

        <KeyPosition
                app:framePosition="30"
                app:keyPositionType="deltaRelative"
                app:motionTarget="@id/name"
                app:percentX="0.9"
                app:percentY="0.1" />
    </KeyFrameSet>

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

        <Constraint
                android:id="@id/icon"
                android:layout_width="wrap_content"
                android:layout_height="64dp"
                android:layout_marginTop="50dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

        <Constraint
                android:id="@id/name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="8dp"
                android:layout_marginTop="8dp"
                android:layout_marginEnd="8dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/icon">

            <CustomAttribute
                    app:attributeName="textSize"
                    app:customFloatValue="22"/>

        </Constraint>

        <Constraint
                android:id="@id/ivMail"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                android:layout_marginBottom="50dp"
                android:layout_marginEnd="8dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@+id/ivPhone"
                app:layout_constraintHorizontal_bias="0.5"
                app:layout_constraintHorizontal_chainStyle="packed"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/name" />

        <Constraint
                android:id="@id/ivPhone"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                android:layout_marginBottom="50dp"
                android:layout_marginStart="8dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.5"
                app:layout_constraintHorizontal_chainStyle="packed"
                app:layout_constraintStart_toEndOf="@+id/ivMail"
                app:layout_constraintTop_toBottomOf="@+id/name" />

        <Constraint
                android:id="@id/ivInfo"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                android:layout_marginEnd="16dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

    </ConstraintSet>

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

        <Constraint
                android:id="@id/icon"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_marginStart="16dp"
                android:layout_marginBottom="16dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent" />

        <Constraint
                android:id="@id/name"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="16dp"
                android:layout_marginBottom="16dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toEndOf="@id/icon">

            <CustomAttribute
                    app:attributeName="textSize"
                    app:customFloatValue="14"/>

        </Constraint>

        <Constraint
                android:id="@id/ivMail"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_marginEnd="16dp"
                android:layout_marginBottom="16dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@id/ivPhone" />

        <Constraint
                android:id="@id/ivPhone"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_marginEnd="16dp"
                android:layout_marginBottom="16dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@id/ivInfo" />

        <Constraint
                android:id="@id/ivInfo"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="16dp"
                android:layout_marginEnd="16dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintBottom_toBottomOf="parent" />

    </ConstraintSet>
</Transition>

Answer 1

我找到了解决此闪烁问题的解决方案。

1.扩展运动布局，增加onChange接口(interface):

class CollapsibleToolbar @JvmOverloads constructor(
        context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : MotionLayout(context, attrs, defStyleAttr), AppBarLayout.OnOffsetChangedListener {
    val TAG : String = "CollapsibleToolbar"
    var onHeaderOffsetChangeed: OnHeaderOffsetChangeed? = null

    override fun onOffsetChanged(appBarLayout: AppBarLayout?, verticalOffset: Int) {
        progress = -verticalOffset / appBarLayout?.totalScrollRange?.toFloat()!!
        onHeaderOffsetChangeed?.let {
           it.onChanged(progress)
        }
    }

    override fun onAttachedToWindow() {
        super.onAttachedToWindow()
        (parent as? AppBarLayout)?.addOnOffsetChangedListener(this)
    }


    interface OnHeaderOffsetChangeed{
        fun onChanged(progress: Float)
    }

}

2.在Activity上设置界面，设置缩放计算

(info_header as CollapsibleToolbar).onHeaderOffsetChangeed = object : CollapsibleToolbar.OnHeaderOffsetChangeed {
            override fun onChanged(progress: Float) {
                // e.g. 23sp zoom to 14sp
                tv_title.textSize = 23 - 9 * progress
            }

        }

3. 从 MotionScene 中删除 textSize CustomAttribute。

            <CustomAttribute
                app:attributeName="textSize"
                app:customFloatValue="14"/>