android - 当 float 按钮到达 NestedScrollView 内 TextView 的相同高度位置时，如何将 float 按钮可见性设置为 GONE？

Question

我有以下 XML 文件 -

<?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/activity_product_page_root_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/activity_product_page_top_product_layout"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <ImageView
            android:id="@+id/activity_product_page_back_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/marketplace_14dp"
            android:layout_marginEnd="@dimen/marketplace_14dp"
            android:contentDescription="@string/marketplace_productvendor_page_back_button"
            android:onClick="backButtonPressed"
            android:src="@drawable/arrow_left"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            android:id="@+id/activity_product_page_vendor_icon_image"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/marketplace_14dp"
            android:layout_marginEnd="@dimen/marketplace_14dp"
            android:contentDescription="@string/marketplace_productvendor_page_vendor_image"
            android:scaleType="centerCrop"
            android:src="@mipmap/ic_launcher"
            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:layout_width="200dp" />

        <FrameLayout
            android:id="@+id/activity_product_page_shopping_cart_framelayout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/marketplace_14dp"
            android:layout_marginEnd="@dimen/marketplace_14dp"
            android:background="@color/white"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent">

            <ImageView
                android:id="@+id/activity_checkout_cart_imageView"
                android:layout_width="25dp"
                android:layout_height="25dp"
                android:layout_margin="20dp"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="10dp"
                android:src="@drawable/icons_32_x_32_black_shopping_cart" />

            <TextView
                android:id="@+id/activity_product_page_shopping_cart_counter"
                android:layout_width="25dp"
                android:layout_height="25dp"
                android:layout_gravity="end"
                android:background="@drawable/textview_round_background"
                android:elevation="1dp"
                android:gravity="center"
                android:maxLines="1"
                android:textAlignment="center"
                android:textColor="@color/white"
                android:textSize="10sp"
                android:textStyle="bold"
                android:visibility="gone"
                app:autoSizeMaxTextSize="16sp"
                app:autoSizeMinTextSize="10sp"
                app:autoSizeStepGranularity="2sp"
                app:layout_constraintStart_toEndOf="@+id/activity_checkout_cart_imageView"
                app:layout_constraintTop_toTopOf="parent"
                tools:ignore="SmallSp"
                tools:text="1"
                tools:visibility="visible" />


        </FrameLayout>

    </androidx.constraintlayout.widget.ConstraintLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/activity_product_page_top_product_layout">

        <com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id="@+id/activity_product_page_share_product_action_button"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:layout_gravity="end"
            android:layout_marginTop="30dp"
            android:layout_marginEnd="20dp"
            android:alpha="0.5"
            android:background="@color/grey_text_cart"
            android:backgroundTint="@color/grey_text_cart"
            android:elevation="1dp"
            android:scaleType="center"
            android:src="@drawable/share_product"
            app:backgroundTint="@color/white"
            app:fabCustomSize="50dp"
            app:fabSize="auto"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <androidx.core.widget.NestedScrollView
            android:id="@+id/activity_product_page_nested_scroll_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fillViewport="true">

            <LinearLayout
                android:id="@+id/activity_product_page_nested_linear_layout"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                android:paddingBottom="@dimen/marketplace_15dp">

                <View
                    android:layout_width="match_parent"
                    android:layout_height="1dp"
                    android:background="@color/very_light_grey" />

                <RelativeLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content">

                    <TextView
                        android:id="@+id/activity_product_page_brands_breadcrumbs"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/breadcrumbs_brands"
                        android:textStyle="bold" />

                    <TextView
                        android:id="@+id/activity_product_page_vendor_breadcrumbs"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_toEndOf="@id/activity_product_page_brands_breadcrumbs"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/products_breadcrumbs_unknown_vendor"
                        android:textStyle="bold" />

                    <TextView
                        android:id="@+id/activity_product_page_product_breadcrumbs"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_toEndOf="@id/activity_product_page_vendor_breadcrumbs"
                        android:ellipsize="end"
                        android:fontFamily="@font/noto_sans"
                        android:maxLines="1"
                        android:text="@string/activity_product_page_unknown_product"
                        android:textColor="#979797" />


                </RelativeLayout>


                <View
                    android:layout_width="match_parent"
                    android:layout_height="1dp"
                    android:layout_marginTop="@dimen/marketplace_15dp"
                    android:background="@color/very_light_grey" />

                <androidx.viewpager.widget.ViewPager
                    android:id="@+id/activity_product_page_view_pager"
                    android:layout_width="match_parent"
                    android:layout_height="300dp"
                    android:paddingStart="40dp"
                    android:paddingEnd="40dp"
                    tools:layout_height="300dp" />

                <me.relex.circleindicator.CircleIndicator
                    android:id="@+id/activity_product_page_image_indicator"
                    android:layout_width="match_parent"
                    android:layout_height="10dp"
                    app:ci_drawable="@drawable/currently_selected_product"
                    app:ci_drawable_unselected="@drawable/currently_unselected_product"
                    app:ci_height="5dp"
                    app:ci_width="5dp" />

                <LinearLayout
                    android:id="@+id/activity_product_page_products_details_viewgroup"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_marginTop="@dimen/marketplace_15dp"
                    android:background="@color/very_light_grey"
                    android:orientation="vertical">

                    <TextView
                        android:id="@+id/activity_product_page_product_title_textview"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:fontFamily="@font/noto_sans"
                        android:textSize="20sp"
                        android:textStyle="bold"
                        tools:text="Products long title" />

                    <TextView
                        android:id="@+id/activity_product_page_product_short_description_textview"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:fontFamily="@font/noto_sans"
                        tools:text="Product short description" />

                    <RelativeLayout
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="30dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp">

                        <TextView
                            android:id="@+id/activity_product_page_sold_by"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_sold_by" />

                        <TextView
                            android:id="@+id/activity_product_page_vendors_name_textview"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_alignTop="@id/activity_product_page_sold_by"
                            android:layout_marginStart="5dp"
                            android:layout_toEndOf="@+id/activity_product_page_sold_by"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_unknown"
                            android:textStyle="bold"
                            tools:text="Vendors name, " />

                        <TextView
                            android:id="@+id/activity_product_page_fulfilled_by_hard_coded_text"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_below="@+id/activity_product_page_vendors_name_textview"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_fulfilled_by" />

                        <TextView
                            android:id="@+id/activity_product_page_fulfilled_by_textview"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_alignTop="@+id/activity_product_page_fulfilled_by_hard_coded_text"
                            android:layout_marginStart="5dp"
                            android:layout_toEndOf="@+id/activity_product_page_fulfilled_by_hard_coded_text"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_unknown"
                            android:textStyle="bold"
                            tools:text="Project Verte." />

                        <TextView
                            android:id="@+id/activity_product_page_sku_textview"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_alignParentEnd="true"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_sku_unknown"
                            tools:text="SKU: K004" />

                    </RelativeLayout>

                    <TextView
                        android:id="@+id/activity_product_page_product_price_textview"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="30dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/activity_product_page_fetching_price"
                        android:textSize="20sp"
                        android:textStyle="bold"
                        tools:text="$35.00" />

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/activity_product_page_additional_tax_may_apply_on_checkout" />

                    <RelativeLayout
                        android:id="@+id/activity_product_page_availability_view_group"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="@dimen/marketplace_15dp">

                        <TextView
                            android:id="@+id/activity_product_page_availability_hardcoded"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_marginStart="@dimen/marketplace_14dp"
                            android:layout_marginEnd="@dimen/marketplace_14dp"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_availability" />

                        <TextView
                            android:id="@+id/activity_product_page_availability_textview"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_alignTop="@+id/activity_product_page_availability_hardcoded"
                            android:layout_toEndOf="@+id/activity_product_page_availability_hardcoded"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_unknown"
                            android:textColor="@color/red_delete"
                            tools:text="In Stock"
                            tools:textColor="@color/product_available" />

                    </RelativeLayout>

                    <RelativeLayout
                        android:id="@+id/activity_product_page_quantity_picker_viewgroup"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:visibility="gone"
                        tools:visibility="visible">

                        <TextView
                            android:id="@+id/activity_product_page_quantity_hardcoded"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:layout_centerVertical="true"
                            android:layout_marginStart="@dimen/marketplace_14dp"
                            android:layout_marginEnd="@dimen/marketplace_14dp"
                            android:fontFamily="@font/noto_sans"
                            android:text="@string/activity_product_page_quantity" />

                        <NumberPicker
                            android:id="@+id/activity_product_page_quantity_number_picker"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:layout_alignStart="@+id/activity_product_page_quantity_hardcoded"
                            android:layout_marginStart="90dp"
                            android:layout_marginEnd="90dp" />

                    </RelativeLayout>

                    <!-- At this point starts the dynamic product attributes (if any exists)
                    Check ProductPageActivity.java 'setProductPurchaseAttributes()'
                     for the code -->

                    <ProgressBar
                        android:id="@+id/activity_product_page_add_to_cart_progress_bar"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_gravity="center"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:visibility="gone"
                        tools:visibility="visible" />

                    <Button
                        android:id="@+id/activity_product_page_add_to_cart_button"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:background="@color/color_black"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/activity_product_page_add_to_cart"
                        android:textColor="@color/white" />

                    <ProgressBar
                        android:id="@+id/activity_product_page_buy_now_progress_bar"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_gravity="center"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:visibility="gone"
                        tools:visibility="visible" />

                    <Button
                        android:id="@+id/activity_product_page_buy_now_button"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:background="@color/color_black"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/activity_product_page_buy_now"
                        android:textColor="@color/white" />

                    <TextView
                        android:id="@+id/activity_product_page_share_textview"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_gravity="center"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="30dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/activity_product_page_share" />

                    <TextView
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="@dimen/marketplace_14dp"
                        android:layout_marginTop="30dp"
                        android:layout_marginEnd="@dimen/marketplace_14dp"
                        android:fontFamily="@font/noto_sans"
                        android:text="@string/activity_product_page_related_products"
                        android:textSize="22sp"
                        android:textStyle="bold" />

                    <androidx.recyclerview.widget.RecyclerView
                        android:id="@+id/activity_product_page_related_recycleview"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent"
                        android:layout_gravity="center"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
                        tools:listitem="@layout/fragment_marketplace_products_row_item" />

                    <View
                        android:id="@+id/activity_product_page_bottom_view"
                        android:layout_width="match_parent"
                        android:layout_height="70dp"
                        android:layout_marginTop="@dimen/marketplace_15dp"
                        android:layout_marginBottom="60dp"
                        android:background="@color/light_black"
                        android:visibility="gone"
                        tools:visibility="visible" />


                </LinearLayout>


            </LinearLayout>

        </androidx.core.widget.NestedScrollView>

    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.constraintlayout.widget.ConstraintLayout>

看起来像这样 -

我正在尝试实现一种逻辑，该逻辑将使 float 栏在到达名为 - activity_product_page_share_textview 的 TextView 时消失。 。我尝试实现 new NestedScrollView.OnScrollChangeListener()在我的 NestedScrollView 上，但我从scrollX和scrollY获得的值完全不相关 - 似乎它根据当前可用的屏幕空间计算值，并且(也许)还根据我的滚动速度 - 绝对不是根据 NestedScrollView ViewGroup。

另外，我希望 float 栏在 TextView 的 Y 位置下方时返回。两者都通过一些简单的淡入/淡出动画出现和消失。

我该如何实现它？

Answer 1

也许是这样的？需要一些优化(例如 float 按钮不需要位于每个滚动条上)，但这与想法有关。

activity_product_page_nested_scroll_view.setOnScrollChangeListener(NestedScrollView.OnScrollChangeListener { _, _, _, _, _ ->
            val locationOfTextView = IntArray(2)
            val locationOfFloatingButton = IntArray(2)
            activity_product_page_share_textview.getLocationInSurface(locationOfTextView)
            activity_product_page_share_product_action_button.getLocationInSurface(
                locationOfFloatingButton
            )

            if (locationOfTextView[1] >= locationOfFloatingButton[1] &&
                locationOfTextView[1] + activity_product_page_share_textview.height <= locationOfFloatingButton[1] + activity_product_page_share_product_action_button.height
            ) {
                if (activity_product_page_share_textview.alpha == 1F)
                    activity_product_page_share_textview.animate().alpha(0F).setDuration(200L).start()
            } else {
                if (activity_product_page_share_textview.alpha < 1F)
                    activity_product_page_share_textview.animate().alpha(1F).setDuration(200L).start()
            }
        })