java - Botón de acción flotante Desplazarse comportamiento extraño

android xamarin

Question

Tengo un FloatingActionButton que implementa un comportamiento para ocultarlo cuando se desplaza hacia abajo y lo muestra cuando se desplaza hacia arriba.

Sin embargo, a veces, cuando me desplazo hacia arriba, se oculta y vuelve a aparecer. Esto no es comprensible de acuerdo con mi código, ya que se supone que se oculta solo cuando se desplaza hacia abajo.

Tal vez está conectado con mi CollapsingToolbar que también se desplaza?

Este es mi diseño:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 
   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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="right"
    android:focusableInTouchMode="true"
    android:clickable="true"
    android:layoutDirection="rtl"
    android:fitsSystemWindows="true"
    android:id="@+id/drawer_layout">
  <android.support.design.widget.CoordinatorLayout
      android:id="@+id/mainCoordinatorLayout"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:fitsSystemWindows="true"
      android:layoutDirection="rtl"
      android:background="#EEEEEE"
      android:clickable="true">
    <android.support.design.widget.AppBarLayout
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:fitsSystemWindows="true"
        android:id="@+id/toolbar_layout">
      <android.support.design.widget.CollapsingToolbarLayout
          android:id="@+id/collapsing_toolbar"
          android:layout_width="match_parent"
          android:layout_height="256dp"
          android:fitsSystemWindows="true"
          app:layout_scrollFlags="scroll|exitUntilCollapsed"
          app:contentScrim="?attr/colorPrimary"
          app:collapsedTitleGravity="right|top"
          app:expandedTitleGravity="bottom|right"
          app:expandedTitleMarginBottom="64dp"
          app:collapsedTitleTextAppearance="@style/CollapsedTitleTextAppearance"
          app:expandedTitleTextAppearance="@style/ExpandedTitleTextAppearance"
          app:expandedTitleMarginEnd="0dp"
          app:expandedTitleMarginStart="30dp">
        <ImageView
            android:id="@+id/headerImage"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true"
            android:scaleType="centerCrop"
            app:layout_collapseMode="parallax"
            android:background="@drawable/soldier" />
        <View
            android:fitsSystemWindows="true"
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:background="@drawable/scrim_top"
            app:layout_collapseMode="pin" />
        <View
            android:fitsSystemWindows="true"
            android:layout_width="match_parent"
            android:layout_height="88dp"
            android:layout_gravity="bottom"
            android:layout_alignBottom="@+id/headerImage"
            android:background="@drawable/scrim_bottom" />
        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="104dp"
            android:gravity="top"
            app:titleTextColor="@color/White"
            android:layout_gravity="right"
            android:layoutDirection="rtl"
             app:layout_scrollFlags="scroll|enterAlways"
            app:layout_collapseMode="pin"
            app:contentScrim="?attr/colorPrimary"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:titleMarginTop="15dp" />
        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:layout_gravity="bottom"
            app:tabIndicatorHeight="3dp"
            android:layoutDirection="ltr"
            app:tabIndicatorColor="@android:color/white"
            app:tabSelectedTextColor="@color/White"
            app:tabTextColor="@color/Black"
            style="@style/MyCustomTabLayout"
            app:tabMode="fixed"
            app:tabGravity="fill">
          <android.support.design.widget.TabItem
              android:icon="@drawable/ic_book_white_24px"
              android:text="ספרים" />
          <android.support.design.widget.TabItem
              android:icon="@drawable/soldierWhite"
              android:text="הלכות" />
          <android.support.design.widget.TabItem
              android:icon="@drawable/ic_home_white_24px"
              android:text="בית" />
        </android.support.design.widget.TabLayout>

      </android.support.design.widget.CollapsingToolbarLayout>

    </android.support.design.widget.AppBarLayout>    
    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/content_frame"
        android:visibility="gone"
        android:animateLayoutChanges="true"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        app:behavior_overlapTop="0dp">
    </FrameLayout>
    <android.support.v4.view.ViewPager
        android:id="@+id/mainPager"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:behavior_overlapTop="0dp"
        />
    <android.support.design.widget.FloatingActionButton
        android:id="@+id/mainFab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_gravity="bottom|end"
        android:layout_marginLeft="16dp"
        android:layout_marginBottom="16dp"
        android:layout_marginTop="5dp"
        android:elevation="8dp"
        app:layout_behavior="@string/fab_scroll_translation_autohide_behavior"
        app:pressedTranslationZ="12dp"
        app:backgroundTint="?android:colorAccent"
        android:src="@drawable/ic_perm_phone_msg_white_24px" />
    <LinearLayout
        android:id="@+id/miniFabFrame"
        android:focusableInTouchMode="true"
        android:orientation="vertical"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="invisible"
        android:layout_alignParentLeft="true"
        android:layout_gravity="bottom|end"
        android:layout_marginLeft="20dp"
        android:layout_marginBottom="80dp"
        android:padding="0dp">
      <android.support.design.widget.FloatingActionButton
          android:id="@+id/messageFab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentBottom="true"
          android:layout_alignParentLeft="true"
          android:elevation="8dp"
          android:layout_marginTop="5dp"
          android:layout_marginRight="0dp"
          android:layout_marginBottom="5dp"
          android:layout_marginLeft="5dp"
          app:pressedTranslationZ="12dp"
          app:backgroundTint="?android:colorPrimary"
          app:fabSize="mini"
          android:src="@drawable/ic_textSMS_white_24px" />
      <android.support.design.widget.FloatingActionButton
          android:id="@+id/callFab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentBottom="true"
          android:layout_alignParentLeft="true"
          android:layout_marginTop="5dp"
          android:layout_marginRight="0dp"
          android:layout_marginBottom="5dp"
          android:layout_marginLeft="5dp"
          android:elevation="8dp"
          app:pressedTranslationZ="12dp"
          app:backgroundTint="?android:colorPrimary"
          app:fabSize="mini"
          android:src="@drawable/ic_call_white_24px" />
    </LinearLayout>
  </android.support.design.widget.CoordinatorLayout>
  <android.support.design.widget.NavigationView
      android:layout_width="wrap_content"
      android:layout_height="match_parent"
      android:layout_gravity="right"
      android:id="@+id/nav_view"
      android:layoutDirection="rtl"
      app:headerLayout="@layout/header"
      app:menu="@menu/nav_menu" />
</android.support.v4.widget.DrawerLayout>

Este es mi comportamiento:

[Register("ToratHamachane.ScrollAwareFABBehavior")]
public class ScrollAwareFABBehavior : CoordinatorLayout.Behavior
{
    public ScrollAwareFABBehavior(Context context, IAttributeSet attrs) : base(context, attrs)
    {
    }

    public override bool OnStartNestedScroll(CoordinatorLayout coordinatorLayout, Java.Lang.Object child, View directTargetChild, View target, int nestedScrollAxes)
    {
        return nestedScrollAxes == ViewCompat.ScrollAxisVertical ||
                 base.OnStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
    }

    public override void OnNestedScroll(CoordinatorLayout coordinatorLayout, Java.Lang.Object child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed)
    {
        base.OnNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);

        var floatingActionButtonChild = child.JavaCast<FloatingActionButton>();

        if (dyConsumed > 0 && floatingActionButtonChild.Visibility == ViewStates.Visible)
            floatingActionButtonChild.Hide();
        else if (dyConsumed < 0 && floatingActionButtonChild.Visibility != ViewStates.Visible)
            floatingActionButtonChild.Show();

    }
}

Alguna idea de por qué esto esta pasando? Agradecería cualquier ayuda.

Gracias.

Answer 1

Llamar súper

public ScrollAwareFABBehavior(Context context, IAttributeSet attrs) : base(context, attrs){
super();
}

Si esto no resolverá su problema, agregue comportamiento a su barra de herramientas colapsing.

¿Y por qué haces eso?

var floatingActionButtonChild = child.JavaCast<FloatingActionButton>();

Simplemente puede usar al niño en lugar de floatingActionButtonChild.

Answer 2

Use esta llamada para establecer el comportamiento de desplazamiento de su botón de acción flotante.

public class ScrollAwareFabBehaviour extends FloatingActionButton.Behavior {

    public ScrollAwareFabBehaviour(Context context, AttributeSet attrs) {
        super();
    }

    @Override
    public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
                                       final View directTargetChild, final View target, final int nestedScrollAxes) {
        // Ensure we react to vertical scrolling
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
    }

    @Override
    public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
                               final View target, final int dxConsumed, final int dyConsumed,
                               final int dxUnconsumed, final int dyUnconsumed) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
            // User scrolled down and the FAB is currently visible -> hide the FAB
            child.hide();
        } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
            // User scrolled up and the FAB is currently not visible -> show the FAB
            child.show();
        }
    }

}

y en tu xml, donde has diseñado tu FAB, establece su comportamiento

<android.support.design.widget.FloatingActionButton
        android:id="@+id/fab_add_note"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        android:layout_margin="@dimen/fab_margin"
        android:clickable="true"
        android:src="@drawable/ic_add_white_24dp"
        app:backgroundTint="@color/blue_grey_accent_color"
        app:layout_anchor="@id/recycler_notes"
        app:layout_anchorGravity="bottom|right|end"
        app:layout_behavior="@string/fab_behaviour"
        app:rippleColor="#FFF" />

en strings.xml define tu clase de comportamiento como esta

<string name="fab_behaviour">com.suman.swets.example.uiviews.ScrollAwareFabBehaviour</string>