Pływający przycisk czynności Przewiń dziwne zachowanie

Question

Mam FloatingActionButton, który implementuje zachowanie do ukrycia go podczas przewijania w dół i pokazywania go podczas przewijania w górę.

Czasami jednak, gdy przewijam w górę, ukrywa się on, a następnie ponownie się pojawia. Nie jest to zrozumiałe zgodnie z moim kodem, ponieważ ma się ukrywać tylko podczas przewijania w dół.

Być może jest on powiązany z moim CollapsingToolbar, który jest również przewijany?

To mój układ:

<?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> 

To moje zachowanie:

[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(); 

    } 
} 

Wszelkie pomysły, dlaczego to może być prawda? Doceniam każdą pomoc.

Dzięki.

Answer 1

Zadzwoń super.

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

Jeśli to nie rozwiąże problemu, dodaj zachowanie do zwijanego paska narzędzi.

I dlaczego to robisz?

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

Możesz po prostu użyć dziecka zamiast floatingActionButtonChild.

Answer 2

Użyj tego połączenia, aby ustawić zachowanie przewijania przycisku operacji swobodnej.

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(); 
     } 
    } 

} 

oraz w XML, w którym został zaprojektowany swoją FAB ustawić jego zachowanie

<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" /> 

w strings.xml zdefiniować klasę zachowań jak ten

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