Recyclerviews and SwipeRefreshLayout using support library 23.2.0

问题

Has anyone figured out a way to get recyclerviews, AppbarLayouts and SwipeRefreshLayout to work together on 23.2 yet? I am using a pretty standard method I think, but the swiperefreshlayout keeps grabbing the scroll gesture when trying to move up the recyclerview.

<android.support.design.widget.CoordinatorLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="?attr/toolbar_theme"
            app:layout_scrollFlags="scroll|enterAlways"
            android:elevation="4dp" />
    </android.support.design.widget.AppBarLayout>
    <FrameLayout
        android:id="@+id/fragment_container"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <!--fragment goes here -->
    </FrameLayout>
</android.support.design.widget.CoordinatorLayout>

with the following inside it

<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/swipe_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="?attr/window_background">
<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ProgressBar
        android:id="@+id/progress_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        style="@style/Widget.AppCompat.ProgressBar.Horizontal"
        android:layout_marginTop="-4dp"
        android:layout_marginBottom="-8dp"
        android:elevation="17dp"
        android:indeterminate="true"
        android:visibility="invisible" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical" />
</FrameLayout>
</android.support.v4.widget.SwipeRefreshLayout>

回答1:

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ImprovedSwipeLayoutAttrs">
        <attr name="scrollableChildId" format="reference" />
    </declare-styleable>
</resources>

layout.xml

<in.nerd_is.inactive_weibo.ui.ImprovedSwipeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    xmlns:isl="http://schemas.android.com/apk/res-auto"
    android:id="@+id/swipe_container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/md_blue_grey_50"
    isl:scrollableChildId="@+id/list_statuses"
    tools:context="in.nerd_is.inactive_weibo.ui.StatusesFragment" >

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ListView
            android:id="@+id/list_statuses"
            android:minHeight="?android:attr/listPreferredItemHeight"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:paddingTop="12dp"
            android:paddingBottom="12dp"
            android:paddingLeft="8dp"
            android:paddingRight="8dp"
            android:clipToPadding="false"
            android:divider="@android:color/transparent"
            android:dividerHeight="12dp"/>

        <com.melnykov.fab.FloatingActionButton
            android:id="@+id/button_floating_action"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|right"
            android:layout_margin="16dp"
            android:src="@drawable/ic_md_create"
            fab:fab_colorNormal="@color/md_blue_400"
            fab:fab_colorPressed="@color/md_blue_grey_500"/>
    </FrameLayout>

</in.nerd_is.inactive_weibo.ui.ImprovedSwipeLayout>

ImprovedSwipeLayout.java

public class ImprovedSwipeLayout extends SwipeRefreshLayout {

    private static final String TAG = ImprovedSwipeLayout.class.getCanonicalName();
    private int mScrollableChildId;
    private View mScrollableChild;

    public ImprovedSwipeLayout(Context context) {
        this(context, null);
    }

    public ImprovedSwipeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray a = context.obtainStyledAttributes(
                attrs, R.styleable.ImprovedSwipeLayoutAttrs);
        mScrollableChildId = a.getResourceId(R.styleable.ImprovedSwipeLayoutAttrs_scrollableChildId, 0);
        mScrollableChild = findViewById(mScrollableChildId);
        a.recycle();
    }

    @Override
    public boolean canChildScrollUp() {
        ensureScrollableChild();

        if (android.os.Build.VERSION.SDK_INT < 14) {
            if (mScrollableChild instanceof AbsListView) {
                final AbsListView absListView = (AbsListView) mScrollableChild;
                return absListView.getChildCount() > 0
                        && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
                        .getTop() < absListView.getPaddingTop());
            } else {
                return mScrollableChild.getScrollY() > 0;
            }
        } else {
            return ViewCompat.canScrollVertically(mScrollableChild, -1);
        }
    }

    private void ensureScrollableChild() {
        if (mScrollableChild == null) {
            mScrollableChild = findViewById(mScrollableChildId);
        }
    }

}

It's from http://nerd-is.in/2014-09/add-multi-child-view-in-swiperefreshlayout/

Create a View extend SwipeRefreshLayout and custom canChildScrollUp.

回答2:

If you put a View that doesn't implement ScrollingView or isn't an AbsListView into SwipeRefreshLayout, SwipeRefreshLayout#canChildScrollUp() always returns false.

So by using a FrameLayout inside of SwipeRefreshLayout you have two issues:

1. SwipeRefreshLayout doesn't accept nested scroll operations of descendant views (see SwipeRefreshLayout#onStartNestedScroll(View, View, int)). This causes the issues with CoordinatorLayout / AppBarLayout.

2. The SwipeRefreshLayout handles touch events itself as long as its child cannot scroll up or there is no nested scroll in progress (see SwipeRefreshLayout#onInterceptTouchEvent(MotionEvent) and SwipeRefreshLayout#onTouchEvent(MotionEvent)). This means the spinner is displayed when "touch moving down".

You can fix this by using your own SwipeRefreshLayout, which overwrites SwipeRefreshLayout#onStartNestedScroll(View, View, int). This way nested scrolls are accepted even if the direct child view can't scroll up:

public class SwipeRefreshLayout extends android.support.v4.widget.SwipeRefreshLayout {

    public SwipeRefreshLayout(Context context) {
        super(context);
    }

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

    @Override
    public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
        return isEnabled()
                && !isRefreshing()
                && (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0;
    }
}

BTW if you look at SwipeRefreshLayout's code in 23.1.1 you'll see, that the canChildScrollUp() check was removed but was added again in 23.2.0. I also removed the check for !mReturningToStart, because mReturningToStart is always false.

回答3:

Faced same issue after updating to 23.2.0. It's an old-new bug which was fixed in 23.1.1 and appears again in 23.2.0.

In my case I downgrade to 23.1.1 and everithing is OK again. So we should wait for new version of libs or use workarounds with overriding SwipeRefreshLayout.

---

Here is link to google bugtracker: RecyclerView v23.2.0 - doesn't play nicely with SwipeRefreshLayout

来源：https://stackoverflow.com/questions/35641630/recyclerviews-and-swiperefreshlayout-using-support-library-23-2-0