View can not be anchored to the the parent CoordinatorLayout

Question

this is not my app, this is nordic app that put its source on github and I am trying to run the soutce on my machine. but i keep having this error :

03-07 07:12:13.641  12622-12622/com.noxel.apppaneladmintry2 E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.noxel.apppaneladmintry2, PID: 12622
java.lang.IllegalStateException: View can not be anchored to the the parent CoordinatorLayout
        at android.support.design.widget.CoordinatorLayout$LayoutParams.resolveAnchorView(CoordinatorLayout.java:2522)
        at android.support.design.widget.CoordinatorLayout$LayoutParams.findAnchorView(CoordinatorLayout.java:2491)
        at android.support.design.widget.CoordinatorLayout.prepareChildren(CoordinatorLayout.java:619)
        at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:670)
        at android.view.View.measure(View.java:17442)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
        at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
        at android.view.View.measure(View.java:17442)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17442)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
        at android.view.View.measure(View.java:17442)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17442)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2560)
        at android.view.View.measure(View.java:17442)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2001)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1166)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1372)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
        at android.view.Choreographer.doCallbacks(Choreographer.java:580)
        at android.view.Choreographer.doFrame(Choreographer.java:550)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5257)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:921)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:716)

an this is the layout of my Mainactivity :

    <?xml version="1.0" encoding="utf-8"?>

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        style="@style/HeaderBar"
        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="?actionBarSize"
            android:theme="@style/ActionBarThemeOverlay"
            app:popupTheme="@style/ActionBarPopupThemeOverlay"
            app:titleTextAppearance="@style/ActionBar.TitleText"/>

        <android.support.design.widget.TabLayout
            android:id="@+id/sliding_tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabSelectedTextColor="@color/tabSelectedTextColor"
            app:tabTextColor="@color/tabTextColor"
            app:tabIndicatorColor="@color/tabIndicatorColor"
            app:tabGravity="fill"
            app:tabMode="fixed"/>

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

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab_add"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="@dimen/fab_margin"
        android:src="@drawable/fab_ic_add"
        app:backgroundTint="@color/fab_normal"
        app:layout_anchor="@+id/container"
        app:layout_anchorGravity="bottom|right|end"
        app:elevation="4dp"/>

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/background_title"
        android:layout_gravity="bottom|center"
        android:layout_marginBottom="6dp"/>

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

and this is my spash screen code:

public class SplashscreenActivity extends Activity {
    /** Splash screen duration time in milliseconds */
    private static final int DELAY = 1000;
    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splashscreen);

        // Jump to MainActivity after DELAY milliseconds
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                final Intent intent = new Intent(SplashscreenActivity.this, MainActivity.class);
                intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
                intent.putExtra(MainActivity.OPENED_FROM_LAUNCHER, true);
                startActivity(intent);
                finish();
            }
        }, DELAY);
    }

    @Override
    public void onBackPressed() {
        // do nothing. Protect from exiting the application when splash screen is shown
    }

}

and this is layout of my splash screen :

<merge xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".SplashscreenActivity" >

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:layout_marginBottom="70dp"
    android:scaleType="center"
    android:src="@drawable/nordic_logo" />

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/background_title"
    android:layout_gravity="bottom|center"
    android:layout_marginBottom="6dp"/>

can anyone tell me how to solve this issue?

Answer 1

This started to happened in support design library v.23.2.0

compile 'com.android.support:design:23.2.0'

I know this started with v23.2.0 because my app was working fine before (v.23.1.2) and started to present same failure after update.

Error is simple:

One of your views is anchored to its parent Coordinator Layout. However, starting at v.23.2.0, this is no longer allowed.

I think the error is in your FAB:

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab_add"
    ...
    app:layout_anchor="@+id/container" 
    ... />

I believe that id/container is a parent CoordinatorLayout

Fixing

Right way is change the layout_anchor and use another view as anchor (parent Layout or any other view which is fixed to bottom of the screen).

Answer 2

The view to which the FAB is anchored must be a descendant view of the CoordinatorLayout.

And if the view is a layout, the FAB must not be inside the layout, otherwise the anchor gravity settings won't work. For example:

<android.support.design.widget.CoordinatorLayout
    android:id="@+id/content_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    .
    .
    .
    <FrameLayout
        android:id="@+id/attachment_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="@dimen/fab_margin_end"
        android:layout_marginTop="@dimen/fab_margin_top"
        android:scaleType="center"
        android:src="@drawable/ic_action_save"
        app:borderWidth="0dp"
        app:elevation="@dimen/fab_elevation"
        app:layout_anchor="@id/attachment_layout"
        app:layout_anchorGravity="top|end"
        app:rippleColor="@color/accent_highlight" />

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