Cannot start this animator on a detached view! reveal effect

Question

I'm trying to create the reveal effect in my application but without success. What i want is reveal a cardview when i open a fragment. What i tried so far is:

private void toggleInformationView(View view) {
        infoContainer = view.findViewById(R.id.contact_card);

        int cx = (view.getLeft() + view.getRight()) / 2;
        int cy = (view.getTop() + view.getBottom()) / 2;
        float radius = Math.max(infoContainer.getWidth(), infoContainer.getHeight()) * 2.0f;

        if (infoContainer.getVisibility() == View.INVISIBLE) {
            infoContainer.setVisibility(View.VISIBLE);
            ViewAnimationUtils.createCircularReveal(infoContainer, cx, cy, 0, radius).start();
        } else {
            Animator reveal = ViewAnimationUtils.createCircularReveal(
                    infoContainer, cx, cy, radius, 0);
            reveal.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    infoContainer.setVisibility(View.INVISIBLE);
                }
            });
            reveal.start();
        }
    }

and in the onCreateView i started the method:

toggleInformationView(view);

this is the cardview:

<android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:id="@+id/contact_card"
        android:visibility="invisible"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:elevation="4dp"
        android:foreground="?android:attr/selectableItemBackground"
        android:orientation="vertical"
        android:padding="10dp"
        card_view:cardCornerRadius="2dp" >

        <LinearLayout   
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            >
            <ImageView
                android:id="@+id/bg_contact"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_centerHorizontal="true"
                android:layout_weight="0"
                android:adjustViewBounds="true"
                android:scaleType="centerCrop"
                android:src="@drawable/banner" />

        </LinearLayout>
    </android.support.v7.widget.CardView>

and the logcat:

11-08 17:25:48.541: E/AndroidRuntime(26925): java.lang.IllegalStateException: Cannot start this animator on a detached view!
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.view.RenderNode.addAnimator(RenderNode.java:817)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.view.RenderNodeAnimator.setTarget(RenderNodeAnimator.java:277)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.view.RenderNodeAnimator.setTarget(RenderNodeAnimator.java:261)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.animation.RevealAnimator.<init>(RevealAnimator.java:37)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.view.ViewAnimationUtils.createCircularReveal(ViewAnimationUtils.java:48)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at com.as.asapp.TFragment.toggleInformationView(TFragment.java:64)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at com.as.asapp.TFragmentshowInformation(TFragment.java:52)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at com.as.asapp.TFragment.onCreateView(TFragment.java:37)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:739)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1489)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:454)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.os.Handler.handleCallback(Handler.java:739)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.os.Handler.dispatchMessage(Handler.java:95)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.os.Looper.loop(Looper.java:135)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at android.app.ActivityThread.main(ActivityThread.java:5221)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at java.lang.reflect.Method.invoke(Native Method)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at java.lang.reflect.Method.invoke(Method.java:372)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
11-08 17:25:48.541: E/AndroidRuntime(26925):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

Checking, seems that getWidth() and getHeight() returns 0. But i don't know if it's the real problem. Thanks

Answer 1

This is how I solved it, I added a onLayoutChange listener to the view in onCreateView callback, so whenever it is attached to the view and ready to draw, it makes the reveal

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        // Inflate the layout for this fragment
        final View view = inflater.inflate(R.layout.fragment_map_list, container, false);
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
                @TargetApi(Build.VERSION_CODES.LOLLIPOP)
                @Override
                public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
                    v.removeOnLayoutChangeListener(this);
                    toggleInformationView(view);
                }
            });
        }
        return view;
    }