Problems with android Fragment animation

Question

I am learning to develop android apps and I am currently trying to add a fragment by sliding it from a side. The fragment is added, but it just appears, without animation.

There is a button in FragmentOne, I attach an event to it in MainActivity so that when clicked FragmentTwo. The event is correctly intercepted

Can anybody spot what I am doing wrong?

MainActivity.java

public class MainActivity extends Activity
{
    LinearLayout ll;
    FragmentOne f1;
    Animation fadeIn;

    @Override
    protected void onCreate ( Bundle savedInstanceState )
    {
        super.onCreate ( savedInstanceState );
        setContentView ( R.layout.activity_main );

        f1 = new FragmentOne ();

        FragmentTransaction ft1 = getFragmentManager ().beginTransaction ();
        ft1.add ( R.id.topFl, f1 );
        ft1.commit ();
    }


    @Override
    protected void onStart ()
    {
        super.onStart ();

        Button b = f1.getAddFragmentButton ();
        b.setOnClickListener
        (
            new Button.OnClickListener () 
            {
                public void onClick ( View v ) 
                {
                    FragmentTransaction ft2 = getFragmentManager ().beginTransaction ();
                    ft2.setCustomAnimations ( R.anim.enter_from_right, R.anim.exit_to_left, R.anim.enter_from_right, R.anim.exit_to_left );

                    ft2.addToBackStack ( null );

                    ft2.add ( R.id.bottomFl, new FragmentTwo () );
                    ft2.commit ();
                }
            }
        );
    }
}

enter_from_right.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:shareInterpolator="false">

    <objectAnimator
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:fromXDelta="-100%" android:toXDelta="0%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="1700"/>
</set>

exit_to_left.xml

<?xml version="1.0" encoding="utf-8"?>
    <set xmlns:android="http://schemas.android.com/apk/res/android"
    android:shareInterpolator="false">
    <objectAnimator
        android:fromXDelta="0%" android:toXDelta="-100%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="1700"/>
</set>

score 2 · Accepted Answer · edited Oct 22 '15 at 08:17

2

Use the support library fragments and instead of using getFragmentManager(), use getSupportFragmentManager().

It might sound counter-intuative, but it's better to use the support library components because any bugs (like this) are updated and fixed, whereas the platform components are tied to platform releases.

edited Oct 22 '15 at 08:17

JiTHiN

6,548
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answered Oct 22 '15 at 08:16

JoeyJubb

2,341
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Thank you so much for the quick reply! I did as instructed straight away, and I am now getting the following error: "java.lang.RuntimeException: Unknown animation name: objectAnimator". I realise it's because objectAnimator in the XML is more recent than the devices that the support library targets, fair enough. But I did a lot of searching and I can't find the right one. Would you happen know to what I should use instead? Even just a keyword which would make my search easier. – Dan Oct 24 '15 at 10:53
1

I'm not at my computer right now so I can't be exact, take a look at the android.R.anim.slide animations. They're supported by older devices. – JoeyJubb Oct 24 '15 at 11:28
That did the trick, thank you very much again. I couldn't find the substitute for objectAnimator because there isn't one :-) – Dan Oct 24 '15 at 11:39

Problems with android Fragment animation

1 Answers1