I'm trying to use the Facebook Keyframes animations framework. I tried their sample and it is working fine, the problem is when I try with another JSON for another animation, I get a null pointer when deserializing the input stream. I'll attach my code and the errors
InputStream stream = getResources().openRawResource(R.raw.animation);
KFImage kfImage = null;
try {
kfImage = KFImageDeserializer.deserialize(stream);
} catch (IOException e) {
e.printStackTrace();
}
KeyframesDrawable kfDrawable = new KeyframesDrawableBuilder().withImage(kfImage).build();
mAnimation.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
mAnimation.setImageDrawable(kfDrawable);
mAnimation.setImageAlpha(0);
kfDrawable.startAnimation();
Error stack trace:
java.lang.NullPointerException: Attempt to get length of null array
at com.facebook.keyframes.util.ArgCheckUtil.checkTimingCurveObjectValidity(ArgCheckUtil.java:53)
at com.facebook.keyframes.model.KFFeature.<init>(KFFeature.java:214)
at com.facebook.keyframes.model.KFFeature$Builder.build(KFFeature.java:170)
at com.facebook.keyframes.deserializers.KFFeatureDeserializer.readObject(KFFeatureDeserializer.java:90)
at com.facebook.keyframes.deserializers.KFFeatureDeserializer$1.readObjectImpl(KFFeatureDeserializer.java:32)
at com.facebook.keyframes.deserializers.KFFeatureDeserializer$1.readObjectImpl(KFFeatureDeserializer.java:29)
at com.facebook.keyframes.deserializers.AbstractListDeserializer.readList(AbstractListDeserializer.java:35)
at com.facebook.keyframes.deserializers.KFImageDeserializer.readObject(KFImageDeserializer.java:57)
at com.facebook.keyframes.deserializers.KFImageDeserializer.deserialize(KFImageDeserializer.java:40)
at MyFragment.onCreateView(MyFragment.java:83)
at android.app.Fragment.performCreateView(Fragment.java:2053)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:894)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.app.BackStackRecord.run(BackStackRecord.java:834)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1452)
at android.app.FragmentManagerImpl$1.run(FragmentManager.java:447)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5597)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:984)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)
Each entry in "feature_animations" array inside of loaded animation must contain "timing_curves" property. Its size must be equal to the number of keyframes - 1.
Keyframes values are stored in "key_values" property that usually resides right above "timing_curves".
This field must be always present. It can be empty but not null.
Timing Curves describe the pace with which a transform changes between each keyframe. Each timing curve is modeled as a cubic bezier curve from point [0, 0] to [1, 1], where the X value is the progression in time from the origin keyframe to the destination keyframe, and the Y value describes the amount of change in the value at a given time: origValue + (destValue - origValue) * Y.
ArgCheckUtil verifies next condition that has failed for your animation file:
/**
* Checks that the format of a timing curve 3D float array is valid. The number of timing curves
* for an animation should be equal to the number of keyframes - 1.
* @param timingCurves the 3D float array to check
* @param keyFrameQuantity the number of key frames this animation has
* @return true if the format is valid, false otherwise
*/
public static boolean checkTimingCurveObjectValidity(...
You can also analyze sample animation file in android-sample project in