Develop Reference

accelerate_decelerate_interpolator no pause when animation ends and the next start

I try to achieve an animation like this one :
The code of my animation look like this :
<rotate
xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="1000"
android:fromDegrees="0"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:pivotX="100%"
android:pivotY="100%"
android:repeatCount="infinite"
android:repeatMode="restart"
android:toDegrees="360"
>
</rotate>
and the result :
it's not that bad, but as you can see, every time the animation ends there is a small pause before the next start so I can't reach the same result as seen in the first gif. And I don't really know what I can modify to achieve that. With a linear_interpolator it's working but there is no accelerate/decelerate anymore.
Any idea ?

Android animations memory leak

If I have infinite animation in activity and navigate away from activity, does it causes memory leak? Do I have to stop animation explicitly or is it somehow managed on framework level? What I mean by infinite animation:
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="false"
android:repeatCount="infinite">
<rotate
android:duration="1000"
android:interpolator="#android:anim/linear_interpolator"
android:pivotX="50%"
android:pivotY="50%"
android:repeatCount="infinite"
android:repeatMode="restart"
android:toDegrees="360" />

From developers webpage :
You should usually use the onPause() callback to:
Stop animations or other ongoing actions that could consume CPU.
Source : http://developer.android.com/training/basics/activity-lifecycle/pausing.html#Pause

Not closely related, but If the leak is caused by the Animator class, e.g. holding a reference to an Activity/Fragment, you should call animatorInstance.removeAllListeners() in your fragment/activity onDestroy callback.

Animation loop in android

I made a background to animate from left to right. Everything works fine but when background-image reaches right, the animation starts over again.
How can i make it to run continuously so that it appears it is traveling from left to right always (no breaks)?

Use this:
<?xml version="1.0" encoding="utf-8"?>
<objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="15000"
android:fromXDelta="-95%p"
android:repeatCount="infinite"
android:repeatMode="restart"
android:toXDelta="-100%p" />

Flip card transition between two activities Android

I am trying to implement the Flip card transition effect between two activities in my app by taking help from :
http://blog.robert-heim.de/karriere/android-startactivity-rotate-3d-animation-activityswitcher/.But I couldn't understand what areActivitySwitcher.java and Roatate3dAnimation.java in the above mentioned site. I have two activities in my app between whom I want to show this transition effect. They are MainActivity.java and About_us.java.Please explain the code with reference to my activities. I also searched on http://developer.android.com/training/animation/cardflip.html but in vain as it not for activities.
Thanks!

Disclaimer: This is not a an actual 3D Animation Flip. This merely imitates it, though some don't agree. Give it a try and if you like it, great! If you don't, my apologies.
In my early days of learning to code, I was having issues implementing a proper 3D Animation flip, so I went with this, it simulated it enough to satisfy my needs, but to each her/his own. To do what I did, first make sure that you have a folder called anim under your res folder for your project. Then you will need to create two xml files (I have mine called from_middle and to_middle). Below is the code for each of those:
from_middle.xml:
<?xml version="1.0" encoding="utf-8"?>
<scale
xmlns:android="http://schemas.android.com/apk/res/android"
android:fromXScale="0.0" android:toXScale="1.0"
android:pivotX="50%"
android:fromYScale="1.0" android:toYScale="1.0"
android:pivotY="50%"
android:duration="500" />
to_middle.xml:
<?xml version="1.0" encoding="utf-8"?>
<scale
xmlns:android="http://schemas.android.com/apk/res/android"
android:fromXScale="1.0" android:toXScale="0.0"
android:pivotX="50%"
android:fromYScale="1.0" android:toYScale="1.0"
android:pivotY="50%"
android:duration="500" />
After those are created, all you need is one line of code to run this animation, which you should be placed after you start your next activity:
overridePendingTransition(R.anim.from_middle, R.anim.to_middle);
Done! Now run it!

Based on user1672053's answer, you need to add a start offset to the from_middle.xml resource which is equal to the duration of the to_middle.xml animation resource.

Avoid animation automatically "unwinding"?

I've a simple view animation, but I can't see to get "rid" of the animation "unwinding" (and I can't seem to find a solution online).
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/linear_interpolator"
android:shareInterpolator="true" >
<scale
android:duration="250"
android:fromXScale="1"
android:fromYScale="1"
android:pivotX="50%"
android:pivotY="50%"
android:repeatCount="0"
android:toXScale="1.1"
android:toYScale="1.1" />
</set>
What this does is, simply, inflates the View by 10% proportionally, from the middle.
But, when it executes, it inflates and, when it reaches the end, it deflates back. I want to avoid that -- the "unwinding" effect -- when it scales back from 110% to 100%.
How can that be done?
Edit:
I'm starting it simply with this:
Animation animation1 = AnimationUtils.loadAnimation(this, R.anim.<name>);
v.startAnimation(animation1);

The correct answer is found here: How can I animate a view in Android and have it stay in the new position/size?
It is putting this:
android:fillAfter="true"
android:fillEnabled="true"
inside the <set tag.