Develop Reference

View animation scale values relative to original

I wanted to make a basic animation on a TextView that would shrink when the user tapped it and then scaled back to the original size in order to provide visual feedback. Reading the docs, it seems that there are various ways to animate properties on Android, but I settled for using a view animation, defined in the following XML:
<set xmlns:android="http://schemas.android.com/apk/res/android" android:shareInterpolator="true" android:interpolator="#android:anim/accelerate_interpolator">
<scale
android:fromXScale="1.0"
android:toXScale="0.5"
android:fromYScale="1.0"
android:toYScale="0.5"
android:pivotX="50%"
android:pivotY="50%"
android:duration="100"/>
<scale
android:startOffset="100"
android:fromXScale="1.0"
android:toXScale="2.0"
android:fromYScale="1.0"
android:toYScale="2.0"
android:pivotX="50%"
android:pivotY="50%"
android:duration="50"/>
This works well enough, but it strikes me as odd that I have to calculate by how much I'm going to need to scale the second tag instead of being able to just use values relative to the original. Is there any way to use values relative to the original element (ie, using fromXscale="0.5" and toXscale="1.0") in the second tag?

If I get your question right try this
tv.animate().scaleXBy(2.0f).scaleYBy(2.0f).setDuration(100).setInterpolator(new LinearInterpolator()).start();
You can add reverse repeat policy or just add scale back animation.

android rotate animation, make it fluid

I have an ImageView that should rotate for 4 times. This is my xml of animation:
<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="500"
android:fromDegrees="0"
android:interpolator="#android:anim/linear_interpolator"
android:pivotX="50%"
android:pivotY="50%"
android:repeatCount="3"
android:repeatMode="restart"
android:toDegrees="360" />
but rotation is not fluid: there's a little delay from end of a rotation, and begin of next one. How can i fix it?

Try to rotate from 0 to 359. 0 and 360 is the same in that context.

why not create an animation the usual way, and if you want it to rotate four times, then create a loop that iterates four times, and for each iteration, it calls the animation. You have to optimize your code so that are no visible drags.

Android - Alter animation in resource file

I have a transition from one activity to another that I am using in overridePendingTransition. Unfortunately all overridePendingTransition uses is the resource id of the file, so I am having trouble about how to edit this file so my transitions are proper.
Basically what I need to do is make changes to the R.anim.flip_in_scale_in so that I can change the value of the transitions fromX/toX so that it is set based on the user's screen size.
overridePendingTransition(R.anim.flip_in_scale_in, R.anim.stationary_item);
How do I update the R.anim.flip_in_scale_in file before use in the overridePendingTransition?

There isn't a way you can alter the animation from the resource file in the way you want.
However, you CAN create the animation to use percentages rather than dp values. When the animation is applied to the Activity's View, it will animate entirely on the view's size (which in most cases is the screen size).
This for example:
<set xmlns:android="http://schemas.android.com/apk/res/android">
<translate
android:fromXDelta="100%"
android:toXDelta="0%"
android:duration="500"
/>
</set>
Will slide in the view from the right side to the screen within half-a-second.
<set xmlns:android="http://schemas.android.com/apk/res/android">
<scale
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:fromXScale="1.0"
android:toXScale="1.4"
android:fromYScale="1.0"
android:toYScale="1.4"
android:pivotX="50%"
android:pivotY="50%"
android:duration="1000" />
</set>
This will increase the view to 40% it's current size over the span of one second. The pivot will be directly in the middle of the view regardless of the view's size.

Efficient way of using TranslateAnimation to move something across the screen over and over

I've had trouble finding good documentation about animations in Android, but I managed to get my animation working. What I'm concerned about the way I did it is efficiency/performance.
My goal was to have a cloud image move across the screen over and over and repeat forever. To do this I ended up putting 2 identical ImageViews positioned over each other and defining 2 animations:
cloud_slide_exit.xml:
<translate
android:fromYDelta="0"
android:toXDelta="-100%p"
android:duration="25000"
android:repeatCount="infinite"
android:repeatMode="restart"
/>
cloud_slide_enter.xml:
<translate
android:fromYDelta="0"
android:fromXDelta="100%p"
android:duration="25000"
android:repeatCount="infinite"
android:repeatMode="restart"
/>
I applied the first animation to "image1" and the second to "image2." The first animation moves "image1" from right (on-screen) to left (off-screen) while the second animation moves "image2" (which starts off screen) from right (off-screen) to left (on-screen). The end result when you view both animations is that the image moves across the screen. When it reaches the left end of the screen it will start coming from the right side of the screen. This is the only way I could think of doing this.
Is there a more efficient way to go about doing this animation? I'd like to find a more efficient way because I actually have 3 clouds moving which means that I have 6 ImageViews/TranslateAnimations.

replace your code by following code:
cloud_slide_exit.xml:
<translate
android:fromXDelta="100%p"
android:toXDelta="0%p"
android:duration="25000"
android:repeatCount="infinite"
android:repeatMode="restart"
/>
cloud_slide_enter.xml:
<translate
android:fromXDelta="100%p"
android:toXDelta="0%p"
android:duration="25000"
android:repeatCount="infinite"
android:repeatMode="restart"
/>

Showing both sides of a coin being flipped using Android standard animation

I'm very close to getting a "coin flipping" animation to work, but due to the limitations (bugs?) in the current Animation system - I cannot find a way to show BOTH sides of a coin flipping in the air.
For example, I have the following Animation .XML:
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:shareInterpolator="false">
<scale
android:repeatCount="17"
android:repeatMode="reverse"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:fromXScale="1.0" android:toXScale="1.0"
android:fromYScale="1.0" android:toYScale="0.0"
android:pivotX="50%" android:pivotY="50%"
android:fillEnabled="true"
android:fillAfter="true"
android:duration="60"
/>
<scale
android:repeatCount="1"
android:repeatMode="reverse"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:fromXScale="1.0" android:toXScale="2.0"
android:fromYScale="1.0" android:toYScale="2.0"
android:pivotX="50%" android:pivotY="50%"
android:fillEnabled="true"
android:fillAfter="true"
android:duration="800"
/>
<translate
android:repeatCount="1"
android:repeatMode="reverse"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:fromXDelta="0%"
android:toXDelta="0%"
android:fromYDelta="0%"
android:toYDelta="-150%"
android:fillEnabled="true"
android:fillAfter="true"
android:duration="800"
/>
</set>
This "fakes" a flipping animation by scaling the coin on the Y-axis and reversing it on a loop. In combination to this, there's a scale to make the overall animation bigger, while also translating it up and down. But it is only ever gonna show the one side of the coin.
I tried having two of these animations, each side of the coin, running at the same time, but I cannot find a way to stagger them due to the REPEATCOUNT not working when applied to an AnimationSet. Otherwise I could introduce some kind of delay after one anim (and before the other one) so they alternate, giving the illusion of a coin flipping.
Does anyone know any way I can tweak this to get the desired result?
I had thought of giving up and doing a frame-based anim (pre-render the flip as frames), but it appears you can't mix Frame & Tween anims, so I'd lose the flip "height" and "distance" effects.
(I have another issue when it comes to the coin landing - e.g. the final result is random, but I'm hoping I can switch in the actual result at the end?)
Thanks in advance!

I recently wanted to implement something like this for a project. I finally came up with a solution and the result was good enough. Hope it helps someone else who is trying to achieve the same animation.
I uploaded the result as a gist on GitHub.
For a preview of the animation click here.
For the full android studio project visit our CoinToss repository.

I was looking for something like this myself, even with the scaling of the image so it appears the imageview is getting closer to the screen.
I combined your animation with this solution to do exactly what you wanted and its fairly lightweight, missing out the need for multiple views.
https://github.com/Lojko/Booty/blob/master/src/game/booty/BootyGameActivity.java
Changed Location of the Original Link: http://www.jasoncavett.com/2011/05/changing-images-during-an-android-animation/#comments
See the FlipCoin class and how its used, I have an animation already existing (created in the same way as detailed by the link)

This code shows the same procedure
http://www.inter-fuser.com/2009/08/android-animations-3d-flip.html