If you are not pleased with the native interpolators on Android. Here are 30 custom ones to make motion look more real.
This small library is a port of Robert Penner's easing equations to kotlin on Android to add flavors to your animations, and it's based on https://easings.net/.

Get the demo from GooglePlay and see the library's custom interpolators in action.
You can also experiment with the path interpolator editor to get the control points for a custom interpolator of your choice using PathInterpolatorCompat.create(x1, y1, x2, y2).

Dependency should be declared in your app module level build.gradle file:

dependencies {

    implementation 'com.ramijemli:easings:1.0.0' 

}

This can be used exactly like the native interpolators.

ValueAnimator.ofFloat(0f,1f).apply {
    interpolator = Interpolators(Easings.SIN_IN)
    start()
}

ObjectAnimator.ofFloat(textView, "translationX", 100f).apply {
    interpolator = Interpolators(Easings.ELASTIC_IN_OUT)
    start()
}

myView.animate().apply {
    translationYBy(100f)
    interpolator = Interpolators(Easings.BOUNCE_OUT)
    start()
}

Interpolator	Behavior
Sinusoidal ease in Easings.SIN_IN
Sinusoidal ease out Easings.SIN_OUT
Sinusoidal ease in out Easings.SIN_IN_OUT
Quadratic ease in Easings.QUAD_IN
Quadratic ease out Easings.QUAD_OUT
Quadratic ease in out Easings.QUAD_IN_OUT
Cubic ease in Easings.CUBIC_IN
Cubic ease out Easings.CUBIC_OUT
Cubic ease in out Easings.CUBIC_IN_OUT
Quartic ease in Easings.QUART_IN
Quartic ease out Easings.QUART_OUT
Quartic ease in out Easings.QUART_IN_OUT
Quintic ease in Easings.QUINT_IN
Quintic ease out Easings.QUINT_OUT
Quintic ease in out Easings.QUINT_IN_OUT
Exponential ease in Easings.EXP_IN
Exponential ease out Easings.EXP_OUT
Exponential ease in out Easings.EXP_IN_OUT
Circular ease in Easings.CIRC_IN
Circular ease out Easings.CIRC_OUT
Circular ease in out Easings.CIRC_IN_OUT
Back ease in Easings.BACK_IN
Back ease out Easings.BACK_OUT
Back ease in out Easings.BACK_IN_OUT
Elastic ease in Easings.ELASTIC_IN
Elastic ease out Easings.ELASTIC_OUT
Elastic ease in out Easings.ELASTIC_IN_OUT
Bounce ease in Easings.BOUNCE_IN
Bounce ease out Easings.BOUNCE_OUT
Bounce ease in out Easings.BOUNCE_IN_OUT

All bugs, feature requests, feedback, etc. are welcome. Please, feel free to create an issue.

If you have new ideas, feel free to contribute by opening pull requests on dev branch.

Are you using this library in your app? Let us know and we'll show it here.

• Add tension modifier for elastic easing
• Add path interpolator editor
• Add sample for google play

Copyright 2019 Rami Jemli  
  
Licensed under the Apache License, Version 2.0 (the "License");  
you may not use this file except in compliance with the License.  
You may obtain a copy of the License at  

	http://www.apache.org/licenses/LICENSE-2.0  
 
Unless required by applicable law or agreed to in writing, software distributed
under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
either express or implied. See the License for the specific language governing permissions 
and limitations under the License.