Q:

Can somebody please draw me a pic on how xdelta work in landscape mode?

I want to use translate animation to implement a menu, but I got totally lost at the xxx% thing. I want to use percentile because I want the app to work on devices with all sorts of resolution. 
The problem is I can't seem to figure out what percentage corresponds to what screen position.
For example, it appears that 200% is still on screen, -50% isn't off screen?
Is there a set of unifying specs or it depends on how OEMs port the android kernel to their device? For example Nexus device's 50% is different from Samsung's 50%???
Here is the problematic animation code:
<set
xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@android:anim/linear_interpolator"
android:fillAfter="true">

<translate
    android:fromXDelta="200%"
    android:toXDelta="160%"
    android:duration="5000" />
</set>

Edit:
To make the matter worse, the whole thing seem to be connected with "constraintLayoutParams.leftMargin". It seems that whenever I adject constraintLayoutParams.leftMargin, the percentage (xx%) change, too. 

A:

From
https://developer.android.com/guide/topics/resources/animation-resource.html
A vertical and/or horizontal motion. Supports the following attributes in any of the following three formats: values from -100 to 100 ending with "%", indicating a percentage relative to itself; values from -100 to 100 ending in "%p", indicating a percentage relative to its parent; a float value with no suffix, indicating an absolute value.
visit the link for more details.

