Artifacts on screen from closed stacks on Android

Sannyasin Brahmanathaswami brahma at
Sun Jan 28 15:04:36 EST 2018

We are getting reports (and screen shot and screen videos) from some Android users that show artifacts from a previously opened Stack A, when opening Stack B


Stack A is explicitly closed and has both destroyStack and destroyWindow set to true.

In the absence of being able to reproduce these residual closed-destroyed stack artifacts issues on my Pixel (and HQ can't either) I am wondering if there is some hack, that will not affect performance too much, to forcibly clear out the pixels of the previously opened stack?  Details below:

There is bug report on this already

You can see screen shots there from a Galaxy A7 (2017) running Nougat… this is not an underpowered phone..

but it's hanging  under "Pending Followup" --  this was a mid-holiday report… so perhaps now that we are all "back at it" we ca work on this.

Two examples are

1) least offensive scenario:

Stack A may have a background image set 1028 X 1028… a lo-res image, centered so that regardless of the device width or height, using fullScreenMode, this background will fill..

Then we open a stack that has no such background and is constrained to 414 wide… if the device screen ration is a bit off then this will be pillar boxed… some stripes, left and right… and these are filled with the image of the previous stack A. Even Though Stack A, and it's window is destroyed.

2) worst case scenario

Entire image map of Stack B is not fully rendered.. even get some bizarre tiles or squares with odd colors or image data from Stack A, and only one area of Stack B is rendered like some weird inlay or overlay on top of the pixel map of Stack A.

Again, all stacks have their stack and window set to destroy and are explicitly closed after Stack B is opened. You must have a stack open and visible on Mobile or the app will crash, so that's why we leave Stack A open and only close it *after* Stack B is opened.

I have no recipe for this, and so HQ is at a loss. we also don't see this on our Pixel. Though I think I did occasionally see #1 above, but never #2.

I have yet to issue an update using "go in window" which Mark W. has recommended. But apparently we still need to explicitly close Stack A even if we "go  "Stack B" in window "Stack A"  and rather than issue this update, only to find it doesn't help.. I was fishing for a "clean up the video display ram" solution…

And side question:

What is the difference between destroyStack and destroyWindow. From the dictionary definitions, they appear to do the same thing, but we have them as separate props in the PI, so I presume they are not synonyms but have separate functions. Mute, because I set both to true for all stacks.. but still wondering the difference?


Svasti Astu, Be Well
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