Don't crash during updateBlur() if viewRoot call save() and restore() an unequal amount of times (Fix #184)
#187
Conversation
…() an unequal amount of times (Fix Dimezis#184)
| public BlurViewCanvas(@NonNull Bitmap bitmap) { | ||
| super(bitmap); | ||
| } | ||
|
|
||
| public void saveRoot() { |
There was a problem hiding this comment.
I don't think the custom method is a good idea.
Some other code might still call regular save on this canvas, invalidating the whole fix.
There was a problem hiding this comment.
saveRoot is only used to get the save index, in fact there is no need to change the save function behavior.
If there is more save than restore the restoreRoot function will restore to the correct index.
If there is more restore than save, we need to keep the original transform intact, so this is why restore need to be overridden.
In fact, code calling the regular save is intended behavior of this PR as there is no need to change how it works.
In fact the saveRoot and restoreRoot should only be called by BlurView.
I will update the javadoc, sorry it is my fault for not making the code more understandable.
There was a problem hiding this comment.
Thank for reviewing the patch, I added the javadoc to make it easier to understand.
The initial version of the patch hooked save and restore, but it doesn't work because of restoreToCount.
If you have any more questions please feel free to ask.
There was a problem hiding this comment.
Alright, could you please explain how this happens exactly?
Because I'm struggling to understand how to reproduce this crash
There was a problem hiding this comment.
It's just bad code calling save() or restore() too much times, this commit goal is to make sure the crash does not come from BlurView when it is not BlurView fault.
This patch doesn't prevent crashes, it just make the stacktrace show the actual error instead of just showing it comes from BlurView when it has nothing to do with BlurView.
To reproduce this crash, it just require to create a View that call restore() in it's draw function without calling save()
(Aka. making bad code)
This match the behavior of
sCompatibilityRestorefor app targeting android 5.1 (sdk 22) and earlier.Reference: Canvas.java from LineageOS 19.1 (Other ROMs should be the same)
This will also help to avoid being mislead that BlurView is the cause of issues that BlurView has nothing to do with.
I also updated the javadoc on
BlurViewCanvas