Normal e-ink operation is slow, display updates result in black intermediate flashes, for scrolling there are multiple flashes.
In order to control the refresh behavior, WebView and other classes in E-ink devices have an added parameter.
The fast e-ink mode results in fast display updates, but leaves some ghosting from previous contents, plus the contrast is somewhat reduced. It appears that it leaves only ghosting from not fast mode, so a clear before entering fast mode might fix it.
Since so far e-ink Androids only (?) exist as rooted versions of bookshop frontends (Kindle, Nook, Sony, ..), there is no official documentation available.
hberntsen on
https://www.mobileread.com/forums/sho...=165376&page=2 proposed a way to control the update behavior. His app code tries to inject the update parameter with a wanted value by try/catch (no need to identify the device first).
As an example application how to change the update mode inside an application, see
http://code.google.com/p/ankidroid/issues/detail?id=971
See the attached code for the adapted WebView class.
At the moment, the fast e-ink mode only gets reset when running a stock (Sony PRS-T1 for me, I guess it is the same for the Nook) application.
The actual meaning of the updatemode parameter values is not well understood.
E.g. I would like to switch back to normal mode, but calling
MyWebView.mUpdateMode = 34;
additionally does a full page refresh. How to do it without?