[Lcd4linux-devel] patches for layer (in)visibility on generic text displays

[Marcus B. <mar...@in...>]

Hi,

I've recently been playing with lcd4linux on an HD44780-compatible 16x2
DFSTN display (JHD162A), and was interested in the 'layer' attribute. It
appears that this functionality hasn't yet been done for generic text
displays (HD44780 inc.) so I've attached some patches+info. Please
excuse any crudeness/CodingStyle issues (hopefully my method of
generating the patches is sufficient + works!). A compressed xvid avi
has been included for illustration, and sample conf to see how it's
done.

layer_patch:
If an icon is marked as invisible, we look for a character in an
underlying widget. I should really have added a visibility check for
that layer as well... oops! I'd like to attack true transparency at some
stage but I suspect that would involve bitmapping some|all of the
device's character set. I imagine that a transparent pixel could be
represented with "_" in the bitmap, as opposed to blank ('.').

frame_patch:
I started with a flashing email icon (left+right), but decided an
animated (sliding) one would be nicer to look at. Running two
(independent) animated icons proved to be problematic as they
occasionally get out of sync. The frame_patch addresses this issue by
giving the user the ability to specify the bitmap frame to be shown by
evaluated formula. Note I should have added a cellgap feature to either
the bitmap or evaluated formula to prevent "stretching", and that the
animations are 2x longer than necessary as the formula (test::bar)
counts up and back... but you get the point ;).

OT notes:
+ I note that icon's are not tested for "full" (block = chr 255) or
"empty" (space). Adding a test for this would free up 2 user chars,
right? Or is this just a waste of time/effort?
+ any plans for an imap plugin, or should I try that too? ;)

Hope this is of use, advice appreciated,

Regards,

Marcus.