When backspace is received at the beginning of a line and the previous line was
wrapped, move the cursor back up to the end of the previous line.
Another one of the forgotten persons requested this quite a while ago (I need
to start noting names on todo items...) when it was quite hard to
implement. Now it is easy and I don't see it can do any harm, so hey presto...
Instead of just checking for an empty buffer, which may not be the case if
there is unconsumed data, save the previous size and use it instead. This means
that activity monitoring should work in this (unlikely) event.
Also remove a debugging statement that no longer seems necessary.
Add a flags member to the grid_line struct and use it to differentiate lines
wrapped at the screen edge from those terminated by a newline. Then use this
when copying to combine wrapped lines together into one.
Using the alternative screen (smcup/rmcup) should also preserve the current
colours and attributes. Found thanks to a report from Taylor Venable.
While here also nuke a couple of extra blank lines.
screen interactive programs to preserve the screen contents. When activated, it
saves a copy of the visible grid and disables scrolling into and resizing out
of the history; when deactivated the visible data is restored and the history
reenabled.
as UTF-8 in a separate array, the code does a lookup into this every time it
gets to a UTF-8 cell. Zero width characters are just appended onto the UTF-8
data for the previous cell. This also means that almost no bytes extra are
wasted non-Unicode data (yay).
Still some oddities, such as copy mode skips over wide characters in a strange
way, and the code could do with some tidying.
Split grid into two arrays, one containing grid attributes/flags/colours (keeps
the name grid_cell for now) and a separate with the character data (called
text). The text is stored as a u_short but is treated as a uint64_t elsewhere;
eventually the grid will have two arrays.
I'm not happy with the naming so that might change.
Still need to decide where to go from here. I'm not sure whether to combine
the peek/set functions together, and also whether to continue to treat the
text as a uint64_t (and convert to/from Unicode) or make it a char array
(of size one when UTF-8 disabled, eight when enabled) and keep everything
as UTF-8.
Also since UTF-8 will eventually become an attribute of the grid itself it
might be nice to move all the padding crap into grid.c.
