Implemented key kombination of Shift + PgUp/PgDn for Gnome terminal.
Same combination copied to all other terminal implementations which use same
codes for Shift + Up/Down but since this is tested on Ubuntu 16.04 with Gnome
Terminal 3.18.3 it could be that it is not correctly implemented for some of the
other terminals.
@klamonte opened this issue against gowid, a package that relies on tcell for
all its terminal handling: https://github.com/gcla/gowid/issues/24. It
describes how a shell inside a terminal widget that the TUI launches freezes
when the user hits backspace. The TUI loads a tcell TermInfo struct for the
screen-256color terminal and that struct codes KeyBackspace as the single byte
0xff - and so the byte 0xff was sent to the tty. On my Ubuntu 19.04 machine,
`infocmp screen-256color` shows `kbs` is `^?` According to
https://en.wikipedia.org/wiki/Caret_notation, `^?` should map to 0x7f (127) -
"The digraph stands for the control character whose ASCII code is the same as
the character's ASCII code with the uppermost bit, in a 7-bit encoding,
reversed". This affects both mkinfo.go, the generator of the JSON terminfo
database files, and the dynamic terminfo generator.
fixes#285 Loss of color/mangled formatting on GNU screen
fixes#93 use the terminfo database instead of the json database
This change falls back to using a dynamically generated terminal
description (using infocmp, which must be on the path) if the builtin
database doesn't have a suitable description.
For most users this should resolve the problem of unknown terminals.
