Sequences like DECSC, DECRC, ESC [?1047l or ESC [?1047h save and restore
cursor attributes, than taken from vt100 manual are:
Save Cursor (DECSC) ESC 7
===========================
Saves the following in terminal memory.
- cursor position
- graphic rendition
- character set shift state
- state of wrap flag
- state of origin mode
Restore Cursor (DECRC) ESC 8
===========================
Restores the states described for (DECSC) above. If none of these
characteristics were saved, the cursor moves to home position; origin
mode is reset; no character attributes are assigned; and the default
character set mapping is established.
This implies that hide attribute of the cursor should not be saved/restored
in these sequences. The best way to fix this problem is moving hide
attribute into the terminal mode, instead of having it in the cursor state.
---
st.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
write can write less bytes than we request, so it is necessary check the
return value, in case of error print a message and don't continnue writing
in the file.
---
st.c | 39 ++++++++++++++++++++++++++++++---------
1 file changed, 30 insertions(+), 9 deletions(-)
This sequence was used by DEC personal in to for verifying the screen adjust
of terminals. It is the unique test sequence implemented by all the
emulators, and I think it is because they want be conforms with vttest which
uses this sequence in some tests.
---
st.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
If vt100_0 is a automatic variable then it is initializated in each call to
tsetchar, but if the variable is static it is initializated only in compile
time.
---
st.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Do not send NUL character in the identification (use (sizeof(VT102ID) - 1),
and finish the sequence once you execute it.
---
st.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
These sequences are used by the host in order to can detect which kind of
terminal is connected. St will answer like a vt102 terminal with this patch.
---
st.c | 9 +++++++++
1 file changed, 9 insertions(+)
Non handled codes must be ignored, except in graphic mode. Also STR
sequences have higher priority than control codes, so they must be handled
before of them.
---
st.c | 160 ++++++++++++++++++++++++++++++++++++------------------------------
1 file changed, 87 insertions(+), 73 deletions(-)
SI and SO allows change the G0 and G1 selection. This implementation is not
full vt100 compatible, but it is complatible with linux virtual terminal
implementation. For full vt100 compatibility we need remake a lot of stuff
relate to the different charmaps.
---
st.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
Add the documentation from the vt100 manual programmer:
Control Octal Action Taken
Character Code
-------------------------------------------
NUL 000 Ignored on input (not stored in input buffer;
see full duplex protocol).
ENQ 005 Transmit answerback message.
BEL 007 Sound bell tone from keyboard.
BS 010 Move the cursor to the left one character position,
unless it is at the left margin,
in which case no action occurs.
HT 011 Move the cursor to the next tab stop,
or to the right margin if no further tab stops
are present on the line.
LF 012 This code causes a line feed or
a new line operation. (See new line mode).
VT 013 Interpreted as LF.
FF 014 Interpreted as LF.
CR 015 Move cursor to the left margin on the current line.
SO 016 Invoke G1 character set, as designated by SCS
control sequence.
SI 017 Select G0 character set, as selected by ESC ( sequence.
XON 021 Causes terminal to resume transmission.
XOFF 023 Causes terminal to stop transmitted all codes
except XOFF and XON.
CAN 030 If sent during a control sequence, the sequence is
immediately terminated and not executed. It also causes
the error character to be displayed.
SUB 032 Interpreted as CAN.
ESC 033 Invokes a control sequence.
DEL 177 Ignored on input (not stored in input buffer).
--------------------------------------------
---
st.c | 28 +++++++++++++++++++---------
1 file changed, 19 insertions(+), 9 deletions(-)
sequences, so we have to support escape sequences in escape sequences that
escape sequences in escape sequences – setting a title won't notify you
anymore.
Taken from vt100 manual programmer:
Control characters (codes \0 to \37 inclusive) are specifically
excluded from the control sequence syntax, but may be embedded
within a control sequence. Embedded control characters are executed
as soon as they are encountered by the VT100. The processing of the
control sequence then continues with the next character received.
---
st.c | 68 +++++++++++++++++++++++++++++++++---------------------------------
1 file changed, 34 insertions(+), 34 deletions(-)
Taken from vt100 programmer manual:
Control characters have values of \000 - \037, and \177. The control
characters recognized by the VT100 are shown in Table 3-10. All
other control codes cause no action to be taken.
We have to take attention when we are using alternate charset, because in
this cases they are not used as control characters.
---
st.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
If -f options is enabled then tputc() writes all the data to a file. Actual
code assumes that all the strings in 'c' parameters have always 1 byte
length, but this is not always true, because due to utf-8 encoding some
characters can have a diferent length. So it is necessary pass string length
to tputc in order it can call to write() correctly.
---
st.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
This sequence lock/unlock the keyboard ignoring all the key pressing events
from X server.
---
st.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
tsetreset() is called when it is necessary a full initialization of the
terminal, so it also should clean the full X window and not only the
terminal content. It is necessary change the order of the
initialization in main(), and put xinit before of tnew(), because tnew()
calls to tsetreset(), and this can cause a call to xreset() with
incorrect values.
---
st.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Some times the size after a resizing is not an exact multiply of a number of
characters, so redrawn the screen using the lines and columns of the neww
size can cause that some old graphics keep in the screen. Solution is clean
all the windows with the background color.
---
st.c | 3 +++
1 file changed, 3 insertions(+)
st selection don't insert in the selection position whose value is not
set. This is correct for the positions in the end of the line, but cause
some problems in the beginning. For example echo -e 'a\tb' will print in the
screen:
a b
but after selecting and copying in some place you get:
ab
because positions from 1 to 7 don't have any value. This patch deals all
positions without value as blank (even at the end of the line).
---
st.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
malloc and realloc are called through xmalloc and xrealloc, so calloc should
be called through xcalloc.
---
st.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
In previous commits draw was removed from all the X events, but I forgot do
it in resize.
---
st.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
After the commit named "Remove timeout in the main loop", selection is not
working in the proper way. After selecting something, press mouse button in
a line outside of selection causes an incorrect highlight. This patch fix
the problem forcing a draw after the press event, but this is only a fast
hack. Real solution means rewriting selection code.
---
st.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
draw() runs over all lines of the screen and renders only the dirty lines,
this avoids render lines which are not modified since last draw() call. In
this moment the main loop is something like:
- Wait something to read from file descriptors
- Read from pseudo tty
- Call draw() for rending
- Read X events
This cause the problem that all the X events that have to update the screen
have to call draw() (because draw() is called before of X events handling),
so you can have multiples renderings in only one iteration, that will waste
a lot of resources.
This patch change the main loop to:
- Wait something to read from file descriptors
- Read from pseudo tty
- Read X events
- Call draw() for rending
So X events don't have to worry about rendering, because draw() is called
after them.
The only place where draw is called outside of the main loop is in redraw(),
but it is necessary for getting a good tput flash.
---
st.c | 29 ++++++-----------------------
1 file changed, 6 insertions(+), 23 deletions(-)
The main loop waits until there is some data to read in file descriptors of
the X server or the pseudo tty. But it uses a timeout in select(), which
causes that st awake each 20 ms, even it doesn't have something to do. This
patch removes this problem removing the timeout, which is not needed.
---
TODO | 1 -
st.c | 27 +++------------------------
2 files changed, 3 insertions(+), 25 deletions(-)
It is necessary call to XSync if you want a good tput flash, because in
other way you can not be sure that white screen will be shown.
---
st.c | 1 +
1 file changed, 1 insertion(+)
XdbeQueryExtension() tells to the caller if the Xdbe extension is present in
the X server, so it should be called for sanity. But like is said in
XdbeQueryExtension(3):
No other Xdbe functions may be called before this function. If a
client violates this rule, the effects of all subsequent Xdbe calls
that it makes are undefined.
it is mandatory call this function.
---
st.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
By default text files are line buffered, and this means that -f option will
not write the line until a \n is printed. This is not very useful for
debugging, so a call to fflush was added. This patch substitute this call
(which will be done by each character painted) by the full remove of the
buffering in the file.
---
st.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
If malloc or realloc fail they return NULL. Theorically this condition
should be tested in the code, but it's a strange condition today (basically
if this is hapenning thenyou have a big problem), and even Linux never returns
NULL in the default configuration (only if the process don't have room in
the space address, something a bit impossible in the case of st). But stis
enough small for being executed in low resources computers where this can be
a real problem. So the easy way is creating a wrappers function for them and
call to die in case of error.
---
st.c | 44 +++++++++++++++++++++++++++++++-------------
1 file changed, 31 insertions(+), 13 deletions(-)
st marks the active selection using reverse colors in the box selection, but
once that another window becomes owner of the selection, it is very
confusing that st keeps highlight the old selection. Usually terminal
emulators remove the highlight when it is not valid anymore.
X sends a SelectionClear event in this situation, so we only have to add a
callback which unhighlight the selectin box.
---
st.c | 9 +++++++++
1 file changed, 9 insertions(+)
Some programs use the alternative screen (vi, less, ...), whose
content is different of the main screen. If you select text in one of
the screen, you don't wait the box selection is painted in the other
screen, so it is necessary check if the selection was done in the same
screen we are going to paint. Before to this commit, you could do
something like:
$ LESS="" ls | less
(select some code)
q
and selection box remains drawing in the main screen, but the content
of selection keeps text of the alternate screen.
---
st.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
When it is called DECSCNM all lines become dirty, because it is necessary
redraw all lines for getting the new colors. It is easy see the problem
running 'echo ^[[?5h'.
In order to get a correct flash when running tput flash is necessary wait
after DECSCNM, until the changes are displayed, because in other case the
switch between reverse on/reverse off will be too much fast and nothing will
happen.
---
st.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
