putty-source/stubs/no-lineedit.c

/*
 * Stubs of functions in lineedit.c, for use in programs that don't
 * have any use for line editing (e.g. because they don't have a
 * terminal either).
 */

#include "putty.h"
#include "terminal.h"

TermLineEditor *lineedit_new(Terminal *term, unsigned flags,
                             TermLineEditorCallbackReceiver *receiver)
{
    return NULL;
}
void lineedit_free(TermLineEditor *le) {}
void lineedit_input(TermLineEditor *le, char ch, bool dedicated) {}
void lineedit_modify_flags(TermLineEditor *le, unsigned clr, unsigned flip) {}
void lineedit_send_line(TermLineEditor *le) {}
New centralised version of local line editing. This takes over from both the implementation in ldisc.c and the one in term_get_userpass_input, which were imperfectly duplicating each other's functionality. The new version should be more consistent between the two already, and also, it means further improvements can now be made in just one place. In the course of this, I've restructured the inside of ldisc.c by moving the input_queue bufchain to the other side of the translation code in ldisc_send. Previously, ldisc_send received a string, an optional 'dedicated key' indication (bodgily signalled by a negative length) and an 'interactive' flag, translated that somehow into a combination of raw backend output and specials, and saved the latter in input_queue. Now it saves the original (string, dedicated flag, interactive flag) data in input_queue, and doesn't do the translation until the data is pulled back _out_ of the queue. That's because the new line editing system expects to receive something much closer to the original data format. The term_get_userpass_input system is also substantially restructured. Instead of ldisc.c handing each individual keystroke to terminal.c so that it can do line editing on it, terminal.c now just gives the Ldisc a pointer to its instance of the new TermLineEditor object - and then ldisc.c can put keystrokes straight into that, in the same way it would put them into its own TermLineEditor, without having to go via terminal.c at all. So the term_get_userpass_input edifice is only called back when the line editor actually delivers the answer to a username or password prompt. (I considered not _even_ having a separate TermLineEditor for password prompts, and just letting ldisc.c use its own. But the problem is that some of the behaviour differences between the two line editors are deliberate, for example the use of ^D to signal 'abort this prompt', and the use of Escape as an alternative line-clearing command. So TermLineEditor has a flags word that allows ldisc and terminal to set it up differently. Also this lets me give the two TermLineEditors a different vtable of callback functions, which is a convenient way for terminal.c to get notified when a prompt has been answered.) The new line editor still passes all the tests I wrote for the old one. But it already has a couple of important improvements, both in the area of UTF-8 handling: Firstly, when we display a UTF-8 character on the terminal, we check with the terminal how many character cells it occupied, and then if the user deletes it again from the editing buffer, we can emit the right number of backspace-space-backspace sequences. (The old ldisc line editor incorrectly assumed all Unicode characters had terminal with 1, partly because its buffer was byte- rather than character- oriented and so it was more than enough work just finding where the character _start_ was.) Secondly, terminal.c's userpass line editor would never emit a byte in the 80-BF range to the terminal at all, which meant that nontrivial UTF-8 characters always came out as U+FFFD blobs! 2023-03-04 12:56:01 +00:00			`/*`
			`* Stubs of functions in lineedit.c, for use in programs that don't`
			`* have any use for line editing (e.g. because they don't have a`
			`* terminal either).`
			`*/`

			`#include "putty.h"`
			`#include "terminal.h"`

			`TermLineEditor lineedit_new(Terminal term, unsigned flags,`
			`TermLineEditorCallbackReceiver *receiver)`
			`{`
			`return NULL;`
			`}`
			`void lineedit_free(TermLineEditor *le) {}`
			`void lineedit_input(TermLineEditor *le, char ch, bool dedicated) {}`
			`void lineedit_modify_flags(TermLineEditor *le, unsigned clr, unsigned flip) {}`
			`void lineedit_send_line(TermLineEditor *le) {}`