From 292829852eb462f45ae0da0b2370992f29b3ee77 Mon Sep 17 00:00:00 2001 From: Přemysl Janouch Date: Thu, 1 Nov 2018 15:54:32 +0100 Subject: Implement simple in-application help It could be made more complicated but I guess it's fine for now. We've learnt to run pagers. --- sdn.cpp | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 111 insertions(+), 8 deletions(-) diff --git a/sdn.cpp b/sdn.cpp index b3b8051..bd71a50 100644 --- a/sdn.cpp +++ b/sdn.cpp @@ -41,6 +41,8 @@ #include #include +#include +#include #include #include @@ -155,6 +157,21 @@ template fun shift (vector &v) -> T { auto front = v.front (); v.erase (begin (v)); return front; } +fun capitalize (const string &s) -> string { + string result; + for (auto c : s) + result += result.empty () ? toupper (c) : tolower (c); + return result; +} + +/// Underlining for teletypes, also imitated in more(1) and less(1) +fun underline (const string& s) -> string { + string result; + for (auto c : s) + result.append ({c, 8, '_'}); + return result; +} + // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - fun xdg_config_home () -> string { @@ -233,6 +250,13 @@ fun print (const ncstring &nc, int limit) -> int { return total_width; } +fun compute_width (const wstring &w) -> int { + int total = 0; + for (const auto &c : w) + total += wcwidth (c); + return total; +} + fun compute_width (const ncstring &nc) -> int { int total = 0; for (const auto &c : nc) @@ -295,7 +319,7 @@ struct entry { } }; -#define ACTIONS(XX) XX(NONE) XX(CHOOSE) XX(CHOOSE_FULL) XX(QUIT) \ +#define ACTIONS(XX) XX(NONE) XX(CHOOSE) XX(CHOOSE_FULL) XX(HELP) XX(QUIT) \ XX(UP) XX(DOWN) XX(TOP) XX(BOTTOM) XX(PAGE_PREVIOUS) XX(PAGE_NEXT) \ XX(SCROLL_UP) XX(SCROLL_DOWN) XX(GO_START) XX(GO_HOME) \ XX(SEARCH) XX(RENAME) XX(RENAME_PREFILL) \ @@ -312,7 +336,7 @@ static const char *g_action_names[] = {ACTIONS(XX)}; static map g_normal_actions = { {ALT | '\r', ACTION_CHOOSE_FULL}, {ALT | KEY (ENTER), ACTION_CHOOSE_FULL}, - {'\r', ACTION_CHOOSE}, {KEY (ENTER), ACTION_CHOOSE}, + {'\r', ACTION_CHOOSE}, {KEY (ENTER), ACTION_CHOOSE}, {'h', ACTION_HELP}, // M-o ought to be the same shortcut the navigator is launched with {ALT | 'o', ACTION_QUIT}, {'q', ACTION_QUIT}, {'k', ACTION_UP}, {CTRL 'p', ACTION_UP}, {KEY (UP), ACTION_UP}, @@ -386,7 +410,9 @@ static struct { map ls_exts; ///< LS_COLORS file extensions bool ls_symlink_as_target; ///< ln=target in dircolors - map key_names; + map name_to_key; + map key_to_name; + string action_names[ACTION_COUNT]; ///< Stylized action names // Refreshed by reload(): @@ -469,7 +495,7 @@ fun make_entry (const struct dirent *f) -> entry { entry e; e.filename = f->d_name; e.info.st_mode = DTTOIF (f->d_type); - auto& info = e.info; + auto &info = e.info; // TODO: benchmark just readdir() vs. lstat(), also on dead mounts; // it might make sense to stat asynchronously in threads @@ -622,6 +648,71 @@ fun reload () { (IN_ALL_EVENTS | IN_ONLYDIR | IN_EXCL_UNLINK) & ~(IN_ACCESS | IN_OPEN)); } +// TODO: we should be able to signal failures to the user +fun run_pager (FILE *contents) { + // We don't really need to set O_CLOEXEC, so we're not going to + rewind (contents); + endwin (); + + switch (pid_t child = fork ()) { + int status; + case -1: + break; + case 0: + // Put the child in a new foreground process group... + setpgid (0, 0); + tcsetpgrp (STDOUT_FILENO, getpgid (0)); + dup2 (fileno (contents), STDIN_FILENO); + + // Behaviour copies man-db's man(1), similar to POSIX man(1) + for (auto pager : {(const char *) getenv ("PAGER"), "pager", "cat"}) + if (pager) execl ("/bin/sh", "/bin/sh", "-c", pager, NULL); + _exit (EXIT_FAILURE); + default: + // ...and make sure of it in the parent as well + (void) setpgid (child, child); + waitpid (child, &status, 0); + tcsetpgrp (STDOUT_FILENO, getpgid (0)); + } + + refresh (); + update (); +} + +fun encode_key (wint_t key) -> string { + string encoded; + if (key & ALT) + encoded.append ("M-"); + wchar_t bare = key & ~ALT; + if (g.key_to_name.count (bare)) + encoded.append (capitalize (g.key_to_name.at (bare))); + else if (bare < 32) + encoded.append ("C-").append ({char (tolower (bare + 64))}); + else + encoded.append (to_mb ({bare})); + return encoded; +} + +fun show_help () { + FILE *contents = tmpfile (); + if (!contents) + return; + + for (const auto &kv : g_binding_contexts) { + fprintf (contents, "%s\n", + underline (capitalize (kv.first + " key bindings")).c_str ()); + for (const auto &kv : *kv.second) { + auto key = encode_key (kv.first); + key.append (max (0, 10 - compute_width (to_wide (key))), ' '); + fprintf (contents, "%s %s\n", + key.c_str (), g.action_names[kv.second].c_str ()); + } + fprintf (contents, "\n"); + } + run_pager (contents); + fclose (contents); +} + fun search (const wstring &needle) { int best = g.cursor, best_n = 0; for (int i = 0; i < int (g.entries.size ()); i++) { @@ -702,6 +793,9 @@ fun handle (wint_t c) -> bool { if (choose (current)) break; return false; + case ACTION_HELP: + show_help (); + return true; case ACTION_QUIT: return false; @@ -920,8 +1014,8 @@ fun parse_key (const string &key_name) -> wint_t { } c |= CTRL *p; p += 1; - } else if (g.key_names.count (p)) { - return c | g.key_names.at (p); + } else if (g.name_to_key.count (p)) { + return c | g.name_to_key.at (p); } else { wchar_t w; mbstate_t mb {}; auto len = strlen (p) + 1, res = mbrtowc (&w, p, len, &mb); @@ -943,8 +1037,13 @@ fun parse_key (const string &key_name) -> wint_t { return c; } +fun learn_named_key (const string &name, wint_t key) { + g.name_to_key[g.key_to_name[key] = name] = key; +} + fun load_bindings () { - g.key_names["space"] = ' '; + learn_named_key ("space", ' '); + learn_named_key ("escape", 0x1b); for (int kc = KEY_MIN; kc < KEY_MAX; kc++) { const char *name = keyname (kc); if (!name) @@ -956,7 +1055,7 @@ fun load_bindings () { if (*name != '(' && *name != ')') filtered += *name; } - g.key_names[filtered] = kc; + learn_named_key (filtered, SYM | kc); } auto config = xdg_config_find ("/" PROJECT_NAME "/bindings"); @@ -970,6 +1069,7 @@ fun load_bindings () { string name; for (; *p; p++) name += *p == '_' ? '-' : *p + 'a' - 'A'; + g.action_names[a] = name; actions[name] = action (a++); } @@ -1016,6 +1116,9 @@ int main (int argc, char *argv[]) { auto output_fd = dup (STDOUT_FILENO); dup2 (STDIN_FILENO, STDOUT_FILENO); + // So that the neither us nor our children stop on tcsetpgrp() + signal (SIGTTOU, SIG_IGN); + if ((g.inotify_fd = inotify_init1 (IN_NONBLOCK)) < 0) { cerr << "cannot initialize inotify" << endl; return 1; -- cgit v1.2.3-70-g09d2