Some major refactoring including moving more stuff into bterm.h (renamed

from keys.h), a custom readline (`read` was buggy), better
customization, and improved renaming bindings.

1 files changed, 431 insertions, 0 deletions

diff --git a/bterm.h b/bterm.h
new file mode 100644
index 0000000..faf6efa
--- /dev/null
+++ b/bterm.h
@@ -0,0 +1,431 @@
+/*
+ * bterm.h
+ * Copyright 2019 Bruce Hill
+ * Released under the MIT License
+ *
+ * Definitions of some basic terminal stuff, like reading keys
+ * and some terminal escape sequences.
+ */
+
+#ifndef FILE__BTERM_H
+#define FILE__BTERM_H
+
+#include <poll.h>
+#include <stdio.h>
+
+#define KEY_F1               (0xFFFF-0)
+#define KEY_F2               (0xFFFF-1)
+#define KEY_F3               (0xFFFF-2)
+#define KEY_F4               (0xFFFF-3)
+#define KEY_F5               (0xFFFF-4)
+#define KEY_F6               (0xFFFF-5)
+#define KEY_F7               (0xFFFF-6)
+#define KEY_F8               (0xFFFF-7)
+#define KEY_F9               (0xFFFF-8)
+#define KEY_F10              (0xFFFF-9)
+#define KEY_F11              (0xFFFF-10)
+#define KEY_F12              (0xFFFF-11)
+#define KEY_INSERT           (0xFFFF-12)
+#define KEY_DELETE           (0xFFFF-13)
+#define KEY_HOME             (0xFFFF-14)
+#define KEY_END              (0xFFFF-15)
+#define KEY_PGUP             (0xFFFF-16)
+#define KEY_PGDN             (0xFFFF-17)
+#define KEY_ARROW_UP         (0xFFFF-18)
+#define KEY_ARROW_DOWN       (0xFFFF-19)
+#define KEY_ARROW_LEFT       (0xFFFF-20)
+#define KEY_ARROW_RIGHT      (0xFFFF-21)
+#define KEY_MOUSE_LEFT       (0xFFFF-22)
+#define KEY_MOUSE_RIGHT      (0xFFFF-23)
+#define KEY_MOUSE_MIDDLE     (0xFFFF-24)
+#define KEY_MOUSE_RELEASE    (0xFFFF-25)
+#define KEY_MOUSE_WHEEL_UP   (0xFFFF-26)
+#define KEY_MOUSE_WHEEL_DOWN (0xFFFF-27)
+#define KEY_MOUSE_DOUBLE_LEFT (0xFFFF-28)
+
+/* These are all ASCII code points below SPACE character and a BACKSPACE key. */
+#define KEY_CTRL_TILDE       0x00
+#define KEY_CTRL_2           0x00 /* clash with 'CTRL_TILDE' */
+#define KEY_CTRL_A           0x01
+#define KEY_CTRL_B           0x02
+#define KEY_CTRL_C           0x03
+#define KEY_CTRL_D           0x04
+#define KEY_CTRL_E           0x05
+#define KEY_CTRL_F           0x06
+#define KEY_CTRL_G           0x07
+#define KEY_BACKSPACE        0x08
+#define KEY_CTRL_H           0x08 /* clash with 'CTRL_BACKSPACE' */
+#define KEY_TAB              0x09
+#define KEY_CTRL_I           0x09 /* clash with 'TAB' */
+#define KEY_CTRL_J           0x0A
+#define KEY_CTRL_K           0x0B
+#define KEY_CTRL_L           0x0C
+#define KEY_ENTER            0x0D
+#define KEY_CTRL_M           0x0D /* clash with 'ENTER' */
+#define KEY_CTRL_N           0x0E
+#define KEY_CTRL_O           0x0F
+#define KEY_CTRL_P           0x10
+#define KEY_CTRL_Q           0x11
+#define KEY_CTRL_R           0x12
+#define KEY_CTRL_S           0x13
+#define KEY_CTRL_T           0x14
+#define KEY_CTRL_U           0x15
+#define KEY_CTRL_V           0x16
+#define KEY_CTRL_W           0x17
+#define KEY_CTRL_X           0x18
+#define KEY_CTRL_Y           0x19
+#define KEY_CTRL_Z           0x1A
+#define KEY_ESC              0x1B
+#define KEY_CTRL_LSQ_BRACKET 0x1B /* clash with 'ESC' */
+#define KEY_CTRL_3           0x1B /* clash with 'ESC' */
+#define KEY_CTRL_4           0x1C
+#define KEY_CTRL_BACKSLASH   0x1C /* clash with 'CTRL_4' */
+#define KEY_CTRL_5           0x1D
+#define KEY_CTRL_RSQ_BRACKET 0x1D /* clash with 'CTRL_5' */
+#define KEY_CTRL_6           0x1E
+#define KEY_CTRL_7           0x1F
+#define KEY_CTRL_SLASH       0x1F /* clash with 'CTRL_7' */
+#define KEY_CTRL_UNDERSCORE  0x1F /* clash with 'CTRL_7' */
+#define KEY_SPACE            0x20
+#define KEY_BACKSPACE2       0x7F
+#define KEY_CTRL_8           0x7F /* clash with 'BACKSPACE2' */
+
+
+// Terminal escape sequences:
+#define CSI           "\033["
+#define T_WRAP        "7"
+#define T_SHOW_CURSOR "25"
+#define T_MOUSE_XY    "1000"
+#define T_MOUSE_CELL  "1002"
+#define T_MOUSE_SGR   "1006"
+#define T_ALT_SCREEN  "1049"
+#define T_ON(opt)  CSI "?" opt "h"
+#define T_OFF(opt) CSI "?" opt "l"
+
+#define move_cursor(f, x, y) fprintf((f), CSI "%d;%dH", (int)(y)+1, (int)(x)+1)
+
+
+#define ESC_DELAY 10
+
+int bgetkey(FILE *in, int *mouse_x, int *mouse_y, int timeout);
+const char *bkeyname(int key);
+char *breadline(FILE *in, FILE *out, const char *prompt, const char *initial);
+
+static inline int nextchar(int fd, int timeout)
+{
+    char c;
+    struct pollfd pfd = {fd, POLLIN, 0};
+    if (poll(&pfd, 1, timeout) > 0)
+        return read(fd, &c, 1) == 1 ? c : -1;
+    return -1;
+}
+
+/**
+ * Get one key of input from the given file. Returns -1 on failure.
+ *
+ * If mouse_x or mouse_y are non-null and a mouse event occurs, they will be
+ * set to the position of the mouse (0-indexed).
+ */
+int bgetkey(FILE *in, int *mouse_x, int *mouse_y, int timeout)
+{
+    int fd = fileno(in);
+    int numcode = 0, super = 0;
+    int c = nextchar(fd, timeout);
+    if (c == '\x1b')
+        goto escape;
+
+    return c;
+
+  escape:
+    c = nextchar(fd, ESC_DELAY);
+    // Actual escape key:
+    if (c < 0)
+        return KEY_ESC;
+
+    switch (c) {
+        case '\x1b': ++super; goto escape;
+        case '[': goto CSI_start;
+        case 'P': goto DCS;
+        case 'O': goto SS3;
+        default: return -1;
+    }
+
+  CSI_start:
+    c = nextchar(fd, ESC_DELAY);
+    if (c == -1)
+        return -1;
+
+    switch (c) {
+        case 'A': return KEY_ARROW_UP;
+        case 'B': return KEY_ARROW_DOWN;
+        case 'C': return KEY_ARROW_RIGHT;
+        case 'D': return KEY_ARROW_LEFT;
+        case 'F': return KEY_END;
+        case 'H': return KEY_HOME;
+        case '~':
+            switch (numcode) {
+                case 3: return KEY_DELETE;
+                case 5: return KEY_PGUP;
+                case 6: return KEY_PGDN;
+                case 15: return KEY_F5;
+                case 17: return KEY_F6;
+                case 18: return KEY_F7;
+                case 19: return KEY_F8;
+                case 20: return KEY_F9;
+                case 21: return KEY_F10;
+                case 23: return KEY_F11;
+                case 24: return KEY_F12;
+            }
+            return -1;
+        case '<': { // Mouse clicks
+            int buttons = 0, x = 0, y = 0;
+            char buf;
+            while (read(fd, &buf, 1) == 1 && '0' <= buf && buf <= '9')
+                buttons = buttons * 10 + (buf - '0');
+            if (buf != ';') return -1;
+            while (read(fd, &buf, 1) == 1 && '0' <= buf && buf <= '9')
+                x = x * 10 + (buf - '0');
+            if (buf != ';') return -1;
+            while (read(fd, &buf, 1) == 1 && '0' <= buf && buf <= '9')
+                y = y * 10 + (buf - '0');
+            if (buf != 'm' && buf != 'M') return -1;
+
+            if (mouse_x) *mouse_x = x - 1;
+            if (mouse_y) *mouse_y = y - 1;
+
+            if (buf == 'm')
+                return KEY_MOUSE_RELEASE;
+            switch (buttons) {
+                case 64: return KEY_MOUSE_WHEEL_UP;
+                case 65: return KEY_MOUSE_WHEEL_DOWN;
+                case 0: return KEY_MOUSE_LEFT;
+                case 1: return KEY_MOUSE_RIGHT;
+                case 2: return KEY_MOUSE_MIDDLE;
+                default: return -1;
+            }
+            break;
+        }
+        default:
+            if ('0' <= c && c <= '9') {
+                // Ps prefix
+                numcode = 10*numcode + (c - '0');
+                goto CSI_start;
+            }
+    }
+    return -1;
+
+  DCS:
+    return -1;
+
+  SS3:
+    switch (nextchar(fd, ESC_DELAY)) {
+        case 'P': return KEY_F1;
+        case 'Q': return KEY_F2;
+        case 'R': return KEY_F3;
+        case 'S': return KEY_F4;
+        default: break;
+    }
+    return -1;
+}
+
+/**
+ * Return the name of a key, if one exists and is different from the key itself
+ * (i.e. bkeyname('c') == NULL, bkeyname(' ') == "Space")
+ */
+const char *bkeyname(int key)
+{
+    // TODO: currently only the keys I'm using are named
+    switch (key) {
+        case KEY_F1: return "F1";
+        case KEY_F2: return "F2";
+        case KEY_F3: return "F3";
+        case KEY_F4: return "F4";
+        case KEY_F5: return "F5";
+        case KEY_F6: return "F6";
+        case KEY_F7: return "F7";
+        case KEY_F8: return "F8";
+        case KEY_F9: return "F9";
+        case KEY_F10: return "F10";
+        case KEY_F11: return "F11";
+        case KEY_F12: return "F12";
+        case KEY_INSERT: return "Insert";
+        case KEY_DELETE: return "Delete";
+        case KEY_HOME: return "Home";
+        case KEY_END: return "End";
+        case KEY_PGUP: return "PgUp";
+        case KEY_PGDN: return "PgDn";
+        case KEY_ARROW_UP: return "Up";
+        case KEY_ARROW_DOWN: return "Down";
+        case KEY_ARROW_LEFT: return "Left";
+        case KEY_ARROW_RIGHT: return "Right";
+        case KEY_MOUSE_LEFT: return "Left click";
+        case KEY_MOUSE_RIGHT: return "Right click";
+        case KEY_MOUSE_MIDDLE: return "Middle click";
+        case KEY_MOUSE_RELEASE: return "Mouse release";
+        case KEY_MOUSE_WHEEL_UP: return "Mouse wheel up";
+        case KEY_MOUSE_WHEEL_DOWN: return "Mouse wheel down";
+        case KEY_MOUSE_DOUBLE_LEFT: return "Mouse double left";
+        case KEY_CTRL_TILDE: return "Ctrl-[2~]";
+        case KEY_CTRL_A: return "Ctrl-a";
+        case KEY_CTRL_B: return "Ctrl-b";
+        case KEY_CTRL_C: return "Ctrl-c";
+        case KEY_CTRL_D: return "Ctrl-d";
+        case KEY_CTRL_E: return "Ctrl-e";
+        case KEY_CTRL_F: return "Ctrl-f";
+        case KEY_CTRL_G: return "Ctrl-g";
+        case KEY_BACKSPACE: return "Backspace";
+        case KEY_TAB: return "Tab";
+        case KEY_CTRL_J: return "Ctrl-j";
+        case KEY_CTRL_K: return "Ctrl-k";
+        case KEY_CTRL_L: return "Ctrl-l";
+        case KEY_ENTER: return "Enter";
+        case KEY_CTRL_N: return "Ctrl-n";
+        case KEY_CTRL_O: return "Ctrl-o";
+        case KEY_CTRL_P: return "Ctrl-p";
+        case KEY_CTRL_Q: return "Ctrl-q";
+        case KEY_CTRL_R: return "Ctrl-r";
+        case KEY_CTRL_S: return "Ctrl-s";
+        case KEY_CTRL_T: return "Ctrl-t";
+        case KEY_CTRL_U: return "Ctrl-u";
+        case KEY_CTRL_V: return "Ctrl-v";
+        case KEY_CTRL_W: return "Ctrl-w";
+        case KEY_CTRL_X: return "Ctrl-x";
+        case KEY_CTRL_Y: return "Ctrl-y";
+        case KEY_CTRL_Z: return "Ctrl-z";
+        case KEY_ESC: return "Esc";
+        case KEY_CTRL_BACKSLASH: return "Ctrl-[4\\]";
+        case KEY_CTRL_RSQ_BRACKET: return "Ctrl-[5]]";
+        case KEY_CTRL_6: return "Ctrl-6";
+        case KEY_CTRL_SLASH: return "Ctrl-[7/_]";
+        case KEY_SPACE: return "Space";
+        case KEY_BACKSPACE2: return "Backspace";
+    }
+    return NULL;
+}
+
+/**
+ * A basic readline implementation. No history, but all the normal editing
+ * key bindings like Ctrl-U to clear to the beginning of the line, backspace,
+ * arrow keys, etc.
+ *
+ * Takes an input file and output file, and an optional prompt and returns
+ * a malloc'd string containing the user's input or NULL if an error occurred
+ * or if the user hit Escape or Ctrl-c.
+ */
+char *breadline(FILE *in, FILE *out, const char *prompt, const char *initial)
+{
+    size_t cap = initial ? strlen(initial) + 100 : 100;
+    char *buf = calloc(cap, 1);
+    if (!buf) return NULL;
+    int i = 0, len = 0;
+    if (prompt) {
+        fputs("\033[1G\033[K\033[37;1m", out);
+        fputs(prompt, out);
+        fputs("\033[0m", out);
+    }
+    if (initial) {
+        strcpy(buf, initial);
+        len = (int)strlen(initial);
+        i = len;
+        fputs(initial, out);
+    }
+    // Show cursor and set to blinking line:
+    fputs("\033[?25h\033[5 q", out);
+    while (1) {
+        fflush(out);
+        int key = bgetkey(in, NULL, NULL, -1);
+        switch (key) {
+            case -1: case -2: case -3: continue;
+            case '\r':
+                // TODO: support backslash-enter
+                goto finished;
+            case KEY_CTRL_C: case KEY_ESC:
+                free(buf);
+                buf = NULL;
+                goto finished;
+            case KEY_CTRL_A:
+                if (i > 0) {
+                    fprintf(out, "\033[%dD", i);
+                    i = 0;
+                }
+                break;
+            case KEY_CTRL_E:
+                if (i < len) {
+                    fprintf(out, "\033[%dC", len-i);
+                    i = len;
+                }
+                break;
+            case KEY_CTRL_U: {
+                int to_clear = i;
+                if (to_clear) {
+                    memmove(buf, buf+i, len-i);
+                    buf[len -= i] = 0;
+                    i = 0;
+                    fprintf(out, "\033[%dD\033[K", to_clear);
+                    if (len > 0)
+                        fprintf(out, "%s\033[%dD", buf, len);
+                }
+                break;
+            }
+            case KEY_CTRL_K:
+                if (i < len) {
+                    buf[len = i] = 0;
+                    fputs("\033[K", out);
+                }
+                break;
+            case KEY_BACKSPACE: case KEY_BACKSPACE2:
+                if (i > 0) {
+                    memmove(buf+i, buf+i+1, len-i);
+                    --i;
+                    buf[--len] = 0;
+                    if (i == len) fputs("\033[D \033[D", out);
+                    else fprintf(out, "\033[D%s\033[K\033[%dD", buf+i, len-i);
+                }
+                break;
+            case KEY_DELETE: case KEY_CTRL_D:
+                if (i < len) {
+                    memmove(buf+i, buf+i+1, len-i);
+                    buf[--len] = 0;
+                    if (i == len) fputs(" \033[D", out);
+                    else fprintf(out, "%s\033[K\033[%dD", buf+i, len-i);
+                }
+                break;
+            case KEY_ARROW_LEFT: case KEY_CTRL_B:
+                if (i > 0) {
+                    --i;
+                    fputs("\033[D", out);
+                }
+                break;
+            case KEY_ARROW_RIGHT: case KEY_CTRL_F:
+                if (i < len) {
+                    ++i;
+                    fputs("\033[C", out);
+                }
+                break;
+            default:
+                if (' ' <= key && key <= '~') {
+                    if (len + 1 >= (int)cap) {
+                        cap += 100;
+                        buf = realloc(buf, cap);
+                        if (!buf) goto finished;
+                    }
+                    if (i < len)
+                        memmove(buf+i+1, buf+i, len-i+1);
+                    buf[i++] = (char)key;
+                    buf[++len] = 0;
+                    if (i == len)
+                        fputc(key, out);
+                    else
+                        fprintf(out, "%c%s\033[%dD", (char)key, buf+i, len-i);
+                }
+                break;
+        }
+    }
+  finished:
+    // Reset cursor to block
+    fputs("\033[1G\033[1 q\033[2K", out);
+    return buf;
+}
+
+#endif
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1