runtime: implement an extensible line editor

the line editor supports custom keybinds and data storage, allowing for a wide range of functionality to be implemented via plugins. included plugins include: * core: basic input and cursor movement. * history: input history storage and retrieval (unfinished) * highlight: support for colour-highlighting the line buffer (unfinished) * syntax: parses the line buffer and uses `highlight` to apply syntax highlighting (unfinished). * shell-integration: - allows a `prompt` function to be defined, which will be called to get the text to be used for the prompt - exposes key properties of the line editor to the shell environment, allowing line editor functionality to be extended via shell scripts.
2026-06-20 15:13:34 +01:00
parent f622c2eba3
commit ad8b284869
21 changed files with 1857 additions and 1 deletions
@@ -0,0 +1,105 @@
+#include "line-editor.h"
+
+#include <fx/encoding.h>
+
+static void convert_offset_to_xy(
+	struct bshell_line_ed_p *ed,
+	unsigned long offset,
+	unsigned long *out_x,
+	unsigned long *out_y)
+{
+	unsigned long x = 0, y = 0;
+	unsigned int w = 0, h = 0;
+	fx_tty_get_dimensions(ed->ed_tty, &w, &h);
+	if (!w || !h) {
+		w = 80;
+		h = 25;
+	}
+
+	fx_string *prompt = line_ed_get_prompt(ed);
+	fx_string *buffer = line_ed_get_buffer(ed);
+	const char *s = fx_string_get_cstr(prompt);
+	size_t len = fx_string_get_size(prompt, FX_STRLEN_CODEPOINTS);
+	fx_wchar prev = FX_WCHAR_INVALID;
+
+	for (unsigned long i = 0; i < len; i++) {
+		fx_wchar c = fx_wchar_utf8_codepoint_decode(s);
+		if (prev != FX_WCHAR_INVALID) {
+			if (prev == '\n' || x + 1 >= w) {
+				x = 0;
+				y++;
+			} else {
+				x += line_ed_get_char_width(c);
+			}
+		}
+
+		unsigned int stride = fx_wchar_utf8_codepoint_size(c);
+		if (stride == 0) {
+			break;
+		}
+
+		s += stride;
+		prev = c;
+	}
+
+	s = fx_string_get_cstr(buffer);
+	len = fx_string_get_size(buffer, FX_STRLEN_CODEPOINTS);
+	for (unsigned long i = 0; i < offset && i < len; i++) {
+		fx_wchar c = fx_wchar_utf8_codepoint_decode(s);
+		if (prev != FX_WCHAR_INVALID) {
+			if (prev == '\n' || x + 1 >= w) {
+				x = 0;
+				y++;
+			} else {
+				x += line_ed_get_char_width(c);
+			}
+		}
+
+		unsigned int stride = fx_wchar_utf8_codepoint_size(c);
+		if (stride == 0) {
+			break;
+		}
+
+		s += stride;
+		prev = c;
+	}
+
+	if (offset > len) {
+		if (x + 1 >= w) {
+			x = 0;
+			y++;
+		} else {
+			x++;
+		}
+	}
+
+	if (out_x) {
+		*out_x = x;
+	}
+
+	if (out_y) {
+		*out_y = y;
+	}
+}
+
+void line_ed_get_points(struct bshell_line_ed_p *ed, struct cursor_points *out)
+{
+	unsigned long cursor = line_ed_get_cursor(ed);
+	fx_string *buffer = line_ed_get_buffer(ed);
+
+	convert_offset_to_xy(
+		ed,
+		cursor + 1,
+		&out->c_cursor_x,
+		&out->c_cursor_y);
+	convert_offset_to_xy(
+		ed,
+		fx_string_get_size(buffer, FX_STRLEN_CODEPOINTS),
+		&out->c_render_limit_x,
+		&out->c_render_limit_y);
+	convert_offset_to_xy(
+		ed,
+		fx_string_get_size(buffer, FX_STRLEN_CODEPOINTS) + 1,
+		&out->c_cursor_limit_x,
+		&out->c_cursor_limit_y);
+}