refactor(odin): Ported scan command.

prompt.odin

@@ -0,0 +1,193 @@
+package main
+
+import "core:fmt"
+import "core:sys/posix"
+
+Raw_State :: struct {
+	original: posix.termios,
+	fd:       posix.FD,
+}
+
+enable_raw_mode :: proc(fd: posix.FD) -> (Raw_State, bool) {
+	state: Raw_State
+	state.fd = fd
+
+	if posix.tcgetattr(fd, &state.original) != .OK {
+		return state, false
+	}
+
+	attr: posix.termios = state.original
+	attr.c_lflag -= {.ICANON, .ECHO, .ISIG, .IEXTEN}
+	attr.c_iflag -= {.IXON, .ICRNL, .BRKINT, .INPCK, .ISTRIP}
+	attr.c_oflag -= {.OPOST}
+	attr.c_cflag += {.CS8}
+	attr.c_cc[.VMIN] = 1
+	attr.c_cc[.VTIME] = 0
+
+	if posix.tcsetattr(fd, .TCSAFLUSH, &attr) != .OK {
+		return state, false
+	}
+
+	return state, true
+}
+
+disable_raw_mode :: proc(state: ^Raw_State) {
+	posix.tcsetattr(state.fd, .TCSAFLUSH, &state.original)
+}
+
+Key :: enum {
+	Up,
+	Down,
+	Space,
+	Enter,
+	Escape,
+	Unknown,
+}
+
+read_key :: proc() -> Key {
+	buf: [3]u8
+
+	n := posix.read(posix.STDIN_FILENO, &buf[0], 1)
+	if n <= 0 {
+		return .Unknown
+	}
+
+	switch buf[0] {
+	case ' ':
+		return .Space
+	case '\n', '\r':
+		return .Enter
+	case 0x03:
+		return .Escape
+	case 0x1b:
+		tv: posix.timeval
+		tv.tv_sec = 0
+		tv.tv_usec = posix.suseconds_t(100000)
+
+		set: posix.fd_set
+		posix.FD_ZERO(&set)
+		posix.FD_SET(posix.STDIN_FILENO, &set)
+
+		ready := posix.select(1, &set, nil, nil, &tv)
+		if ready <= 0 {
+			return .Escape
+		}
+
+		n2 := posix.read(posix.STDIN_FILENO, &buf[1], 1)
+		if n2 <= 0 || buf[1] != '[' {
+			return .Escape
+		}
+
+		posix.FD_ZERO(&set)
+		posix.FD_SET(posix.STDIN_FILENO, &set)
+		tv.tv_sec = 0
+		tv.tv_usec = posix.suseconds_t(100000)
+
+		ready = posix.select(1, &set, nil, nil, &tv)
+		if ready <= 0 {
+			return .Escape
+		}
+
+		n3 := posix.read(posix.STDIN_FILENO, &buf[2], 1)
+		if n3 <= 0 {
+			return .Escape
+		}
+
+		switch buf[2] {
+		case 'A':
+			return .Up
+		case 'B':
+			return .Down
+		case:
+			return .Escape
+		}
+	case:
+		return .Unknown
+	}
+}
+
+MultiSelect_Result :: enum {
+	Confirm,
+	Cancel,
+}
+
+MAX_VISIBLE :: 7
+
+multi_select :: proc(
+	prompt: string,
+	options: []string,
+) -> (selected: [dynamic]bool, result: MultiSelect_Result) {
+	if len(options) == 0 {
+		return
+	}
+
+	selected = make([dynamic]bool, len(options))
+	cursor: int = 0
+	scroll_offset: int = 0
+
+	fmt.printf("\x1b[?25l")
+	visible := render_options(prompt, options, selected[:], cursor, scroll_offset)
+
+	raw, ok := enable_raw_mode(posix.STDIN_FILENO)
+	if !ok {
+		fmt.printf("\x1b[?25h")
+		return
+	}
+	defer disable_raw_mode(&raw)
+
+	for {
+		key := read_key()
+
+		switch key {
+		case .Up:
+			if cursor > 0 {
+				cursor -= 1
+			}
+		case .Down:
+			if cursor < len(options) - 1 {
+				cursor += 1
+			}
+		case .Space:
+			selected[cursor] = !selected[cursor]
+		case .Enter:
+			fmt.printf("\x1b[%dA\x1b[J\x1b[?25h", visible + 1)
+			result = .Confirm
+			return
+		case .Escape:
+			fmt.printf("\x1b[%dA\x1b[J\x1b[?25h", visible + 1)
+			result = .Cancel
+			return
+		case .Unknown:
+		}
+
+		scroll_offset = max(0, min(cursor - MAX_VISIBLE / 2, len(options) - MAX_VISIBLE))
+		fmt.printf("\x1b[%dA\x1b[0J", visible + 1)
+		visible = render_options(prompt, options, selected[:], cursor, scroll_offset)
+	}
+}
+
+render_options :: proc(prompt: string, options: []string, selected: []bool, cursor: int, scroll_offset: int) -> int {
+	fmt.printf(
+		"\x1b[1;36m%s\x1b[0m (↑/↓ move, space select, enter confirm)\r\n",
+		prompt,
+	)
+
+	end := scroll_offset + MAX_VISIBLE
+	if end > len(options) {
+		end = len(options)
+	}
+
+	for i in scroll_offset..<end {
+		checkbox := " "
+		if selected[i] {
+			checkbox = "x"
+		}
+		if i == cursor {
+			fmt.printf("\x1b[1;32m> \x1b[0m[\x1b[32m%s\x1b[0m] %s\r\n", checkbox, options[i])
+		} else {
+			fmt.printf("  [\x1b[2m%s\x1b[0m] %s\r\n", checkbox, options[i])
+		}
+	}
+
+	return end - scroll_offset
+}