More work on readline

tools/tui/readline/api.go

@@ -0,0 +1,81 @@
+// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package readline
+
+import (
+	"fmt"
+
+	"kitty/tools/tui/loop"
+	"kitty/tools/wcswidth"
+)
+
+var _ = fmt.Print
+
+const ST = "\x1b\\"
+const PROMPT_MARK = "\x1b]133;"
+
+type RlInit struct {
+	Prompt                  string
+	ContinuationPrompt      string
+	EmptyContinuationPrompt bool
+	DontMarkPrompts         bool
+}
+
+type Readline struct {
+	prompt                  string
+	prompt_len              int
+	continuation_prompt     string
+	continuation_prompt_len int
+	mark_prompts            bool
+	loop                    *loop.Loop
+
+	// The number of lines after the initial line
+	cursor_y int
+	// Input lines
+	lines []string
+	// The line the cursor is at currently
+	cursor_line int
+	// The offset into the text of the cursor line
+	cursor_pos_in_line int
+}
+
+func New(loop *loop.Loop, r RlInit) *Readline {
+	ans := &Readline{
+		prompt: r.Prompt, prompt_len: wcswidth.Stringwidth(r.Prompt), mark_prompts: !r.DontMarkPrompts,
+		loop: loop, lines: []string{""},
+	}
+	if r.ContinuationPrompt != "" || !r.EmptyContinuationPrompt {
+		ans.continuation_prompt = r.ContinuationPrompt
+		if ans.continuation_prompt == "" {
+			ans.continuation_prompt = "> "
+		}
+	}
+	if ans.mark_prompts {
+		ans.prompt = PROMPT_MARK + "A" + ST + ans.prompt
+		ans.continuation_prompt = PROMPT_MARK + "A;k=s" + ST + ans.continuation_prompt
+	}
+	return ans
+}
+
+func (self *Readline) Start() {
+	self.loop.SetCursorShape(loop.BAR_CURSOR, true)
+	self.Redraw()
+}
+
+func (self *Readline) Redraw() {
+	self.loop.StartAtomicUpdate()
+	self.RedrawNonAtomic()
+	self.loop.EndAtomicUpdate()
+}
+
+func (self *Readline) RedrawNonAtomic() {
+	self.redraw()
+}
+
+func (self *Readline) End() {
+	self.loop.QueueWriteString("\r\n")
+	self.loop.SetCursorShape(loop.BLOCK_CURSOR, true)
+	if self.mark_prompts {
+		self.loop.QueueWriteString(PROMPT_MARK + "C" + ST)
+	}
+}