Add input components 086-105; park focus off disabled controls

input/autocomplete.go

@@ -0,0 +1,63 @@
+package input
+
+import (
+	"log/slog"
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type AutocompleteOptions struct {
+	Placeholder string
+	// Width is in dots; zero means 120.
+	Width    int
+	Disabled bool
+}
+
+type AutocompleteResult struct {
+	Element *ui.Element
+	// Accepted reports a completion taken by Tab or Enter.
+	Changed, Accepted, Submitted bool
+}
+
+// Autocomplete ghosts the first completion; Tab or Enter takes it.
+func Autocomplete(c *ui.Context, text string, value *string, suggestions []string, o AutocompleteOptions) AutocompleteResult {
+	k := pixel.K(c)
+	ed, e := field(c, value, pixel.EditorOptions{Label: text, Placeholder: o.Placeholder, Disabled: o.Disabled}, o.Width, nil, nil, nil)
+	res := AutocompleteResult{Element: e, Changed: ed.Changed, Submitted: ed.Submitted}
+	best := completion(suggestions, *value)
+	tab, enter := best != "" && e.Shortcut(0, ui.KeyTab), best != "" && e.Shortcut(0, ui.KeyEnter)
+	if tab || enter {
+		*value, res.Changed, res.Accepted = best, true, true
+		slog.Debug("8bit: autocomplete accepted", "label", text, "value", best)
+		return res
+	}
+	if best != "" {
+		ed.Input.Description(best)
+		typed := *value
+		ed.Element.DrawOver(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			rest := string([]rune(best)[len([]rune(typed)):])
+			if x := pixel.Measure(typed); x+pixel.Measure(rest) <= g.W {
+				g.Text(x, 0, rest, pixel.Faint, 1)
+			}
+		})
+	}
+	return res
+}
+
+// completion is the first suggestion extending v, ignoring case.
+func completion(suggestions []string, v string) string {
+	if v == "" {
+		return ""
+	}
+	n := len([]rune(v))
+	for _, s := range suggestions {
+		if r := []rune(s); len(r) > n && strings.EqualFold(string(r[:n]), v) {
+			return s
+		}
+	}
+	return ""
+}