Add account components 386-405; Reduce setting, PinInput Cmd+V

Twenty account components: SettingsList, OptionCycler, KeyBindings,
ControllerMap, ProfileCard, CharacterCreator, LoginForm, PasswordGrid,
SessionList, LanguagePicker, PalettePicker, VolumeMixer,
DifficultySelect, AccessibilityOptions, AccountSwitcher, PlayerSelect,
TwoFactor, About, PatchNotes and FeedbackForm.

The components never check credentials, and no secret reaches the log:
LoginForm reports Submitted and the caller counts Failures; each new
failure clears the password, refocuses it, shakes the form and names no
field. TwoFactor builds on input.PinInput and drains an epoch-aligned
period bar. PalettePicker draws each tile in its own palette on a
pixel.Pad grid.

pixel.Settings.Reduce stills motion like the system preference, the
micro font gains '?', display.Face draws avatar faces anywhere, and
input.PinInput pastes on Cmd+V as native hosts send it.

account/keybindings.go

@@ -0,0 +1,138 @@
+package account
+
+import (
+	"fmt"
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// Binding is an action and the key that does it.
+type Binding struct {
+	Action string
+	Key    ui.Key
+}
+
+// caps hold every key but Escape, which cancels.
+var caps = map[ui.Key]string{
+	ui.KeyA: "A", ui.KeyB: "B", ui.KeyC: "C", ui.KeyD: "D", ui.KeyE: "E", ui.KeyF: "F", ui.KeyG: "G", ui.KeyH: "H", ui.KeyI: "I",
+	ui.KeyJ: "J", ui.KeyK: "K", ui.KeyL: "L", ui.KeyM: "M", ui.KeyN: "N", ui.KeyO: "O", ui.KeyP: "P", ui.KeyQ: "Q", ui.KeyR: "R",
+	ui.KeyS: "S", ui.KeyT: "T", ui.KeyU: "U", ui.KeyV: "V", ui.KeyW: "W", ui.KeyX: "X", ui.KeyY: "Y", ui.KeyZ: "Z",
+	ui.Key0: "0", ui.Key1: "1", ui.Key2: "2", ui.Key3: "3", ui.Key4: "4", ui.Key5: "5", ui.Key6: "6", ui.Key7: "7", ui.Key8: "8", ui.Key9: "9",
+	ui.KeyUp: "↑", ui.KeyDown: "↓", ui.KeyLeft: "←", ui.KeyRight: "→",
+	ui.KeySpace: "SPACE", ui.KeyEnter: "ENTER", ui.KeyTab: "TAB", ui.KeyBackspace: "BKSP",
+	ui.KeyDelete: "DEL", ui.KeyInsert: "INS", ui.KeyHome: "HOME", ui.KeyEnd: "END", ui.KeyPageUp: "PGUP", ui.KeyPageDown: "PGDN",
+	ui.KeyF1: "F1", ui.KeyF2: "F2", ui.KeyF3: "F3", ui.KeyF4: "F4", ui.KeyF5: "F5", ui.KeyF6: "F6",
+	ui.KeyF7: "F7", ui.KeyF8: "F8", ui.KeyF9: "F9", ui.KeyF10: "F10", ui.KeyF11: "F11", ui.KeyF12: "F12",
+	ui.KeyMinus: "-", ui.KeyEqual: "=", ui.KeyComma: ",", ui.KeyPeriod: ".", ui.KeySlash: "/", ui.KeySemicolon: ";",
+	ui.KeyQuote: "'", ui.KeyBracketLeft: "[", ui.KeyBracketRight: "]", ui.KeyBackslash: "\\", ui.KeyBackquote: "`",
+	ui.KeyContextMenu: "MENU", ui.KeyBack: "BACK", ui.KeyForward: "FWD",
+}
+
+type KeyBindingsOptions struct {
+	// Width is in dots; zero means 200.
+	Width    int
+	Disabled bool
+}
+
+type KeyBindingsResult struct {
+	Element *ui.Element
+	Changed bool
+}
+
+type bindKey struct{}
+
+// capture is the row in hand and whether it waits.
+type capture struct {
+	cur     int
+	waiting bool
+}
+
+// KeyBindings lists actions with keys; Enter, then a key, rebinds.
+func KeyBindings(c *ui.Context, text string, binds []Binding, o KeyBindingsOptions) KeyBindingsResult {
+	k := pixel.K(c)
+	used := map[ui.Key]int{}
+	for _, b := range binds {
+		if _, ok := caps[b.Key]; !ok {
+			panic(fmt.Sprintf("account: KeyBindings %q has a key without a cap", b.Action))
+		}
+		used[b.Key]++
+	}
+	if len(binds) == 0 {
+		panic("account: KeyBindings has no bindings")
+	}
+	w, rh := pixel.Or("KeyBindings Width", o.Width, 200), pixel.LineHeight+4
+	shell, base, st := pixel.Shell(c, func() *ui.Element {
+		return ui.Box(c).Focusable().Role(ui.RoleList).Label(text).Disabled(o.Disabled)
+	})
+	kb := ui.Local(base, bindKey{}, func() capture { return capture{} })
+	kb.cur = min(kb.cur, len(binds)-1)
+	res := KeyBindingsResult{Element: shell}
+	switch {
+	case base.IsDisabled():
+		kb.waiting = false
+	case kb.waiting:
+		// Waiting, every key binds, arrows too; Escape gives up.
+		if base.Shortcut(0, ui.KeyEscape) {
+			kb.waiting = false
+		}
+		for key := range caps {
+			if base.Shortcut(0, key) && kb.waiting {
+				binds[kb.cur].Key, kb.waiting, res.Changed = key, false, true
+				slog.Debug("8bit: key bindings", "label", text, "action", binds[kb.cur].Action, "key", caps[key])
+			}
+		}
+	default:
+		if base.Shortcut(0, ui.KeyUp) {
+			kb.cur = max(0, kb.cur-1)
+		}
+		if base.Shortcut(0, ui.KeyDown) {
+			kb.cur = min(len(binds)-1, kb.cur+1)
+		}
+		if base.Shortcut(0, ui.KeyEnter) || base.Shortcut(0, ui.KeySpace) {
+			kb.waiting = true
+		}
+		if base.Clicked() {
+			if _, y, _ := base.PointerPosition(); int(y/k.Dot())/rh < len(binds) {
+				kb.cur, kb.waiting = int(y/k.Dot())/rh, true
+			}
+		}
+	}
+	b := binds[kb.cur]
+	say := b.Action + ", " + caps[b.Key]
+	switch {
+	case kb.waiting:
+		say = b.Action + ", " + k.Msg("press_key")
+	case used[b.Key] > 1:
+		say += ", " + k.Msg("conflict")
+	}
+	base.Description(say)
+	cur, waiting := kb.cur, kb.waiting
+	shell.Size(k.D(w), k.D(len(binds)*rh)).Draw(func(p *ui.Painter, r ui.Rect) {
+		g := k.Canvas(p, r)
+		for i, b := range binds {
+			y := i * rh
+			if i == cur && st.Focus {
+				g.Cursor(0, y, w, rh)
+			}
+			g.Text(4, y+2, b.Action, pixel.Ink, 1)
+			cap, ink, edge := caps[b.Key], pixel.Ink, pixel.Edge
+			switch {
+			case i == cur && waiting:
+				cap, ink = k.Msg("press_key"), pixel.Accent
+			case used[b.Key] > 1:
+				ink, edge = pixel.Bad, pixel.Bad
+			}
+			cw := pixel.Measure(cap) + 8
+			g.Frame(w-cw-2, y+1, cw, rh-2, pixel.Raised, pixel.Face)
+			if edge == pixel.Bad {
+				g.Rect(w-cw-2, y+rh-2, cw, 1, pixel.Bad)
+			}
+			g.Text(w-cw+2, y+2, cap, ink, 1)
+		}
+		g.Finish(st)
+	})
+	return res
+}