Cthulhu is no longer a fork. Now it is a screen reader written in Golang.

internal/input/input.go

@@ -0,0 +1,125 @@
+package input
+
+import (
+	"strconv"
+	"strings"
+)
+
+type KeyKind uint8
+
+const (
+	KeyUnknown KeyKind = iota
+	KeyModifier
+	KeyFunction
+	KeyAction
+	KeyNavigation
+	KeyDiacritical
+)
+
+type Event struct {
+	Timestamp uint32 // X server milliseconds, for ordering independent listeners.
+	Keycode   uint8
+	Pressed   bool
+	Repeat    bool // X11 autorepeat, distinct from a new physical key press.
+	Name      string
+	Text      string
+	Kind      KeyKind
+}
+
+type EchoSettings struct {
+	EnableKeyEcho         bool
+	EnableModifierKeys    bool
+	EnableFunctionKeys    bool
+	EnableActionKeys      bool
+	EnableNavigationKeys  bool
+	EnableDiacriticalKeys bool
+	CthulhuModifierKeys   []string
+}
+
+func NewKeyEvent(keycode uint8, pressed bool, name string) Event {
+	kind, text := classifyKey(name)
+	return Event{Keycode: keycode, Pressed: pressed, Name: name, Text: text, Kind: kind}
+}
+
+func EchoText(event Event, settings EchoSettings) string {
+	if !event.Pressed || !settings.EnableKeyEcho {
+		return ""
+	}
+	var enabled bool
+	switch event.Kind {
+	case KeyModifier:
+		enabled = settings.EnableModifierKeys
+	case KeyFunction:
+		enabled = settings.EnableFunctionKeys
+	case KeyAction:
+		enabled = settings.EnableActionKeys
+	case KeyNavigation:
+		enabled = settings.EnableNavigationKeys
+	case KeyDiacritical:
+		enabled = settings.EnableDiacriticalKeys
+	}
+	if !enabled {
+		return ""
+	}
+	return event.Text
+}
+
+func classifyKey(name string) (KeyKind, string) {
+	if text, exists := map[string]string{
+		"Shift_L": "left shift", "Shift_R": "right shift",
+		"Control_L": "left control", "Control_R": "right control",
+		"Alt_L": "left alt", "Alt_R": "right alt",
+		"Meta_L": "left meta", "Meta_R": "right meta",
+		"ISO_Level3_Shift": "Alt Gr",
+	}[name]; exists {
+		return KeyModifier, text
+	}
+	if strings.HasPrefix(name, "F") {
+		number, err := strconv.Atoi(strings.TrimPrefix(name, "F"))
+		if err == nil && number >= 1 && number <= 12 {
+			return KeyFunction, strings.ToLower(name)
+		}
+	}
+	if text, exists := map[string]string{
+		"Return": "return", "KP_Enter": "enter", "Escape": "escape",
+		"Tab": "tab", "ISO_Left_Tab": "left tab", "BackSpace": "backspace",
+		"Delete": "delete", "KP_Delete": "delete",
+		"Page_Up": "page up", "KP_Page_Up": "page up", "Prior": "page up", "KP_Prior": "page up",
+		"Page_Down": "page down", "KP_Page_Down": "page down", "Next": "page down", "KP_Next": "page down",
+	}[name]; exists {
+		return KeyAction, text
+	}
+	if text, exists := map[string]string{
+		"Left": "left", "KP_Left": "left", "Right": "right", "KP_Right": "right",
+		"Up": "up", "KP_Up": "up", "Down": "down", "KP_Down": "down",
+		"Home": "home", "KP_Home": "home", "End": "end", "KP_End": "end",
+	}[name]; exists {
+		return KeyNavigation, text
+	}
+	if strings.HasPrefix(name, "dead_") {
+		text := strings.ReplaceAll(strings.TrimPrefix(name, "dead_"), "_", " ")
+		if text == "abovering" {
+			text = "ring"
+		}
+		return KeyDiacritical, text
+	}
+	return KeyUnknown, ""
+}
+
+type ModifierKeycodes [256]bool
+
+func NewModifierKeycodes(keycodes ...uint8) ModifierKeycodes {
+	var modifiers ModifierKeycodes
+	for _, keycode := range keycodes {
+		modifiers[keycode] = true
+	}
+	return modifiers
+}
+
+func (modifiers ModifierKeycodes) Contains(keycode uint8) bool {
+	return modifiers[keycode]
+}
+
+func ShouldInterruptSpeech(event Event) bool {
+	return event.Pressed
+}