Better focus check code using FocustState enum

wtf/focus_tracker.go

@@ -4,6 +4,14 @@ import (
 	"github.com/rivo/tview"
 )
 
+type FocusState int
+
+const (
+	Widget FocusState = iota
+	NonWidget
+	NeverFocused
+)
+
 // FocusTracker is used by the app to track which onscreen widget currently has focus,
 // and to move focus between widgets.
 type FocusTracker struct {
@@ -17,11 +25,13 @@ type FocusTracker struct {
 // Next sets the focus on the next widget in the widget list. If the current widget is
 // the last widget, sets focus on the first widget.
 func (tracker *FocusTracker) Next() {
-	if tracker.widgetHasFocus() {
+	if tracker.focusState() == NonWidget {
+		return
+	}
+
 	tracker.blur(tracker.Idx)
 	tracker.increment()
 	tracker.focus(tracker.Idx)
-	}
 }
 
 // None removes focus from the currently-focused widget.
@@ -32,11 +42,13 @@ func (tracker *FocusTracker) None() {
 // Prev sets the focus on the previous widget in the widget list. If the current widget is
 // the last widget, sets focus on the last widget.
 func (tracker *FocusTracker) Prev() {
-	if tracker.widgetHasFocus() {
+	if tracker.focusState() == NonWidget {
+		return
+	}
+
 	tracker.blur(tracker.Idx)
 	tracker.decrement()
 	tracker.focus(tracker.Idx)
-	}
 }
 
 func (tracker *FocusTracker) Refocus() {
@@ -107,16 +119,17 @@ func (tracker *FocusTracker) increment() {
 
 // widgetHasFocus returns true if one of the widgets currently has the app's focus,
 // false if none of them do (ie: perhaps a modal dialog currently has it instead)
-func (tracker *FocusTracker) widgetHasFocus() bool {
+// If there's no index, it returns true because focus has never been assigned
+func (tracker *FocusTracker) focusState() FocusState {
 	if tracker.Idx < 0 {
-		return true
+		return NeverFocused
 	}
 
 	for _, widget := range tracker.Widgets {
 		if widget.TextView() == tracker.App.GetFocus() {
-			return true
+			return Widget
 		}
 	}
 
-	return false
+	return NonWidget
 }