Refactor: EditableTextView.Changed() and the Canceled spelling

EditableTextView.Changed is a method like every other result's.
AlertDialogResult, PopconfirmResult and DateTimeResult spell Canceled
the American way, matching EditableTextView and LoadingOverlayResult.
Callers, Gallery and docs updated.

examples/gallery/composite_files.go

@@ -351,7 +351,7 @@ func (g *gallery) deleteDialog(c *ui.Context, log func(string)) {
 		mujica.ShowToast(c, mujica.ToastMessage{ID: "files-deleted", Severity: mujica.SeveritySuccess,
 			Message: fmt.Sprintf(g.t("Deleted %d files", "已删除 %d 个文件"), len(s.doomed))})
 		s.doomed = nil
-	case r.Cancelled:
+	case r.Canceled:
 		s.doomed = nil
 		log("delete canceled")
 	}

examples/gallery/pages_datetime.go

@@ -163,8 +163,8 @@ func dtDateRangeDemo(c *ui.Context, log func(string)) {
 		if r.Changed() {
 			log(fmt.Sprintf("DateRangePicker changed: %v – %v (%d days)", s.a.Start, s.a.End, s.a.Days()))
 		}
-		if r.Cancelled() {
-			log("DateRangePicker cancelled")
+		if r.Canceled() {
+			log("DateRangePicker canceled")
 		}
 	})
 }
@@ -264,8 +264,8 @@ func dtDateTimeDemo(c *ui.Context, log func(string)) {
 		if r.Changed() {
 			log("DateTimePicker changed: " + s.v.Format(time.RFC3339))
 		}
-		if r.Cancelled() {
-			log("DateTimePicker cancelled")
+		if r.Canceled() {
+			log("DateTimePicker canceled")
 		}
 		k := mujica.Tokens(c)
 		ui.Text(c, "Try 2026-03-08 02:30 in America/New_York: the picker reports the DST gap.").

examples/gallery/pages_display.go

@@ -61,7 +61,7 @@ func textDemo(c *ui.Context, log func(string)) {
 	})
 	displaySection(c, "Editable", func() {
 		e := mujica.EditableText(c, &s.name, mujica.EditableTextOptions{Saving: s.saving, Error: s.saveErr, Label: "File name"})
-		if e.Changed {
+		if e.Changed() {
 			if s.failNext {
 				s.saveErr = "Save failed: the name is already taken."
 				log("save failed: " + s.name)
@@ -78,7 +78,7 @@ func textDemo(c *ui.Context, log func(string)) {
 
 const textCode = `mujica.Text(c, "Order ID: 4821-AX", mujica.TextOptions{Selectable: true})
 mujica.Text(c, "A long note that stops after two lines.", mujica.TextOptions{MaxLines: 2})
-if mujica.EditableText(c, &name, mujica.EditableTextOptions{Error: saveErr}).Changed {
+if mujica.EditableText(c, &name, mujica.EditableTextOptions{Error: saveErr}).Changed() {
 	saveErr = "" // save name here; set saveErr on failure
 }`
 

examples/gallery/pages_overlay.go

@@ -140,8 +140,8 @@ func alertDialogDemo(c *ui.Context, log func(string)) {
 	if r.Confirmed {
 		log("confirmed")
 	}
-	if r.Cancelled {
-		log("cancelled")
+	if r.Canceled {
+		log("canceled")
 	}
 }
 
@@ -428,8 +428,8 @@ func popconfirmDemo(c *ui.Context, log func(string)) {
 	if r.Confirmed {
 		log("confirmed")
 	}
-	if r.Cancelled {
-		log("cancelled")
+	if r.Canceled {
+		log("canceled")
 	}
 }