remove double announcement on on/off cusotm texts

Author: hinzzx

packages/main/src/Switch.ts

@@ -17,6 +17,8 @@ import "@ui5/webcomponents-icons/dist/less.js";
 import SwitchDesign from "./types/SwitchDesign.js";
 import {
 	FORM_CHECKABLE_REQUIRED,
+	SWITCH_ON,
+	SWITCH_OFF,
 } from "./generated/i18n/i18n-defaults.js";
 
 // Template
@@ -301,6 +303,20 @@ class Switch extends UI5Element implements IFormInputElement {
 		return this.graphical ? "" : this.textOff;
 	}
 
+	/**
+	 * Determines if custom on/off texts duplicate the default role announcement.
+	 * When textOn/textOff match the localized "On"/"Off" strings (case-insensitive),
+	 * they duplicate what role="switch" with aria-checked already announces,
+	 * so they should be aria-hidden to avoid duplicate screen reader announcements.
+	 */
+	get _textAriaHidden(): boolean | undefined {
+		const on = this.textOn?.toLowerCase();
+		const off = this.textOff?.toLowerCase();
+		const i18nOn = Switch.i18nBundle.getText(SWITCH_ON).toLowerCase();
+		const i18nOff = Switch.i18nBundle.getText(SWITCH_OFF).toLowerCase();
+		return (on === i18nOn && off === i18nOff) || undefined;
+	}
+
 	get effectiveTabIndex() {
 		return this.disabled ? undefined : 0;
 	}

packages/main/src/SwitchTemplate.tsx

@@ -52,8 +52,8 @@ export default function SwitchTemplate(this: Switch) {
 									</>
 									:
 									<>
-										<span class="ui5-switch-text ui5-switch-text--on" part="text-on">{this._textOn}</span>
-										<span class="ui5-switch-text ui5-switch-text--off" part="text-off">{this._textOff}</span>
+										<span class="ui5-switch-text ui5-switch-text--on" part="text-on" aria-hidden={this._textAriaHidden}>{this._textOn}</span>
+										<span class="ui5-switch-text ui5-switch-text--off" part="text-off" aria-hidden={this._textAriaHidden}>{this._textOff}</span>
 									</>
 								}
 							</>

packages/main/src/i18n/messagebundle.properties

@@ -1005,6 +1005,12 @@ DYNAMIC_DATE_RANGE_NEXT_COMBINED_TEXT=Next X {0} (included)
 #XFLD: Suffix text for included date range options.
 DYNAMIC_DATE_RANGE_INCLUDED_TEXT=(included)
 
+#XACT: Default text for switch "on" state, used to detect duplicate screen reader announcements
+SWITCH_ON=On
+
+#XACT: Default text for switch "off" state, used to detect duplicate screen reader announcements
+SWITCH_OFF=Off
+
 #XACT: ARIA announcement for icon type image
 ICON_ARIA_TYPE_IMAGE=Image