Resolving duplicate “Fingerprint Sensor” talkback in Side-FPS SUW

Prevents Talkback from announcing “Fingerprint Sensor” twice in the
side-FPS fingerprint enrollment page in setup wizard. Two accessibility
events that speak “Fingerprint Sensor” are sent when the Talkback focus
lands on the sensor location indicator, so we override the
AccessibilityDelegate dispatcher to intercept and ignore the first
event.

Fixes: 209933998
Test: atest SidefpsControllerTest
Change-Id: Ib5fad6dc0b36eb69b6084296956c12a9b25e28bb

packages/SystemUI/src/com/android/systemui/biometrics/SidefpsController.kt

@@ -33,6 +33,8 @@ import android.hardware.fingerprint.FingerprintSensorPropertiesInternal
 import android.hardware.fingerprint.ISidefpsController
 import android.os.Handler
 import android.util.Log
+import android.view.View.AccessibilityDelegate
+import android.view.accessibility.AccessibilityEvent
 import android.view.Display
 import android.view.Gravity
 import android.view.LayoutInflater
@@ -181,6 +183,23 @@ class SidefpsController @Inject constructor(
         }
         lottie.addOverlayDynamicColor(context)
 
+        /**
+         * Intercepts TYPE_WINDOW_STATE_CHANGED accessibility event, preventing Talkback from
+         * speaking @string/accessibility_fingerprint_label twice when sensor location indicator
+         * is in focus
+         */
+        view.setAccessibilityDelegate(object : AccessibilityDelegate() {
+            override fun dispatchPopulateAccessibilityEvent(
+                host: View,
+                event: AccessibilityEvent
+            ): Boolean {
+                return if (event.getEventType() === AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED) {
+                    true
+                } else {
+                    super.dispatchPopulateAccessibilityEvent(host, event)
+                }
+            }
+        })
         return view
     }