[TextInputLayout][a11y] Fixed prefix/suffix not being properly announced when the text field is focused and they show up. Also improved their screen reader focus order to align with the visual order of the elements: navigating to the left will focus on the prefix and navigating to the right will focus on the suffix.

Resolves #2497

PiperOrigin-RevId: 430208388

Author: leticiarossi

lib/java/com/google/android/material/textfield/TextInputLayout.java

@@ -2549,8 +2549,11 @@ public TextView getPrefixTextView() {
   }
 
   private void updatePrefixTextVisibility() {
-    prefixTextView.setVisibility((prefixText != null && !isHintExpanded()) ? VISIBLE : GONE);
+    int visibility = (prefixText != null && !isHintExpanded()) ? VISIBLE : GONE;
     updateStartLayoutVisibility();
+    // Set visibility after updating start layout's visibility so screen readers correctly announce
+    // when prefix text appears.
+    prefixTextView.setVisibility(visibility);
     updateDummyDrawables();
   }
 
@@ -2636,13 +2639,15 @@ public TextView getSuffixTextView() {
   }
 
   private void updateSuffixTextVisibility() {
-    int oldSuffixVisibility = suffixTextView.getVisibility();
-    boolean visible = suffixText != null && !isHintExpanded();
-    suffixTextView.setVisibility(visible ? VISIBLE : GONE);
-    if (oldSuffixVisibility != suffixTextView.getVisibility()) {
-      getEndIconDelegate().onSuffixVisibilityChanged(visible);
+    int oldVisibility = suffixTextView.getVisibility();
+    int newVisibility = (suffixText != null && !isHintExpanded()) ? VISIBLE : GONE;
+    if (oldVisibility != newVisibility) {
+      getEndIconDelegate().onSuffixVisibilityChanged(/* visible= */ newVisibility == VISIBLE);
     }
     updateEndLayoutVisibility();
+    // Set visibility after updating end layout's visibility so screen readers correctly announce
+    // when suffix text appears.
+    suffixTextView.setVisibility(newVisibility);
     updateDummyDrawables();
   }
 
@@ -3976,15 +3981,17 @@ private void updateEndLayoutVisibility() {
     endIconFrame.setVisibility(
         (endIconView.getVisibility() == VISIBLE && !isErrorIconVisible()) ? VISIBLE : GONE);
 
+    int suffixTextVisibility = (suffixText != null && !isHintExpanded()) ? VISIBLE : GONE;
     boolean shouldBeVisible =
-        isEndIconVisible() || isErrorIconVisible() || suffixTextView.getVisibility() == VISIBLE;
+        isEndIconVisible() || isErrorIconVisible() || suffixTextVisibility == VISIBLE;
     endLayout.setVisibility(shouldBeVisible ? VISIBLE : GONE);
   }
 
   private void updateStartLayoutVisibility() {
     // Set startLayout to visible if start icon or prefix text is present.
+    int prefixTextVisibility = (prefixText != null && !isHintExpanded()) ? VISIBLE : GONE;
     boolean shouldBeVisible =
-        startIconView.getVisibility() == VISIBLE || prefixTextView.getVisibility() == VISIBLE;
+        startIconView.getVisibility() == VISIBLE || prefixTextVisibility == VISIBLE;
     startLayout.setVisibility(shouldBeVisible ? VISIBLE : GONE);
   }
 
@@ -4598,9 +4605,18 @@ public void onInitializeAccessibilityNodeInfo(
       boolean isHintCollapsed = !layout.isHintExpanded();
       boolean showingError = !TextUtils.isEmpty(errorText);
       boolean contentInvalid = showingError || !TextUtils.isEmpty(counterOverflowDesc);
-
+      boolean isShowingPrefixText = layout.getPrefixTextView().getVisibility() == VISIBLE;
       String hint = hasHint ? hintText.toString() : "";
 
+      // Screen readers should follow visual order of the elements of the text field.
+      if (isShowingPrefixText) {
+        info.setLabelFor(layout.getPrefixTextView());
+        info.setTraversalAfter(layout.getPrefixTextView());
+      } else {
+        info.setTraversalAfter(layout.startIconView);
+      }
+
+      // Make sure text field has the appropriate announcements.
       if (showingText) {
         info.setText(inputText);
       } else if (!TextUtils.isEmpty(hint)) {