[a11y][TextInputLayout] Removed TextInputLayout's placeholder text duplicated announcement, and fixed edge case where placeholder text was being enabled and added to the input frame while it was set to null.

Before, when swiping with TalkBack on, the placeholder text would be mistakenly announced. This change makes it so it's only announced when it appears, for API >= 16. It's still announced as part of the description announcement when the text field is selected, as before, so it's still accessible for APIs < 16.

PiperOrigin-RevId: 404871534

Author: leticiarossi

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

@@ -2266,8 +2266,22 @@ private static void updateCounterContentDescription(
    * @see #getPlaceholderText()
    */
   public void setPlaceholderText(@Nullable final CharSequence placeholderText) {
-    // If placeholder text is null, disable placeholder if it's enabled.
-    if (placeholderEnabled && TextUtils.isEmpty(placeholderText)) {
+    if (placeholderTextView == null) {
+      placeholderTextView = new AppCompatTextView(getContext());
+      placeholderTextView.setId(R.id.textinput_placeholder);
+      ViewCompat.setImportantForAccessibility(
+          placeholderTextView, ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO);
+
+      placeholderFadeIn = createPlaceholderFadeTransition();
+      placeholderFadeIn.setStartDelay(PLACEHOLDER_START_DELAY);
+      placeholderFadeOut = createPlaceholderFadeTransition();
+
+      setPlaceholderTextAppearance(placeholderTextAppearance);
+      setPlaceholderTextColor(placeholderTextColor);
+    }
+
+    // If placeholder text is null, disable placeholder.
+    if (TextUtils.isEmpty(placeholderText)) {
       setPlaceholderTextEnabled(false);
     } else {
       if (!placeholderEnabled) {
@@ -2298,19 +2312,6 @@ private void setPlaceholderTextEnabled(boolean placeholderEnabled) {
 
     // Otherwise, adjust enabled state.
     if (placeholderEnabled) {
-      placeholderTextView = new AppCompatTextView(getContext());
-      placeholderTextView.setId(R.id.textinput_placeholder);
-
-      placeholderFadeIn = createPlaceholderFadeTransition();
-      placeholderFadeIn.setStartDelay(PLACEHOLDER_START_DELAY);
-
-      placeholderFadeOut = createPlaceholderFadeTransition();
-
-      ViewCompat.setAccessibilityLiveRegion(
-          placeholderTextView, ViewCompat.ACCESSIBILITY_LIVE_REGION_POLITE);
-
-      setPlaceholderTextAppearance(placeholderTextAppearance);
-      setPlaceholderTextColor(placeholderTextColor);
       addPlaceholderTextView();
     } else {
       removePlaceholderTextView();
@@ -2344,6 +2345,9 @@ private void showPlaceholderText() {
       TransitionManager.beginDelayedTransition(inputFrame, placeholderFadeIn);
       placeholderTextView.setVisibility(VISIBLE);
       placeholderTextView.bringToFront();
+      if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN) {
+        announceForAccessibility(placeholderText);
+      }
     }
   }
 

tests/javatests/com/google/android/material/textfield/TextInputLayoutTest.java

@@ -361,11 +361,11 @@ public void testDispatchProvideAutofillStructure() {
     final ViewStructureImpl structure = new ViewStructureImpl();
     layout.dispatchProvideAutofillStructure(structure, 0);
 
-    // 1 x EditText, 3 x TextView (prefix/suffix/placeholder).
-    assertEquals(4, structure.getChildCount());
+    // 1 x EditText, 2 x TextView (prefix/suffix).
+    assertEquals(3, structure.getChildCount());
 
     // Asserts the structure.
-    ViewStructureImpl childStructure = structure.getChildAt(1);
+    ViewStructureImpl childStructure = structure.getChildAt(0);
     assertEquals(EditText.class.getName(), childStructure.getClassName());
     assertEquals("Nested hint", childStructure.getHint().toString());
 
@@ -751,7 +751,7 @@ public void hintSetOnNestedEditText_propagateInnerHintToAutofillProvider() {
 
     textInputLayout.dispatchProvideAutofillStructure(structure, /* flags= */ 0);
 
-    final ViewStructureImpl editText = structure.getChildAt(1);
+    final ViewStructureImpl editText = structure.getChildAt(0);
     assertEquals(EditText.class.getName(), editText.getClassName());
     assertEquals(structure.getAutofillId(), textInputLayout.getAutofillId());
     assertEquals("Nested hint", editText.getHint().toString());
@@ -767,7 +767,7 @@ public void hintSetOnOuterLayout_propagateOuterHintToAutofillProvider() {
 
     textInputLayout.dispatchProvideAutofillStructure(structure, /* flags= */ 0);
 
-    final ViewStructureImpl editText = structure.getChildAt(1);
+    final ViewStructureImpl editText = structure.getChildAt(0);
     assertEquals(EditText.class.getName(), editText.getClassName());
     assertEquals(structure.getAutofillId(), textInputLayout.getAutofillId());
     assertEquals("Outer hint", editText.getHint().toString());