[NavigationRail] Fix active indicator label jump when expanding

PiperOrigin-RevId: 713436233

Author: imhappi

lib/java/com/google/android/material/navigation/NavigationBarItemView.java

@@ -1175,7 +1175,7 @@ public void setActiveIndicatorExpandedHeight(int height) {
    *
    * @param availableWidth The total width of this item layout.
    */
-  private void updateActiveIndicatorLayoutParams(int availableWidth) {
+  public void updateActiveIndicatorLayoutParams(int availableWidth) {
     // Set width to the min of either the desired indicator width or the available width minus
     // a horizontal margin.
     if (availableWidth <= 0 && getVisibility() == VISIBLE) {

lib/java/com/google/android/material/navigation/NavigationBarMenuView.java

@@ -1484,4 +1484,14 @@ private void validateMenuItemId(int viewId) {
       throw new IllegalArgumentException(viewId + " is not a valid view id");
     }
   }
+
+  public void updateActiveIndicator(int availableWidth) {
+    if (buttons != null) {
+      for (NavigationBarMenuItemView item : buttons) {
+        if (item instanceof NavigationBarItemView) {
+          ((NavigationBarItemView) item).updateActiveIndicatorLayoutParams(availableWidth);
+        }
+      }
+    }
+  }
 }

lib/java/com/google/android/material/navigationrail/NavigationRailView.java

@@ -470,6 +470,10 @@ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
       }
       // Measure properly with the max child width
       minWidthSpec = makeExpandedWidthMeasureSpec(widthMeasureSpec, getMaxChildWidth());
+      // If the active indicator is match_parent, it should be notified to update its width
+      if (getItemActiveIndicatorExpandedWidth() == MATCH_PARENT) {
+        getNavigationRailMenuView().updateActiveIndicator(MeasureSpec.getSize(minWidthSpec));
+      }
     }
     super.onMeasure(minWidthSpec, heightMeasureSpec);
     // If the content container is measured to be less than the measured height of the nav rail,