Updated FloatingActionButton to support dark theme elevation overlays.

PiperOrigin-RevId: 239611087

Author: raajkumars

lib/java/com/google/android/material/floatingactionbutton/FloatingActionButton.java

@@ -33,6 +33,7 @@
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import android.os.Parcelable;
 import androidx.annotation.AnimatorRes;
@@ -44,6 +45,7 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.Px;
+import androidx.annotation.RequiresApi;
 import androidx.annotation.RestrictTo;
 import androidx.annotation.VisibleForTesting;
 import com.google.android.material.animation.MotionSpec;
@@ -1163,6 +1165,13 @@ private void offsetIfNeeded(CoordinatorLayout parent, FloatingActionButton fab)
     }
   }
 
+  @RequiresApi(VERSION_CODES.LOLLIPOP)
+  @Override
+  public void setElevation(float elevation) {
+    super.setElevation(elevation);
+    getImpl().updateShapeElevation(elevation);
+  }
+
   /**
    * Returns the backward compatible elevation of the FloatingActionButton.
    *

lib/java/com/google/android/material/floatingactionbutton/FloatingActionButtonImpl.java

@@ -189,6 +189,7 @@ void setBackgroundDrawable(
     }
 
     shapeDrawable.setShadowColor(Color.DKGRAY);
+    shapeDrawable.initializeElevationOverlay(view.getContext());
 
     // Now we created a mask Drawable which will be used for touch feedback.
     MaterialShapeDrawable touchFeedbackShape = createShapeDrawable();
@@ -360,7 +361,7 @@ void onElevationsChanged(
     updateShapeElevation(elevation);
   }
 
-  private void updateShapeElevation(float elevation) {
+  void updateShapeElevation(float elevation) {
     if (shapeDrawable != null) {
       shapeDrawable.setElevation(elevation);
     }

lib/java/com/google/android/material/floatingactionbutton/FloatingActionButtonImplLollipop.java

@@ -65,6 +65,7 @@ void setBackgroundDrawable(
     if (backgroundTintMode != null) {
       shapeDrawable.setTintMode(backgroundTintMode);
     }
+    shapeDrawable.initializeElevationOverlay(view.getContext());
 
     final Drawable rippleContent;
     if (borderWidth > 0) {
@@ -99,6 +100,7 @@ void onElevationsChanged(
       final float elevation,
       final float hoveredFocusedTranslationZ,
       final float pressedTranslationZ) {
+
     if (Build.VERSION.SDK_INT == VERSION_CODES.LOLLIPOP) {
       // Animations produce NPE in version 21. Bluntly set the values instead in
       // #onDrawableStateChanged (matching the logic in the animations below).