[AppBarLayout] Fix dynamic status bar foreground lift on scroll color when using Tonal Surface Color

Resolves #3530

PiperOrigin-RevId: 564364138

Author: dsn5ft

catalog/java/io/material/catalog/topappbar/TopAppBarCompressEffectFragment.java

@@ -31,7 +31,7 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.material.appbar.AppBarLayout;
-import com.google.android.material.shape.MaterialShapeDrawable;
+import com.google.android.material.color.MaterialColors;
 import com.google.android.material.tabs.TabLayout;
 import io.material.catalog.feature.DemoFragment;
 import io.material.catalog.feature.DemoUtils;
@@ -59,8 +59,8 @@ public View onCreateDemoView(
     activity.setSupportActionBar(toolbar);
 
     AppBarLayout appBarLayout = view.findViewById(R.id.appbarlayout);
-    appBarLayout.setStatusBarForeground(
-        MaterialShapeDrawable.createWithElevationOverlay(requireContext()));
+    appBarLayout.setStatusBarForegroundColor(
+        MaterialColors.getColor(appBarLayout, R.attr.colorSurface));
 
     TabLayout tabs = view.findViewById(R.id.tabs);
     ToggleButton showHideTabsButton = view.findViewById(R.id.show_hide_tabs_button);

catalog/java/io/material/catalog/topappbar/TopAppBarScrollingDemoFragment.java

@@ -29,7 +29,7 @@
 import android.view.ViewGroup;
 import androidx.annotation.Nullable;
 import com.google.android.material.appbar.AppBarLayout;
-import com.google.android.material.shape.MaterialShapeDrawable;
+import com.google.android.material.color.MaterialColors;
 import io.material.catalog.feature.DemoFragment;
 import io.material.catalog.feature.DemoUtils;
 
@@ -52,8 +52,8 @@ public View onCreateDemoView(
     activity.setSupportActionBar(toolbar);
 
     AppBarLayout appBarLayout = view.findViewById(R.id.appbarlayout);
-    appBarLayout.setStatusBarForeground(
-        MaterialShapeDrawable.createWithElevationOverlay(requireContext()));
+    appBarLayout.setStatusBarForegroundColor(
+        MaterialColors.getColor(appBarLayout, R.attr.colorSurface));
 
     return view;
   }

docs/components/TopAppBar.md

@@ -327,6 +327,15 @@ appBarLayout.setStatusBarForeground(
     MaterialShapeDrawable.createWithElevationOverlay(getContext()));
 ```
 
+Or if using Tonal Surface Colors instead of Elevation Overlays, you can simply
+set the `statusBarForeground` to `colorSurface` to let `AppBarLayout`
+automatically match the status bar color to its own background:
+
+```
+appBarLayout.setStatusBarForegroundColor(
+    MaterialColors.getColor(appBarLayout, R.attr.colorSurface));
+```
+
 ### Center aligned top app bar example
 
 All of the same guidance and code from the sections above is relevant for Center

lib/java/com/google/android/material/appbar/AppBarLayout.java

@@ -75,6 +75,7 @@
 import com.google.android.material.animation.AnimationUtils;
 import com.google.android.material.animation.ArgbEvaluatorCompat;
 import com.google.android.material.appbar.AppBarLayout.BaseBehavior.SavedState;
+import com.google.android.material.color.MaterialColors;
 import com.google.android.material.drawable.DrawableUtils;
 import com.google.android.material.internal.ThemeEnforcement;
 import com.google.android.material.motion.MotionUtils;
@@ -220,6 +221,7 @@ public interface LiftOnScrollListener {
   private int[] tmpStatesArray;
 
   @Nullable private Drawable statusBarForeground;
+  @Nullable private Integer statusBarForegroundOriginalColor;
 
   private final float appBarElevation;
 
@@ -332,19 +334,29 @@ private void initializeLiftOnScrollWithColor(MaterialShapeDrawable background) {
     liftBackground.setAlpha(lifted ? 255 : 0);
     background.setAlpha(lifted ? 0 : 255);
 
+    ColorStateList colorSurface =
+        MaterialColors.getColorStateListOrNull(getContext(), R.attr.colorSurface);
+
     liftOnScrollColorUpdateListener =
         valueAnimator -> {
           float liftAlpha = (float) valueAnimator.getAnimatedValue();
           background.setAlpha((int) (255f - liftAlpha));
           liftBackground.setAlpha((int) liftAlpha);
 
+          int mixedColor =
+              ArgbEvaluatorCompat.getInstance()
+                  .evaluate(
+                      liftAlpha / 255f,
+                      background.getResolvedTintColor(),
+                      liftBackground.getResolvedTintColor());
+          if (statusBarForeground != null
+              && statusBarForegroundOriginalColor != null
+              && colorSurface != null
+              && statusBarForegroundOriginalColor == colorSurface.getDefaultColor()) {
+            DrawableCompat.setTint(statusBarForeground, mixedColor);
+          }
+
           if (!liftOnScrollListeners.isEmpty()) {
-            int mixedColor =
-                ArgbEvaluatorCompat.getInstance()
-                    .evaluate(
-                        liftAlpha / 255f,
-                        background.getResolvedTintColor(),
-                        liftBackground.getResolvedTintColor());
             for (LiftOnScrollListener liftOnScrollListener : liftOnScrollListeners) {
               if (background.getFillColor() != null) {
                 liftOnScrollListener.onUpdate(0, mixedColor);
@@ -447,6 +459,7 @@ public void setStatusBarForeground(@Nullable Drawable drawable) {
         statusBarForeground.setCallback(null);
       }
       statusBarForeground = drawable != null ? drawable.mutate() : null;
+      statusBarForegroundOriginalColor = extractStatusBarForegroundColor();
       if (statusBarForeground != null) {
         if (statusBarForeground.isStateful()) {
           statusBarForeground.setState(getDrawableState());
@@ -497,6 +510,19 @@ public Drawable getStatusBarForeground() {
     return statusBarForeground;
   }
 
+  @Nullable
+  private Integer extractStatusBarForegroundColor() {
+    if (statusBarForeground instanceof MaterialShapeDrawable) {
+      return ((MaterialShapeDrawable) statusBarForeground).getResolvedTintColor();
+    }
+    ColorStateList statusBarForegroundColorStateList =
+        DrawableUtils.getColorStateListOrNull(statusBarForeground);
+    if (statusBarForegroundColorStateList != null) {
+      return statusBarForegroundColorStateList.getDefaultColor();
+    }
+    return null;
+  }
+
   @Override
   public void draw(@NonNull Canvas canvas) {
     super.draw(canvas);