[BottomAppBar] Add attribute to remove shadow on container

resolves #2953 PiperOrigin-RevId: 476451267
material-components · Sep 26, 2022 · 1322e61 · 1322e61
1 parent 11e98f2
commit 1322e61
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Showing 5 changed files with 27 additions and 8 deletions.
diff --git a/docs/components/BottomAppBar.md b/docs/components/BottomAppBar.md
@@ -228,11 +228,12 @@ floating action button (FAB), action item(s) and an overflow menu.
 
 ### Container attributes
 
-Element       | Attribute            | Related method(s)                          | Default value
-------------- | -------------------- | ------------------------------------------ | -------------
-**Color**     | `app:backgroundTint` | `setBackgroundTint`<br>`getBackgroundTint` | `?attr/colorSurface`
-**Elevation** | `app:elevation`      | `setElevation`                             | `3dp`
-**Height**    | `android:minHeight`  | `setMinimumHeight`<br>`getMinimumHeight`   | `80dp`
+Element       | Attribute                | Related method(s)                          | Default value
+------------- | ------------------------ | ------------------------------------------ | -------------
+**Color**     | `app:backgroundTint`     | `setBackgroundTint`<br>`getBackgroundTint` | `?attr/colorSurface`
+**Elevation** | `app:elevation`          | `setElevation`                             | `3dp`
+**Height**    | `android:minHeight`      | `setMinimumHeight`<br>`getMinimumHeight`   | `80dp`
+**Shadows**   | `app:addElevationShadow` | N/A                                        | `false`
 
 ### Navigation icon attributes
 

diff --git a/lib/java/com/google/android/material/bottomappbar/BottomAppBar.java b/lib/java/com/google/android/material/bottomappbar/BottomAppBar.java
@@ -19,7 +19,7 @@
 import com.google.android.material.R;
 
 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
-import static com.google.android.material.shape.MaterialShapeDrawable.SHADOW_COMPAT_MODE_ALWAYS;
+import static com.google.android.material.shape.MaterialShapeDrawable.SHADOW_COMPAT_MODE_NEVER;
 import static com.google.android.material.theme.overlay.MaterialThemeOverlay.wrap;
 
 import android.animation.Animator;
@@ -29,10 +29,13 @@
 import android.content.Context;
 import android.content.res.ColorStateList;
 import android.content.res.TypedArray;
+import android.graphics.Color;
 import android.graphics.Paint.Style;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.drawable.Drawable;
+import android.os.Build.VERSION;
+import android.os.Build.VERSION_CODES;
 import android.os.Parcel;
 import android.os.Parcelable;
 import androidx.appcompat.widget.ActionMenuView;
@@ -342,6 +345,7 @@ public BottomAppBar(@NonNull Context context, @Nullable AttributeSet attrs, int
         a.getDimensionPixelOffset(
             R.styleable.BottomAppBar_fabAlignmentModeEndMargin, NO_FAB_END_MARGIN);
 
+    boolean addElevationShadow = a.getBoolean(R.styleable.BottomAppBar_addElevationShadow, true);
     a.recycle();
 
     fabOffsetEndMode =
@@ -352,7 +356,16 @@ public BottomAppBar(@NonNull Context context, @Nullable AttributeSet attrs, int
     ShapeAppearanceModel shapeAppearanceModel =
         ShapeAppearanceModel.builder().setTopEdge(topEdgeTreatment).build();
     materialShapeDrawable.setShapeAppearanceModel(shapeAppearanceModel);
-    materialShapeDrawable.setShadowCompatibilityMode(SHADOW_COMPAT_MODE_ALWAYS);
+    if (addElevationShadow) {
+      materialShapeDrawable.setShadowCompatibilityMode(
+          MaterialShapeDrawable.SHADOW_COMPAT_MODE_ALWAYS);
+    } else {
+      materialShapeDrawable.setShadowCompatibilityMode(SHADOW_COMPAT_MODE_NEVER);
+      if (VERSION.SDK_INT >= VERSION_CODES.P) {
+        setOutlineAmbientShadowColor(Color.TRANSPARENT);
+        setOutlineSpotShadowColor(Color.TRANSPARENT);
+      }
+    }
     materialShapeDrawable.setPaintStyle(Style.FILL);
     materialShapeDrawable.initializeElevationOverlay(context);
     setElevation(elevation);

diff --git a/lib/java/com/google/android/material/bottomappbar/res-public/values/public.xml b/lib/java/com/google/android/material/bottomappbar/res-public/values/public.xml
@@ -26,6 +26,7 @@
   <public name="menuAlignmentMode" type="attr"/>
   <public name="hideOnScroll" type="attr"/>
   <public name="removeEmbeddedFabElevation" type="attr"/>
+  <public name="addElevationShadow" type="attr"/>
   <public name="Widget.MaterialComponents.BottomAppBar" type="style"/>
   <public name="Widget.MaterialComponents.BottomAppBar.Colored" type="style"/>
   <public name="Widget.MaterialComponents.BottomAppBar.PrimarySurface" type="style"/>

diff --git a/lib/java/com/google/android/material/bottomappbar/res/values/attrs.xml b/lib/java/com/google/android/material/bottomappbar/res/values/attrs.xml
@@ -54,6 +54,8 @@
     <attr name="fabAlignmentModeEndMargin" format="dimension"/>
     <!-- Whether or not to remove elevation for embedded fabs in the bottom app bar. -->
     <attr name="removeEmbeddedFabElevation" format="boolean"/>
+    <!-- Whether or not to add shadows for the bottom app bar. -->
+    <attr name="addElevationShadow" format="boolean"/>
     <!-- Whether the BottomAppBar should hide when a NestedScrollView is scrolled. -->
     <attr name="hideOnScroll" format="boolean"/>
     <!-- Whether the BottomAppBar should apply padding to be above the bottom window insets. -->

diff --git a/lib/java/com/google/android/material/bottomappbar/res/values/styles.xml b/lib/java/com/google/android/material/bottomappbar/res/values/styles.xml
@@ -14,7 +14,7 @@
   ~ See the License for the specific language governing permissions and
   ~ limitations under the License.
 -->
-<resources>
+<resources xmlns:tools="http://schemas.android.com/tools">
 
   <style name="Widget.MaterialComponents.BottomAppBar" parent="Widget.AppCompat.Toolbar">
     <item name="enforceMaterialTheme">true</item>
@@ -33,6 +33,7 @@
     <item name="fabAnchorMode">cradle</item>
     <item name="fabAlignmentMode">center</item>
     <item name="menuAlignmentMode">auto</item>
+    <item name="addElevationShadow">true</item>
   </style>
 
   <style name="Widget.MaterialComponents.BottomAppBar.Colored" parent="Widget.MaterialComponents.BottomAppBar">
@@ -71,6 +72,7 @@
       @dimen/m3_bottomappbar_fab_cradle_vertical_offset
     </item>
     <item name="elevation">@dimen/m3_comp_bottom_app_bar_container_elevation</item>
+    <item name="addElevationShadow">false</item>
 
     <item name="backgroundTint">@macro/m3_comp_bottom_app_bar_container_color</item>
     <item name="navigationIconTint">?attr/colorOnSurfaceVariant</item>