Remove StaticShadowHelper API abstractions.

Bug: 75289452
Test: ./gradlew :leanback:build :leanback:cC
Change-Id: I8c7a3d92f8f73d786cfc17e2c4bc4b512fc6efaf
diff --git a/leanback/build.gradle b/leanback/build.gradle
index fe04a8a..56b7fc5 100644
--- a/leanback/build.gradle
+++ b/leanback/build.gradle
@@ -23,7 +23,6 @@
     sourceSets {
         main.java.srcDirs += [
                 'common',
-                'jbmr2',
                 'kitkat',
                 'api21',
         ]
diff --git a/leanback/jbmr2/androidx/leanback/widget/ShadowHelperJbmr2.java b/leanback/jbmr2/androidx/leanback/widget/ShadowHelperJbmr2.java
deleted file mode 100644
index 49e5532..0000000
--- a/leanback/jbmr2/androidx/leanback/widget/ShadowHelperJbmr2.java
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
- * in compliance with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software distributed under the License
- * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
- * or implied. See the License for the specific language governing permissions and limitations under
- * the License.
- */
-package androidx.leanback.widget;
-
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-
-import androidx.annotation.RequiresApi;
-import androidx.leanback.R;
-
-@RequiresApi(18)
-class ShadowHelperJbmr2 {
-
-    static class ShadowImpl {
-        View mNormalShadow;
-        View mFocusShadow;
-    }
-
-    /* prepare parent for allowing shadows of a child */
-    public static void prepareParent(ViewGroup parent) {
-        parent.setLayoutMode(ViewGroup.LAYOUT_MODE_OPTICAL_BOUNDS);
-    }
-
-    /* add shadows and return a implementation detail object */
-    public static Object addShadow(ViewGroup shadowContainer) {
-        shadowContainer.setLayoutMode(ViewGroup.LAYOUT_MODE_OPTICAL_BOUNDS);
-        LayoutInflater inflater = LayoutInflater.from(shadowContainer.getContext());
-        inflater.inflate(R.layout.lb_shadow, shadowContainer, true);
-        ShadowImpl impl = new ShadowImpl();
-        impl.mNormalShadow = shadowContainer.findViewById(R.id.lb_shadow_normal);
-        impl.mFocusShadow = shadowContainer.findViewById(R.id.lb_shadow_focused);
-        return impl;
-    }
-
-    /* set shadow focus level 0 for unfocused 1 for fully focused */
-    public static void setShadowFocusLevel(Object impl, float level) {
-        ShadowImpl shadowImpl = (ShadowImpl) impl;
-        shadowImpl.mNormalShadow.setAlpha(1 - level);
-        shadowImpl.mFocusShadow.setAlpha(level);
-    }
-}
diff --git a/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayContainer.java b/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayContainer.java
index 20abd7f..b0b45de 100644
--- a/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayContainer.java
+++ b/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayContainer.java
@@ -119,7 +119,7 @@
      * Return true if the platform sdk supports shadow.
      */
     public static boolean supportsShadow() {
-        return StaticShadowHelper.getInstance().supportsShadow();
+        return StaticShadowHelper.supportsShadow();
     }
 
     /**
@@ -135,7 +135,7 @@
      * to parent.
      */
     public static void prepareParentForShadow(ViewGroup parent) {
-        StaticShadowHelper.getInstance().prepareParent(parent);
+        StaticShadowHelper.prepareParent(parent);
     }
 
     /**
@@ -226,7 +226,7 @@
                         this, mUnfocusedZ, mFocusedZ, mRoundedCornerRadius);
                 break;
             case SHADOW_STATIC:
-                mShadowImpl = StaticShadowHelper.getInstance().addStaticShadow(this);
+                mShadowImpl = StaticShadowHelper.addStaticShadow(this);
                 break;
         }
         if (hasColorDimOverlay) {
diff --git a/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayHelper.java b/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayHelper.java
index 0299142..1dfd653 100644
--- a/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayHelper.java
+++ b/leanback/src/main/java/androidx/leanback/widget/ShadowOverlayHelper.java
@@ -280,7 +280,7 @@
      * Return true if the platform sdk supports shadow.
      */
     public static boolean supportsShadow() {
-        return StaticShadowHelper.getInstance().supportsShadow();
+        return StaticShadowHelper.supportsShadow();
     }
 
     /**
@@ -316,7 +316,7 @@
      */
     public void prepareParentForShadow(ViewGroup parent) {
         if (mShadowType == SHADOW_STATIC) {
-            StaticShadowHelper.getInstance().prepareParent(parent);
+            StaticShadowHelper.prepareParent(parent);
         }
     }
 
@@ -458,7 +458,7 @@
                     ShadowHelper.setShadowFocusLevel(impl, level);
                     break;
                 case SHADOW_STATIC:
-                    StaticShadowHelper.getInstance().setShadowFocusLevel(impl, level);
+                    StaticShadowHelper.setShadowFocusLevel(impl, level);
                     break;
             }
         }
diff --git a/leanback/src/main/java/androidx/leanback/widget/StaticShadowHelper.java b/leanback/src/main/java/androidx/leanback/widget/StaticShadowHelper.java
index 5b3ff45..5ab0c61 100644
--- a/leanback/src/main/java/androidx/leanback/widget/StaticShadowHelper.java
+++ b/leanback/src/main/java/androidx/leanback/widget/StaticShadowHelper.java
@@ -16,107 +16,52 @@
 package androidx.leanback.widget;
 
 import android.os.Build;
+import android.view.LayoutInflater;
+import android.view.View;
 import android.view.ViewGroup;
 
-import androidx.annotation.RequiresApi;
-
+import androidx.leanback.R;
 
 /**
  * Helper for static (nine patch) shadows.
  */
 final class StaticShadowHelper {
-
-    final static StaticShadowHelper sInstance = new StaticShadowHelper();
-    boolean mSupportsShadow;
-    ShadowHelperVersionImpl mImpl;
-
-    /**
-     * Interface implemented by classes that support Shadow.
-     */
-    static interface ShadowHelperVersionImpl {
-        public void prepareParent(ViewGroup parent);
-        public Object addStaticShadow(ViewGroup shadowContainer);
-        public void setShadowFocusLevel(Object impl, float level);
-    }
-
-    /**
-     * Interface used when we do not support Shadow animations.
-     */
-    private static final class ShadowHelperStubImpl implements ShadowHelperVersionImpl {
-        ShadowHelperStubImpl() {
-        }
-
-        @Override
-        public void prepareParent(ViewGroup parent) {
-            // do nothing
-        }
-
-        @Override
-        public Object addStaticShadow(ViewGroup shadowContainer) {
-            // do nothing
-            return null;
-        }
-
-        @Override
-        public void setShadowFocusLevel(Object impl, float level) {
-            // do nothing
-        }
-    }
-
-    /**
-     * Implementation used on JBMR2 (and above).
-     */
-    @RequiresApi(19)
-    private static final class ShadowHelperJbmr2Impl implements ShadowHelperVersionImpl {
-        ShadowHelperJbmr2Impl() {
-        }
-
-        @Override
-        public void prepareParent(ViewGroup parent) {
-            ShadowHelperJbmr2.prepareParent(parent);
-        }
-
-        @Override
-        public Object addStaticShadow(ViewGroup shadowContainer) {
-            return ShadowHelperJbmr2.addShadow(shadowContainer);
-        }
-
-        @Override
-        public void setShadowFocusLevel(Object impl, float level) {
-            ShadowHelperJbmr2.setShadowFocusLevel(impl, level);
-        }
-    }
-
-    /**
-     * Returns the StaticShadowHelper.
-     */
     private StaticShadowHelper() {
+    }
+
+    static boolean supportsShadow() {
+        return Build.VERSION.SDK_INT >= 21;
+    }
+
+    static void prepareParent(ViewGroup parent) {
         if (Build.VERSION.SDK_INT >= 21) {
-            mSupportsShadow = true;
-            mImpl = new ShadowHelperJbmr2Impl();
-        } else {
-            mSupportsShadow = false;
-            mImpl = new ShadowHelperStubImpl();
+            parent.setLayoutMode(ViewGroup.LAYOUT_MODE_OPTICAL_BOUNDS);
         }
     }
 
-    public static StaticShadowHelper getInstance() {
-        return sInstance;
+    static Object addStaticShadow(ViewGroup shadowContainer) {
+        if (Build.VERSION.SDK_INT >= 21) {
+            shadowContainer.setLayoutMode(ViewGroup.LAYOUT_MODE_OPTICAL_BOUNDS);
+            LayoutInflater inflater = LayoutInflater.from(shadowContainer.getContext());
+            inflater.inflate(R.layout.lb_shadow, shadowContainer, true);
+            ShadowImpl impl = new ShadowImpl();
+            impl.mNormalShadow = shadowContainer.findViewById(R.id.lb_shadow_normal);
+            impl.mFocusShadow = shadowContainer.findViewById(R.id.lb_shadow_focused);
+            return impl;
+        }
+        return null;
     }
 
-    public boolean supportsShadow() {
-        return mSupportsShadow;
+    static void setShadowFocusLevel(Object impl, float level) {
+        if (Build.VERSION.SDK_INT >= 21) {
+            ShadowImpl shadowImpl = (ShadowImpl) impl;
+            shadowImpl.mNormalShadow.setAlpha(1 - level);
+            shadowImpl.mFocusShadow.setAlpha(level);
+        }
     }
 
-    public void prepareParent(ViewGroup parent) {
-        mImpl.prepareParent(parent);
-    }
-
-    public Object addStaticShadow(ViewGroup shadowContainer) {
-        return mImpl.addStaticShadow(shadowContainer);
-    }
-
-    public void setShadowFocusLevel(Object impl, float level) {
-        mImpl.setShadowFocusLevel(impl, level);
+    static class ShadowImpl {
+        View mNormalShadow;
+        View mFocusShadow;
     }
 }