add system bar protection views snippet (#470)

* add system bar protection views snippet

* add license header

* fix region tags

* fix region tags again

* moved SystemBarProtection.kt into its own package & simplified layout of system_bar_protection.xml

* fix region tag in xml

* add in an alpha gradient

---------

Co-authored-by: Alex Vanyo <[email protected]>

Author: ashnohe

gradle/libs.versions.toml

@@ -8,7 +8,7 @@ androidx-compose-ui-test = "1.7.0-alpha08"
 androidx-constraintlayout = "2.2.0"
 androidx-constraintlayout-compose = "1.1.0"
 androidx-coordinator-layout = "1.2.0"
-androidx-corektx = "1.15.0"
+androidx-corektx = "1.16.0-beta01"
 androidx-credentials = "1.5.0"
 androidx-credentials-play-services-auth = "1.5.0"
 androidx-emoji2-views = "1.5.0"

views/src/main/java/insets/SystemBarProtectionSnippet.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2025 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
+ *
+ *     https://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 insets
+
+import android.graphics.Color
+import android.os.Bundle
+import android.view.View
+import androidx.activity.enableEdgeToEdge
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.insets.GradientProtection
+import androidx.core.view.insets.ProtectionLayout
+import com.example.example.snippet.views.R
+
+class SystemBarProtectionSnippet : AppCompatActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.system_bar_protection)
+
+        enableEdgeToEdge()
+
+        ViewCompat.setOnApplyWindowInsetsListener(
+            findViewById(R.id.item_list)
+        ) { v: View, insets: WindowInsetsCompat ->
+            val innerPadding = insets.getInsets(
+                WindowInsetsCompat.Type.systemBars() or
+                        WindowInsetsCompat.Type.displayCutout()
+            )
+            v.setPadding(
+                innerPadding.left,
+                innerPadding.top,
+                innerPadding.right,
+                innerPadding.bottom
+            )
+            insets
+        }
+
+        // [START android_system_bar_protection_kotlin]
+        val red = 52
+        val green = 168
+        val blue = 83
+        findViewById<ProtectionLayout>(R.id.list_protection)
+            .setProtections(
+                listOf(
+                    GradientProtection(
+                        WindowInsetsCompat.Side.TOP,
+                        // Ideally, this is the pane's background color
+                        // alpha = 204 for an 80% gradient
+                        Color.argb(204, red, green, blue)
+                    )
+                )
+            )
+        // [END android_system_bar_protection_kotlin]
+    }
+}

views/src/main/res/layout/system_bar_protection.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+
+  Copyright 2025 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
+
+      https://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.
+
+-->
+
+<!-- [START android_system_bar_protection_xml] -->
+<androidx.core.view.insets.ProtectionLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/list_protection"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <ScrollView
+        android:id="@+id/item_list"
+        android:clipToPadding="false"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <!--items-->
+
+    </ScrollView>
+
+</androidx.core.view.insets.ProtectionLayout>
+<!-- [END android_system_bar_protection_xml] -->