[sb] status_bar_simple_fragment flag

Test: none flags
Flag: com.android.systemui.status_bar_simple_fragment
Bug: 364360986
Change-Id: I342a7c04d9b8bb23b437b0d518ce0a1946563139
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index 98c491b..855ebe3 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -555,6 +555,13 @@
 }
 
 flag {
+    name: "status_bar_simple_fragment"
+    namespace: "systemui"
+    description: "Feature flag for refactoring the collapsed status bar fragment"
+    bug: "364360986"
+}
+
+flag {
     name: "new_volume_panel"
     namespace: "systemui"
     description: "Switches to the new volume panel (without Slices)."
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/core/StatusBarSimpleFragment.kt b/packages/SystemUI/src/com/android/systemui/statusbar/core/StatusBarSimpleFragment.kt
new file mode 100644
index 0000000..2141513
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/core/StatusBarSimpleFragment.kt
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2024 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 com.android.systemui.statusbar.core
+
+import com.android.systemui.Flags
+import com.android.systemui.flags.FlagToken
+import com.android.systemui.flags.RefactorFlagUtils
+
+/** Helper for reading and using the status bar simple fragment flag state */
+object StatusBarSimpleFragment {
+    /** Aconfig flag for removing the fragment */
+    const val FLAG_NAME = Flags.FLAG_STATUS_BAR_SIMPLE_FRAGMENT
+
+    /** A token used for dependency declaration */
+    val token: FlagToken
+        get() = FlagToken(FLAG_NAME, isEnabled)
+
+    /** Is the refactor enabled */
+    @JvmStatic
+    inline val isEnabled
+        get() = Flags.statusBarSimpleFragment()
+
+    /**
+     * Called to ensure code is only run when the flag is enabled. This protects users from the
+     * unintended behaviors caused by accidentally running new logic, while also crashing on an eng
+     * build to ensure that the refactor author catches issues in testing.
+     */
+    @JvmStatic
+    inline fun isUnexpectedlyInLegacyMode() =
+        RefactorFlagUtils.isUnexpectedlyInLegacyMode(isEnabled, FLAG_NAME)
+
+    /**
+     * Called to ensure code is only run when the flag is disabled. This will throw an exception if
+     * the flag is not enabled to ensure that the refactor author catches issues in testing.
+     * Caution!! Using this check incorrectly will cause crashes in nextfood builds!
+     */
+    @JvmStatic
+    inline fun assertInNewMode() = RefactorFlagUtils.assertInNewMode(isEnabled, FLAG_NAME)
+
+    /**
+     * Called to ensure code is only run when the flag is disabled. This will throw an exception if
+     * the flag is enabled to ensure that the refactor author catches issues in testing.
+     */
+    @JvmStatic
+    inline fun assertInLegacyMode() = RefactorFlagUtils.assertInLegacyMode(isEnabled, FLAG_NAME)
+}