Add task menu item to move task to Desktop

- Call SystemUiProxy.moveToDesktop to move existing Overview tasks to desktop
- Animation polish will be handled separately
- Refactored AbstractFloatingView method into a helper to allow testing

Fix: 320310347
Test: DesktopSystemShortcutTest, AbstractFloatingViewHelperTest
Flag: ACONFIG com.android.window.flags.enable_desktop_windowing_mode DEVELOPMENT
Change-Id: I2e4e04182e46ba4750e0683ee1789ba8fada06ea
diff --git a/src/com/android/launcher3/AbstractFloatingViewHelper.kt b/src/com/android/launcher3/AbstractFloatingViewHelper.kt
new file mode 100644
index 0000000..0bfbc6e
--- /dev/null
+++ b/src/com/android/launcher3/AbstractFloatingViewHelper.kt
@@ -0,0 +1,38 @@
+/*
+ * 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.launcher3
+
+import com.android.launcher3.AbstractFloatingView.FloatingViewType
+import com.android.launcher3.views.ActivityContext
+
+/**
+ * Helper class for manaing AbstractFloatingViews which shows a floating UI on top of the launcher
+ * UI.
+ */
+class AbstractFloatingViewHelper {
+    fun closeOpenViews(activity: ActivityContext, animate: Boolean, @FloatingViewType type: Int) {
+        val dragLayer = activity.getDragLayer()
+        // Iterate in reverse order. AbstractFloatingView is added later to the dragLayer,
+        // and will be one of the last views.
+        for (i in dragLayer.getChildCount() - 1 downTo 0) {
+            val child = dragLayer.getChildAt(i)
+            if (child is AbstractFloatingView && child.isOfType(type)) {
+                child.close(animate)
+            }
+        }
+    }
+}