App Pairs (behind flag): Add new ItemInfo types and DB save functionality

This is the second of several patches implementing the App Pairs feature behind a flag.

This patch includes:
- AppPairsController, a new controller that will handle creation, launching, and deletion of app pairs
- ITEM_TYPE_APP_PAIR is a new type of FolderInfo (FolderInfo now can be either a folder or an app pair, and should probably be renamed to CollectionInfo or something more generic in future)
- Necessary plumbing for these new types
- Database code that handles saving a new app pair to the database with the correct schema

Flag: ENABLE_APP_PAIRS (set to false)
Bug: 274189428
Test: Not included in this CL, but will follow
Change-Id: Ie3aefd4eb9171f471789f54876de742849d3013b
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 4f7380a..0e155a2 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -63,6 +63,8 @@
 import static com.android.launcher3.popup.SystemShortcut.WIDGETS;
 import static com.android.launcher3.states.RotationHelper.REQUEST_LOCK;
 import static com.android.launcher3.states.RotationHelper.REQUEST_NONE;
+import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
+import static com.android.launcher3.util.Executors.MODEL_EXECUTOR;
 import static com.android.launcher3.util.ItemInfoMatcher.forFolderMatch;
 
 import android.animation.Animator;
@@ -2475,6 +2477,12 @@
                             (FolderInfo) item);
                     break;
                 }
+                case LauncherSettings.Favorites.ITEM_TYPE_APP_PAIR: {
+                    FolderInfo info = (FolderInfo) item;
+                    // TODO (jeremysim b/274189428): Create app pair icon
+                    view = null;
+                    break;
+                }
                 case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
                 case LauncherSettings.Favorites.ITEM_TYPE_CUSTOM_APPWIDGET: {
                     view = inflateAppWidget((LauncherAppWidgetInfo) item);
diff --git a/src/com/android/launcher3/LauncherSettings.java b/src/com/android/launcher3/LauncherSettings.java
index 1cd2a30..ad03221 100644
--- a/src/com/android/launcher3/LauncherSettings.java
+++ b/src/com/android/launcher3/LauncherSettings.java
@@ -112,6 +112,10 @@
          */
         public static final int ITEM_TYPE_DEEP_SHORTCUT = 6;
 
+        /**
+         * The favorite is an app pair for launching split screen
+         */
+        public static final int ITEM_TYPE_APP_PAIR = 10;
 
         // *** Below enum values are used for metrics purpose but not used in Favorites DB ***
 
@@ -256,6 +260,7 @@
                 case ITEM_TYPE_DEEP_SHORTCUT: return "DEEPSHORTCUT";
                 case ITEM_TYPE_TASK: return "TASK";
                 case ITEM_TYPE_QSB: return "QSB";
+                case ITEM_TYPE_APP_PAIR: return "APP_PAIR";
                 default: return String.valueOf(type);
             }
         }
diff --git a/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
index 27119ae..a7a25f4 100644
--- a/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
+++ b/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
@@ -408,6 +408,14 @@
                         LauncherSettings.Favorites.CONTAINER_DESKTOP,
                         screenId, coordinates[0], coordinates[1]);
                 mContext.bindItems(Collections.singletonList(info), true, accessibility);
+            } else if (item instanceof FolderInfo fi) {
+                mContext.getModelWriter().addItemToDatabase(fi,
+                        LauncherSettings.Favorites.CONTAINER_DESKTOP, screenId, coordinates[0],
+                        coordinates[1]);
+                fi.contents.forEach(member -> {
+                    mContext.getModelWriter().addItemToDatabase(member, fi.id, -1, -1, -1);
+                });
+                mContext.bindItems(Collections.singletonList(fi), true, accessibility);
             }
         }));
         return true;
diff --git a/src/com/android/launcher3/model/BgDataModel.java b/src/com/android/launcher3/model/BgDataModel.java
index b0f6e13..0e3b06c 100644
--- a/src/com/android/launcher3/model/BgDataModel.java
+++ b/src/com/android/launcher3/model/BgDataModel.java
@@ -190,14 +190,15 @@
         for (ItemInfo item : items) {
             switch (item.itemType) {
                 case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
+                case LauncherSettings.Favorites.ITEM_TYPE_APP_PAIR:
                     folders.remove(item.id);
                     if (FeatureFlags.IS_STUDIO_BUILD) {
                         for (ItemInfo info : itemsIdMap) {
                             if (info.container == item.id) {
                                 // We are deleting a folder which still contains items that
                                 // think they are contained by that folder.
-                                String msg = "deleting a folder (" + item + ") which still " +
-                                        "contains items (" + info + ")";
+                                String msg = "deleting a collection (" + item + ") which still "
+                                        + "contains items (" + info + ")";
                                 Log.e(TAG, msg);
                             }
                         }
@@ -238,6 +239,7 @@
         itemsIdMap.put(item.id, item);
         switch (item.itemType) {
             case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
+            case LauncherSettings.Favorites.ITEM_TYPE_APP_PAIR:
                 folders.put(item.id, (FolderInfo) item);
                 workspaceItems.add(item);
                 break;
@@ -250,15 +252,14 @@
                 } else {
                     if (newItem) {
                         if (!folders.containsKey(item.container)) {
-                            // Adding an item to a folder that doesn't exist.
-                            String msg = "adding item: " + item + " to a folder that " +
-                                    " doesn't exist";
+                            // Adding an item to a nonexistent collection.
+                            String msg = "attempted to add item: " + item + " to a nonexistent app"
+                                    + " collection";
                             Log.e(TAG, msg);
                         }
                     } else {
                         findOrMakeFolder(item.container).add((WorkspaceItemInfo) item, false);
                     }
-
                 }
                 break;
             case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
diff --git a/src/com/android/launcher3/model/data/FolderInfo.java b/src/com/android/launcher3/model/data/FolderInfo.java
index 524b769..e5a0eb1 100644
--- a/src/com/android/launcher3/model/data/FolderInfo.java
+++ b/src/com/android/launcher3/model/data/FolderInfo.java
@@ -114,6 +114,17 @@
     }
 
     /**
+     * Create an app pair, a type of app collection that launches multiple apps into split screen
+     */
+    public static FolderInfo createAppPair(WorkspaceItemInfo app1, WorkspaceItemInfo app2) {
+        FolderInfo newAppPair = new FolderInfo();
+        newAppPair.itemType = LauncherSettings.Favorites.ITEM_TYPE_APP_PAIR;
+        newAppPair.contents.add(app1);
+        newAppPair.contents.add(app2);
+        return newAppPair;
+    }
+
+    /**
      * Add an app or shortcut
      *
      * @param item
diff --git a/src/com/android/launcher3/model/data/ItemInfo.java b/src/com/android/launcher3/model/data/ItemInfo.java
index 41a603d..bfb80b3 100644
--- a/src/com/android/launcher3/model/data/ItemInfo.java
+++ b/src/com/android/launcher3/model/data/ItemInfo.java
@@ -90,6 +90,7 @@
      * {@link Favorites#ITEM_TYPE_SHORTCUT},
      * {@link Favorites#ITEM_TYPE_DEEP_SHORTCUT}
      * {@link Favorites#ITEM_TYPE_FOLDER},
+     * {@link Favorites#ITEM_TYPE_APP_PAIR},
      * {@link Favorites#ITEM_TYPE_APPWIDGET} or
      * {@link Favorites#ITEM_TYPE_CUSTOM_APPWIDGET}.
      */