Refactor code to be used in LauncherLily features

Refactor add to workspace code to be used in Lily Launcher.
Also utilising code swap feature to swap out functionality of sorting
items on workspaces and finding next vacant space.

Bug: b/218186705
Test: Manually tested Launcher3 works.
Change-Id: I42a44eabeb307e1d23ef333e0a169437f9062bb6

1 files changed, 56 insertions, 0 deletions

diff --git a/go/src/com/android/launcher3/util/AbsGridOccupancy.java b/go/src/com/android/launcher3/util/AbsGridOccupancy.java
new file mode 100644
index 0000000000..4a46bd193f
--- /dev/null
+++ b/go/src/com/android/launcher3/util/AbsGridOccupancy.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2022 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.util;
+
+/**
+ * Defines method to find the next vacant cell on a grid.
+ * This uses the default top-down, left-right approach and can be over-written through
+ * code swaps in different launchers.
+ */
+public abstract class AbsGridOccupancy {
+
+    /**
+     * Find the first vacant cell, if there is one.
+     *
+     * @param vacantOut Holds the x and y coordinate of the vacant cell
+     * @param spanX Horizontal cell span.
+     * @param spanY Vertical cell span.
+     *
+     * @return true if a vacant cell was found
+     */
+    protected boolean findVacantCell(int[] vacantOut, boolean[][] cells, int countX, int countY,
+            int spanX, int spanY) {
+        for (int y = 0; (y + spanY) <= countY; y++) {
+            for (int x = 0; (x + spanX) <= countX; x++) {
+                boolean available = !cells[x][y];
+                out:
+                for (int i = x; i < x + spanX; i++) {
+                    for (int j = y; j < y + spanY; j++) {
+                        available = available && !cells[i][j];
+                        if (!available) break out;
+                    }
+                }
+                if (available) {
+                    vacantOut[0] = x;
+                    vacantOut[1] = y;
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+}