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;
+    }
+}