Refactoring out grid occupancy management in a separate class

Change-Id: I37a830c0f2eb0a0dd4f5fc78fa29127cb18cb3c2

1 files changed, 101 insertions, 0 deletions

diff --git a/src/com/android/launcher3/util/GridOccupancy.java b/src/com/android/launcher3/util/GridOccupancy.java
new file mode 100644
index 000000000..3f5f0b4ed
--- /dev/null
+++ b/src/com/android/launcher3/util/GridOccupancy.java
@@ -0,0 +1,101 @@
+package com.android.launcher3.util;
+
+import android.graphics.Rect;
+
+import com.android.launcher3.ItemInfo;
+
+/**
+ * Utility object to manage the occupancy in a grid.
+ */
+public class GridOccupancy {
+
+    private final int mCountX;
+    private final int mCountY;
+
+    public final boolean[][] cells;
+
+    public GridOccupancy(int countX, int countY) {
+        mCountX = countX;
+        mCountY = countY;
+        cells = new boolean[countX][countY];
+    }
+
+    /**
+     * 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
+     */
+    public boolean findVacantCell(int[] vacantOut, int spanX, int spanY) {
+        for (int y = 0; (y + spanY) <= mCountY; y++) {
+            for (int x = 0; (x + spanX) <= mCountX; 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;
+    }
+
+    public void copyTo(GridOccupancy dest) {
+        for (int i = 0; i < mCountX; i++) {
+            for (int j = 0; j < mCountY; j++) {
+                dest.cells[i][j] = cells[i][j];
+            }
+        }
+    }
+
+    public boolean isRegionVacant(int x, int y, int spanX, int spanY) {
+        int x2 = x + spanX - 1;
+        int y2 = y + spanY - 1;
+        if (x < 0 || y < 0 || x2 >= mCountX || y2 >= mCountY) {
+            return false;
+        }
+        for (int i = x; i <= x2; i++) {
+            for (int j = y; j <= y2; j++) {
+                if (cells[i][j]) {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    public void markCells(int cellX, int cellY, int spanX, int spanY, boolean value) {
+        if (cellX < 0 || cellY < 0) return;
+        for (int x = cellX; x < cellX + spanX && x < mCountX; x++) {
+            for (int y = cellY; y < cellY + spanY && y < mCountX; y++) {
+                cells[x][y] = value;
+            }
+        }
+    }
+
+    public void markCells(Rect r, boolean value) {
+        markCells(r.left, r.top, r.width(), r.height(), value);
+    }
+
+    public void markCells(CellAndSpan cell, boolean value) {
+        markCells(cell.cellX, cell.cellY, cell.spanX, cell.spanY, value);
+    }
+
+    public void markCells(ItemInfo item, boolean value) {
+        markCells(item.cellX, item.cellY, item.spanX, item.spanY, value);
+    }
+
+    public void clear() {
+        markCells(0, 0, mCountX, mCountY, false);
+    }
+}