1 package com.android.launcher3.util; 2 3 import android.graphics.Rect; 4 5 import com.android.launcher3.ItemInfo; 6 7 /** 8 * Utility object to manage the occupancy in a grid. 9 */ 10 public class GridOccupancy { 11 12 private final int mCountX; 13 private final int mCountY; 14 15 public final boolean[][] cells; 16 GridOccupancy(int countX, int countY)17 public GridOccupancy(int countX, int countY) { 18 mCountX = countX; 19 mCountY = countY; 20 cells = new boolean[countX][countY]; 21 } 22 23 /** 24 * Find the first vacant cell, if there is one. 25 * 26 * @param vacantOut Holds the x and y coordinate of the vacant cell 27 * @param spanX Horizontal cell span. 28 * @param spanY Vertical cell span. 29 * 30 * @return true if a vacant cell was found 31 */ findVacantCell(int[] vacantOut, int spanX, int spanY)32 public boolean findVacantCell(int[] vacantOut, int spanX, int spanY) { 33 for (int y = 0; (y + spanY) <= mCountY; y++) { 34 for (int x = 0; (x + spanX) <= mCountX; x++) { 35 boolean available = !cells[x][y]; 36 out: 37 for (int i = x; i < x + spanX; i++) { 38 for (int j = y; j < y + spanY; j++) { 39 available = available && !cells[i][j]; 40 if (!available) break out; 41 } 42 } 43 if (available) { 44 vacantOut[0] = x; 45 vacantOut[1] = y; 46 return true; 47 } 48 } 49 } 50 return false; 51 } 52 copyTo(GridOccupancy dest)53 public void copyTo(GridOccupancy dest) { 54 for (int i = 0; i < mCountX; i++) { 55 for (int j = 0; j < mCountY; j++) { 56 dest.cells[i][j] = cells[i][j]; 57 } 58 } 59 } 60 isRegionVacant(int x, int y, int spanX, int spanY)61 public boolean isRegionVacant(int x, int y, int spanX, int spanY) { 62 int x2 = x + spanX - 1; 63 int y2 = y + spanY - 1; 64 if (x < 0 || y < 0 || x2 >= mCountX || y2 >= mCountY) { 65 return false; 66 } 67 for (int i = x; i <= x2; i++) { 68 for (int j = y; j <= y2; j++) { 69 if (cells[i][j]) { 70 return false; 71 } 72 } 73 } 74 return true; 75 } 76 markCells(int cellX, int cellY, int spanX, int spanY, boolean value)77 public void markCells(int cellX, int cellY, int spanX, int spanY, boolean value) { 78 if (cellX < 0 || cellY < 0) return; 79 for (int x = cellX; x < cellX + spanX && x < mCountX; x++) { 80 for (int y = cellY; y < cellY + spanY && y < mCountY; y++) { 81 cells[x][y] = value; 82 } 83 } 84 } 85 markCells(Rect r, boolean value)86 public void markCells(Rect r, boolean value) { 87 markCells(r.left, r.top, r.width(), r.height(), value); 88 } 89 markCells(CellAndSpan cell, boolean value)90 public void markCells(CellAndSpan cell, boolean value) { 91 markCells(cell.cellX, cell.cellY, cell.spanX, cell.spanY, value); 92 } 93 markCells(ItemInfo item, boolean value)94 public void markCells(ItemInfo item, boolean value) { 95 markCells(item.cellX, item.cellY, item.spanX, item.spanY, value); 96 } 97 clear()98 public void clear() { 99 markCells(0, 0, mCountX, mCountY, false); 100 } 101 } 102