grid.py

"""
Grid definition

MIT License

Copyright (c) 2017 Gaurav Mathur

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    SOFTWARE.
"""

from cell import Cell
import random

class Grid(object):
    def __init__(self, rows, columns):
        self.rows = rows
        self.columns = columns
        self.grid = self.prepare_grid()
        self.configure_cells()

    def size(self):
        return rows*columns

    def prepare_grid(self):
        grid = [[Cell(row, col) for col in range(self.columns)] for row in range(self.rows)]
        return grid

    def each_row(self):
        """
        Iterate over each row in the grid
        """
        for row in self.grid:
            yield row

    def each_cell(self):
        """
        Iterator over all cells in the grid
        """
        for row in self.each_row():
            for cell in row:
                # Need the if clause for masked grids where a cell might or not 
                # be present at a specific (row, column)
                if cell:
                    yield cell

    def configure_cells(self):
        for cell in self.each_cell():
            row, col = cell.row, cell.column
            cell.cellNorth = self[row-1, col]
            cell.cellSouth = self[row+1, col]
            cell.cellWest = self[row, col-1]
            cell.cellEast = self[row, col+1]

    def random_cell(self):
        """
        Get a random cell from the grid
        """
        row = random.randint(0, self.rows-1)
        col = random.randint(0, self.columns-1)
        return self[row, col]

    def __getitem__(self, pos):
        row, col = pos
        if self.rows-1 >= row >= 0 and self.columns-1 >= col >= 0:
            return self.grid[row][col]
        return None

    def grid_cells(self):
        """ Print the grid in a way where each grid cell shows the cell 
        coordinates """
        s = ""
        for row in range(self.rows):
            L = []
            for col in range(self.columns):
                L.append(str(self.grid[row][col]))
            s = s + ' '.join(L) + '\n'
        return s

    def contents_of(self, cell):
        """ This routine returns the 'contents' of a cell object """
        return " "

    def dimensions(self):
        return self.rows, self.columns

    def __str__(self):
        """ Overloaded function called when the grid is printed """
        output = '+' + "---+" * self.columns + '\n'
        for row in self.each_row():
            top = '|'
            bottom = '+'
            for cell in row:
                if cell is None:
                    # This clause handles the case where there is no cell object 
                    # at the specified location because it has been masked 
                    cell = Cell(-1, -1)
                body = '{:3s}'.format(self.contents_of(cell))
                east_boundary = ' ' if cell.isLinked(cell.cellEast) else '|'
                top = top + body + east_boundary
                south_boundary = '   ' if cell.isLinked(cell.cellSouth) else '---'
                corner = '+'
                bottom = bottom + south_boundary + corner
            output = output + top + '\n'
            output = output + bottom + '\n'
        return output
                
if __name__ == "__main__":
    """
    Unit tests
    """
    print Grid(10, 10)
    for row in Grid(4,4).prepare_grid():
        print row

    for cell in Grid(4,4).each_cell():
        print cell

    print
    g = Grid(4, 4)
    print g
    print g[1,2]
    print "Neighbors of g[1,2]"
    for cell in g[1,2].neighbors():
        print cell
    print "Neighbors of g[3,3]"
    for cell in g[3,3].neighbors():
        print cell

    print "A random cell"
    print g.random_cell()