I am trying to produce a star algorithm using Tkinter 2d graphical user interface. I have modified the following code having found it originally on here:
from tkinter import *
class CellGrid(Canvas):
def __init__(self,master, rowNumber, columnNumber, cellSize, theMap):
Canvas.__init__(self, master, width = cellSize * columnNumber , height = cellSize * rowNumber)
self.cellSize = cellSize
self.grid = []
for row in range(rowNumber):
line = []
for column in range(columnNumber):
line.append(Cell(self, column, row, cellSize, theMap[row][column]))
self.grid.append(line)
print (self.grid[0][0].value)
self.draw()
def draw(self):
for row in self.grid:
for cell in row:
cell.draw()
class Cell():
colors = {
0: 'white', # untried
1: 'black', # obstacle
2: 'green', # start
3: 'red', # finish
4: 'blue', # open
5: 'gray', # closed
6: 'orange', # path
}
def __init__(self, master, x, y, size, value):
self.master = master
self.abs = x
self.ord = y
self.size= size
self.fill = "white"
self.value = value
def setValue(self, value):
self.value = value
def draw(self):
if self.master != None :
if self.value == 0:
self.fill = self.white
elif self.value == 1:
self.fill = self.black
elif self.value == 2:
self.fill = self.green
elif self.value == 3:
self.fill = self.red
elif self.value == 4:
self.fill = self.blue
elif self.value == 5:
self.fill = self.gray
elif self.value == 6:
self.fill = self.orange
xmin = self.abs * self.size
xmax = xmin + self.size
ymin = self.ord * self.size
ymax = ymin + self.size
self.master.create_rectangle(xmin, ymin, xmax, ymax, fill = self.fill, outline = "black")
def main():
Map = [
[2, 0, 0, 0, 0],
[0, 1, 1, 1, 1],
[0, 1, 3, 0, 0],
[0, 1, 1, 1, 0],
[0, 0, 0, 0, 0],
]
root = Tk()
c = tk.Canvas(root, height=1000, width=1000, bg='white')
my_gui = CellGrid(root, len(Map), len(Map[0]), 40, Map)
root.mainloop()
But when I go to run it, nothing displays.
A lot of small and not-small misunderstandings are blocking the display of the star algorithm.
Problem 1 - incomplete calling main() function.
As @avysk suggests as comment, the first blocking point is due to the missing of
main()preamble in Python.
Just add the following code after the def main() function:
if __name__ == '__main__':
main()
Problem 2 - typo and missing pack() to the main Canvas display.
Because the tk symbol is not defined, the main Canvas shall be declared as follow:
c = Canvas(root, height=1000, width=1000, bg='white')
Instead of:
c = tk.Canvas(root, height=1000, width=1000, bg='white')
And after the magic missing call is pack():
c.pack() # magic call to display the (1000 x 1000) white canvas
Problem 3 - missing call to the secondary Canvas display.
As for the main Canvas, it was missing the call of pack(), two possibilities could be used to display the secondary Canvas.
my_gui.pack() to fit the main Canvas to the size of the secondary Canvas,my_gui.place(relx=0.5, rely=0.5, anchor=CENTER) to center the secondary Canvas to the main Canvas.To display the secondary Canvas:
my_gui = CellGrid(c, len(Map), len(Map[0]), 40, Map)
my_gui.place(relx=0.5, rely=0.5, anchor=CENTER)
Problem 4 - misunderstanding of dictionary use in the Cell::draw() function.
The displayed error is "
AttributeError: 'Cell' object has no attribute 'green'".
The value of the first cell self.grid[0][0].value = 2 and when drawing the cell, the following self.fill = self.green generates the error.
Three possibilities could be used to solve that error:
self.fill = self.<color> (7 cases) by self.fill = '<color>',colors and replace the 7 cases by a unique call.The use of dictionary could be (sol 2):
if 0 <= self.value <= 6: # check if value in range of colors
self.fill = Cell.colors[self.value]
Instead of the long if-elif (sol 1):
if self.value == 0:
self.fill = 'white' # Error: self.white
elif self.value == 1:
self.fill = 'black' # Error: self.black
elif self.value == 2:
self.fill = 'green' # Error: self.green
elif self.value == 3:
self.fill = 'red' # Error: self.red
elif self.value == 4:
self.fill = 'blue' # Error: self.blue
elif self.value == 5:
self.fill = 'gray' # Error: self.gray
elif self.value == 6:
self.fill = 'orange' # Error: self.orange