howto update table shown with a whole new table content

[hanscees]

Hi,

I am making a variation on conways game of life.
I have succeeded in letting beeware draw the first iteration (generation) of the world on screen.

My idea is if a user pushed the start button, the world must:

1. in the background compute the new generation. This result in a new table where all cells are different in content
2. the table thats presented to the user should refresh every X seconds in a loop until stop button is pushed

I have two questions:

A. In the tutorial are examples howto delete a column of insert a row. What is the best way to refresh the whole datasource at once with a new one?

B. can somebody coin a code snippit howto keep looping this. I have created something but it blocks the drawing of the screen somehow since I am totally new on coding with a gui.

the data of a " world" looks like this:

[[3, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3], [1, 2, 1, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3], [3, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 2, 2, 2, 3, 3, 2, 3, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 1, 1, 2, 1, 3, 1, 2, 3, 3, 2, 2, 2, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 1, 1, 2, 1, 1, 2, 3, 2, 3, 3, 2, 3, 3, 3, 3], [2, 2, 3, 3, 3, 3, 3, 3, 2, 1, 1, 1, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3], [2, 2, 3, 3, 3, 3, 3, 3, 3, 2, 1, 2, 3, 3, 3, 3, 1, 3, 3, 2, 2, 3], [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 1, 1, 1, 1, 2, 2, 3], [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 3, 1, 1, 2, 2, 2, 3, 1], [1, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1], [3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 1, 1], [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3], [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 2, 3, 3, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 2, 3, 3, 3, 2, 2, 2, 3, 3, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 3, 2, 1, 2, 1, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3], [3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 3, 1, 3, 2, 2, 2, 3], [2, 2, 1, 3, 1, 3, 3, 3, 3, 3, 1, 1, 3, 3, 3, 1, 3, 1, 3, 2, 3, 3], [2, 1, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 3, 3, 3, 3, 3], [1, 2, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 3, 3, 3]]
above is WolfDeerWorldToga

Most of the code that relevant:

#class definition
class WolfEatDeer(toga.App):

        # we need a table to start with. We can later re-draw it
   def load_data(self, WolfDeerWorldToga, Xcol, Yrow):
       yak = toga.Icon.DEFAULT_ICON
       wolf = toga.Icon("icons/wolf")
       deer = toga.Icon("icons/deer")
       tree = toga.Icon("icons/tree")
       helloworld = toga.Icon("icons/helloworld")

       StartRowNumber = 0
       StartCellNumber = 0
       LastCellNumber = StartCellNumber + Xcol
       LastRowNumber = StartRowNumber + Yrow
       print(" last cell number is: " , LastCellNumber)
       for RowNumber in range(StartRowNumber, LastRowNumber):
          for CollNumber in range(StartCellNumber, LastCellNumber):
             #print( " colnr is ", CollNumber, " rownr is " , RowNumber, "value is ", WolfDeerWorldToga[RowNumber][CollNumber])
             #print( " xcol is ", Xcol, " Yrow is " , Yrow)
             if WolfDeerWorldToga[RowNumber][CollNumber] == 1:
                #print("wolf")
                WolfDeerWorldToga[RowNumber][CollNumber] = (wolf, "")
             elif WolfDeerWorldToga[RowNumber][CollNumber] == 2:
                #print("deer")
                WolfDeerWorldToga[RowNumber][CollNumber] = (deer, "")
             elif WolfDeerWorldToga[RowNumber][CollNumber] == 3:
                #print("tree")
                WolfDeerWorldToga[RowNumber][CollNumber] = (tree, "")
             elif WolfDeerWorldToga[RowNumber][CollNumber] == 4:
                WolfDeerWorldToga[RowNumber][CollNumber] = (helloworld, "")
       #print(WolfDeerWorldToga)
       self.WolfDeer_DisplayTable = WolfDeerWorldToga
       self.initial_data = self.WolfDeer_DisplayTable

   def top_handler(self, widget, **kwargs):
      self.table.scroll_to_top()

  def startup(self):
      """Construct and show the Toga application.
      show the main window.
          """
      # ok this is where we startup things
      self.main_window = toga.MainWindow()
      # The table and its data: we call function directly above
      self.load_data(WolfDeerWorldToga, Xcol, Yrow)
      # construct headings, although we dont want them
      # we need the number of headings of Xcol
      headingsHC=[]
      accessorsHC=[]
      Xcolcounter = 0
      while Xcolcounter <  Xcol:
         headingsHC.append(" ")
         accessorsHC.append(str(Xcolcounter))
         #print("xcolcount is: " , Xcolcounter)
         Xcolcounter += 1
      #headingsHC=["Title", "Year", "Rating", "Genre"]
      print("heading  is: ", headingsHC)

      self.table = toga.Table(
         headings= headingsHC,
         accessors= accessorsHC,
         data=self.initial_data,  ## this is the data it shows in this widget
         flex=1,
         margin=-1,
         missing_value="Unknown",
         )

      # Buttons
      btn_style = {"flex": 1, "margin": 3}


      btn_top = toga.Button("Scroll to top", on_press=self.top_handler, **btn_style)
      btn_bottom = toga.Button("Scroll to wop", on_press=self.top_handler, **btn_style)



     controls_1 = toga.Box(
          children=[btn_top, btn_bottom],
          direction=ROW,
      )
      controls_2 = toga.Box(
          children=[btn_top, btn_bottom],
          direction=ROW,
      )

      # Outermost box
      outer_box = toga.Box(
          children=[
              controls_1,
              controls_2,
              self.table,
          ],
          direction=COLUMN,
          margin=10,
      )

      # Add the content on the main window
      self.main_window.content = outer_box
      self.main_window.show()                                    # window is shown

      #ok, thats the initial world, but after pressing start it should redraw until pressed stop
      KeepUpdating = 1
      #StartUpdatingWorld(Xcol, Yrow, WolfDeerWorld)



def main():
    return WolfEatDeer()

[hanscees]

Been fiddling with this for a few hours and havent solved it yet.

However, I have a short program showing the problem so its reproducable.
I have two problems:

1. There is a start button that fires automatically without being pressed (in linux while doing briefcase dev). Why does the button fire before being pressed?
2. When the start button fires, it updates what I think is the data source of the table. I would expect the table on screen to update, but it does not.

If anyone can run this code and show what I am doing wrong that would be greatly appreciated!!
What it should do is first show world 1, and after pressing start show world two.

Code below and also as a zip, as well as the icons

"""
Wolf eats deer like conways game of life
"""

import toga
from toga.style import Pack
from toga.style.pack import COLUMN, ROW
import random
import time


Xcol = 22
Yrow = 20
WolfDeerWorldToga1 = [[3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3], [1, 3, 2, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2], [2, 1, 2, 2, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1], [1, 1, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3], [1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 1, 1], [1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3], [3, 1, 1, 3, 3, 3, 3, 3, 3, 3, 1, 2, 1, 2, 3, 3, 3, 3, 3, 3, 3, 2], [2, 1, 3, 3, 3, 3, 1, 3, 3, 1, 1, 1, 1, 3, 2, 3, 2, 3, 3, 3, 3, 1], [1, 1, 3, 3, 3, 1, 3, 1, 3, 3, 1, 1, 1, 3, 2, 2, 2, 3, 3, 3, 1, 1], [1, 1, 3, 3, 3, 3, 1, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 3, 3, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3], [2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 2, 2, 3, 1, 3, 3, 3, 3, 3, 2, 3], [2, 3, 3, 3, 2, 2, 2, 3, 3, 3, 3, 2, 2, 1, 2, 1, 3, 3, 3, 2, 2, 2], [2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 1, 3, 1, 3, 3, 3, 2, 3, 2, 2], [2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 2, 1, 3, 3, 3, 2, 2, 2, 3, 2], [2, 3, 1, 3, 1, 3, 3, 3, 3, 3, 1, 3, 1, 3, 1, 3, 3, 3, 2, 3, 3, 2], [1, 2, 1, 1, 1, 3, 3, 3, 3, 3, 3, 1, 3, 1, 2, 1, 3, 3, 3, 3, 3, 2], [2, 1, 3, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 2, 1, 2, 3, 3, 3, 3, 3, 1], [1, 2, 2, 3, 3, 3, 3, 3, 2, 2, 2, 3, 3, 3, 2, 3, 3, 2, 2, 3, 3, 3], [3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 3, 3, 2, 2, 2, 3, 2, 2, 3, 3, 3]]



WolfDeerWorldToga2 = [[3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 3, 3, 3, 2, 2, 2, 2, 2, 2, 3, 3], [1, 1, 1, 2, 3, 3, 3, 3, 1, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 1], [3, 1, 2, 2, 2, 3, 3, 3, 3, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 1], [1, 1, 3, 2, 3, 2, 3, 3, 3, 2, 3, 2, 2, 3, 3, 3, 3, 3, 3, 3, 1, 3], [1, 3, 1, 1, 2, 3, 2, 3, 3, 3, 2, 2, 3, 2, 3, 3, 3, 3, 3, 1, 1, 1], [1, 1, 1, 3, 3, 2, 3, 2, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 1, 3, 3], [1, 1, 1, 3, 3, 3, 2, 3, 2, 1, 1, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 1], [3, 1, 3, 3, 3, 1, 1, 2, 1, 1, 3, 3, 1, 3, 2, 2, 2, 3, 3, 3, 1, 1], [1, 1, 3, 3, 1, 1, 3, 1, 2, 3, 1, 1, 1, 3, 2, 3, 3, 2, 3, 1, 1, 1], [1, 1, 3, 3, 1, 3, 1, 1, 3, 2, 1, 3, 3, 3, 3, 2, 2, 3, 2, 1, 3, 3], [1, 3, 3, 3, 3, 3, 1, 3, 3, 3, 3, 1, 2, 3, 3, 3, 2, 2, 3, 2, 3, 1], [2, 3, 3, 3, 2, 2, 3, 3, 3, 3, 2, 2, 1, 3, 1, 1, 1, 2, 3, 2, 3, 1], [1, 2, 3, 3, 2, 3, 2, 3, 3, 3, 2, 3, 2, 1, 1, 1, 3, 3, 3, 2, 3, 1], [3, 2, 2, 3, 3, 2, 3, 2, 3, 3, 3, 3, 1, 3, 1, 2, 3, 2, 2, 2, 3, 1], [3, 3, 2, 2, 3, 3, 2, 3, 2, 3, 1, 1, 1, 1, 1, 3, 3, 2, 3, 3, 3, 2], [3, 1, 1, 3, 1, 1, 3, 2, 3, 2, 1, 3, 1, 3, 1, 3, 3, 3, 2, 3, 2, 2], [1, 1, 3, 1, 1, 3, 3, 3, 2, 3, 2, 1, 1, 1, 1, 1, 3, 3, 3, 2, 2, 3], [1, 1, 3, 1, 1, 3, 3, 3, 2, 3, 3, 2, 3, 2, 1, 3, 3, 3, 2, 2, 3, 1], [1, 3, 2, 1, 3, 3, 3, 3, 2, 3, 1, 1, 3, 2, 3, 3, 2, 2, 2, 3, 2, 1], [3, 3, 3, 2, 3, 3, 3, 3, 1, 1, 1, 3, 3, 2, 3, 2, 2, 3, 3, 3, 3, 2]]


print (WolfDeerWorldToga1)
print ("above is WolfDeerWorldToga used for first screen, before inserting icons")



#class definition
class WolfEatDeer(toga.App):

## handler definition must be in class, but not in startup self apparently
## after troubleshooting an hour or so
##AttributeError: 'WolfEatDeer' object has no attribute 'top_handler'


   def tart_Generation(self, widget, WolfDeerWorld, Xcol, Yrow):
      ## lets start to tinker
       print("Hello, start button is firing, why??")
       print("this is def start generation in toga loop")
       #switching to second world
       WolfDeerWorldToga = WolfDeerWorldToga2
       print(" def generation here, wdw toga is: " , WolfDeerWorldToga)
       # got new data, now update the toga datasource
       self.load_data(WolfDeerWorldToga, Xcol, Yrow)
       print("we finished  now with updating data source")
       print("Hopefully a listener updates the screen")

   def top_handler(self, widget, **kwargs):  # does nothing yet
      self.table.scroll_to_top()

   def load_data(self, WolfDeerWorldToga, Xcol, Yrow):
       # function to produce a toga lists of lists with nice icons of deer and wolf
       # input is list of lists with only numbers in it
       # 1 stands for wolf, 2 for deer, 3 for tree
       print(" this is def load data  " )
       yak = toga.Icon.DEFAULT_ICON
       wolf = toga.Icon("icons/wolf")
       deer = toga.Icon("icons/deer")
       tree = toga.Icon("icons/tree")
       helloworld = toga.Icon("icons/helloworld")

       StartRowNumber = 0
       StartCellNumber = 0
       LastCellNumber = StartCellNumber + Xcol
       LastRowNumber = StartRowNumber + Yrow
       print(" last cell number is: " , LastCellNumber)
       for RowNumber in range(StartRowNumber, LastRowNumber):
          for CollNumber in range(StartCellNumber, LastCellNumber):
             #print( " colnr is ", CollNumber, " rownr is " , RowNumber, "value is ", WolfDeerWorldToga[RowNumber][CollNumber])
             #print( " xcol is ", Xcol, " Yrow is " , Yrow)
             if WolfDeerWorldToga[RowNumber][CollNumber] == 1:
                #print("wolf")
                WolfDeerWorldToga[RowNumber][CollNumber] = (wolf, "")
             elif WolfDeerWorldToga[RowNumber][CollNumber] == 2:
                #print("deer")
                WolfDeerWorldToga[RowNumber][CollNumber] = (deer, "")
             elif WolfDeerWorldToga[RowNumber][CollNumber] == 3:
                #print("tree")
                WolfDeerWorldToga[RowNumber][CollNumber] = (tree, "")
             elif WolfDeerWorldToga[RowNumber][CollNumber] == 4:
                WolfDeerWorldToga[RowNumber][CollNumber] = (helloworld, "")
       #print(WolfDeerWorldToga)
       self.WolfDeer_DisplayTable = WolfDeerWorldToga
       self.initial_data = self.WolfDeer_DisplayTable


   def startup(self):
      """Construct and show the Toga application.
      show the main window.
          """
      # ok this is where we startup things
      print("This is def startup self in toga part")
      self.main_window = toga.MainWindow()
      # The table and its data: we call function directly above
      WolfDeerWorldToga = WolfDeerWorldToga1 # lets load the first world defined above
      self.load_data(WolfDeerWorldToga, Xcol, Yrow)
      # construct headings, although we dont want them
      # need to be as many as Xcol
      # we need the number of headings of Xcol
      headingsHC=[]
      accessorsHC=[]
      Xcolcounter = 0
      while Xcolcounter <  Xcol:
         headingsHC.append(" ")
         accessorsHC.append(str(Xcolcounter))
         Xcolcounter += 1
      #headingsHC=["Title", "Year", "Rating", "Genre"]
      print("heading  is: ", headingsHC)

      ## probably, because its now a toga table, the data source is listned to automagically by toga??
      ## so updating the data should be seen by a listener and screen should update
      self.table = toga.Table(
         headings= headingsHC,
         accessors= accessorsHC,
         data=self.initial_data,  ## this is the data it shows in this widget
         flex=1,
         margin=-1,
         missing_value="Unknown",
         )



## to update the world on screen
## lets try updating self.initial_data


      # Buttons
      btn_style = {"flex": 1, "margin": 3}

      btn_flop = toga.Button("Scroll to wop", on_press=self.top_handler, **btn_style)
      btn_tart = toga.Button("Start ", on_press=self.tart_Generation(self, WolfDeerWorldToga, Xcol, Yrow), **btn_style)
      btn_flop2 = toga.Button("Scroll to wop", on_press=self.top_handler, **btn_style)
      btn_flop3 = toga.Button("Scroll to wop", on_press=self.top_handler, **btn_style)
   #def Start_Generation(self, widget, WolfDeerWorld, Yrow, Yrow):
      btn_bottom = toga.Button("Scroll to wop", on_press=self.top_handler, **btn_style)

      controls_1 = toga.Box(
          children=[btn_tart, btn_bottom],
          direction=ROW,
      )
      controls_2 = toga.Box(
          children=[btn_flop2, btn_flop3],
          direction=ROW,
      )

      # Outermost box
      outer_box = toga.Box(
          children=[
              controls_1,
              controls_2,
              self.table,
          ],
          direction=COLUMN,
          margin=10,
      )


      # Add the content on the main window
      self.main_window.content = outer_box
      self.main_window.show()                                    # window is shown




def main():
    return WolfEatDeer("Wolf eat Deer", "com.hanscees")



[app.py.zip](https://github.com/user-attachments/files/21815846/app.py.zip)
[iconsbeeware21.zip](https://github.com/user-attachments/files/21815847/iconsbeeware21.zip)

[hanscees]

solved one issue. One line added and so the main screen does read the updated data.

However the start button still fires on its own.

   self.load_data(WolfDeerWorldToga, Xcol, Yrow)
   self.table.data = self.initial_data

[freakboy3742]

A. In the tutorial are examples howto delete a column of insert a row. What is the best way to refresh the whole datasource at once with a new one?

table.data = new_data

That is - to change all the data for the table... provide a complete definition of new data for the table.

B. can somebody coin a code snippit howto keep looping this. I have created something but it blocks the drawing of the screen somehow since I am totally new on coding with a gui.

The cause of the "block" you describe is covered in the BeeWare tutorial.

In your case, you're not hitting an API that is blocking - but the underlying problem is the same - you're entering a loop that isn't releasing control to the GUI to allow the GUI to redraw.

The general form of the fix will be the same - the loop that you're using to update the app needs to occasionally release control back to the GUI event loop. You can do this by calling await asyncio.sleep(0) - that is, "sleep" for 0 seconds, but do so in a way that explicitly hands control back to the GUI to do redraws once per iteration:

        async def on_running(self, app, **kwargs):
            while True:
                self.do_one_update()
                await asyncio.sleep(0)

The async on_running() handler is invoked when the app has finished starting up, so you don't need to do anything other than define the method and it will be invoked at a point soon after the startup() method has completed. I don't know what your do_one_update() method needs to do - that's entirely up to your application.

[hanscees]

Hi,

I know I must use async programming, but have little clue about howto do that exactly.
Your example does not result in the screen updating in a while loop in my program.

but await asyncio.sleep(2) does. Thats good enough :)