Pascal Muller
I need help to manage time in my kivy-python code.
For example, I don't know how to make a very simple application : the pyhon code increments a variable from 0 to 9 (0, 2, 3...9) and each time waits one second and only then change a label text with the value of the variable.
When I code that with time.sleep(1) I only see the last value : 9
I have the same problem if I want to draw lines : I only see all the lines at the end.
Thank you for your help.
Here is my code
from kivy.base import runTouchApp
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics.vertex_instructions import (Rectangle,Ellipse,Line)
from kivy.graphics import Color
import time
Builder.load_string('''
<FloatLayout>:
Button:
text: "Exécute"
on_press: root.execute()
Label:
id: label_name
size_hint_y: 0.5
text: "Text"
''')
class FloatLayout(FloatLayout):
def execute(self):
mylabel = self.ids.label_name
for i in range(10):
print i
time.sleep(1)
mylabel.text=str(i)
with self.canvas:
Color(0, 1, 0, 1)
Line(points=[0,0,100+10*i,200])
runTouchApp(FloatLayout())
Monty Mole
please include the indentations next time so the code will run properly and is readable.
You must avoid to spend too much time in a subroutine so kivy can update the layout.
Instead you have to register a call to a subroutine with clock.interval which is then called
automatically at given periods of time. To unregister it you have to return False. More on this here:
https://kivy.org/docs/api-kivy.clock.html
This way you can alter graphics or text, do running sliders etc.
#---------------------------------------------------------------------------------------
from kivy.base import runTouchApp
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics.vertex_instructions import (Rectangle,Ellipse,Line)
from kivy.graphics import Color
import time
Builder.load_string('''
<FloatLayout>:
Button:
text: "Exécute"
Label:
id: label_name
size_hint_y: 0.5
text: "Text"
''')
class FloatLayout(FloatLayout):
def print_to_label(self,*args):
self.ids.label_name.text = str(self.counter )
if self.counter == 0:
self.ids.label_name.text = 'finished'
return False # unschedule
else:
self.counter -= 1
def execute(self,btn):
self.counter = 10 #reset counter
Clock.schedule_interval(self.print_to_label, 1.)
runTouchApp(FloatLayout())
Pascal Muller
It's exactly what I was looking for.
Thank you for you help and excuse me for the indentation, I'll be careful next time.
Pascal.
Monty Mole
Pascal Muller
I'm trying to use Monty Mole's advices in another project : the Hanoi towers.
I would like to display each move and each state in a label and wait a delay before displaying next ones.
But once again, only last one is displayed.
Conversely, it works well with print function.
Here is my code.
Thank you for your help.
from kivy.base import runTouchApp
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics.vertex_instructions import (Rectangle,Ellipse,Line)
from kivy.graphics import Color
from kivy.clock import Clock
import math
import time
from kivy.clock import Clock
Builder.load_string('''
<FloatLayout>:
BoxLayout:
orientation: 'vertical'
Label:
text:"Hanoi towers"
size_hint_y: 0.2
BoxLayout:
size_hint_y: 0.3
Label:
size_hint_x: 0.5
Label:
size_hint_x: 0.3
text:"LEGO NXT : "
CheckBox:
size_hint_x: 0.2
id: checkbox_name
Label:
size_hint_x: 0.5
BoxLayout:
size_hint_y: 0.3
Label:
size_hint_x: 0.5
text:"Number of rings : "
Label:
size_hint_x: 0.1
text: str(int(slider_name.value))
Slider:
id: slider_name
size_hint_x: 2
step: 1
min:1
max:9
value: 2
BoxLayout:
size_hint_y: 0.3
Label:
size_hint_x: 0.5
text:"Delay : "
Label:
size_hint_x: 0.1
text: str(int(slider2_name.value))
Slider:
id: slider2_name
size_hint_x: 2
step: 1
min:0
max:9
value: 1
Label:
size_hint_y: 0.4
text: 'Time estimation : ' + str(int((2**slider_name.value-1)*slider2_name.value)) + ' second(s)'
Button:
size_hint_y: 0.5
text: "Execute"
on_press: root.execute(self)
Label:
id: label_action__name
size_hint_y: 0.5
text: "Action : "
Label:
id: label_result__name
size_hint_y: 0.5
text: "Rings position : "
Label:
size_hint_y: 3
''')
class FloatLayout(FloatLayout):
m1=[]
m2=[]
m3=[]
text_action=''
end = 0
def hanoi(self,n,s,d,t):
if n>0:
self.hanoi(n-1,s,t,d)
if s==1:
self.m1.remove(n)
if d==1:
self.m1.append(n)
if s==2:
self.m2.remove(n)
if d==2:
self.m2.append(n)
if s==3:
self.m3.remove(n)
if d==3:
self.m3.append(n)
self.m1.sort()
self.m2.sort()
self.m3.sort()
self.text_action='Move ring ' + str(n) + ' from ' + str(s) + ' to '+ str(d)
print self.text_action,self.m1,self.m2,self.m3
time.sleep(1)
self.hanoi(n-1,t,d,s)
def update(self,*args):
self.ids.label_result__name.text='Rings position : ' + str(self.m1)+' '+str(self.m2)+' '+str(self.m3)
self.ids.label_action__name.text=self.text_action
if self.end == 1:
return False # unschedule
def execute(self,btn):
delai = self.ids.slider2_name
Clock.schedule_interval(self.update,delai.value)
level = self.ids.slider_name
self.m1=range(1,int(level.value)+1)
self.m2=[]
self.m3=[]
self.hanoi(int(level.value),1,3,2)
end = 1
print 'End'
runTouchApp(FloatLayout())
ZenCODE
#time.sleep(1)
from kivy.clock import Clock
Clock.schedule_once(lambda dt: self.hanoi(n - 1, t, d, s), 1)
Pascal Muller
I tried to delete "time.sleep" and to use "clock.schedule once" but it doesn't work.
Here is my new code.
Thnak you for your help.
Pascal.
#self.hanoi(n-1,s,t,d)
Clock.schedule_once(lambda dt: self.hanoi(n-1,s,t,d), 5)
if s==1:
self.m1.remove(n)
if d==1:
self.m1.append(n)
if s==2:
self.m2.remove(n)
if d==2:
self.m2.append(n)
if s==3:
self.m3.remove(n)
if d==3:
self.m3.append(n)
self.m1.sort()
self.m2.sort()
self.m3.sort()
self.text_action='Move ring ' + str(n) + ' from ' + str(s) + ' to '+ str(d)
print self.text_action,self.m1,self.m2,self.m3
# time.sleep(1)
Clock.schedule_once(lambda dt: self.hanoi(n - 1, t, d, s), 5)
# self.hanoi(n-1,t,d,s)
def update(self,*args):
self.ids.label_result__name.text='Rings position : ' + str(self.m1)+' '+str(self.m2)+' '+str(self.m3)
self.ids.label_action__name.text=self.text_action
if self.end == 1:
return False # unschedule
def execute(self,btn):
delai = self.ids.slider2_name
Clock.schedule_interval(self.update,0.1)
level = self.ids.slider_name
self.m1=range(1,int(level.value)+1)
self.m2=[]
self.m3=[]
Clock.schedule_once(lambda dt: self.hanoi(int(level.value),1,3,2), 5)
# self.hanoi(int(level.value),1,3,2)
end = 1
print 'End'
runTouchApp(FloatLayout())
ZenCODE
Bill Janssen
Bill
Pascal Muller
Thank you for being interested in my project.
And excuse me for not having posted before : I wasn't home last weeks.
First of all I changed the name of my class. Thank you for this advice.
Then I tried to use clock.schedule_once in lines from 94 to 101 in the hanoi function
I explain : moving number rings from start position to end position using the third position (temp) as a help is equivalent to three moves :
- move number-1 rings from start to temp
- move one ring from start to end
- move number-1 rings from temp to end
It's recursion
The function does something other than calling itself only when n=1 : it then prints move and result and change label texts so that the user can see what is done in the gaphical interface.
My original problem is that I didn't succed in updating these labels : they only update at the end.
And I don't see how using clock.schedule_once would solve it.
When I use it, nothing happens during a while and and all moves are printed at once and in the label I only see last position.
Thank you for your help.
from kivy.base import runTouchApp
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics.vertex_instructions import (Rectangle,Ellipse,Line)
from kivy.graphics import Color
from kivy.clock import Clock
import math
import time
from kivy.clock import Clock
Builder.load_string('''
<Hanoi_Class>:
class Hanoi_Class(FloatLayout):
text_action=''
end = 0
def hanoi(self,number,start,end,temp):
if number==1:
self.text_action="Move ring "+str(rings[start-1][0])+" altitude "+str(len(rings[start-1]))+" from position "+str(start)+" to position "+str(end)
print (self.text_action)
rings[end-1].insert(0,rings[start-1][0])
del(rings[start-1][0])
print("Result : "+str(rings)+"\n")
else:
Clock.schedule_once(lambda dt: self.hanoi(number-1,start,temp,end),delay.value)
Clock.schedule_once(lambda dt: self.hanoi(1,start,end,temp),delay.value)
time.sleep(delay.value+1)
Clock.schedule_once(lambda dt: self.hanoi(number-1,temp,end,start),delay.value)
def update(self,*args):
self.ids.label_result__name.text='Rings position : ' + str(rings)
self.ids.label_action__name.text=self.text_action
if self.end == 1:
return False # unschedule
def execute(self,btn):
global rings
global delay
delay = self.ids.slider2_name
Clock.schedule_interval(self.update,0.1)
level = self.ids.slider_name
rings=[list(range(1,level.value+1)),[],[]]
self.hanoi(int(level.value),1,3,2)
end = 1
print ('End')
runTouchApp(Hanoi_Class())