Please explain my mistake

[bubuuns]

i=3
def minus():
	global i
	i-=1
app.exit_key_handler=minus
while i>0:
	print i

When I press 'Exit' button, it should decrease 'i' untill 'i' is zero and then exit, but it does not decreases 'i'. Where is my mistake?

[jplauril]

Your while loop doesn't allow UI events to be processed. Add e32.ao_yield() in the loop to make it possible.

[bubuuns]

It prints:
3
3
3
3
3
3
3
3
3
3
3
3
...

When I press that Exit button, it prints the same, only on phone display not in Hyperterm. If I press that Exit button again - it exits python. (Im using BT console).

[lfd]

Hi bubuuns,

Check the following source and twist it to get what you want

# Copyright (c) 2005 Jurgen Scheible

# use keyboard keys Arrow up,down,lefet,right, 1 and * to trigger pop-up note

import appuifw
import e32
from key_codes import *

# you can use this class as a chunk as it is.
class Keyboard(object):
    def __init__(self,onevent=lambda:None):
        self._keyboard_state={}
        self._downs={}
        self._onevent=onevent
    def handle_event(self,event):
        if event['type'] == appuifw.EEventKeyDown:
            code=event['scancode']
            if not self.is_down(code):
                self._downs[ccode]=self._downs.get(code,0)+1    # change ccode to code. modified cause the code tag breaks
            self._keyboard_state[ccode]=1    # change ccode to code. modified cause the code tag breaks
        elif event['type'] == appuifw.EEventKeyUp:
            self._keyboard_state[event['scancode']]=0
        self._onevent()
    def is_down(self,scancode):
        return self._keyboard_state.get(scancode,0)
    def pressed(self,scancode):
        if self._downs.get(scancode,0):
            self._downs[scancode]-=1
            return True
        return False

# set and instance of Keyboard (so you can use all the functions of
# that class later in the script by typing e.g. keyboard.pressed...)
keyboard=Keyboard()

# define the function that lets the application quit
def quit():
    global running
    running=0
    appuifw.app.set_exit()

running=1

appuifw.app.screen='normal'

# use the appuifw.Canvas function and as "event_callback" put "
# keyboard.handle_event", a function which does the keyboard scan
canvas=appuifw.Canvas(event_callback=keyboard.handle_event, redraw_callback=None)

# set the application body to canvas
appuifw.app.body=canvas

appuifw.app.exit_key_handler=quit

# create a loop which the script runs all the time through to check whether a
# key has been pressed.
while running:
    # check if the left arrow key has been pressed
    if keyboard.pressed(EScancodeLeftArrow):
        appuifw.note(u"Arrow left", "info")
    # check if the right arrow key has been pressed
    if keyboard.pressed(EScancodeRightArrow):
        appuifw.note(u"Arrow right", "info")


    if keyboard.pressed(EScancodeDownArrow):
        appuifw.note(u"Arrow down", "info")


    if keyboard.pressed(EScancodeUpArrow):
        appuifw.note(u"Arrow up", "info")
        
    if keyboard.pressed(EScancodeSelect):
        appuifw.note(u"Select", "info")

    if keyboard.pressed(EScancode1):
        appuifw.note(u"1", "info")
    
    if keyboard.pressed(EScancodeStar):
        appuifw.note(u"*", "info")
        
    e32.ao_yield()

LFD

[krzysiekj]

isn't it like exit key always exits app even if you change it handler to do something else? I've read something like this on forum

[lfd]

Noups. Exit key handler does what you want if you implement it properly. If there's an error in the method or function you make it point to, it will then exit.

I'm for example using it to navigate in some application by making it switching listboxes. So it works I confirm.

LFD