Screen resizing doesn't update screen.height/screen.width about asciimatics

[peterbrittain]

As you will see in all of the samples, you can handle resizing by creating a new Screen object. The bars demo (https://github.com/peterbrittain/asciimatics/blob/master/samples/bars.py) in particular shows how to handle resizing for a desired size.

I get that this isn't ideal, but the knock-on impact on the other objects that need to be resized and re-positioned means that you effectively go through the whole initialization sequence again. I have been thinking about changing this, but it will radically change the implementation and so will almost certainly not be back compatible. See #24.

[peterbrittain]

I've updated the docs (see bb6ce87) to try to address this confusion.

Am assuming that this covers it. Please let me know if there was anything else that could help clarify it further.

[lduczmal]

This way cannot be used with

screen.print_at(...)
screen.refresh()

screen.refresh() does not have argument stop_on_resize

[peterbrittain]

@lduczmal If you are not using the Screen.play() method you have full control of when things happen in your application and you can just call Screen.has_resized() to see if things have changed whenever you like.

[lduczmal]

@peterbrittain Thank you for you answer.
Problem is that Screen.has_resized() seems to do not work... I create such simple script which open new terminal windows and shows current screen dimensions, some changing value and info whether screen dimensions was changed. Maybe I make something wrong, but printed dimensions will not change when I change terminal window size during script is running. One note: I run it on Windows 10 and on Python downloaded from www.python.org/downloads

from asciimatics.screen import Screen
from asciimatics.exceptions import ResizeScreenError
import time

screen_changes = []
screen_changes.append("start")

def demo(screen):
    x = 0
    while True:
        x += 1
        mytext = "[Screen height: {0}, width: {1}] changing value: {2}".format(screen.height,screen.width,x)
        mytext2 = "Screen was resized? {0}".format(Screen.has_resized(screen))
        screen_changes.append(Screen.has_resized(screen))
        screen.print_at(mytext, 1, 1, colour=7, bg=0)
        if Screen.has_resized(screen):
            screen.print_at(mytext2, 1, 2, colour=1, bg=0)
        else:
            screen.print_at(mytext2, 1, 2, colour=2, bg=0)
        ev = screen.get_key()
        if ev in (ord('Q'), ord('q')):
            return
        screen.refresh()
        time.sleep(0.5)

Screen.wrapper(demo)
print(screen_changes)
sys.exit(0)

Best regards

[peterbrittain]

@lduczmal That's because has_resized is not a static method, you just need to call screen.has_resized(). Note that this only guarantees to check if there has been a resize since the last time you checked. For Windows, it will continue to tell you on each call, but that's not a cross-platform guarantee and so you should fix your code. What should work is this:

    mytext2 = "Screen was resized? {0}".format(screen.has_resized())
    screen_changes.append(mytext2)

[lduczmal]

@peterbrittain Hi, thank you - now it works! almost... ;-) When I'm resizing terminal window during script run it sometimes returns to previous dimensions...
My code:

from asciimatics.screen import Screen
from asciimatics.exceptions import ResizeScreenError
import time
import sys

screen_changes = []
screen_changes.append("start")
quit_script = False
x = 0
def demo(screen):
    global quit_script
    global x
    while True:
        x += 1
        mytext = "[Screen height: {0}, width: {1}] changing value: {2}".format(screen.height,screen.width,x)
        #screen_changes.append(screen.dimensions)
        screen.print_at(mytext, 1, 1, colour=7, bg=0)
        if screen.has_resized():
            return
        ev = screen.get_key()
        if ev in (ord('Q'), ord('q')):
            quit_script = True
            return
        screen.refresh()
        time.sleep(0.5)

k = 0
while not quit_script:
    Screen.wrapper(demo)
    time.sleep(0.5)

I have one more question: function demo in code above has the only one argument screen. What about situation if I would like to add others arguments to this function and how use wrapper to pass additional params to function demo

[peterbrittain]

Quick answers are that I think you're hitting a race condition in the Windows Console where you are delaying any processing for half a second. Simply removing this delay prevents the issue. And look at the samples for how to use the arguments parameter on wrapper to pass in other parameters to thde demo function.

Finally, could I ask that you please continue any questions in Gitter instead of in this closed issue? For example, go to: https://gitter.im/asciimatics/Lobby