So here is a semi-live blog as I delve into Kivy.
Mission #1: Attempt to resize the default window
Ok let’s start at the start.
We first create an object that inherits from App. Done.
Ok, and the examples all return a widget from the App’s build() method. So we don’t over-ride __init__… ok… thats… unique.
Perhaps the widget is the window if it is returned from the build() method?
Widget is not the window. Widget returned from build() is added to the window. So… where is the window created?
Window docs state the window has a constructor that lets you set the window size. Ok, cool. But we don’t create the window… so.. we can’t use the constructor… sigh.
Ok, Window has a static accessor.
kivy.core.window.Window = None
No comment on what is stored here but I assume it’s the instantiated window. It doesn’t mention when it is set… handy!
Only 1 window allowed. Ok… weird. Well… let’s try that.
import kivy.core.window.Window
AttributeError: 'module' object has no attribute 'window'
Awesome…
Let’s scour the code.
Screen capture of Kivy window module
No Window.py file……… how far does this rabbit hole go.
Ok, let’s check out the __init__.py file in the window module.
class WindowBase(EventDispatcher):
'''WindowBase is a abstract window widget, for any window implementation.
So… window base is in there. Feel free to scream now.
So we can get this by importing kivy.core.window and just leaving the class off the end.
import kivy.core.window
...
def build(self):
print kivy.core.window.Window.size
return None
(800, 600)
Ok sweet, thats our window.
So let’s change its size.
def build(self):
print kivy.core.window.Window.size
kivy.core.window.Window.size = (1024, 768)
print kivy.core.window.Window.size
return None
File "/Users/adamgriffiths/Workspace/VirtualEnvs/progress_quest/lib/python2.7/site-packages/kivy/core/window/__init__.py", line 243, in _set_size
if super(WindowBase, self)._set_size(size):
AttributeError: 'super' object has no attribute '_set_size'
FFFFFFFUUUUUUUUUUU
Ok, so after some googling we find this post about the relationship between the App and Window classes.
His solution is to pass the size as a command line parameter……….. LAME. That kinda throws the whole configuration settings thing out the window.
Looking through the Kivy code we find this block inside their base window class’ __init__ method.
if 'fullscreen' not in kwargs:
fullscreen = Config.get('graphics', 'fullscreen')
if fullscreen not in ('auto', 'fake'):
fullscreen = fullscreen.lower() in ('true', '1', 'yes', 'yup')
kwargs['fullscreen'] = fullscreen
if 'width' not in kwargs:
kwargs['width'] = Config.getint('graphics', 'width')
if 'height' not in kwargs:
kwargs['height'] = Config.getint('graphics', 'height')
Ok, so we can try and set it via the global config object.
So let’s add that to our App class.
def build_config(self, config):
config.adddefaultsection('graphics')
config.setdefault('graphics', 'width', 1024)
config.setdefault('graphics', 'height', 768)
config.set('graphics', 'height', 1024)
config.set('graphics', 'width', 768)
Run the code and……
(800, 600)
……. sigh
So let’s put some debug INSIDE kivy and see what is happening. We’ll also force it to pull the ‘graphics’ setting and ignore kwargs.
if True: #'width' not in kwargs:
kwargs['width'] = Config.getint('graphics', 'width')
print kwargs['width']
if True: #'height' not in kwargs:
kwargs['height'] = Config.getint('graphics', 'height')
print kwargs['height']
And the output…
800
600
…. calm blue ocean…. calm blue ocean….
Ok… google…
Hmm.. ok, this post on the kivy-users forum (because documentation is for lusers) shows a similar method.
They use the Config module directly instead of the config object passed to App….. because….. they’re not the same? Well.. let’s try it anyway.
from kivy.config import Config
Config.set('graphics', 'width', 1024)
Config.set('graphics', 'height', 768)
And our output
(800, 600)
Ok, weird because the window HAS ACTUALLY CHANGED SIZE.
Whatever. We’re all living in crazy-ville atm so let’s just pretend everything is normal.
So let’s move that inside our build_config() method.
def build_config(self, config):
Config.set('graphics', 'height', 1024)
Config.set('graphics', 'width', 768)
And the output
[INFO ] Kivy v1.1.1
[INFO ] [Logger ] Record log in /Users/adamgriffiths/.kivy/logs/kivy_12-03-22_40.txt
[INFO ] [Factory ] 102 symbols loaded
[INFO ] [Text ] using <pygame> as text provider
[INFO ] [Loader ] using <pygame> as thread loader
[INFO ] [Window ] using <pygame> as window provider
[WARNING] [Window ] Unable to use <pygame> as windowprovider
[CRITICAL] [Window ] Unable to find any valuable Window provider at all!
Fatal Python error: (pygame parachute) Segmentation Fault
Abort trap: 6
(╯°□°）╯︵ ┻━┻
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