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| from kivy.animation import Animation | |
| from kivy.network.urlrequest import UrlRequest | |
| from functools import partial | |
| from kivy.uix.image import Image | |
| from kivy.properties import StringProperty | |
| from kivy.clock import Clock | |
| from kivy.core.image import Image as CoreImage | |
| from io import BytesIO | |
| class RemoteImage(Image): | |
| """ | |
| This class (attempts to) provide an alternative to the Kivy AsyncImage that | |
| does not glitch when displayed in CAMIScreens. | |
| """ | |
| remote_source = StringProperty() | |
| ''' Specifies the URL for the remove image to be downloaded. ''' | |
| default_source = StringProperty('graphics/question.png') | |
| ''' Specifies the image to use if the download fails. ''' | |
| _requests = {} | |
| ''' | |
| In order to prevent duplicate requests for the the same resource, we | |
| maintain a dictionary tracking what images have been requested, their | |
| raw data and a list of RemoteImages waiting for the same data. e.g | |
| {'http://coolness.com/im.png': {'data': '<raw png data>', | |
| {'waiting': [wid1, wid2....]}} | |
| ''' | |
| def __init__(self, **kwargs): | |
| super(RemoteImage, self).__init__(**kwargs) | |
| # Not sure why, but it seems we have to delay the setting or source for | |
| # the trophy screens. Setting it immediately gives us a black area | |
| Clock.schedule_once(lambda dt: self._set_image('graphics/download.png'), | |
| False) | |
| self._start_animation(True) | |
| def _data_arrived(self, req, resp, state): | |
| """ The data has arrived back from the UrlRequest. """ | |
| if state: | |
| from kivy.logger import Logger | |
| Logger.warn("camiasyncimage.py: Download of image failed. " | |
| "resp={0}".format(resp)) | |
| Clock.schedule_once( | |
| lambda dt: self._set_image(self.default_source, True), 0.1) | |
| else: | |
| req = RemoteImage._requests[self.remote_source] | |
| if req['data'] is None: | |
| # Send the data to the images the are waiting for it | |
| [img.set_image_data(resp) for img in req['waiting']] | |
| req['data'] = resp | |
| req['waiting'] = [] | |
| self.set_image_data(resp) | |
| def _set_image(self, source, stop_anim=False): | |
| """ Set the image source property. """ | |
| self.source = source | |
| if stop_anim: | |
| self._stop_animation() | |
| def set_image_data(self, resp): | |
| """ Set the image data based on the raw data from the webserver. """ | |
| resp = BytesIO(resp) | |
| self._coreimage = ci = CoreImage(resp, | |
| ext="png", | |
| mipmap=self.mipmap, | |
| anim_delay=self.anim_delay, | |
| keep_data=self.keep_data, | |
| nocache=self.nocache) | |
| ci.bind(on_texture=self._on_tex_change) | |
| self.texture = ci.texture | |
| self._stop_animation() | |
| def _start_animation(self, fade_out): | |
| """ Start the animation and keep it looping. """ | |
| anim = Animation(opacity=0 if fade_out else 1, duration=0.75) | |
| anim.bind(on_complete=lambda w, v: self._start_animation(not fade_out)) | |
| anim.start(self) | |
| def _stop_animation(self): | |
| """ Stop all animation on the widget. """ | |
| Animation.cancel_all(self) | |
| self.opacity = 1 | |
| def on_remote_source(self, widget, value): | |
| """ Respond to the change of source image. This should be a URL. """ | |
| if value[0:4] == "http": | |
| req = RemoteImage._requests | |
| if value in req: | |
| # The URL has been requested. | |
| if req[value]['data'] is None: | |
| req[value]['waiting'].append(self) | |
| else: | |
| Clock.schedule_once( | |
| lambda dt: self.set_image_data(req[value]['data']), | |
| 0.1) | |
| else: | |
| req[value] = {'data': None, 'waiting': []} | |
| UrlRequest(value, | |
| partial(self._data_arrived, state=""), | |
| partial(self._data_arrived, state="redirected"), | |
| partial(self._data_arrived, state="failed"), | |
| partial(self._data_arrived, state="error")) | |
| else: | |
| # Delay the call by 0.1 to prevent the initial clock scheduling from | |
| # interfering. | |
| Clock.schedule_once( | |
| lambda dt: self._set_image(self.default_source, True), 0.1) |
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