First "real" version of billboard.

README.md

@@ -0,0 +1,30 @@
+## billboard
+
+Periodically pulls images and text from Reddit and displays them full-screen. 
+Inspired by
+
+http://imgur.com/a/Io3xi
+
+
+### Note
+
+This requires PyQt4 to be installed on the system. It seems it currently cannot
+be deployed with pip, so it's not mentioned in the dependencies.
+
+
+### TODO
+
+- Currently a buch of stuff is hard-coded that should be configurable (e.g.
+  subpreddits to pull images/text from)
+- Add more sources (currenltly, only Reddit)
+- An ability to remotely send images/text to the billboard for immediate display
+- Support Python 2
+- Switch to PyQt5
+- ...
+
+
+### LICENSE
+
+3-clause BSD
+
+

billboard/app.py

@@ -0,0 +1,37 @@
+import sys
+import argparse
+
+from PyQt4.QtGui import QApplication
+
+from billboard.billboard import Billboard
+from billboard.display import BillboardDisplay
+from billboard.sources.reddit import RedditSource
+
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-p', '--period', type=int, default=60*15,
+                        help='''
+                        Period for switching billboard display in seconds.
+                        Defaults to 15 minutes.
+                        ''')
+    return parser.parse_args(sys.argv[1:])
+
+
+def main():
+    args = parse_args()
+    app = QApplication(sys.argv)
+
+    display = BillboardDisplay()
+    sources = [RedditSource()]
+
+    billboard = Billboard(display, sources, args.period)
+
+    billboard.start()
+    display.show()
+    app.exec_()
+
+
+if __name__ == '__main__':
+    main()
+

billboard/billboard.py

@@ -0,0 +1,24 @@
+import time
+from threading import Thread
+from itertools import cycle
+
+
+class Billboard(Thread):
+
+    def __init__(self, display, sources, period):
+        super(Billboard, self).__init__()
+        self.display = display
+        self.sources = sources
+        self.period = period
+        self.daemon = True
+
+    def run(self):
+        for source in cycle(self.sources):
+            image, text = source.next()
+            if image is None and text is None:
+                continue
+            if image is not None:
+                self.display.update_image(image)
+            if text is not None:
+                self.display.display_text(text)
+            time.sleep(self.period)

billboard/display.py

@@ -0,0 +1,59 @@
+import os
+
+from PyQt4.QtCore import Qt, QObject, SIGNAL
+from PyQt4.QtGui import (QMainWindow, QWidget, QPixmap, QLabel,
+                         QGraphicsDropShadowEffect, QColor,
+                         QDesktopWidget)
+
+
+class BillboardDisplay(QMainWindow):
+
+    def __init__(self, parent=None, fontsize=42):
+        super(BillboardDisplay, self).__init__(parent)
+        desktop = QDesktopWidget()
+        self.display = QWidget(self)
+        size  = desktop.availableGeometry(desktop.primaryScreen());
+        self.display.resize(size.width(), size.height())
+        self.display.setWindowTitle("Billboard")
+
+        self.image_label = QLabel(self.display)
+        self.image_label.resize(size.width(), size.height())
+
+        self.text_label = QLabel(self.display)
+        self.text_label.resize(size.width(), size.height())
+        self.text_label.setMargin(100)
+        self.text_label.setStyleSheet('''
+            QLabel {{
+                        font-size: {}pt;
+                        color: #eeeeee;
+                        text-align: center;
+                    }}
+        '''.format(fontsize))
+        self.text_label.setWordWrap(True)
+        self.text_label.setAlignment(Qt.AlignCenter)
+
+        dse = QGraphicsDropShadowEffect()
+        dse.setBlurRadius(10)
+        dse.setXOffset(0)
+        dse.setYOffset(0)
+        dse.setColor(QColor(0, 0, 0, 255))
+        self.text_label.setGraphicsEffect(dse)
+        QObject.connect(self, SIGNAL("updateimage"),
+                        self.display_image)
+
+    def update_image(self, imagepath):
+        self.emit(SIGNAL("updateimage"), imagepath)
+
+    def display(self, imagepath, text):
+        self.display_text(text)
+        self.display_image(imagepath)
+        self.showFullScreen()
+
+    def display_image(self, imagepath):
+        pix = QPixmap(imagepath)
+        self.image_label.setPixmap(pix.scaled(self.display.size(),
+                                              Qt.KeepAspectRatioByExpanding))
+
+    def display_text(self, text):
+        self.text_label.setText('"{}"'.format(text))
+

proof_of_concept.py → billboard/sources/reddit.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 import os
 import sys
 import shutil
@@ -7,18 +6,17 @@
 
 import praw
 import requests
-from PyQt4.QtCore import Qt
-from PyQt4.QtGui import QApplication, QWidget, QPixmap, QLabel
-from PyQt4.QtGui import QGraphicsDropShadowEffect, QColor
 
+from billboard.utils import DroppingSet
 
-class ImageGetter():
+
+class ImageGetter:
 
     def __init__(self, reddit, subreddit='earthporn', aspect_ratio=1.6):
         self.reddit = reddit
         self.subreddit = subreddit
         self.aspect_ratio = aspect_ratio
-        self._seen = set()
+        self._seen = DroppingSet(50)
 
     def get_image(self, path):
         try:
@@ -46,7 +44,7 @@ def _get_image_url(self, subs):
                 return source['url']
 
 
-class TextGetter():
+class TextGetter:
 
     def __init__(self, reddit, subreddit='showerthoughts', badlist='bad-words.txt'):
         self.reddit = reddit
@@ -56,7 +54,7 @@ def __init__(self, reddit, subreddit='showerthoughts', badlist='bad-words.txt'):
                 self.bad_words = fh.read().splitlines()
         else:
             self.bad_words = []
-        self._seen = set()
+        self._seen = DroppingSet(50)
 
     def get_text(self):
         try:
@@ -75,60 +73,20 @@ def get_text(self):
             return None
 
 
-def show_billboard(imagepath, text, fontsize=42):
-    app = QApplication(sys.argv)
-    w = QWidget()
-    w.resize(1600, 1000)
-    w.setWindowTitle("Billboard")
-
-    pix = QPixmap(imagepath)
-
-    image_label = QLabel(w)
-    image_label.resize(1600, 1000)
-    image_label.setPixmap(pix.scaled(w.size(), Qt.KeepAspectRatioByExpanding))
-
-    text_label = QLabel(w)
-    text_label.resize(1600, 1000)
-    text_label.setMargin(100)
-    text_label.setText('"{}"'.format(text))
-    text_label.setStyleSheet('''
-        QLabel {{
-                    font-size: {}pt;
-                    color: #eeeeee;
-                    text-align: center;
-                }}
-    '''.format(fontsize))
-    text_label.setWordWrap(True)
-    text_label.setAlignment(Qt.AlignCenter)
-
-    dse = QGraphicsDropShadowEffect()
-    dse.setBlurRadius(10)
-    dse.setXOffset(0)
-    dse.setYOffset(0)
-    dse.setColor(QColor(0, 0, 0, 255))
-    text_label.setGraphicsEffect(dse)
-
-    w.show()
-    app.exec_()
-
-
-def main():
-    reddit = praw.Reddit(user_agent='billboard')
-    imagegetter = ImageGetter(reddit)
-    textgetter = TextGetter(reddit)
-
-    image_path = tempfile.mktemp()
-    if not imagegetter.get_image(image_path):
-        logging.error("Did not find a suitable image.")
-        sys.exit(1)
-    text = textgetter.get_text()
-    if not text:
-        logging.error("Did not find a suitable text.")
-        sys.exit(1)
-
-    show_billboard(image_path, text)
-    os.unlink(image_path)
+class RedditSource:
 
+    def __init__(self):
+        self.reddit = praw.Reddit(user_agent='billboard')
+        self.imagegetter = ImageGetter(self.reddit)
+        badlist = os.path.join(os.path.dirname(__file__), 'bad-words.txt')
+        self.textgetter = TextGetter(self.reddit, badlist=badlist)
+        self.image_path = tempfile.mktemp()
+        self.logger = logging.getLogger('reddit')
 
-if __name__ == '__main__':
-    main()
+    def next(self):
+        if not self.imagegetter.get_image(self.image_path):
+            self.logger.error("Did not find a suitable image.")
+        text = self.textgetter.get_text()
+        if not text:
+            self.logger.error("Did not find a suitable text.")
+        return self.image_path, text

billboard/utils.py

@@ -0,0 +1,81 @@
+from collections import MutableSet
+
+# based on OrderedSet recipe:
+#     https://code.activestate.com/recipes/576694/
+class DroppingSet(MutableSet):
+    """
+    A set with a maximum size. It keeps track of the order in which elements
+    are added. Once max_size is reached, oldest elements are dropped.
+
+
+    """
+
+    @property
+    def max_size(self):
+        return self._max_size
+
+    @max_size.setter
+    def max_size(self, value):
+        self._max_size = value
+        while len(self) > self._max_size:
+            self.pop(last=False)
+
+    def __init__(self, max_size, iterable=None):
+        self._max_size = max_size
+        self.end = end = []
+        end += [None, end, end]         # sentinel node for doubly linked list
+        self.map = {}                   # key --> [key, prev, next]
+        if iterable is not None:
+            self |= iterable
+
+    def __len__(self):
+        return len(self.map)
+
+    def __contains__(self, key):
+        return key in self.map
+
+    def add(self, key):
+        while len(self) >= self.max_size:
+            self.pop(last=False)
+        if key not in self.map:
+            end = self.end
+            curr = end[1]
+            curr[2] = end[1] = self.map[key] = [key, curr, end]
+
+    def discard(self, key):
+        if key in self.map:
+            key, prev, next = self.map.pop(key)
+            prev[2] = next
+            next[1] = prev
+
+    def __iter__(self):
+        end = self.end
+        curr = end[2]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[2]
+
+    def __reversed__(self):
+        end = self.end
+        curr = end[1]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[1]
+
+    def pop(self, last=True):
+        if not self:
+            raise KeyError('set is empty')
+        key = self.end[1][0] if last else self.end[2][0]
+        self.discard(key)
+        return key
+
+    def __repr__(self):
+        if not self:
+            return '%s()' % (self.__class__.__name__,)
+        return '%s(%r)' % (self.__class__.__name__, list(self))
+
+    def __eq__(self, other):
+        if isinstance(other, OrderedSet):
+            return len(self) == len(other) and list(self) == list(other)
+        return set(self) == set(other)
+

scripts/billboard

@@ -0,0 +1,3 @@
+#!/usr/bin/env python3
+from billboard.app import main
+main()