1 files changed, 13 insertions, 10 deletions
diff --git a/pixelcore/Screen.py b/pixelcore/Screen.py
index a6fc8c4..9a81df7 100644
--- a/pixelcore/Screen.py
+++ b/pixelcore/Screen.py
@@ -10,38 +10,40 @@ import itertools
 import sys
 import pdb
 from logger import main_log
-#Class representing a collection of Pixels grouped into PixelStrips.  Needs a
-#PixelMapper, currently set via setMapper by may be migrated into the argDict.
 class Screen:
+    """Class representing a collection of Pixels grouped into PixelStrips.  Needs a
+    PixelMapper, currently set via setMapper by may be migrated into the argDict."""
+    
     def __init__(self):
         self.responseQueue = []
         self.pixelStrips = []
         self.xSortedPixels = []
         self.xPixelLocs = []
         sizeValid = False 
-        
+        self.pixelsSorted = False 
+    
     def addStrip(self, lS):
         self.pixelStrips.append(lS)
         self.sizeValid = False #keep track of whether or not our screen size has
+        self.pixelsSorted = False
         #been invalidated by adding more pixels
-        self.computeXSortedPixels()
         
-    #Returns (pixelIndex, pixel).  Does a binary search.
     def pixelsInRange(self, minX, maxX):
+        """Returns (pixelIndex, pixel).  Does a binary search."""
+        if not self.pixelsSorted:
+            self.computeXSortedPixels()
         minIndex = Search.find_ge(self.xPixelLocs, minX) 
         maxIndex = Search.find_le(self.xPixelLocs, maxX)+1
         return self.xSortedPixels[minIndex:maxIndex]
         
     def computeXSortedPixels(self):
+        self.xSortedPixels = []
         for pixel in self:
             self.xSortedPixels.append((pixel.location[0], pixel))
         self.xSortedPixels.sort()
         self.xPixelLocs = [p[0] for p in self.xSortedPixels]
-        
-    #For debug only    
-    def allOn(self):
-        [lS.allOn(-1) for lS in self.pixelStrips]
-        
+        self.pixelsSorted = True 
+    
     def __iter__(self): #the iterator of all our pixel strips chained togther
         return itertools.chain(*[strip.__iter__() for strip in \
             self.pixelStrips]) #the * operator breaks the list into args 
@@ -77,6 +79,7 @@ class Screen:
             maxY = max(y, maxY)
         self.size = (0,0, maxX, maxY)
         self.sizeValid = True
+        print self.size
         return (0, 0, maxX+100, maxY+100) #TODO: cleaner
         
     #private