Add stuff to support new bitmap format.

scripts/newbitmaps/lib/bmpblock.py

+#!/usr/bin/python -tt
+# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""A BmpBlock class"""
+
+import os
+import yaml
+
+class BmpBlock(object):
+  """A wrapper for the config.yaml file.
+  It has a few special attributes to specify which part we're focusing on.
+  """
+
+  def __init__(self, filename=None):
+    self.yaml = None
+    self.filename = None
+    self.current_screen = None
+    self.filename = filename                    # always set, so we can reload
+    if filename:
+      self.LoadFile(filename)
+
+  def LoadFile(self, filename):
+    """Load the specified yaml file and verify that it's a valid BmpBlock"""
+    print "Loading", filename
+    with open(filename, 'rb') as f:
+      stuff = yaml.safe_load(f)
+    # FIXME: this is pretty lame

[Randall Spangler, 2011/03/01 17:37:18]

# FIXME: lame that we need to chdir to the same dir as the file?

+    if os.path.dirname(filename):
+      os.chdir(os.path.dirname(filename))
+    if self.IsValidSyntax(stuff):
+      self.yaml = stuff
+      self.current_screen = sorted(self.yaml["screens"].keys())[0]
+
+  def Reload(self):
+    tmp = self.current_screen
+    self.LoadFile(self.filename)
+    if tmp in self.yaml["screens"]:
+      self.current_screen = tmp
+
+  def IsValidSyntax(self, thing):
+    """Raise an error if the specified dict is not a valid BmpBlock structure"""
+
+    assert isinstance(thing, dict)
+    assert thing["bmpblock"] == 1.0
+
+    seen_images = {}
+    seen_screens = {}
+
+    images = thing["images"]
+    assert isinstance(images, dict)
+    assert len(images) > 0
+    # image values should all be filenames (ie, strings)
+    for val in images.values():
+      assert type(val) == str and len(val) > 0

[Randall Spangler, 2011/03/01 17:37:18]

assert val and type(val) == str

(since an empty string evaluates as false)

Or to handle unicode and things that subclass string,

val and isinstance(val, types.StringTypes)

+
+    screens = thing["screens"]
+    assert isinstance(screens, dict)
+    assert len(screens) > 0

[Randall Spangler, 2011/03/01 17:37:18]

Can just assert screens, since empty dict evaluates to false

(similarly in other places below)

+    # screen values should all be lists of 3-tuples
+    for scrname, imglist in screens.items():
+      assert len(imglist) <= 8
+      for img in imglist:
+        assert 3 == len(img)
+        # must have defined all referenced bitmaps
+        x,y,i = img
+        assert i in images
+        seen_images[i] = True
+
+    localizations = thing["localizations"]
+    assert isinstance(localizations, (list, tuple))

[Randall Spangler, 2011/03/01 17:37:18]

Slightly more pythonic way of seeing if something is iterable:

hasattr(localizations,'__iter__')

+    assert len(localizations) > 0
+    # localizations should all be lists with the same number of screens
+    len0 = len(localizations[0])
+    assert len0 > 0
+    for elt in localizations:
+      assert len0 == len(elt)
+      # we must have defined all referenced screens
+      for scr in elt:
+        assert scr in screens
+        seen_screens[scr] = True
+
+    # TODO: should these be fatal?

[Randall Spangler, 2011/03/01 17:37:18]

It'll still work if there are unused images; just wastes space, right?  I'd say
just warn.

+    for unused_img in [x for x in images if x not in seen_images]:
+      print "  Unused image:", unused_img
+    for unused_scr in [x for x in screens if x not in seen_screens]:
+      print "  Unused screen:", unused_scr
+
+    return True
+
+  def RegisterScreenDisplayObject(self, displayer):
+    """Register an object with a .Redisplay() function to display updates."""
+    self.displayer = displayer
+
+
+  def Redisplay(self):
+    """Redisplay contents."""
+    if self.displayer:
+      if self.current_screen:
+        sc = self.yaml['screens'][self.current_screen]
+        slist = [(x,y,self.yaml['images'][z]) for x,y,z in sc]
+        self.displayer.DisplayScreen(self.current_screen, slist)