Make the cover grid re-useable

src/pyj/book_list/cover_grid.pyj

@@ -2,17 +2,15 @@
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 from __python__ import hash_literals, bound_methods
 
-from dom import clear, set_css, build_rule, unique_id
+from dom import clear, set_css, build_rule
 from elementmaker import E
 from gettext import gettext as _
 
 THUMBNAIL_MAX_WIDTH = 300
 THUMBNAIL_MAX_HEIGHT = 400
 
-COVER_GRID = unique_id('cover-grid')
-
 def cover_grid_css():
-    sel = '#' + COVER_GRID
+    sel = '#' + this
     ans = build_rule(sel, display='flex', flex_wrap='wrap', justify_content='space-around', align_items='flex-end', align_content='flex-start', user_select='none', overflow='hidden')
 
     sel += ' > div'
@@ -29,7 +27,7 @@ def cover_grid_css():
 
 def init(container):
     clear(container)
-    container.appendChild(E.div(id=COVER_GRID))
+    container.appendChild(E.div(id=this))
 
 def on_img_load_error(err):
     img = err.target

src/pyj/book_list/views.pyj

@@ -4,7 +4,7 @@ from __python__ import hash_literals
 
 import traceback
 from ajax import ajax_send
-from dom import set_css, add_extra_css
+from dom import set_css, add_extra_css, unique_id
 from elementmaker import E
 from gettext import gettext as _
 from modals import error_dialog, ajax_progress_dialog
@@ -16,9 +16,10 @@ from widgets import create_button, create_spinner
 bv_counter = 0
 
 CLASS_NAME = 'books-main-list'
+COVER_GRID = unique_id('cover-grid')
 
 add_extra_css(def():
-    ans = cover_grid_css()
+    ans = cover_grid_css.call(COVER_GRID)
     return ans
 )
 
@@ -65,7 +66,7 @@ class BooksView:
         self.mode = mode
         if mode is 'cover_grid':
             self.render_book = create_cover_grid_item
-            self.init_grid = init_cover_grid
+            self.init_grid = init_cover_grid.bind(COVER_GRID)
             self.append_item = cover_grid_append_item
         self.clear()
         self.render_ids()