Add a tweak that permits setting a style sheet for the selected cell.

resources/default_tweaks.py

@@ -544,3 +544,22 @@ highlight_virtual_library_book_count = True
 # for a list of valid color names
 column_header_highlight_color = 'lightgrey'
 
+#: Control how the currently selected cell is marked.
+# You can control how the currently selected cell is marked using something
+# very similar to a CSS style sheet.
+# This is a very experimental feature. There may be problems using this on some
+# platforms or with some setting values. Some system defaults cannot be
+# overridded. See
+# http://qt-project.org/doc/qt-4.8/stylesheet-reference.html#list-of-properties
+# for a list of the CSS properties that are (in theory) supported.
+# Example: on windows 7 the following style sheet results in a cell with the
+# default background color, black text, and a black border around the cell.
+# selected_cell_highlight_css = ('QTableView::item:focus { '
+#                                    'background:transparent; '
+#                                    'color:black;  '
+#                                    'border: 1px; '
+#                                    'border-style: solid; '
+#                                    'border-color: black; '
+#                                    '}')
+# Default (no style): cell_highlight_css = ''
+selected_cell_highlight_css = ''

src/calibre/gui2/library/views.py

@@ -169,6 +169,9 @@ class BooksView(QTableView): # {{{
         self._model.sorting_done.connect(self.sorting_done,
                 type=Qt.QueuedConnection)
 
+        if tweaks['selected_cell_highlight_css']:
+            self.setStyleSheet(tweaks['selected_cell_highlight_css'])
+
     def currentChanged(self, current, previous):
         self.model().set_current_cell(current)
         QTableView.currentChanged(self, current, previous)