Unfreeze StyleDict

weasyprint/css/__init__.py

@@ -69,14 +69,17 @@
 
 
 class StyleDict(dict):
-    """A frozen dict that allows attribute access to values.
+    """A dict allowing attribute access to values.
 
     Allow eg. ``style.font_size`` instead of ``style['font-size']``.
 
     """
 
-    # Hide modification
-    __setitem__ = update = None
+    # TODO: this dict should be frozen, but modification is currently
+    # authorized for some corner cases when building the structure:
+    # - table wrapping,
+    # - border modification for tables with collapsing borders, and
+    # - viewport overflow.
 
     # TODO: We should remove that. Some attributes (eg. "clear") exist as
     # dict methods and can only be accessed with getitem.
@@ -86,21 +89,6 @@ def get_color(self, key):
         value = self[key]
         return value if value != 'currentColor' else self['color']
 
-    def copy(self, update):
-        """Copy the ``StyleDict`` with updated values."""
-        # Don't copy when the updated values are already set
-        for key, value in update.items():
-            if self[key] != value:
-                break
-        else:
-            return self
-
-        style = dict(self)
-        style.update(update)
-        style = type(self)(style)
-        style.anonymous = self.anonymous
-        return style
-
     def inherit_from(self):
         """Return a new StyleDict with inherited properties from this one.
 

weasyprint/formatting_structure/build.py

@@ -636,14 +636,9 @@ def wrap_table(box, children):
         # Non-inherited properties of the table element apply to one
         # of the wrapper and the table. The other get the initial value.
         # TODO: put this in a method of the table object
-        wrapper_style = {
-            name: table.style[name]
-            for name in properties.TABLE_WRAPPER_BOX_PROPERTIES}
-        table_style = {
-            name: properties.INITIAL_VALUES[name]
-            for name in properties.TABLE_WRAPPER_BOX_PROPERTIES}
-        wrapper.style = wrapper.style.copy(wrapper_style)
-        table.style = table.style.copy(table_style)
+        for name in properties.TABLE_WRAPPER_BOX_PROPERTIES:
+            wrapper.style[name] = table.style[name]
+            table.style[name] = properties.INITIAL_VALUES[name]
     # else: non-inherited properties already have their initial values
 
     return wrapper
@@ -747,10 +742,9 @@ def set_borders(box, x, y, w, h):
     # the correct widths on each box. The actual border grid will be
     # painted separately.
     def set_transparent_border(box, side, twice_width):
-        box.style = box.style.copy({
-            'border_%s_style' % side: 'solid',
-            'border_%s_width' % side: twice_width / 2,
-            'border_%s_color' % side: transparent})
+        box.style['border_%s_style' % side] = 'solid',
+        box.style['border_%s_width' % side] = twice_width / 2
+        box.style['border_%s_color' % side] = transparent
 
     def remove_borders(box):
         set_transparent_border(box, 'top', 0)
@@ -1125,7 +1119,7 @@ def set_viewport_overflow(root_box):
                 break
 
     root_box.viewport_overflow = chosen_box.style.overflow
-    chosen_box.style = chosen_box.style.copy({'overflow': 'visible'})
+    chosen_box.style['overflow'] = 'visible'
     return root_box
 
 

weasyprint/layout/inlines.py

@@ -282,13 +282,14 @@ def first_letter_to_box(box, skip_stack, first_letter_style):
                     # "This type of initial letter is similar to an
                     # inline-level element if its 'float' property is 'none',
                     # otherwise it is similar to a floated element."
+                    letter_box_inherit = letter_box.style.inherit_from()
                     if first_letter_style['float'] == 'none':
                         letter_box = boxes.InlineBox(
                             '%s::first-letter' % box.element_tag,
                             first_letter_style, [])
                         text_box = boxes.TextBox(
                             '%s::first-letter' % box.element_tag,
-                            letter_box.style.inherit_from(), first_letter)
+                            letter_box_inherit, first_letter)
                         letter_box.children = (text_box,)
                         box.children = (letter_box,) + tuple(box.children)
                     else:
@@ -298,11 +299,11 @@ def first_letter_to_box(box, skip_stack, first_letter_style):
                         letter_box.first_letter_style = None
                         line_box = boxes.LineBox(
                             '%s::first-letter' % box.element_tag,
-                            letter_box.style.inherit_from(), [])
+                            letter_box_inherit, [])
                         letter_box.children = (line_box,)
                         text_box = boxes.TextBox(
                             '%s::first-letter' % box.element_tag,
-                            letter_box.style.inherit_from(), first_letter)
+                            letter_box_inherit, first_letter)
                         line_box.children = (text_box,)
                         box.children = (letter_box,) + tuple(box.children)
                     if skip_stack and child_skip_stack: