Merge pull request #882 from hbrunn/master-running

[ADD] position: running(); content: element();

docs/features.rst

@@ -313,7 +313,6 @@ according to their position in the document:
 
 The other features of GCPM are **not** implemented:
 
-- running elements (``running()`` and ``element()``);
 - footnotes (``float: footnote``, ``footnote-display``, ``footnote`` counter,
   ``::footnote-call``, ``::footnote-marker``, ``@footnote`` rule,
   ``footnote-policy``);

weasyprint/css/computed_values.py

@@ -497,7 +497,10 @@ def _content_list(computer, values):
         elif value[0] == 'attr()':
             assert value[1][1] == 'string'
             computed_value = compute_attr_function(computer, value)
-        elif value[0] in ('counter()', 'counters()', 'content()', 'string()'):
+        elif value[0] in (
+                'counter()', 'counters()', 'content()', 'element()',
+                'string()',
+        ):
             # Other values need layout context, their computed value cannot be
             # better than their specified value yet.
             # See build.compute_content_list.

weasyprint/css/properties.py

@@ -14,6 +14,7 @@
 from tinycss2.color3 import parse_color
 
 Dimension = collections.namedtuple('Dimension', ['value', 'unit'])
+Running = collections.namedtuple('Running', ['element'])
 
 
 # See http://www.w3.org/TR/CSS21/propidx.html

weasyprint/css/utils.py

@@ -743,3 +743,7 @@ def get_content_list_token(token, base_url):
         elif arg.type == 'string':
             string = arg.value
         return ('leader()', ('string', string))
+    elif name == 'element':
+        if len(args) != 1 or args[0].type != 'ident':
+            return
+        return ('element()', args[0])

weasyprint/css/validation/properties.py

@@ -14,7 +14,7 @@
 
 from ...formatting_structure import counters
 from .. import computed_values
-from ..properties import KNOWN_PROPERTIES, Dimension
+from ..properties import KNOWN_PROPERTIES, Dimension, Running
 from ..utils import (
     InvalidValues, check_var_function, comma_separated_list, get_angle,
     get_content_list, get_content_list_token, get_custom_ident, get_image,
@@ -967,10 +967,17 @@ def text_overflow(keyword):
 
 
 @property()
-@single_keyword
-def position(keyword):
+@single_token
+def position(token):
     """``position`` property validation."""
-    return keyword in ('static', 'relative', 'absolute', 'fixed')
+    if (
+            token.type == 'function' and token.name == 'running' and
+            len(token.arguments) == 1 and token.arguments[0].type == 'ident'
+    ):
+        return Running(token.arguments[0].value)
+    keyword = get_single_keyword([token])
+    if keyword in ('static', 'relative', 'absolute', 'fixed'):
+        return keyword
 
 
 @property()

weasyprint/formatting_structure/boxes.py

@@ -59,7 +59,7 @@
 import itertools
 
 from ..css import computed_from_cascaded
-from ..css.properties import Dimension
+from ..css.properties import Dimension, Running
 
 
 class Box(object):
@@ -274,9 +274,17 @@ def is_absolutely_positioned(self):
         """Return whether this box is in the absolute positioning scheme."""
         return self.style['position'] in ('absolute', 'fixed')
 
+    def is_running(self):
+        """Return whether this box is a running element.
+        (https://www.w3.org/TR/css-gcpm-3/#running-elements)"""
+        return isinstance(self.style['position'], Running)
+
     def is_in_normal_flow(self):
         """Return whether this box is in normal flow."""
-        return not (self.is_floated() or self.is_absolutely_positioned())
+        return not (
+            self.is_floated() or self.is_absolutely_positioned() or
+            self.is_running()
+        )
 
     # Start and end page values for named pages
 
@@ -333,6 +341,14 @@ def copy_with_children(self, new_children, is_start=True, is_end=True):
             new_box._remove_decoration(not is_start, not is_end)
         return new_box
 
+    def __deepcopy__(self):
+        result = self.copy()
+        result.children = tuple([
+            getattr(child, '__deepcopy__', child.copy)()
+            for child in self.children
+        ])
+        return result
+
     def descendants(self):
         """A flat generator for a box, its children and descendants."""
         yield self
@@ -704,3 +720,32 @@ class InlineFlexBox(FlexContainerBox, InlineLevelBox):
     It behaves as inline on the outside and as a flex container on the inside.
 
     """
+
+
+class RunningPlaceholder(BlockBox):
+    """A box to anchor a running element within the document flow"""
+    def __init__(self, identifier, style):
+        self.position_x = 0
+        self.position_y = 0
+        self.width = 0
+        self.height = 0
+        self.padding_left = 0
+        self.padding_right = 0
+        self.padding_top = 0
+        self.padding_bottom = 0
+        self.margin_left = 0
+        self.margin_right = 0
+        self.margin_top = 0
+        self.margin_bottom = 0
+        self.border_left_width = 0
+        self.border_right_width = 0
+        self.border_top_width = 0
+        self.border_bottom_width = 0
+        self.identifier = identifier
+        super(RunningPlaceholder, self).__init__(
+            None, dict(style, display='block', content=[('running', None)]),
+            children=[],
+        )
+
+    def translate(self, dx=0, dy=0, ignore_floats=False):
+        pass

weasyprint/formatting_structure/build.py

@@ -492,6 +492,26 @@ def compute_content_list(content_list, parent_box, counter_values, css_token,
                 texts.append(quotes[min(quote_depth[0], len(quotes) - 1)])
             if is_open:
                 quote_depth[0] += 1
+        elif type_ == 'element()':
+            if value.value not in context.running_elements:
+                # TODO: emit warning
+                continue
+            new_box = None
+            for i in range(context.current_page - 1, -1, -1):
+                if i not in context.running_elements[value.value]:
+                    continue
+                running_box = context.running_elements[value.value][i]
+                new_box = running_box.__deepcopy__()
+                break
+            new_box.style['position'] = 'static'
+            for child in new_box.descendants():
+                if child.style['content'] in ('normal', 'none'):
+                    continue
+                child.children = content_to_boxes(
+                    child.style, child, quote_depth, counter_values,
+                    get_image_from_uri, target_collector, context=context,
+                    page=page)
+            boxlist.append(new_box)
     text = ''.join(texts)
     if text:
         boxlist.append(boxes.TextBox.anonymous_from(parent_box, text))
@@ -1247,7 +1267,7 @@ def inline_in_block(box):
         ]
 
     """
-    if not isinstance(box, boxes.ParentBox):
+    if not isinstance(box, boxes.ParentBox) or box.is_running():
         return box
 
     box_children = list(box.children)
@@ -1382,7 +1402,7 @@ def block_in_inline(box):
         ]
 
     """
-    if not isinstance(box, boxes.ParentBox):
+    if not isinstance(box, boxes.ParentBox) or box.is_running():
         return box
 
     new_children = []

weasyprint/layout/__init__.py

@@ -205,6 +205,9 @@ def __init__(self, enable_hinting, style_for, get_image_from_uri,
         self.tables = {}
         self.dictionaries = {}
 
+        # TODO: this is probably the wrong place to put this
+        self.running_elements = {}
+
     def create_block_formatting_context(self):
         self.excluded_shapes = []
         self._excluded_shapes_lists.append(self.excluded_shapes)

weasyprint/layout/blocks.py

@@ -352,6 +352,15 @@ def block_container_layout(context, box, max_position_y, skip_stack,
                             break
                     resume_at = (index, None)
                     break
+            elif child.is_running():
+                placeholder = boxes.RunningPlaceholder(
+                    child.style['position'].element, child.style,
+                )
+                placeholder.index = index
+                new_children.append(placeholder)
+                context.running_elements.setdefault(
+                    child.style['position'].element, {}
+                )[placeholder] = child
             continue
 
         if isinstance(child, boxes.LineBox):

weasyprint/layout/pages.py

@@ -345,10 +345,11 @@ def make_box(at_keyword, containing_block):
                 box.style, box, quote_depth, counter_values,
                 context.get_image_from_uri, context.target_collector, context,
                 page)
-            # content_to_boxes() only produces inline-level boxes, no need to
-            # run other post-processors from build.build_formatting_structure()
-            box = build.inline_in_block(box)
             build.process_whitespace(box)
+            box = build.anonymous_table_boxes(box)
+            box = build.flex_boxes(box)
+            box = build.inline_in_block(box)
+            box = build.block_in_inline(box)
         resolve_percentages(box, containing_block)
         if not box.is_generated:
             box.width = box.height = 0
@@ -664,6 +665,9 @@ def make_page(context, root_box, page_type, resume_at, page_number,
             if call_parse_again:
                 remake_state['content_changed'] = True
                 counter_lookup.parse_again(page_counter_values)
+        if isinstance(child, boxes.RunningPlaceholder):
+            elements = context.running_elements[child.identifier]
+            elements[page.page_type.index] = elements[child]
 
     if page_type.blank:
         resume_at = previous_resume_at

weasyprint/tests/test_layout/test_page.py

@@ -1214,3 +1214,62 @@ def test_margin_boxes_vertical_align():
     assert line_1.position_y == 3
     assert line_2.position_y == 43
     assert line_3.position_y == 83
+
+
+@assert_no_logs
+def test_margin_boxes_element():
+    pages = render_pages('''
+        <html>
+            <head>
+                <style type="text/css">
+                    .footer {
+                        position: running(footer);
+                    }
+                    @page {
+                        @bottom-center {
+                            content: element(footer);
+                        }
+                    }
+                    h1 {
+                        margin-bottom: 15cm;
+                    }
+                    .page:before {
+                        content: counter(page);
+                    }
+                    .pages:after {
+                        content: counter(pages);
+                    }
+                </style>
+            </head>
+            <body>
+                <div class="footer">
+                    <span class="page" /> of <span class="pages" />
+                </div>
+                <h1>test1</h1>
+                <h1>test2</h1>
+                <h1>test3</h1>
+                <h1>test4</h1>
+                <h1>test5</h1>
+                <h1>test6</h1>
+                <div class="footer">
+                    Last page will be a static footer
+                </div>
+            </body>
+        </html>
+    ''')
+    # first footer
+    footer1_text = ''.join(
+        getattr(node, 'text', '')
+        for node in pages[0].children[1].descendants())
+    assert footer1_text == '1 of 3'
+
+    # second footer
+    footer2_text = ''.join(
+        getattr(node, 'text', '')
+        for node in pages[1].children[1].descendants())
+    assert footer2_text == '2 of 3'
+    # last footer
+    footer3_text = ''.join(
+        getattr(node, 'text', '')
+        for node in pages[2].children[1].descendants())
+    assert footer3_text == 'Last page will be a static footer'