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LibWeb: Parse grid track placements using TokenStream

I'm not entirely happy with this, but I barely understand grid, and this
does still work.
This commit is contained in:
Sam Atkins 2023-12-08 12:07:48 +00:00 committed by Sam Atkins
parent b172c29d9a
commit 14e2e2bac4
2 changed files with 74 additions and 50 deletions

View file

@ -5376,8 +5376,12 @@ RefPtr<StyleValue> Parser::parse_grid_auto_track_sizes(Vector<ComponentValue> co
return GridTrackSizeListStyleValue::create(CSS::GridTrackSizeList(track_list, {}));
}
RefPtr<StyleValue> Parser::parse_grid_track_placement(Vector<ComponentValue> const& component_values)
RefPtr<StyleValue> Parser::parse_grid_track_placement(TokenStream<ComponentValue>& tokens)
{
// FIXME: This shouldn't be needed. Right now, the below code returns a StyleValue even if no tokens are consumed!
if (!tokens.has_next_token())
return nullptr;
// https://www.w3.org/TR/css-grid-2/#line-placement
// Line-based Placement: the grid-row-start, grid-column-start, grid-row-end, and grid-column-end properties
// <grid-line> =
@ -5391,59 +5395,65 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement(Vector<ComponentValue> con
return true;
return false;
};
auto is_identifier = [](auto& token) -> bool {
auto is_custom_ident = [](auto& token) -> bool {
// The <custom-ident> additionally excludes the keywords span and auto.
if (token.is(Token::Type::Ident) && !token.token().ident().equals_ignoring_ascii_case("span"sv) && !token.token().ident().equals_ignoring_ascii_case("auto"sv))
if (token.is(Token::Type::Ident) && !token.is_ident("span"sv) && !token.is_ident("auto"sv))
return true;
return false;
};
auto tokens = TokenStream { component_values };
tokens.skip_whitespace();
auto current_token = tokens.next_token();
auto transaction = tokens.begin_transaction();
if (!tokens.has_next_token()) {
if (current_token.is_ident("auto"sv))
// FIXME: Handle the single-token case inside the loop instead, so that we can more easily call this from
// `parse_grid_area_shorthand_value()` using a single TokenStream.
if (tokens.remaining_token_count() == 1) {
auto& token = tokens.next_token();
if (token.is_ident("auto"sv)) {
transaction.commit();
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_auto());
if (current_token.is_ident("span"sv))
}
if (token.is_ident("span"sv)) {
transaction.commit();
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_span(1));
if (is_valid_integer(current_token))
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line(static_cast<int>(current_token.token().number_value()), {}));
if (is_identifier(current_token))
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line({}, current_token.token().to_string()));
}
if (is_valid_integer(token)) {
transaction.commit();
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line(static_cast<int>(token.token().number_value()), {}));
}
if (is_custom_ident(token)) {
transaction.commit();
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line({}, token.token().ident().to_string()));
}
return nullptr;
}
auto span_value = false;
auto span_or_position_value = 0;
String identifier_value;
while (true) {
if (current_token.is_ident("auto"sv))
while (tokens.has_next_token()) {
auto& token = tokens.peek_token();
if (token.is_ident("auto"sv))
return nullptr;
if (current_token.is_ident("span"sv)) {
if (span_value == false)
span_value = true;
else
if (token.is_ident("span"sv)) {
if (span_value)
return nullptr;
(void)tokens.next_token(); // span
span_value = true;
continue;
}
if (is_valid_integer(current_token)) {
if (span_or_position_value == 0)
span_or_position_value = static_cast<int>(current_token.token().number_value());
else
if (is_valid_integer(token)) {
if (span_or_position_value != 0)
return nullptr;
span_or_position_value = static_cast<int>(tokens.next_token().token().to_integer());
continue;
}
if (is_identifier(current_token)) {
if (identifier_value.is_empty()) {
identifier_value = current_token.token().ident().to_string();
} else {
if (is_custom_ident(token)) {
if (!identifier_value.is_empty())
return nullptr;
}
identifier_value = tokens.next_token().token().ident().to_string();
continue;
}
tokens.skip_whitespace();
if (tokens.has_next_token())
current_token = tokens.next_token();
else
break;
break;
}
// Negative integers or zero are invalid.
@ -5454,6 +5464,7 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement(Vector<ComponentValue> con
if (span_or_position_value == 0)
span_or_position_value = 1;
transaction.commit();
if (!identifier_value.is_empty())
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_line(span_or_position_value, identifier_value));
return GridTrackPlacementStyleValue::create(GridTrackPlacement::make_span(span_or_position_value));
@ -5488,7 +5499,8 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement_shorthand_value(PropertyID
}
}
auto parsed_start_value = parse_grid_track_placement(track_start_placement_tokens);
TokenStream track_start_placement_token_stream { track_start_placement_tokens };
auto parsed_start_value = parse_grid_track_placement(track_start_placement_token_stream);
if (parsed_start_value && track_end_placement_tokens.is_empty()) {
transaction.commit();
return ShorthandStyleValue::create(property_id,
@ -5496,7 +5508,8 @@ RefPtr<StyleValue> Parser::parse_grid_track_placement_shorthand_value(PropertyID
{ parsed_start_value.release_nonnull(), GridTrackPlacementStyleValue::create(GridTrackPlacement::make_auto()) });
}
auto parsed_end_value = parse_grid_track_placement(track_end_placement_tokens);
TokenStream track_end_placement_token_stream { track_end_placement_tokens };
auto parsed_end_value = parse_grid_track_placement(track_end_placement_token_stream);
if (parsed_start_value && parsed_end_value) {
transaction.commit();
return ShorthandStyleValue::create(property_id,
@ -5559,15 +5572,11 @@ RefPtr<StyleValue> Parser::parse_grid_area_shorthand_value(TokenStream<Component
auto transaction = tokens.begin_transaction();
auto parse_placement_tokens = [&](Vector<ComponentValue>& placement_tokens, bool check_for_delimiter = true) -> void {
auto current_token = tokens.next_token();
while (true) {
while (tokens.has_next_token()) {
auto& current_token = tokens.next_token();
if (check_for_delimiter && current_token.is_delim('/'))
break;
placement_tokens.append(current_token);
tokens.skip_whitespace();
if (!tokens.has_next_token())
break;
current_token = tokens.next_token();
}
};
@ -5589,10 +5598,25 @@ RefPtr<StyleValue> Parser::parse_grid_area_shorthand_value(TokenStream<Component
// https://www.w3.org/TR/css-grid-2/#placement-shorthands
// The grid-area property is a shorthand for grid-row-start, grid-column-start, grid-row-end and
// grid-column-end.
auto row_start_style_value = parse_grid_track_placement(row_start_placement_tokens);
auto column_start_style_value = parse_grid_track_placement(column_start_placement_tokens);
auto row_end_style_value = parse_grid_track_placement(row_end_placement_tokens);
auto column_end_style_value = parse_grid_track_placement(column_end_placement_tokens);
TokenStream row_start_placement_token_stream { row_start_placement_tokens };
auto row_start_style_value = parse_grid_track_placement(row_start_placement_token_stream);
if (row_start_placement_token_stream.has_next_token())
return nullptr;
TokenStream column_start_placement_token_stream { column_start_placement_tokens };
auto column_start_style_value = parse_grid_track_placement(column_start_placement_token_stream);
if (column_start_placement_token_stream.has_next_token())
return nullptr;
TokenStream row_end_placement_token_stream { row_end_placement_tokens };
auto row_end_style_value = parse_grid_track_placement(row_end_placement_token_stream);
if (row_end_placement_token_stream.has_next_token())
return nullptr;
TokenStream column_end_placement_token_stream { column_end_placement_tokens };
auto column_end_style_value = parse_grid_track_placement(column_end_placement_token_stream);
if (column_end_placement_token_stream.has_next_token())
return nullptr;
// If four <grid-line> values are specified, grid-row-start is set to the first value, grid-column-start
// is set to the second value, grid-row-end is set to the third value, and grid-column-end is set to the
@ -5833,11 +5857,11 @@ Parser::ParseErrorOr<NonnullRefPtr<StyleValue>> Parser::parse_css_value(Property
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridColumnEnd:
if (auto parsed_value = parse_grid_track_placement(component_values))
if (auto parsed_value = parse_grid_track_placement(tokens); parsed_value && !tokens.has_next_token())
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridColumnStart:
if (auto parsed_value = parse_grid_track_placement(component_values))
if (auto parsed_value = parse_grid_track_placement(tokens); parsed_value && !tokens.has_next_token())
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridRow:
@ -5845,11 +5869,11 @@ Parser::ParseErrorOr<NonnullRefPtr<StyleValue>> Parser::parse_css_value(Property
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridRowEnd:
if (auto parsed_value = parse_grid_track_placement(component_values))
if (auto parsed_value = parse_grid_track_placement(tokens); parsed_value && !tokens.has_next_token())
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridRowStart:
if (auto parsed_value = parse_grid_track_placement(component_values))
if (auto parsed_value = parse_grid_track_placement(tokens); parsed_value && !tokens.has_next_token())
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Grid: