servo/components/style/legacy.rs

214 lines
12 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//! Legacy presentational attributes defined in the HTML5 specification: `<td width>`,
//! `<input size>`, and so forth.
use node::{TElement, TElementAttributes, TNode};
use properties::{BackgroundColorDeclaration, BorderBottomWidthDeclaration};
use properties::{BorderLeftWidthDeclaration, BorderRightWidthDeclaration};
use properties::{BorderTopWidthDeclaration, SpecifiedValue, WidthDeclaration, specified};
use selector_matching::{DeclarationBlock, Stylist};
use cssparser::RGBAColor;
use servo_util::geometry::Au;
use servo_util::smallvec::VecLike;
use servo_util::str::{AutoLpa, LengthLpa, PercentageLpa};
/// Legacy presentational attributes that take a length as defined in HTML5 § 2.4.4.4.
pub enum LengthAttribute {
/// `<td width>`
WidthLengthAttribute,
}
/// Legacy presentational attributes that take an integer as defined in HTML5 § 2.4.4.2.
pub enum IntegerAttribute {
/// `<input size>`
SizeIntegerAttribute,
}
/// Legacy presentational attributes that take a nonnegative integer as defined in HTML5 § 2.4.4.2.
pub enum UnsignedIntegerAttribute {
/// `<td border>`
BorderUnsignedIntegerAttribute,
/// `<td colspan>`
ColSpanUnsignedIntegerAttribute,
}
/// Legacy presentational attributes that take a simple color as defined in HTML5 § 2.4.6.
pub enum SimpleColorAttribute {
/// `<body bgcolor>`
BgColorSimpleColorAttribute,
}
/// Extension methods for `Stylist` that cause rules to be synthesized for legacy attributes.
pub trait PresentationalHintSynthesis {
/// Synthesizes rules from various HTML attributes (mostly legacy junk from HTML4) that confer
/// *presentational hints* as defined in the HTML5 specification. This handles stuff like
/// `<body bgcolor>`, `<input size>`, `<td width>`, and so forth.
///
/// NB: Beware! If you add an attribute to this list, be sure to add it to
/// `common_style_affecting_attributes` or `rare_style_affecting_attributes` as appropriate. If
/// you don't, you risk strange random nondeterministic failures due to false positives in
/// style sharing.
fn synthesize_presentational_hints_for_legacy_attributes<'a,E,N,V>(
&self,
node: &N,
matching_rules_list: &mut V,
shareable: &mut bool)
where E: TElement<'a> +
TElementAttributes,
N: TNode<'a,E>,
V: VecLike<DeclarationBlock>;
/// Synthesizes rules for the legacy `bgcolor` attribute.
fn synthesize_presentational_hint_for_legacy_background_color_attribute<'a,E,V>(
&self,
element: E,
matching_rules_list:
&mut V,
shareable: &mut bool)
where
E: TElement<'a> +
TElementAttributes,
V: VecLike<
DeclarationBlock>;
/// Synthesizes rules for the legacy `border` attribute.
fn synthesize_presentational_hint_for_legacy_border_attribute<'a,E,V>(
&self,
element: E,
matching_rules_list: &mut V,
shareable: &mut bool)
where
E: TElement<'a> +
TElementAttributes,
V: VecLike<DeclarationBlock>;
}
impl PresentationalHintSynthesis for Stylist {
fn synthesize_presentational_hints_for_legacy_attributes<'a,E,N,V>(
&self,
node: &N,
matching_rules_list: &mut V,
shareable: &mut bool)
where E: TElement<'a> +
TElementAttributes,
N: TNode<'a,E>,
V: VecLike<DeclarationBlock> {
let element = node.as_element();
match element.get_local_name() {
name if *name == atom!("td") => {
match element.get_length_attribute(WidthLengthAttribute) {
AutoLpa => {}
PercentageLpa(percentage) => {
let width_value = specified::LPA_Percentage(percentage);
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
WidthDeclaration(SpecifiedValue(width_value))));
*shareable = false
}
LengthLpa(length) => {
let width_value = specified::LPA_Length(specified::Au_(length));
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
WidthDeclaration(SpecifiedValue(width_value))));
*shareable = false
}
}
self.synthesize_presentational_hint_for_legacy_background_color_attribute(
element,
matching_rules_list,
shareable);
self.synthesize_presentational_hint_for_legacy_border_attribute(
element,
matching_rules_list,
shareable);
}
name if *name == atom!("table") => {
self.synthesize_presentational_hint_for_legacy_background_color_attribute(
element,
matching_rules_list,
shareable);
self.synthesize_presentational_hint_for_legacy_border_attribute(
element,
matching_rules_list,
shareable);
}
name if *name == atom!("body") || *name == atom!("tr") || *name == atom!("thead") ||
*name == atom!("tbody") || *name == atom!("tfoot") => {
self.synthesize_presentational_hint_for_legacy_background_color_attribute(
element,
matching_rules_list,
shareable);
}
name if *name == atom!("input") => {
match element.get_integer_attribute(SizeIntegerAttribute) {
Some(value) if value != 0 => {
// Per HTML 4.01 § 17.4, this value is in characters if `type` is `text` or
// `password` and in pixels otherwise.
//
// FIXME(pcwalton): More use of atoms, please!
let value = match element.get_attr(&ns!(""), &atom!("type")) {
Some("text") | Some("password") => {
specified::ServoCharacterWidth(value)
}
_ => specified::Au_(Au::from_px(value as int)),
};
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
WidthDeclaration(SpecifiedValue(specified::LPA_Length(
value)))));
*shareable = false
}
Some(_) | None => {}
}
}
_ => {}
}
}
fn synthesize_presentational_hint_for_legacy_background_color_attribute<'a,E,V>(
&self,
element: E,
matching_rules_list:
&mut V,
shareable: &mut bool)
where
E: TElement<'a> +
TElementAttributes,
V: VecLike<
DeclarationBlock> {
match element.get_simple_color_attribute(BgColorSimpleColorAttribute) {
None => {}
Some(color) => {
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
BackgroundColorDeclaration(SpecifiedValue(RGBAColor(color)))));
*shareable = false
}
}
}
fn synthesize_presentational_hint_for_legacy_border_attribute<'a,E,V>(
&self,
element: E,
matching_rules_list: &mut V,
shareable: &mut bool)
where
E: TElement<'a> +
TElementAttributes,
V: VecLike<DeclarationBlock> {
match element.get_unsigned_integer_attribute(BorderUnsignedIntegerAttribute) {
None => {}
Some(length) => {
let width_value = specified::Au_(Au::from_px(length as int));
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
BorderTopWidthDeclaration(SpecifiedValue(width_value))));
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
BorderLeftWidthDeclaration(SpecifiedValue(width_value))));
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
BorderBottomWidthDeclaration(SpecifiedValue(width_value))));
matching_rules_list.vec_push(DeclarationBlock::from_declaration(
BorderRightWidthDeclaration(SpecifiedValue(width_value))));
*shareable = false
}
}
}
}