servo/components/layout/css/node_util.rs
2014-09-08 20:21:42 -06:00

90 lines
3.5 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/. */
use incremental::RestyleDamage;
use util::LayoutDataAccess;
use wrapper::{TLayoutNode, ThreadSafeLayoutNode};
use wrapper::{After, AfterBlock, Before, BeforeBlock, Normal};
use std::mem;
use style::ComputedValues;
use sync::Arc;
pub trait NodeUtil {
fn get_css_select_results<'a>(&'a self) -> &'a Arc<ComputedValues>;
fn have_css_select_results(&self) -> bool;
fn get_restyle_damage(&self) -> RestyleDamage;
fn set_restyle_damage(&self, damage: RestyleDamage);
}
impl<'ln> NodeUtil for ThreadSafeLayoutNode<'ln> {
/// Returns the style results for the given node. If CSS selector
/// matching has not yet been performed, fails.
#[inline]
fn get_css_select_results<'a>(&'a self) -> &'a Arc<ComputedValues> {
unsafe {
let layout_data_ref = self.borrow_layout_data();
match self.get_pseudo_element_type() {
Before | BeforeBlock => {
mem::transmute(layout_data_ref.as_ref()
.unwrap()
.data
.before_style
.as_ref()
.unwrap())
}
After | AfterBlock => {
mem::transmute(layout_data_ref.as_ref()
.unwrap()
.data
.after_style
.as_ref()
.unwrap())
}
Normal => {
mem::transmute(layout_data_ref.as_ref()
.unwrap()
.shared_data
.style
.as_ref()
.unwrap())
}
}
}
}
/// Does this node have a computed style yet?
fn have_css_select_results(&self) -> bool {
let layout_data_ref = self.borrow_layout_data();
layout_data_ref.get_ref().shared_data.style.is_some()
}
/// Get the description of how to account for recent style changes.
/// This is a simple bitfield and fine to copy by value.
fn get_restyle_damage(&self) -> RestyleDamage {
// For DOM elements, if we haven't computed damage yet, assume the worst.
// Other nodes don't have styles.
let default = if self.node_is_element() {
RestyleDamage::all()
} else {
RestyleDamage::empty()
};
let layout_data_ref = self.borrow_layout_data();
layout_data_ref
.get_ref()
.data
.restyle_damage
.unwrap_or(default)
}
/// Set the restyle damage field.
fn set_restyle_damage(&self, damage: RestyleDamage) {
let mut layout_data_ref = self.mutate_layout_data();
match &mut *layout_data_ref {
&Some(ref mut layout_data) => layout_data.data.restyle_damage = Some(damage),
_ => fail!("no layout data for this node"),
}
}
}