servo/components/layout/css/node_style.rs
2015-03-21 10:27:32 +01:00

77 lines
3 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/. */
//! Style retrieval from DOM elements.
use wrapper::{PseudoElementType, ThreadSafeLayoutNode};
use std::mem;
use style::properties::ComputedValues;
use std::sync::Arc;
/// Node mixin providing `style` method that returns a `NodeStyle`
pub trait StyledNode {
/// Returns the style results for the given node. If CSS selector matching has not yet been
/// performed, fails.
fn style<'a>(&'a self) -> &'a Arc<ComputedValues>;
/// Does this node have a computed style yet?
fn has_style(&self) -> bool;
/// Removes the style from this node.
fn unstyle(self);
}
impl<'ln> StyledNode for ThreadSafeLayoutNode<'ln> {
#[inline]
#[allow(unsafe_code)]
fn style<'a>(&'a self) -> &'a Arc<ComputedValues> {
unsafe {
let layout_data_ref = self.borrow_layout_data();
match self.get_pseudo_element_type() {
PseudoElementType::Before(_) => {
mem::transmute(layout_data_ref.as_ref()
.unwrap()
.data
.before_style
.as_ref()
.unwrap())
}
PseudoElementType::After(_) => {
mem::transmute(layout_data_ref.as_ref()
.unwrap()
.data
.after_style
.as_ref()
.unwrap())
}
PseudoElementType::Normal => {
mem::transmute(layout_data_ref.as_ref()
.unwrap()
.shared_data
.style
.as_ref()
.unwrap())
}
}
}
}
fn has_style(&self) -> bool {
let layout_data_ref = self.borrow_layout_data();
layout_data_ref.as_ref().unwrap().shared_data.style.is_some()
}
fn unstyle(self) {
let mut layout_data_ref = self.mutate_layout_data();
let layout_data = layout_data_ref.as_mut().expect("no layout data");
let style =
match self.get_pseudo_element_type() {
PseudoElementType::Before(_) => &mut layout_data.data.before_style,
PseudoElementType::After (_) => &mut layout_data.data.after_style,
PseudoElementType::Normal => &mut layout_data.shared_data.style,
};
*style = None;
}
}