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

123 lines
3.8 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/. */
//! Data needed by the layout task.
use css::matching::{ApplicableDeclarationsCache, StyleSharingCandidateCache};
use geom::{Rect, Size2D};
use gfx::display_list::OpaqueNode;
use gfx::font_context::FontContext;
use gfx::font_cache_task::FontCacheTask;
use script::layout_interface::LayoutChan;
use servo_msg::constellation_msg::ConstellationChan;
use servo_net::local_image_cache::LocalImageCache;
use servo_util::geometry::Au;
use servo_util::opts::Opts;
use sync::{Arc, Mutex};
use std::mem;
use style::Stylist;
use url::Url;
struct LocalLayoutContext {
font_context: FontContext,
applicable_declarations_cache: ApplicableDeclarationsCache,
style_sharing_candidate_cache: StyleSharingCandidateCache,
}
local_data_key!(local_context_key: *mut LocalLayoutContext)
fn create_or_get_local_context(shared_layout_context: &SharedLayoutContext) -> *mut LocalLayoutContext {
let maybe_context = local_context_key.get();
let context = match maybe_context {
None => {
let context = box LocalLayoutContext {
font_context: FontContext::new(shared_layout_context.font_cache_task.clone()),
applicable_declarations_cache: ApplicableDeclarationsCache::new(),
style_sharing_candidate_cache: StyleSharingCandidateCache::new(),
};
local_context_key.replace(Some(unsafe { mem::transmute(context) }));
local_context_key.get().unwrap()
},
Some(context) => context
};
*context
}
pub struct SharedLayoutContext {
/// The local image cache.
pub image_cache: Arc<Mutex<LocalImageCache>>,
/// The current screen size.
pub screen_size: Size2D<Au>,
/// A channel up to the constellation.
pub constellation_chan: ConstellationChan,
/// A channel up to the layout task.
pub layout_chan: LayoutChan,
/// Interface to the font cache task.
pub font_cache_task: FontCacheTask,
/// The CSS selector stylist.
///
/// FIXME(#2604): Make this no longer an unsafe pointer once we have fast `RWArc`s.
pub stylist: *const Stylist,
/// The root node at which we're starting the layout.
pub reflow_root: OpaqueNode,
/// The URL.
pub url: Url,
/// The command line options.
pub opts: Opts,
/// The dirty rectangle, used during display list building.
pub dirty: Rect<Au>,
}
pub struct LayoutContext<'a> {
pub shared: &'a SharedLayoutContext,
cached_local_layout_context: *mut LocalLayoutContext,
}
impl<'a> LayoutContext<'a> {
pub fn new(shared_layout_context: &'a SharedLayoutContext) -> LayoutContext<'a> {
let local_context = create_or_get_local_context(shared_layout_context);
LayoutContext {
shared: shared_layout_context,
cached_local_layout_context: local_context,
}
}
#[inline(always)]
pub fn font_context<'a>(&'a self) -> &'a mut FontContext {
unsafe {
let cached_context = &*self.cached_local_layout_context;
mem::transmute(&cached_context.font_context)
}
}
#[inline(always)]
pub fn applicable_declarations_cache<'a>(&'a self) -> &'a mut ApplicableDeclarationsCache {
unsafe {
let cached_context = &*self.cached_local_layout_context;
mem::transmute(&cached_context.applicable_declarations_cache)
}
}
#[inline(always)]
pub fn style_sharing_candidate_cache<'a>(&'a self) -> &'a mut StyleSharingCandidateCache {
unsafe {
let cached_context = &*self.cached_local_layout_context;
mem::transmute(&cached_context.style_sharing_candidate_cache)
}
}
}