servo/components/style/stylesheet_set.rs
2017-05-12 13:50:10 -07:00

137 lines
4.5 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/. */
//! A centralized set of stylesheets for a document.
use std::slice;
use stylearc::Arc;
use stylesheets::Stylesheet;
/// Entry for a StylesheetSet. We don't bother creating a constructor, because
/// there's no sensible defaults for the member variables.
pub struct StylesheetSetEntry {
unique_id: u64,
sheet: Arc<Stylesheet>,
}
/// A iterator over the stylesheets of a list of entries in the StylesheetSet.
#[derive(Clone)]
pub struct StylesheetIterator<'a>(slice::Iter<'a, StylesheetSetEntry>);
impl<'a> Iterator for StylesheetIterator<'a> {
type Item = &'a Arc<Stylesheet>;
fn next(&mut self) -> Option<Self::Item> {
self.0.next().map(|entry| &entry.sheet)
}
}
/// The set of stylesheets effective for a given document.
pub struct StylesheetSet {
/// The actual list of all the stylesheets that apply to the given document,
/// each stylesheet associated with a unique ID.
///
/// This is only a list of top-level stylesheets, and as such it doesn't
/// include recursive `@import` rules.
entries: Vec<StylesheetSetEntry>,
/// Whether the entries list above has changed since the last restyle.
dirty: bool,
/// Has author style been disabled?
author_style_disabled: bool,
}
impl StylesheetSet {
/// Create a new empty StylesheetSet.
pub fn new() -> Self {
StylesheetSet {
entries: vec![],
dirty: false,
author_style_disabled: false,
}
}
/// Returns whether author styles have been disabled for the current
/// stylesheet set.
pub fn author_style_disabled(&self) -> bool {
self.author_style_disabled
}
fn remove_stylesheet_if_present(&mut self, unique_id: u64) {
self.entries.retain(|x| x.unique_id != unique_id);
}
/// Appends a new stylesheet to the current set.
pub fn append_stylesheet(&mut self, sheet: &Arc<Stylesheet>,
unique_id: u64) {
self.remove_stylesheet_if_present(unique_id);
self.entries.push(StylesheetSetEntry {
unique_id: unique_id,
sheet: sheet.clone(),
});
self.dirty = true;
}
/// Prepend a new stylesheet to the current set.
pub fn prepend_stylesheet(&mut self, sheet: &Arc<Stylesheet>,
unique_id: u64) {
self.remove_stylesheet_if_present(unique_id);
self.entries.insert(0, StylesheetSetEntry {
unique_id: unique_id,
sheet: sheet.clone(),
});
self.dirty = true;
}
/// Insert a given stylesheet before another stylesheet in the document.
pub fn insert_stylesheet_before(&mut self,
sheet: &Arc<Stylesheet>,
unique_id: u64,
before_unique_id: u64) {
self.remove_stylesheet_if_present(unique_id);
let index = self.entries.iter().position(|x| {
x.unique_id == before_unique_id
}).expect("`before_unique_id` stylesheet not found");
self.entries.insert(index, StylesheetSetEntry {
unique_id: unique_id,
sheet: sheet.clone(),
});
self.dirty = true;
}
/// Remove a given stylesheet from the set.
pub fn remove_stylesheet(&mut self, unique_id: u64) {
self.remove_stylesheet_if_present(unique_id);
self.dirty = true;
}
/// Notes that the author style has been disabled for this document.
pub fn set_author_style_disabled(&mut self, disabled: bool) {
if self.author_style_disabled == disabled {
return;
}
self.author_style_disabled = disabled;
self.dirty = true;
}
/// Returns whether the given set has changed from the last flush.
pub fn has_changed(&self) -> bool {
self.dirty
}
/// Flush the current set, unmarking it as dirty, and returns an iterator
/// over the new stylesheet list.
pub fn flush(&mut self) -> StylesheetIterator {
self.dirty = false;
StylesheetIterator(self.entries.iter())
}
/// Mark the stylesheets as dirty, because something external may have
/// invalidated it.
///
/// FIXME(emilio): Make this more granular.
pub fn force_dirty(&mut self) {
self.dirty = true;
}
}