Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-06-06 16:45:39 +00:00
Code Issues Projects Releases Packages Wiki Activity

Share line breaking state across text runs

Browse source 
Fixes #874
This commit is contained in:
Manish Goregaokar 2018-01-10 18:08:38 +05:30
parent bda560d01b
commit f3c81fcda8
39 changed files with 160 additions and 76 deletions
Download patch file Download diff file Expand all files Collapse all files

45
components/layout/text.rs
View file

@ -32,6 +32,7 @@ use style::properties::style_structs;
use style::values::generics::text::LineHeight;
use unicode_bidi as bidi;
use unicode_script::{Script, get_script};
use xi_unicode::LineBreakLeafIter;
/// Returns the concatenated text of a list of unscanned text fragments.
fn text(fragments: &LinkedList<Fragment>) -> String {
@ -91,6 +92,15 @@ impl TextRunScanner {
let mut last_whitespace = false;
let mut paragraph_bytes_processed = 0;
// The first time we process a text run we will set this
// linebreaker. There is no way for the linebreaker to start
// with an empty state; you must give it its first input immediately.
//
// This linebreaker is shared across text runs, so we can know if
// there is a break at the beginning of a text run or clump, e.g.
// in the case of FooBar<span>Baz</span>
let mut linebreaker = None;
while !fragments.is_empty() {
// Create a clump.
split_first_fragment_at_newline_if_necessary(&mut fragments);
@ -109,7 +119,8 @@ impl TextRunScanner {
&mut new_fragments,
&mut paragraph_bytes_processed,
bidi_levels,
last_whitespace);
last_whitespace,
&mut linebreaker);
}
debug!("TextRunScanner: complete.");
@ -129,7 +140,8 @@ impl TextRunScanner {
out_fragments: &mut Vec<Fragment>,
paragraph_bytes_processed: &mut usize,
bidi_levels: Option<&[bidi::Level]>,
mut last_whitespace: bool)
mut last_whitespace: bool,
linebreaker: &mut Option<LineBreakLeafIter>)
-> bool {
debug!("TextRunScanner: flushing {} fragments in range", self.clump.len());
@ -309,22 +321,26 @@ impl TextRunScanner {
flags: flags,
};
// FIXME(https://github.com/rust-lang/rust/issues/23338)
run_info_list.into_iter().map(|run_info| {
let mut result = Vec::with_capacity(run_info_list.len());
for run_info in run_info_list {
let mut options = options;
options.script = run_info.script;
if run_info.bidi_level.is_rtl() {
options.flags.insert(ShapingFlags::RTL_FLAG);
}
let mut font = fontgroup.fonts.get(run_info.font_index).unwrap().borrow_mut();
ScannedTextRun {
run: Arc::new(TextRun::new(&mut *font,
run_info.text,
&options,
run_info.bidi_level)),
let (run, break_at_zero) = TextRun::new(&mut *font,
run_info.text,
&options,
run_info.bidi_level,
linebreaker);
result.push((ScannedTextRun {
run: Arc::new(run),
insertion_point: run_info.insertion_point,
}
}).collect::<Vec<_>>()
}, break_at_zero))
}
result
};
// Make new fragments with the runs and adjusted text indices.
@ -351,12 +367,17 @@ impl TextRunScanner {
}
};
let mapping = mappings.next().unwrap();
let scanned_run = runs[mapping.text_run_index].clone();
let (scanned_run, break_at_zero) = runs[mapping.text_run_index].clone();
let mut byte_range = Range::new(ByteIndex(mapping.byte_range.begin() as isize),
ByteIndex(mapping.byte_range.length() as isize));
let mut flags = ScannedTextFlags::empty();
if !break_at_zero && mapping.byte_range.begin() == 0 {
// If this is the first segment of the text run,
// and the text run doesn't break at zero, suppress line breaks
flags.insert(ScannedTextFlags::SUPPRESS_LINE_BREAK_BEFORE)
}
let text_size = old_fragment.border_box.size;
let requires_line_break_afterward_if_wrapping_on_newlines =