1 // Copyright 2015 The Servo Project Developers. See the 2 // COPYRIGHT file at the top-level directory of this distribution. 3 // 4 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or 5 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license 6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your 7 // option. This file may not be copied, modified, or distributed 8 // except according to those terms. 9 10 //! This module holds deprecated assets only. 11 12 // Doesn't worth updating API here 13 #![cfg_attr(feature="cargo-clippy", allow(needless_pass_by_value))] 14 15 use super::*; 16 17 /// Find the level runs within a line and return them in visual order. 18 /// 19 /// NOTE: This implementation is incomplete. The algorithm needs information about the text, 20 /// including original `BidiClass` property of each character, to be able to perform correctly. 21 /// Please see [`BidiInfo::visual_runs()`](../struct.BidiInfo.html#method.visual_runs) for the 22 /// improved implementation. 23 /// 24 /// `line` is a range of bytes indices within `levels`. 25 /// 26 /// <http://www.unicode.org/reports/tr9/#Reordering_Resolved_Levels> 27 #[deprecated(since = "0.3.0", note = "please use `BidiInfo::visual_runs()` instead.")] 28 pub fn visual_runs(line: Range<usize>, levels: &[Level]) -> Vec<LevelRun> { 29 assert!(line.start <= levels.len()); 30 assert!(line.end <= levels.len()); 31 32 let mut runs = Vec::new(); 33 34 // Find consecutive level runs. 35 let mut start = line.start; 36 let mut run_level = levels[start]; 37 let mut min_level = run_level; 38 let mut max_level = run_level; 39 40 for (i, &new_level) in levels.iter().enumerate().take(line.end).skip(start + 1) { 41 if new_level != run_level { 42 // End of the previous run, start of a new one. 43 runs.push(start..i); 44 start = i; 45 run_level = new_level; 46 47 min_level = min(run_level, min_level); 48 max_level = max(run_level, max_level); 49 } 50 } 51 runs.push(start..line.end); 52 53 let run_count = runs.len(); 54 55 // Re-order the odd runs. 56 // <http://www.unicode.org/reports/tr9/#L2> 57 58 // Stop at the lowest *odd* level. 59 min_level = min_level.new_lowest_ge_rtl().expect("Level error"); 60 61 while max_level >= min_level { 62 // Look for the start of a sequence of consecutive runs of max_level or higher. 63 let mut seq_start = 0; 64 while seq_start < run_count { 65 if levels[runs[seq_start].start] < max_level { 66 seq_start += 1; 67 continue; 68 } 69 70 // Found the start of a sequence. Now find the end. 71 let mut seq_end = seq_start + 1; 72 while seq_end < run_count { 73 if levels[runs[seq_end].start] < max_level { 74 break; 75 } 76 seq_end += 1; 77 } 78 79 // Reverse the runs within this sequence. 80 runs[seq_start..seq_end].reverse(); 81 82 seq_start = seq_end; 83 } 84 max_level.lower(1).expect( 85 "Lowering embedding level below zero", 86 ); 87 } 88 89 runs 90 } 91