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Diffstat (limited to 'src/components/layout/text.rs')
| -rw-r--r-- | src/components/layout/text.rs | 327 |
1 files changed, 0 insertions, 327 deletions
diff --git a/src/components/layout/text.rs b/src/components/layout/text.rs deleted file mode 100644 index e90272e218a..00000000000 --- a/src/components/layout/text.rs +++ /dev/null @@ -1,327 +0,0 @@ -/* 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/. */ - -//! Text layout. - -#![deny(unsafe_block)] - -use flow::Flow; -use fragment::{Fragment, ScannedTextFragment, ScannedTextFragmentInfo, UnscannedTextFragment}; - -use gfx::font::{FontMetrics, FontStyle, RunMetrics}; -use gfx::font_context::FontContext; -use gfx::text::glyph::CharIndex; -use gfx::text::text_run::TextRun; -use gfx::text::util::{CompressWhitespaceNewline, transform_text, CompressNone}; -use servo_util::geometry::Au; -use servo_util::logical_geometry::{LogicalSize, WritingMode}; -use servo_util::range::Range; -use style::ComputedValues; -use style::computed_values::{font_family, line_height, text_orientation, white_space}; -use sync::Arc; - -struct NewLinePositions { - new_line_pos: Vec<CharIndex>, -} - -// A helper function. -fn can_coalesce_text_nodes(fragments: &[Fragment], left_i: uint, right_i: uint) -> bool { - assert!(left_i != right_i); - fragments[left_i].can_merge_with_fragment(&fragments[right_i]) -} - -/// A stack-allocated object for scanning an inline flow into `TextRun`-containing `TextFragment`s. -pub struct TextRunScanner { - pub clump: Range<CharIndex>, -} - -impl TextRunScanner { - pub fn new() -> TextRunScanner { - TextRunScanner { - clump: Range::empty(), - } - } - - pub fn scan_for_runs(&mut self, font_context: &mut FontContext, flow: &mut Flow) { - { - let inline = flow.as_immutable_inline(); - debug!("TextRunScanner: scanning {:u} fragments for text runs...", inline.fragments.len()); - } - - let fragments = &mut flow.as_inline().fragments; - - let mut last_whitespace = true; - let mut new_fragments = Vec::new(); - for fragment_i in range(0, fragments.fragments.len()) { - debug!("TextRunScanner: considering fragment: {:u}", fragment_i); - if fragment_i > 0 && !can_coalesce_text_nodes(fragments.fragments.as_slice(), fragment_i - 1, fragment_i) { - last_whitespace = self.flush_clump_to_list(font_context, - fragments.fragments.as_slice(), - &mut new_fragments, - last_whitespace); - } - - self.clump.extend_by(CharIndex(1)); - } - - // Handle remaining clumps. - if self.clump.length() > CharIndex(0) { - drop(self.flush_clump_to_list(font_context, - fragments.fragments.as_slice(), - &mut new_fragments, - last_whitespace)) - } - - debug!("TextRunScanner: swapping out fragments."); - - fragments.fragments = new_fragments; - } - - /// A "clump" is a range of inline flow leaves that can be merged together into a single - /// fragment. Adjacent text with the same style can be merged, and nothing else can. - /// - /// The flow keeps track of the fragments contained by all non-leaf DOM nodes. This is necessary - /// for correct painting order. Since we compress several leaf fragments here, the mapping must - /// be adjusted. - /// - /// FIXME(#2267, pcwalton): Stop cloning fragments. Instead we will need to replace each - /// `in_fragment` with some smaller stub. - fn flush_clump_to_list(&mut self, - font_context: &mut FontContext, - in_fragments: &[Fragment], - out_fragments: &mut Vec<Fragment>, - last_whitespace: bool) - -> bool { - assert!(self.clump.length() > CharIndex(0)); - - debug!("TextRunScanner: flushing fragments in range={}", self.clump); - let is_singleton = self.clump.length() == CharIndex(1); - - let is_text_clump = match in_fragments[self.clump.begin().to_uint()].specific { - UnscannedTextFragment(_) => true, - _ => false, - }; - - let mut new_whitespace = last_whitespace; - match (is_singleton, is_text_clump) { - (false, false) => { - fail!("WAT: can't coalesce non-text nodes in flush_clump_to_list()!") - } - (true, false) => { - // FIXME(pcwalton): Stop cloning fragments, as above. - debug!("TextRunScanner: pushing single non-text fragment in range: {}", self.clump); - let new_fragment = in_fragments[self.clump.begin().to_uint()].clone(); - out_fragments.push(new_fragment) - }, - (true, true) => { - let old_fragment = &in_fragments[self.clump.begin().to_uint()]; - let text = match old_fragment.specific { - UnscannedTextFragment(ref text_fragment_info) => &text_fragment_info.text, - _ => fail!("Expected an unscanned text fragment!"), - }; - - let font_style = old_fragment.font_style(); - - let compression = match old_fragment.white_space() { - white_space::normal => CompressWhitespaceNewline, - white_space::pre => CompressNone, - }; - - let mut new_line_pos = vec![]; - - let (transformed_text, whitespace) = transform_text(text.as_slice(), - compression, - last_whitespace, - &mut new_line_pos); - - new_whitespace = whitespace; - - if transformed_text.len() > 0 { - // TODO(#177): Text run creation must account for the renderability of text by - // font group fonts. This is probably achieved by creating the font group above - // and then letting `FontGroup` decide which `Font` to stick into the text run. - let fontgroup = font_context.get_layout_font_group_for_style(&font_style); - let run = box fontgroup.create_textrun( - transformed_text.clone()); - - debug!("TextRunScanner: pushing single text fragment in range: {} ({})", - self.clump, - *text); - let range = Range::new(CharIndex(0), run.char_len()); - let new_metrics = run.metrics_for_range(&range); - let bounding_box_size = bounding_box_for_run_metrics( - &new_metrics, old_fragment.style.writing_mode); - let new_text_fragment_info = ScannedTextFragmentInfo::new(Arc::new(run), range); - let mut new_fragment = old_fragment.transform( - bounding_box_size, ScannedTextFragment(new_text_fragment_info)); - new_fragment.new_line_pos = new_line_pos; - out_fragments.push(new_fragment) - } - }, - (false, true) => { - // TODO(#177): Text run creation must account for the renderability of text by - // font group fonts. This is probably achieved by creating the font group above - // and then letting `FontGroup` decide which `Font` to stick into the text run. - let in_fragment = &in_fragments[self.clump.begin().to_uint()]; - let font_style = in_fragment.font_style(); - let fontgroup = font_context.get_layout_font_group_for_style(&font_style); - - let compression = match in_fragment.white_space() { - white_space::normal => CompressWhitespaceNewline, - white_space::pre => CompressNone, - }; - - let mut new_line_positions: Vec<NewLinePositions> = vec![]; - - // First, transform/compress text of all the nodes. - let mut last_whitespace_in_clump = new_whitespace; - let transformed_strs: Vec<String> = Vec::from_fn(self.clump.length().to_uint(), |i| { - let idx = CharIndex(i as int) + self.clump.begin(); - let in_fragment = match in_fragments[idx.to_uint()].specific { - UnscannedTextFragment(ref text_fragment_info) => &text_fragment_info.text, - _ => fail!("Expected an unscanned text fragment!"), - }; - - let mut new_line_pos = vec![]; - - let (new_str, new_whitespace) = transform_text(in_fragment.as_slice(), - compression, - last_whitespace_in_clump, - &mut new_line_pos); - new_line_positions.push(NewLinePositions { new_line_pos: new_line_pos }); - - last_whitespace_in_clump = new_whitespace; - new_str - }); - new_whitespace = last_whitespace_in_clump; - - // Next, concatenate all of the transformed strings together, saving the new - // character indices. - let mut run_str = String::new(); - let mut new_ranges: Vec<Range<CharIndex>> = vec![]; - let mut char_total = CharIndex(0); - for i in range(0, transformed_strs.len() as int) { - let added_chars = CharIndex(transformed_strs[i as uint].as_slice().char_len() as int); - new_ranges.push(Range::new(char_total, added_chars)); - run_str.push_str(transformed_strs[i as uint].as_slice()); - char_total = char_total + added_chars; - } - - // Now create the run. - // TextRuns contain a cycle which is usually resolved by the teardown - // sequence. If no clump takes ownership, however, it will leak. - let clump = self.clump; - let run = if clump.length() != CharIndex(0) && run_str.len() > 0 { - Some(Arc::new(box TextRun::new( - &mut *fontgroup.fonts[0].borrow_mut(), - run_str.to_string()))) - } else { - None - }; - - // Make new fragments with the run and adjusted text indices. - debug!("TextRunScanner: pushing fragment(s) in range: {}", self.clump); - for i in clump.each_index() { - let logical_offset = i - self.clump.begin(); - let range = new_ranges[logical_offset.to_uint()]; - if range.length() == CharIndex(0) { - debug!("Elided an `UnscannedTextFragment` because it was zero-length after \ - compression; {}", in_fragments[i.to_uint()]); - continue - } - - let new_text_fragment_info = ScannedTextFragmentInfo::new(run.get_ref().clone(), range); - let old_fragment = &in_fragments[i.to_uint()]; - let new_metrics = new_text_fragment_info.run.metrics_for_range(&range); - let bounding_box_size = bounding_box_for_run_metrics( - &new_metrics, old_fragment.style.writing_mode); - let mut new_fragment = old_fragment.transform( - bounding_box_size, ScannedTextFragment(new_text_fragment_info)); - new_fragment.new_line_pos = new_line_positions[logical_offset.to_uint()].new_line_pos.clone(); - out_fragments.push(new_fragment) - } - } - } // End of match. - - let end = self.clump.end(); // FIXME: borrow checker workaround - self.clump.reset(end, CharIndex(0)); - - new_whitespace - } // End of `flush_clump_to_list`. -} - - -#[inline] -fn bounding_box_for_run_metrics(metrics: &RunMetrics, writing_mode: WritingMode) - -> LogicalSize<Au> { - - // This does nothing, but it will fail to build - // when more values are added to the `text-orientation` CSS property. - // This will be a reminder to update the code below. - let dummy: Option<text_orientation::T> = None; - match dummy { - Some(text_orientation::sideways_right) | - Some(text_orientation::sideways_left) | - Some(text_orientation::sideways) | - None => {} - } - - // In vertical sideways or horizontal upgright text, - // the "width" of text metrics is always inline - // This will need to be updated when other text orientations are supported. - LogicalSize::new( - writing_mode, - metrics.bounding_box.size.width, - metrics.bounding_box.size.height) - -} - -/// Returns the metrics of the font represented by the given `FontStyle`, respectively. -/// -/// `#[inline]` because often the caller only needs a few fields from the font metrics. -#[inline] -pub fn font_metrics_for_style(font_context: &mut FontContext, font_style: &FontStyle) - -> FontMetrics { - let fontgroup = font_context.get_layout_font_group_for_style(font_style); - fontgroup.fonts[0].borrow().metrics.clone() -} - -/// Converts a computed style to a font style used for rendering. -/// -/// FIXME(pcwalton): This should not be necessary; just make the font part of the style sharable -/// with the display list somehow. (Perhaps we should use an ARC.) -pub fn computed_style_to_font_style(style: &ComputedValues) -> FontStyle { - debug!("(font style) start"); - - // FIXME: Too much allocation here. - let mut font_families = style.get_font().font_family.iter().map(|family| { - match *family { - font_family::FamilyName(ref name) => (*name).clone(), - } - }); - debug!("(font style) font families: `{:?}`", font_families); - - let font_size = style.get_font().font_size.to_f64().unwrap() / 60.0; - debug!("(font style) font size: `{:f}px`", font_size); - - FontStyle { - pt_size: font_size, - weight: style.get_font().font_weight, - style: style.get_font().font_style, - families: font_families.collect(), - } -} - -/// Returns the line block-size needed by the given computed style and font size. -pub fn line_height_from_style(style: &ComputedValues, metrics: &FontMetrics) -> Au { - let font_size = style.get_font().font_size; - let from_inline = match style.get_inheritedbox().line_height { - line_height::Normal => metrics.line_gap, - line_height::Number(l) => font_size.scale_by(l), - line_height::Length(l) => l - }; - let minimum = style.get_inheritedbox()._servo_minimum_line_height; - Au::max(from_inline, minimum) -} - |