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layout: Refactor inline layout a bit

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Patrick Walton 2013-05-07 10:15:52 -07:00
parent 066d1bf1c8
commit b7ac688136
1 changed files with 107 additions and 91 deletions
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174
src/servo/layout/inline.rs
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@ -61,28 +61,28 @@ struct ElementMapping {
priv entries: ~[NodeRange], priv entries: ~[NodeRange],
} }
pub impl ElementMapping { impl ElementMapping {
fn new() -> ElementMapping { pub fn new() -> ElementMapping {
ElementMapping { entries: ~[] } ElementMapping { entries: ~[] }
} }
fn add_mapping(&mut self, node: AbstractNode, range: &Range) { pub fn add_mapping(&mut self, node: AbstractNode, range: &Range) {
self.entries.push(NodeRange::new(node, range)) self.entries.push(NodeRange::new(node, range))
} }
fn each(&self, cb: &fn(nr: &NodeRange) -> bool) { pub fn each(&self, cb: &fn(nr: &NodeRange) -> bool) {
do self.entries.each |nr| { cb(nr) } do self.entries.each |nr| { cb(nr) }
} }
fn eachi(&self, cb: &fn(i: uint, nr: &NodeRange) -> bool) { pub fn eachi(&self, cb: &fn(i: uint, nr: &NodeRange) -> bool) {
do self.entries.eachi |i, nr| { cb(i, nr) } do self.entries.eachi |i, nr| { cb(i, nr) }
} }
fn eachi_mut(&self, cb: &fn(i: uint, nr: &NodeRange) -> bool) { pub fn eachi_mut(&self, cb: &fn(i: uint, nr: &NodeRange) -> bool) {
do self.entries.eachi |i, nr| { cb(i, nr) } do self.entries.eachi |i, nr| { cb(i, nr) }
} }
fn repair_for_box_changes(&mut self, pub fn repair_for_box_changes(&mut self,
old_boxes: &[@mut RenderBox], old_boxes: &[@mut RenderBox],
new_boxes: &[@mut RenderBox]) { new_boxes: &[@mut RenderBox]) {
let entries = &mut self.entries; let entries = &mut self.entries;
@ -154,13 +154,12 @@ pub impl ElementMapping {
} }
} }
// stack-allocated object for scanning an inline flow into /// A stack-allocated object for scanning an inline flow into `TextRun`-containing `TextBox`es.
// TextRun-containing TextBoxes. struct TextRunScanner {
priv struct TextRunScanner {
clump: Range, clump: Range,
} }
priv impl TextRunScanner { impl TextRunScanner {
fn new() -> TextRunScanner { fn new() -> TextRunScanner {
TextRunScanner { TextRunScanner {
clump: Range::empty(), clump: Range::empty(),
@ -168,7 +167,7 @@ priv impl TextRunScanner {
} }
} }
priv impl TextRunScanner { impl TextRunScanner {
fn scan_for_runs(&mut self, ctx: &mut LayoutContext, flow: FlowContext) { fn scan_for_runs(&mut self, ctx: &mut LayoutContext, flow: FlowContext) {
let inline = &mut *flow.inline(); let inline = &mut *flow.inline();
assert!(inline.boxes.len() > 0); assert!(inline.boxes.len() > 0);
@ -206,18 +205,16 @@ priv impl TextRunScanner {
} }
} }
// a 'clump' is a range of inline flow leaves that can be merged /// A "clump" is a range of inline flow leaves that can be merged together into a single
// together into a single RenderBox. Adjacent text with the same /// `RenderBox`. Adjacent text with the same style can be merged, and nothing else can.
// style can be merged, and nothing else can. ///
// /// The flow keeps track of the `RenderBox`es contained by all non-leaf DOM nodes. This is
// the flow keeps track of the RenderBoxes contained by all /// necessary for correct painting order. Since we compress several leaf `RenderBox`es here,
// non-leaf DOM nodes. This is necessary for correct painting /// the mapping must be adjusted.
// order. Since we compress several leaf RenderBoxes here, the ///
// mapping must be adjusted. /// N.B. `in_boxes` is passed by reference, since the old code used a `DVec`. The caller is
// /// responsible for swapping out the list. It is not clear to me (pcwalton) that this is still
// N.B. in_boxes is passed by reference, since we cannot /// necessary.
// recursively borrow or swap the flow's dvec of boxes. When all
// boxes are appended, the caller swaps the flow's box list.
fn flush_clump_to_list(&mut self, fn flush_clump_to_list(&mut self,
ctx: &mut LayoutContext, ctx: &mut LayoutContext,
flow: FlowContext, flow: FlowContext,
@ -227,8 +224,8 @@ priv impl TextRunScanner {
debug!("TextRunScanner: flushing boxes in range=%?", self.clump); debug!("TextRunScanner: flushing boxes in range=%?", self.clump);
let is_singleton = self.clump.length() == 1; let is_singleton = self.clump.length() == 1;
let is_text_clump = match in_boxes[self.clump.begin()] { let is_text_clump = match *in_boxes[self.clump.begin()] {
@UnscannedTextBox(*) => true, UnscannedTextBox(*) => true,
_ => false _ => false
}; };
@ -244,14 +241,18 @@ priv impl TextRunScanner {
let old_box = in_boxes[self.clump.begin()]; let old_box = in_boxes[self.clump.begin()];
let text = old_box.raw_text(); let text = old_box.raw_text();
let font_style = old_box.font_style(); let font_style = old_box.font_style();
// TODO(Issue #115): use actual CSS 'white-space' property of relevant style.
// TODO(#115): Use the actual CSS `white-space` property of the relevant style.
let compression = CompressWhitespaceNewline; let compression = CompressWhitespaceNewline;
let transformed_text = transform_text(text, compression); let transformed_text = transform_text(text, compression);
// TODO(Issue #177): text run creation must account for text-renderability by fontgroup fonts.
// this is probably achieved by creating fontgroup above, and then letting FontGroup decide // TODO(#177): Text run creation must account for the renderability of text by
// which Font to stick into the TextRun. // 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 = ctx.font_ctx.get_resolved_font_for_style(&font_style); let fontgroup = ctx.font_ctx.get_resolved_font_for_style(&font_style);
let run = @fontgroup.create_textrun(transformed_text); let run = @fontgroup.create_textrun(transformed_text);
debug!("TextRunScanner: pushing single text box in range: %?", self.clump); debug!("TextRunScanner: pushing single text box in range: %?", self.clump);
let new_box = adapt_textbox_with_range(old_box.d(), let new_box = adapt_textbox_with_range(old_box.d(),
run, run,
@ -259,23 +260,23 @@ priv impl TextRunScanner {
out_boxes.push(new_box); out_boxes.push(new_box);
}, },
(false, true) => { (false, true) => {
// TODO(Issue #115): use actual CSS 'white-space' property of relevant style. // TODO(#115): Use the actual CSS `white-space` property of the relevant style.
let compression = CompressWhitespaceNewline; let compression = CompressWhitespaceNewline;
// first, transform/compress text of all the nodes // First, transform/compress text of all the nodes.
let transformed_strs : ~[~str] = vec::from_fn(self.clump.length(), |i| { let transformed_strs: ~[~str] = do vec::from_fn(self.clump.length()) |i| {
// TODO(Issue #113): we shoud be passing compression context // TODO(#113): We should be passing the compression context between calls to
// between calls to transform_text, so that boxes // `transform_text`, so that boxes starting and/or ending with whitespace can
// starting/ending with whitespace &c can be // be compressed correctly with respect to the text run.
// compressed correctly w.r.t. the TextRun.
let idx = i + self.clump.begin(); let idx = i + self.clump.begin();
transform_text(in_boxes[idx].raw_text(), compression) transform_text(in_boxes[idx].raw_text(), compression)
}); };
// next, concatenate all of the transformed strings together, saving the new char indices // Next, concatenate all of the transformed strings together, saving the new
let mut run_str : ~str = ~""; // character indices.
let mut new_ranges : ~[Range] = ~[]; let mut run_str: ~str = ~"";
let mut char_total = 0u; let mut new_ranges: ~[Range] = ~[];
let mut char_total = 0;
for uint::range(0, transformed_strs.len()) |i| { for uint::range(0, transformed_strs.len()) |i| {
let added_chars = str::char_len(transformed_strs[i]); let added_chars = str::char_len(transformed_strs[i]);
new_ranges.push(Range::new(char_total, added_chars)); new_ranges.push(Range::new(char_total, added_chars));
@ -283,28 +284,32 @@ priv impl TextRunScanner {
char_total += added_chars; char_total += added_chars;
} }
// create the run, then make new boxes with the run and adjusted text indices // Now create the run.
//
// TODO(Issue #177): text run creation must account for text-renderability by fontgroup fonts. // TODO(#177): Text run creation must account for the renderability of text by
// this is probably achieved by creating fontgroup above, and then letting FontGroup decide // font group fonts. This is probably achieved by creating the font group above
// which Font to stick into the TextRun. // and then letting `FontGroup` decide which `Font` to stick into the text run.
let font_style = in_boxes[self.clump.begin()].font_style(); let font_style = in_boxes[self.clump.begin()].font_style();
let fontgroup = ctx.font_ctx.get_resolved_font_for_style(&font_style); let fontgroup = ctx.font_ctx.get_resolved_font_for_style(&font_style);
let run = @TextRun::new(fontgroup.fonts[0], run_str); let run = @TextRun::new(fontgroup.fonts[0], run_str);
// Make new boxes with the run and adjusted text indices.
debug!("TextRunScanner: pushing box(es) in range: %?", self.clump); debug!("TextRunScanner: pushing box(es) in range: %?", self.clump);
let clump = self.clump; let clump = self.clump;
for clump.eachi |i| { for clump.eachi |i| {
let range = &new_ranges[i - self.clump.begin()]; let range = &new_ranges[i - self.clump.begin()];
if range.length() == 0 { if range.length() == 0 {
error!("Elided an UnscannedTextbox because it was zero-length after compression; %s", error!("Elided an `UnscannedTextbox` because it was zero-length after \
compression; %s",
in_boxes[i].debug_str()); in_boxes[i].debug_str());
loop loop
} }
let new_box = adapt_textbox_with_range(in_boxes[i].d(), run, range); let new_box = adapt_textbox_with_range(in_boxes[i].d(), run, range);
out_boxes.push(new_box); out_boxes.push(new_box);
} }
} }
} /* /match */ } // End of match.
debug!("--- In boxes: ---"); debug!("--- In boxes: ---");
for in_boxes.eachi |i, box| { for in_boxes.eachi |i, box| {
@ -327,7 +332,7 @@ priv impl TextRunScanner {
let end = self.clump.end(); // FIXME: borrow checker workaround let end = self.clump.end(); // FIXME: borrow checker workaround
self.clump.reset(end, 0); self.clump.reset(end, 0);
} /* /fn flush_clump_to_list */ } // End of `flush_clump_to_list`.
} }
struct PendingLine { struct PendingLine {
@ -343,7 +348,8 @@ struct LineboxScanner {
line_spans: ~[Range], line_spans: ~[Range],
} }
fn LineboxScanner(inline: FlowContext) -> LineboxScanner { impl LineboxScanner {
fn new(inline: FlowContext) -> LineboxScanner {
assert!(inline.starts_inline_flow()); assert!(inline.starts_inline_flow());
LineboxScanner { LineboxScanner {
@ -353,9 +359,8 @@ fn LineboxScanner(inline: FlowContext) -> LineboxScanner {
pending_line: PendingLine {mut range: Range::empty(), mut width: Au(0)}, pending_line: PendingLine {mut range: Range::empty(), mut width: Au(0)},
line_spans: ~[] line_spans: ~[]
} }
} }
impl LineboxScanner {
priv fn reset_scanner(&mut self) { priv fn reset_scanner(&mut self) {
debug!("Resetting line box scanner's state for flow f%d.", self.flow.id()); debug!("Resetting line box scanner's state for flow f%d.", self.flow.id());
self.line_spans = ~[]; self.line_spans = ~[];
@ -636,10 +641,11 @@ impl InlineFlowData {
/// Recursively (top-down) determines the actual width of child contexts and boxes. When called /// Recursively (top-down) determines the actual width of child contexts and boxes. When called
/// on this context, the context has had its width set by the parent context. /// on this context, the context has had its width set by the parent context.
pub fn assign_widths_inline(@mut self, ctx: &mut LayoutContext) { pub fn assign_widths_inline(@mut self, ctx: &mut LayoutContext) {
// Initialize content box widths if they haven't been initialized already.
//
// TODO: Combine this with `LineboxScanner`'s walk in the box list, or put this into
// `RenderBox`.
{ {
// initialize (content) box widths, if they haven't been
// already. This could be combined with LineboxScanner's walk
// over the box list, and/or put into RenderBox.
let this = &mut *self; let this = &mut *self;
for this.boxes.each |&box| { for this.boxes.each |&box| {
let box2 = &mut *box; let box2 = &mut *box;
@ -652,17 +658,18 @@ impl InlineFlowData {
// Text boxes are initialized with dimensions. // Text boxes are initialized with dimensions.
box.d().position.size.width box.d().position.size.width
}, },
// TODO(Issue #225): different cases for 'inline-block', other replaced content // TODO(#225): There will be different cases here for `inline-block` and other
// replaced content.
GenericBox(*) => Au::from_px(45), GenericBox(*) => Au::from_px(45),
_ => fail!(fmt!("Tried to assign width to unknown Box variant: %?", box)) _ => fail!(fmt!("Tried to assign width to unknown Box variant: %?", box))
}; };
} // for boxes.each |box| } // End of for loop.
} }
let mut scanner = LineboxScanner(InlineFlow(self)); let mut scanner = LineboxScanner::new(InlineFlow(self));
scanner.scan_for_lines(ctx); scanner.scan_for_lines(ctx);
/* There are no child contexts, so stop here. */ // There are no child contexts, so stop here.
// TODO(Issue #225): once there are 'inline-block' elements, this won't be // TODO(Issue #225): once there are 'inline-block' elements, this won't be
// true. In that case, set the InlineBlockBox's width to the // true. In that case, set the InlineBlockBox's width to the
@ -671,7 +678,7 @@ impl InlineFlowData {
// 'inline-block' box that created this flow before recursing. // 'inline-block' box that created this flow before recursing.
} }
pub fn assign_height_inline(&mut self, _ctx: &mut LayoutContext) { pub fn assign_height_inline(&mut self, _: &mut LayoutContext) {
// TODO(#226): Get the CSS `line-height` property from the containing block's style to // TODO(#226): Get the CSS `line-height` property from the containing block's style to
// determine minimum linebox height. // determine minimum linebox height.
// //
@ -683,16 +690,16 @@ impl InlineFlowData {
for self.lines.eachi |i, line_span| { for self.lines.eachi |i, line_span| {
debug!("assign_height_inline: processing line %u with box span: %?", i, line_span); debug!("assign_height_inline: processing line %u with box span: %?", i, line_span);
// coords relative to left baseline
// These coordinates are relative to the left baseline.
let mut linebox_bounding_box = Au::zero_rect(); let mut linebox_bounding_box = Au::zero_rect();
let boxes = &mut self.boxes; let boxes = &mut self.boxes;
for line_span.eachi |box_i| { for line_span.eachi |box_i| {
let cur_box: &mut RenderBox = boxes[box_i]; // FIXME: borrow checker workaround let cur_box = boxes[box_i]; // FIXME: borrow checker workaround
// Compute the height of each box. // Compute the height of each box.
let d = cur_box.d(); // FIXME: borrow checker workaround let d = cur_box.d(); // FIXME: borrow checker workaround
let cur_box: &mut RenderBox = boxes[box_i]; // FIXME: borrow checker workaround let cur_box = &mut *cur_box; // FIXME: borrow checker workaround
d.position.size.height = match *cur_box { d.position.size.height = match *cur_box {
ImageBox(_, ref img) => { ImageBox(_, ref img) => {
Au::from_px(img.size().height) Au::from_px(img.size().height)
@ -710,8 +717,9 @@ impl InlineFlowData {
} }
}; };
// Compute the bounding rect with the left baseline as origin. Linebox height is a // Compute the bounding rect with the left baseline as origin. Determining line box
// matter of lining up ideal baselines and then using the union of all these rects. // height is a matter of lining up ideal baselines and then taking the union of all
// these rects.
let bounding_box = match *cur_box { let bounding_box = match *cur_box {
// Adjust to baseline coordinates. // Adjust to baseline coordinates.
// //
@ -726,6 +734,7 @@ impl InlineFlowData {
}, },
// Adjust the bounding box metric to the box's horizontal offset. // Adjust the bounding box metric to the box's horizontal offset.
//
// TODO: We can use font metrics directly instead of re-measuring for the // TODO: We can use font metrics directly instead of re-measuring for the
// bounding box. // bounding box.
TextBox(_, data) => { TextBox(_, data) => {
@ -739,32 +748,39 @@ impl InlineFlowData {
cur_box.debug_str())) cur_box.debug_str()))
} }
}; };
debug!("assign_height_inline: bounding box for box b%d = %?", debug!("assign_height_inline: bounding box for box b%d = %?",
cur_box.d().id, cur_box.d().id,
bounding_box); bounding_box);
linebox_bounding_box = linebox_bounding_box.union(&bounding_box); linebox_bounding_box = linebox_bounding_box.union(&bounding_box);
debug!("assign_height_inline: linebox bounding box = %?", linebox_bounding_box); debug!("assign_height_inline: linebox bounding box = %?", linebox_bounding_box);
} }
let linebox_height = linebox_bounding_box.size.height; let linebox_height = linebox_bounding_box.size.height;
let baseline_offset = -linebox_bounding_box.origin.y; let baseline_offset = -linebox_bounding_box.origin.y;
// now go back and adjust y coordinates to match determined baseline
// Now go back and adjust the Y coordinates to match the baseline we determined.
for line_span.eachi |box_i| { for line_span.eachi |box_i| {
let cur_box = boxes[box_i]; let cur_box = boxes[box_i];
// TODO(Issue #226): this is completely wrong. Need to use element's
// 'line-height' when calculating linebox height. Then, go back over // TODO(#226): This is completely wrong. We need to use the element's `line-height`
// and set y offsets according to 'vertical-align' property of containing block. // when calculating line box height. Then we should go back over and set Y offsets
let halfleading = match cur_box { // according to the `vertical-align` property of the containing block.
@TextBox(_, data) => { let halfleading = match *cur_box {
TextBox(_, data) => {
(data.run.font.metrics.em_size - line_height).scale_by(0.5f) (data.run.font.metrics.em_size - line_height).scale_by(0.5f)
}, },
_ => Au(0), _ => Au(0),
}; };
cur_box.d().position.origin.y = cur_box.d().position.origin.y =
cur_y + halfleading + (baseline_offset - cur_box.d().position.size.height); cur_y + halfleading + (baseline_offset - cur_box.d().position.size.height);
} }
cur_y += Au::max(line_height, linebox_height); cur_y += Au::max(line_height, linebox_height);
} // /lines.each |line_span| } // End of `lines.each` loop.
self.common.position.size.height = cur_y; self.common.position.size.height = cur_y;
} }
@ -774,8 +790,8 @@ impl InlineFlowData {
dirty: &Rect<Au>, dirty: &Rect<Au>,
offset: &Point2D<Au>, offset: &Point2D<Au>,
list: &Cell<DisplayList>) { list: &Cell<DisplayList>) {
// TODO(Issue #228): once we form line boxes and have their cached bounds, we can be // TODO(#228): Once we form line boxes and have their cached bounds, we can be smarter and
// smarter and not recurse on a line if nothing in it can intersect dirty // not recurse on a line if nothing in it can intersect the dirty region.
debug!("FlowContext[%d]: building display list for %u inline boxes", debug!("FlowContext[%d]: building display list for %u inline boxes",
self.common.id, self.common.id,
self.boxes.len()); self.boxes.len());
@ -784,8 +800,8 @@ impl InlineFlowData {
box.build_display_list(builder, dirty, offset, list) box.build_display_list(builder, dirty, offset, list)
} }
// TODO(Issue #225): should inline-block elements have flows as children // TODO(#225): Should `inline-block` elements have flows as children of the inline flow or
// of the inline flow, or should the flow be nested inside the box somehow? // should the flow be nested inside the box somehow?
} }
}
} // @FlowContext : InlineLayout