Add Multicolumn support block fragmentation.

This commit is contained in:
Simon Sapin 2015-12-30 23:50:24 +00:00
parent 359b984348
commit 5498b54347
10 changed files with 373 additions and 51 deletions

View file

@ -35,7 +35,7 @@ use flow_ref::{self, FlowRef, WeakFlowRef};
use fragment::{Fragment, FragmentBorderBoxIterator, SpecificFragmentInfo};
use gfx::display_list::{ClippingRegion, DisplayList};
use gfx_traits::{LayerId, LayerType};
use incremental::{RECONSTRUCT_FLOW, REFLOW, REFLOW_OUT_OF_FLOW, RestyleDamage};
use incremental::{RECONSTRUCT_FLOW, REFLOW, REFLOW_OUT_OF_FLOW, REPAINT, RestyleDamage};
use inline::InlineFlow;
use model::{CollapsibleMargins, IntrinsicISizes, MarginCollapseInfo};
use multicol::MulticolFlow;
@ -203,22 +203,21 @@ pub trait Flow: fmt::Debug + Sync + Send + 'static {
/// Like `assign_block_size`, but is recurses explicitly into descendants.
/// Fit as much content as possible within `available_block_size`.
/// If thats not all of it,
/// return an indication of where in the tree to break and start the next fragment.
///
/// FIXME: replace `()` in the return value with something meaningful.
/// If thats not all of it, truncate the contents of `self`
/// and return a new flow similar to `self` with the rest of the content.
///
/// The default is to make a flow "atomic": it can not be fragmented.
fn fragment<'a>(&mut self, ctx: &'a LayoutContext<'a>, _available_block_size: Au)
-> Option<()> {
fn recursive_assign_block_size<'a, F: ?Sized + Flow>
(flow: &mut F, ctx: &'a LayoutContext<'a>) {
fn fragment(&mut self,
layout_context: &LayoutContext,
_fragmentation_context: Option<FragmentationContext>)
-> Option<FlowRef> {
fn recursive_assign_block_size<F: ?Sized + Flow>(flow: &mut F, ctx: &LayoutContext) {
for child in mut_base(flow).children.iter_mut() {
recursive_assign_block_size(child, ctx)
}
flow.assign_block_size(ctx);
}
recursive_assign_block_size(self, ctx);
recursive_assign_block_size(self, layout_context);
None
}
@ -538,6 +537,7 @@ pub enum FlowClass {
TableCaption,
TableCell,
Multicol,
MulticolColumn,
Flex,
}
@ -799,6 +799,7 @@ pub type AbsoluteDescendantOffsetIter<'a> = Zip<AbsoluteDescendantIter<'a>, Iter
/// Information needed to compute absolute (i.e. viewport-relative) flow positions (not to be
/// confused with absolutely-positioned flows) that is computed during block-size assignment.
#[derive(Copy, Clone)]
pub struct EarlyAbsolutePositionInfo {
/// The size of the containing block for relatively-positioned descendants.
pub relative_containing_block_size: LogicalSize<Au>,
@ -836,6 +837,12 @@ impl LateAbsolutePositionInfo {
}
}
#[derive(Copy, Clone, Debug)]
pub struct FragmentationContext {
pub available_block_size: Au,
pub this_fragment_is_empty: bool,
}
/// Data common to all flows.
pub struct BaseFlow {
pub restyle_damage: RestyleDamage,
@ -1092,6 +1099,23 @@ impl BaseFlow {
}
}
/// Return a new BaseFlow like this one but with the given children list
pub fn clone_with_children(&self, children: FlowList) -> BaseFlow {
BaseFlow {
children: children,
restyle_damage: self.restyle_damage | REPAINT | REFLOW_OUT_OF_FLOW | REFLOW,
parallel: FlowParallelInfo::new(),
display_list_building_result: None,
floats: self.floats.clone(),
abs_descendants: self.abs_descendants.clone(),
absolute_cb: self.absolute_cb.clone(),
clip: self.clip.clone(),
..*self
}
}
pub fn child_iter(&mut self) -> MutFlowListIterator {
self.children.iter_mut()
}
@ -1454,6 +1478,7 @@ impl MutableOwnedFlowUtils for FlowRef {
/// invalidation and use-after-free.
///
/// FIXME(pcwalton): I think this would be better with a borrow flag instead of `unsafe`.
#[derive(Clone)]
pub struct ContainingBlockLink {
/// The pointer up to the containing block.
link: Option<WeakFlowRef>,