Fix various issues with overflow clipping

When dealing absolutely positioned items, we should use clip of our
containing block, even if our containing block doesn't itself establish
a new overflow clip. Additionally, we need to properly handle
assigning scroll root ids to fragments of inline elements.

We add a test for this behavior.
This commit is contained in:
Martin Robinson 2017-04-14 20:07:42 +02:00
parent f537fbd08f
commit 4213b320d1
4 changed files with 111 additions and 6 deletions

View file

@ -92,6 +92,13 @@ fn convert_repeat_mode(from: RepeatKeyword) -> RepeatMode {
}
}
fn establishes_containing_block_for_absolute(positioning: position::T) -> bool {
match positioning {
position::T::absolute | position::T::relative | position::T::fixed => true,
_ => false,
}
}
trait RgbColor {
fn rgb(r: u8, g: u8, b: u8) -> Self;
}
@ -1953,6 +1960,10 @@ impl BlockFlowDisplayListBuilding for BlockFlow {
// we don't want it to be clipped by its own scroll root.
let containing_scroll_root_id = self.setup_scroll_root_for_block(state);
if establishes_containing_block_for_absolute(self.positioning()) {
state.containing_block_scroll_root_id = state.current_scroll_root_id;
}
match block_stacking_context_type {
BlockStackingContextType::NonstackingContext => {
self.base.collect_stacking_contexts_for_children(state);
@ -2038,12 +2049,6 @@ impl BlockFlowDisplayListBuilding for BlockFlow {
self.base.scroll_root_id = new_scroll_root_id;
state.current_scroll_root_id = new_scroll_root_id;
match self.positioning() {
position::T::absolute | position::T::relative | position::T::fixed =>
state.containing_block_scroll_root_id = new_scroll_root_id,
_ => {}
}
containing_scroll_root_id
}
@ -2153,6 +2158,11 @@ impl InlineFlowDisplayListBuilding for InlineFlow {
self.base.scroll_root_id = state.current_scroll_root_id;
for mut fragment in self.fragments.fragments.iter_mut() {
let previous_containing_block_scroll_root_id = state.containing_block_scroll_root_id;
if establishes_containing_block_for_absolute(fragment.style.get_box().position) {
state.containing_block_scroll_root_id = state.current_scroll_root_id;
}
match fragment.specific {
SpecificFragmentInfo::InlineBlock(ref mut block_flow) => {
let block_flow = FlowRef::deref_mut(&mut block_flow.flow_ref);
@ -2162,6 +2172,10 @@ impl InlineFlowDisplayListBuilding for InlineFlow {
let block_flow = FlowRef::deref_mut(&mut block_flow.flow_ref);
block_flow.collect_stacking_contexts(state);
}
SpecificFragmentInfo::InlineAbsolute(ref mut block_flow) => {
let block_flow = FlowRef::deref_mut(&mut block_flow.flow_ref);
block_flow.collect_stacking_contexts(state);
}
_ if fragment.establishes_stacking_context() => {
fragment.stacking_context_id =
StackingContextId::new_of_type(fragment.fragment_id(),
@ -2178,6 +2192,7 @@ impl InlineFlowDisplayListBuilding for InlineFlow {
}
_ => fragment.stacking_context_id = state.current_stacking_context_id,
}
state.containing_block_scroll_root_id = previous_containing_block_scroll_root_id;
}
}