LibWeb: Don't lose track of inline margins when collapsing whitespace

When iterating inline level chunks for a piece of text like " hello ",
we will get three separate items from InlineLevelIterator:

- Text " "
- Text "hello"
- Text " "

If the first item also had some leading margin (e.g margin-left: 10px)
we would lose that information when deciding that the whitespace is
collapsible.

This patch fixes the issue by accumulating the amount of leading margin
present in any collapsed whitespace items, and then adding them to the
next non-whitespace item in IFC.

It's a wee bit hackish, but so is the rest of the leading/trailing
margin mechanism.

This makes the header menu on https://www.gimp.org/ look proper. :^)
This commit is contained in:
Andreas Kling 2024-01-20 20:15:09 +01:00
parent c1161111a7
commit 1041dbb007
Notes: sideshowbarker 2024-07-17 04:10:16 +09:00
3 changed files with 39 additions and 0 deletions

View file

@ -0,0 +1,20 @@
Viewport <#document> at (0,0) content-size 800x600 children: not-inline
BlockContainer <html> at (0,0) content-size 800x33 [BFC] children: not-inline
BlockContainer <body> at (8,8) content-size 784x17 children: inline
InlineNode <div>
frag 0 from TextNode start: 1, length: 9, rect: [28,8 82.125x17] baseline: 13.296875
"Download "
TextNode <#text>
InlineNode <div>
frag 0 from TextNode start: 1, length: 4, rect: [150,8 39.5625x17] baseline: 13.296875
"News"
TextNode <#text>
TextNode <#text>
ViewportPaintable (Viewport<#document>) [0,0 800x600]
PaintableWithLines (BlockContainer<HTML>) [0,0 800x33]
PaintableWithLines (BlockContainer<BODY>) [8,8 784x17]
InlinePaintable (InlineNode<DIV>)
TextPaintable (TextNode<#text>)
InlinePaintable (InlineNode<DIV>)
TextPaintable (TextNode<#text>)

View file

@ -0,0 +1,10 @@
<!doctype html><style>
* {
outline: 1px solid black;
}
div {
display: inline;
margin-left: 20px;
margin-right: 20px;
}
</style><body><div> Download </div><div> News </div>

View file

@ -249,6 +249,11 @@ void InlineFormattingContext::generate_line_boxes(LayoutMode layout_mode)
InlineLevelIterator iterator(*this, m_state, containing_block(), layout_mode);
LineBuilder line_builder(*this, m_state);
// NOTE: When we ignore collapsible whitespace chunks at the start of a line,
// we have to remember how much start margin that chunk had in the inline
// axis, so that we can add it to the first non-whitespace chunk.
CSSPixels leading_margin_from_collapsible_whitespace = 0;
for (;;) {
auto item_opt = iterator.next();
if (!item_opt.has_value())
@ -262,9 +267,13 @@ void InlineFormattingContext::generate_line_boxes(LayoutMode layout_mode)
if (next_width > 0)
line_builder.break_if_needed(next_width);
}
leading_margin_from_collapsible_whitespace += item.margin_start;
continue;
}
item.margin_start += leading_margin_from_collapsible_whitespace;
leading_margin_from_collapsible_whitespace = 0;
switch (item.type) {
case InlineLevelIterator::Item::Type::ForcedBreak: {
line_builder.break_line(LineBuilder::ForcedBreak::Yes);