LibWeb: First slightly naive implementation of CSS floats :^)

Boxes can now be floated left or right, which makes text within the
same block formatting context flow around them.

We were creating way too many block formatting contexts. As it turns
out, we don't need one for every new block, but rather there's a set
of rules that determines whether a given block creates a new block
formatting context.

Each BFC keeps track of the floating boxes within it, and IFC's can
then query it to find the available space for line boxes.

There's a huge hack in here where we assume all lines are the exact
line-height. Making this work with vertically non-uniform lines will
require some architectural changes.

1 files changed, 14 insertions, 12 deletions

diff --git a/Libraries/LibWeb/Layout/TextNode.cpp b/Libraries/LibWeb/Layout/TextNode.cpp
index 3846627fa0..0433167093 100644
--- a/Libraries/LibWeb/Layout/TextNode.cpp
+++ b/Libraries/LibWeb/Layout/TextNode.cpp
@@ -31,6 +31,7 @@
 #include <LibGfx/Font.h>
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/Layout/BlockBox.h>
+#include <LibWeb/Layout/InlineFormattingContext.h>
 #include <LibWeb/Layout/TextNode.h>
 #include <LibWeb/Page/Frame.h>
 #include <ctype.h>
@@ -189,14 +190,15 @@ void TextNode::for_each_chunk(Callback callback, LayoutMode layout_mode, bool do
         commit_chunk(view.end(), false, true);
 }
 
-void TextNode::split_into_lines_by_rules(BlockBox& container, LayoutMode layout_mode, bool do_collapse, bool do_wrap_lines, bool do_wrap_breaks)
+void TextNode::split_into_lines_by_rules(InlineFormattingContext& context, LayoutMode layout_mode, bool do_collapse, bool do_wrap_lines, bool do_wrap_breaks)
 {
+    auto& containing_block = context.context_box();
     auto& font = specified_style().font();
     float space_width = font.glyph_width(' ') + font.glyph_spacing();
 
-    auto& line_boxes = container.line_boxes();
-    container.ensure_last_line_box();
-    float available_width = container.width() - line_boxes.last().width();
+    auto& line_boxes = containing_block.line_boxes();
+    containing_block.ensure_last_line_box();
+    float available_width = context.available_width_at_line(line_boxes.size()) - line_boxes.last().width();
 
     // Collapse whitespace into single spaces
     if (do_collapse) {
@@ -261,8 +263,8 @@ void TextNode::split_into_lines_by_rules(BlockBox& container, LayoutMode layout_
                 chunk_width = font.width(chunk.view) + font.glyph_spacing();
 
             if (line_boxes.last().width() > 0 && chunk_width > available_width) {
-                container.add_line_box();
-                available_width = container.width();
+                containing_block.add_line_box();
+                available_width = context.available_width_at_line(line_boxes.size());
             }
             if (need_collapse & line_boxes.last().fragments().is_empty())
                 continue;
@@ -275,21 +277,21 @@ void TextNode::split_into_lines_by_rules(BlockBox& container, LayoutMode layout_
 
         if (do_wrap_lines) {
             if (available_width < 0) {
-                container.add_line_box();
-                available_width = container.width();
+                containing_block.add_line_box();
+                available_width = context.available_width_at_line(line_boxes.size());
             }
         }
 
         if (do_wrap_breaks) {
             if (chunk.is_break) {
-                container.add_line_box();
-                available_width = container.width();
+                containing_block.add_line_box();
+                available_width = context.available_width_at_line(line_boxes.size());
             }
         }
     }
 }
 
-void TextNode::split_into_lines(BlockBox& container, LayoutMode layout_mode)
+void TextNode::split_into_lines(InlineFormattingContext& context, LayoutMode layout_mode)
 {
     bool do_collapse = true;
     bool do_wrap_lines = true;
@@ -313,7 +315,7 @@ void TextNode::split_into_lines(BlockBox& container, LayoutMode layout_mode)
         do_wrap_breaks = true;
     }
 
-    split_into_lines_by_rules(container, layout_mode, do_collapse, do_wrap_lines, do_wrap_breaks);
+    split_into_lines_by_rules(context, layout_mode, do_collapse, do_wrap_lines, do_wrap_breaks);
 }
 
 }