Make NGInlineItemsBuilder construct whitespace-collapsed offset mapping

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.cc

Index: third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.cc b/third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.cc
index 8533bd9907a97669386f62a25511a084d274f610..a90f5e958330b01b567110ee7db8afd8e04c31c4 100644
--- a/third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.cc
+++ b/third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.cc
@@ -5,6 +5,7 @@
 #include "core/layout/ng/inline/ng_inline_items_builder.h"
 
 #include "core/layout/LayoutObject.h"
+#include "core/layout/ng/api/ng_offset_mapping_builder.h"
 #include "core/layout/ng/inline/ng_inline_node.h"
 #include "core/style/ComputedStyle.h"
 
@@ -156,8 +157,14 @@ void NGInlineItemsBuilder::AppendWithWhiteSpaceCollapsing(
         return;
       }
 
-      if (last_collapsible_space_ == CollapsibleSpace::kNone)
+      if (last_collapsible_space_ == CollapsibleSpace::kNone) {
         text_.Append(kSpaceCharacter);
+        if (mapping_builder_)
+          mapping_builder_->AppendIdentityMapping(1);
+      } else {
+        if (mapping_builder_)
+          mapping_builder_->AppendCollapsedMapping(1);
+      }
       last_collapsible_space_ = CollapsibleSpace::kNewline;
       i++;
       continue;
@@ -167,6 +174,11 @@ void NGInlineItemsBuilder::AppendWithWhiteSpaceCollapsing(
       if (last_collapsible_space_ == CollapsibleSpace::kNone) {
         text_.Append(kSpaceCharacter);
         last_collapsible_space_ = CollapsibleSpace::kSpace;
+        if (mapping_builder_)
+          mapping_builder_->AppendIdentityMapping(1);
+      } else {
+        if (mapping_builder_)
+          mapping_builder_->AppendCollapsedMapping(1);
       }
       i++;
       continue;
@@ -181,6 +193,8 @@ void NGInlineItemsBuilder::AppendWithWhiteSpaceCollapsing(
     if (end_of_non_space == kNotFound)
       end_of_non_space = string.length();
     text_.Append(string, i, end_of_non_space - i);
+    if (mapping_builder_)
+      mapping_builder_->AppendIdentityMapping(end_of_non_space - i);

[yosin_UTC9, 2017/06/28 01:44:21]

So, do we call mapping builder for every word?

[Xiaocheng, 2017/06/28 02:05:20]

Yes. To decouple the mapping builder with impl details in whitespace collapsing
and inline collection, it should be notified of every change to |text_| and
every collapsed space.

     i = end_of_non_space;
     last_collapsible_space_ = CollapsibleSpace::kNone;
   }
@@ -210,6 +224,8 @@ void NGInlineItemsBuilder::AppendWithoutWhiteSpaceCollapsing(
       end = string.length();
     unsigned start_offset = text_.length();
     text_.Append(string, start, end - start);
+    if (mapping_builder_)
+      mapping_builder_->AppendIdentityMapping(end - start);
     AppendItem(items_, NGInlineItem::kText, start_offset, text_.length(), style,
                layout_object);
     start = end;
@@ -256,6 +272,8 @@ void NGInlineItemsBuilder::Append(NGInlineItem::NGInlineItemType type,
   DCHECK_NE(character, kZeroWidthSpaceCharacter);
 
   text_.Append(character);
+  if (mapping_builder_)
+    mapping_builder_->AppendIdentityMapping(1);
   unsigned end_offset = text_.length();
   AppendItem(items_, type, end_offset - 1, end_offset, style, layout_object);
   last_collapsible_space_ = CollapsibleSpace::kNone;
@@ -264,6 +282,8 @@ void NGInlineItemsBuilder::Append(NGInlineItem::NGInlineItemType type,
 void NGInlineItemsBuilder::AppendOpaque(NGInlineItem::NGInlineItemType type,
                                         UChar character) {
   text_.Append(character);
+  if (mapping_builder_)
+    mapping_builder_->AppendIdentityMapping(1);
   unsigned end_offset = text_.length();
   AppendItem(items_, type, end_offset - 1, end_offset, nullptr, nullptr);
 }
@@ -327,6 +347,8 @@ void NGInlineItemsBuilder::RemoveTrailingCollapsibleSpace(unsigned index) {
 
   text_.erase(index);
   last_collapsible_space_ = CollapsibleSpace::kNone;
+  if (mapping_builder_)
+    mapping_builder_->CollapseTrailingSpace(text_.length() - index);
 
   // Adjust items if the removed space is already included.
   for (unsigned i = items_->size(); i > 0;) {