Separate LineBreaker from RenderBlockLineLayout

Source/core/rendering/line/BreakingContext.cpp

Index: Source/core/rendering/line/BreakingContext.cpp
diff --git a/Source/core/rendering/line/BreakingContext.cpp b/Source/core/rendering/line/BreakingContext.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..95bd0a781eb870a5ac36082e9f1bfbf93f25ce70
--- /dev/null
+++ b/Source/core/rendering/line/BreakingContext.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
+ * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
+ * Copyright (C) 2010 Google Inc. All rights reserved.
+ * Copyright (C) 2013 Adobe Systems Incorporated.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "config.h"
+#include "core/rendering/line/BreakingContextInlineHeaders.h"
+
+namespace WebCore {
+
+InlineIterator BreakingContext::handleEndOfLine()
+{
+    ShapeInsideInfo* shapeInfo = m_block->layoutShapeInsideInfo();
+    bool segmentAllowsOverflow = !shapeInfo || !shapeInfo->hasSegments();
+
+    if (m_lineBreak == m_resolver.position() && (!m_lineBreak.object() || !m_lineBreak.object()->isBR()) && segmentAllowsOverflow) {
+        // we just add as much as possible
+        if (m_blockStyle->whiteSpace() == PRE && !m_current.offset()) {
+            m_lineBreak.moveTo(m_lastObject, m_lastObject->isText() ? m_lastObject->length() : 0);
+        } else if (m_lineBreak.object()) {
+            // Don't ever break in the middle of a word if we can help it.
+            // There's no room at all. We just have to be on this line,
+            // even though we'll spill out.
+            m_lineBreak.moveTo(m_current.object(), m_current.offset());
+        }
+    }
+
+    // FIXME Bug 100049: We do not need to consume input in a multi-segment line
+    // unless no segment will.
+    // make sure we consume at least one char/object.
+    if (m_lineBreak == m_resolver.position() && segmentAllowsOverflow)
+        m_lineBreak.increment();
+
+    // Sanity check our midpoints.
+    m_lineMidpointState.checkMidpoints(m_lineBreak);
+
+    m_trailingObjects.updateMidpointsForTrailingBoxes(m_lineMidpointState, m_lineBreak, TrailingObjects::CollapseFirstSpace);
+
+    // We might have made lineBreak an iterator that points past the end
+    // of the object. Do this adjustment to make it point to the start
+    // of the next object instead to avoid confusing the rest of the
+    // code.
+    if (m_lineBreak.offset()) {
+        // This loop enforces the invariant that line breaks should never point
+        // at an empty inline. See http://crbug.com/305904.
+        do {
+            m_lineBreak.setOffset(m_lineBreak.offset() - 1);
+            m_lineBreak.increment();
+        } while (!m_lineBreak.atEnd() && isEmptyInline(m_lineBreak.object()));
+    }
+
+    return m_lineBreak;
+}
+
+}