Make first-letter style to work with editing

Source/core/dom/Position.cpp

Index: Source/core/dom/Position.cpp
diff --git a/Source/core/dom/Position.cpp b/Source/core/dom/Position.cpp
index c917fb5bf97a64c57766a55d202d19a370c2d1c6..7aaad8f3763b03fcd163760beb468c559717f566 100644
--- a/Source/core/dom/Position.cpp
+++ b/Source/core/dom/Position.cpp
@@ -42,7 +42,7 @@
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/RenderBlock.h"
 #include "core/rendering/RenderInline.h"
-#include "core/rendering/RenderText.h"
+#include "core/rendering/RenderTextFragment.h"
 #include "wtf/text/CString.h"
 #include "wtf/unicode/CharacterNames.h"
 
@@ -457,16 +457,45 @@ bool Position::atEndOfTree() const
     return !findParent(deprecatedNode()) && m_offset >= lastOffsetForEditing(deprecatedNode());
 }
 
-int Position::renderedOffset() const
+RenderObject* Position::renderer() const
 {
-    if (!deprecatedNode()->isTextNode())
-        return m_offset;
+    if (!m_anchorNode)
+        return 0;
+    RenderObject* renderer = m_anchorNode->renderer();
+    if (!renderer || !renderer->isText() || !toRenderText(renderer)->isTextFragment())
+        return renderer;
+    if (m_offset >= static_cast<int>(toRenderTextFragment(renderer)->textStartOffset()))
+        return renderer;
+    return toRenderTextFragment(renderer)->firstRenderTextInFirstLetter();
+}
+
+int Position::offsetInRenderer() const
+{
+    switch (m_isLegacyEditingPosition ? PositionIsOffsetInAnchor : m_anchorType) {
+    case PositionIsBeforeChildren:
+    case PositionIsBeforeAnchor:
+    case PositionIsOffsetInAnchor: {
+        RenderObject* renderer = this->renderer();
+        if (!renderer || !renderer->isText())
+            return m_offset;
+        return m_offset - toRenderText(renderer)->textStartOffset();
+    }
+    case PositionIsAfterChildren:
+    case PositionIsAfterAnchor:
+        return offsetForPositionAfterAnchor();
+    }
+    ASSERT_NOT_REACHED();
+    return m_offset;
+}
 
-    if (!deprecatedNode()->renderer())
+int Position::renderedOffset() const
+{
+    RenderObject* renderer = this->renderer();
+    if (!renderer || !renderer->isText())
         return m_offset;
 
-    int result = 0;
-    RenderText* textRenderer = toRenderText(deprecatedNode()->renderer());
+    RenderText* textRenderer = toRenderText(renderer);
+    int result = textRenderer->textStartOffset();
     for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
         int start = box->start();
         int end = box->start() + box->len();
@@ -596,14 +625,17 @@ Position Position::upstream(EditingBoundaryCrossingRule rule) const
     PositionIterator lastVisible = m_anchorType == PositionIsAfterAnchor ? createLegacyEditingPosition(m_anchorNode.get(), caretMaxOffset(m_anchorNode.get())) : *this;
     PositionIterator currentPos = lastVisible;
     bool startEditable = startNode->rendererIsEditable();
+    RenderObject* startRenderer = renderer();
     Node* lastNode = startNode;
+    RenderObject* lastRenderer = startRenderer;
     bool boundaryCrossed = false;
     for (; !currentPos.atStart(); currentPos.decrement()) {
         Node* currentNode = currentPos.node();
+        RenderObject* currentRenderer = currentPos.renderer();
 
         // Don't check for an editability change if we haven't moved to a different node,
         // to avoid the expense of computing rendererIsEditable().
-        if (currentNode != lastNode) {
+        if (currentRenderer != lastRenderer) {
             // Don't change editability.
             bool currentEditable = currentNode->rendererIsEditable();
             if (startEditable != currentEditable) {
@@ -612,6 +644,7 @@ Position Position::upstream(EditingBoundaryCrossingRule rule) const
                 boundaryCrossed = true;
             }
             lastNode = currentNode;
+            lastRenderer = currentPos.renderer();
         }
 
         // If we've moved to a position that is visually distinct, return the last saved position. There
@@ -620,8 +653,7 @@ Position Position::upstream(EditingBoundaryCrossingRule rule) const
             return lastVisible;
 
         // skip position in unrendered or invisible node
-        RenderObject* renderer = currentNode->renderer();
-        if (!renderer || renderer->style()->visibility() != VISIBLE)
+        if (!currentRenderer || currentRenderer->style()->visibility() != VISIBLE)
             continue;
 
         if (rule == CanCrossEditingBoundary && boundaryCrossed) {
@@ -646,18 +678,12 @@ Position Position::upstream(EditingBoundaryCrossingRule rule) const
         }
 
         // return current position if it is in rendered text
-        if (renderer->isText() && toRenderText(renderer)->firstTextBox()) {
-            if (currentNode != startNode) {
-                // This assertion fires in layout tests in the case-transform.html test because
-                // of a mix-up between offsets in the text in the DOM tree with text in the
-                // render tree which can have a different length due to case transformation.
-                // Until we resolve that, disable this so we can run the layout tests!
-                //ASSERT(currentOffset >= renderer->caretMaxOffset());
-                return createLegacyEditingPosition(currentNode, renderer->caretMaxOffset());
-            }
+        if (currentRenderer->isText() && toRenderText(currentRenderer)->firstTextBox()) {
+            RenderText* textRenderer = toRenderText(currentRenderer);
+            if (currentRenderer != startRenderer)
+                return createLegacyEditingPosition(currentNode, textRenderer->caretMaxOffset() + textRenderer->textStartOffset());
 
-            unsigned textOffset = currentPos.offsetInLeafNode();
-            RenderText* textRenderer = toRenderText(renderer);
+            unsigned textOffset = currentPos.offsetInLeafNode() - textRenderer->textStartOffset();
             InlineTextBox* lastTextBox = textRenderer->lastTextBox();
             for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                 if (textOffset <= box->start() + box->len()) {
@@ -719,14 +745,17 @@ Position Position::downstream(EditingBoundaryCrossingRule rule) const
     PositionIterator lastVisible = m_anchorType == PositionIsAfterAnchor ? createLegacyEditingPosition(m_anchorNode.get(), caretMaxOffset(m_anchorNode.get())) : *this;
     PositionIterator currentPos = lastVisible;
     bool startEditable = startNode->rendererIsEditable();
+    RenderObject* startRenderer = renderer();
     Node* lastNode = startNode;
+    RenderObject* lastRenderer = startRenderer;
     bool boundaryCrossed = false;
     for (; !currentPos.atEnd(); currentPos.increment()) {
         Node* currentNode = currentPos.node();
+        RenderObject* currentRenderer = currentPos.renderer();
 
         // Don't check for an editability change if we haven't moved to a different node,
         // to avoid the expense of computing rendererIsEditable().
-        if (currentNode != lastNode) {
+        if (currentRenderer!= lastRenderer) {
             // Don't change editability.
             bool currentEditable = currentNode->rendererIsEditable();
             if (startEditable != currentEditable) {
@@ -736,6 +765,7 @@ Position Position::downstream(EditingBoundaryCrossingRule rule) const
             }
 
             lastNode = currentNode;
+            lastRenderer = currentRenderer;
         }
 
         // stop before going above the body, up into the head
@@ -753,8 +783,7 @@ Position Position::downstream(EditingBoundaryCrossingRule rule) const
             return lastVisible;
 
         // skip position in unrendered or invisible node
-        RenderObject* renderer = currentNode->renderer();
-        if (!renderer || renderer->style()->visibility() != VISIBLE)
+        if (!currentRenderer || currentRenderer->style()->visibility() != VISIBLE)
             continue;
 
         if (rule == CanCrossEditingBoundary && boundaryCrossed) {
@@ -768,20 +797,18 @@ Position Position::downstream(EditingBoundaryCrossingRule rule) const
 
         // Return position before tables and nodes which have content that can be ignored.
         if (editingIgnoresContent(currentNode) || isTableElement(currentNode)) {
-            if (currentPos.offsetInLeafNode() <= renderer->caretMinOffset())
-                return createLegacyEditingPosition(currentNode, renderer->caretMinOffset());
+            if (currentPos.offsetInLeafNode() <= currentRenderer->caretMinOffset())
+                return createLegacyEditingPosition(currentNode, currentRenderer->caretMinOffset());
             continue;
         }
 
         // return current position if it is in rendered text
-        if (renderer->isText() && toRenderText(renderer)->firstTextBox()) {
-            if (currentNode != startNode) {
-                ASSERT(currentPos.atStartOfNode());
-                return createLegacyEditingPosition(currentNode, renderer->caretMinOffset());
-            }
+        if (currentRenderer->isText() && toRenderText(currentRenderer)->firstTextBox()) {
+            RenderText* textRenderer = toRenderText(currentRenderer);
+            if (currentRenderer != startRenderer)
+                return createLegacyEditingPosition(currentNode, textRenderer->caretMinOffset() + textRenderer->textStartOffset());
 
-            unsigned textOffset = currentPos.offsetInLeafNode();
-            RenderText* textRenderer = toRenderText(renderer);
+            unsigned textOffset = currentPos.offsetInLeafNode() - textRenderer->textStartOffset();
             InlineTextBox* lastTextBox = textRenderer->lastTextBox();
             for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
                 if (textOffset <= box->end()) {
@@ -842,9 +869,16 @@ bool Position::hasRenderedNonAnonymousDescendantsWithHeight(RenderObject* render
     return false;
 }
 
+// FIXME: Caller of nodeIsUserSelectNode() should consider first letter and
+// remaining text have different user-select CSS property.
 bool Position::nodeIsUserSelectNone(Node* node)
 {
-    return node && node->renderer() && node->renderer()->style()->userSelect() == SELECT_NONE && node->renderer()->style()->userModify() == READ_ONLY;
+    return node && rendererIsUserSelectNone(node->renderer());
+}
+
+bool Position::rendererIsUserSelectNone(RenderObject* renderer)
+{
+    return renderer && renderer->style()->userSelect() == SELECT_NONE && renderer->style()->userModify() == READ_ONLY;
 }
 
 ContainerNode* Position::findParent(const Node* node)
@@ -883,10 +917,7 @@ Node* Position::rootUserSelectAllForNode(Node* node)
 
 bool Position::isCandidate() const
 {
-    if (isNull())
-        return false;
-
-    RenderObject* renderer = deprecatedNode()->renderer();
+    RenderObject* renderer = this->renderer();
     if (!renderer)
         return false;
 
@@ -898,7 +929,7 @@ bool Position::isCandidate() const
         return !m_offset && m_anchorType != PositionIsAfterAnchor && !nodeIsUserSelectNone(deprecatedNode()->parentNode());
 
     if (renderer->isText())
-        return !nodeIsUserSelectNone(deprecatedNode()) && inRenderedText();
+        return !rendererIsUserSelectNone(renderer) && inRenderedText();
 
     if (isTableElement(deprecatedNode()) || editingIgnoresContent(deprecatedNode()))
         return (atFirstEditingPositionForNode() || atLastEditingPositionForNode()) && !nodeIsUserSelectNone(deprecatedNode()->parentNode());
@@ -920,24 +951,23 @@ bool Position::isCandidate() const
 
 bool Position::inRenderedText() const
 {
-    if (isNull() || !deprecatedNode()->isTextNode())
+    RenderObject* renderer = this->renderer();
+    if (!renderer || !renderer->isText())
         return false;
 
-    RenderObject* renderer = deprecatedNode()->renderer();
-    if (!renderer)
-        return false;
-
-    RenderText *textRenderer = toRenderText(renderer);
+    RenderText* textRenderer = toRenderText(renderer);
+    int offset = m_offset - textRenderer->textStartOffset();
     for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
-        if (m_offset < static_cast<int>(box->start()) && !textRenderer->containsReversedText()) {
+        if (offset < static_cast<int>(box->start()) && !textRenderer->containsReversedText()) {
             // The offset we're looking for is before this node
             // this means the offset must be in content that is
             // not rendered. Return false.
             return false;
         }
-        if (box->containsCaretOffset(m_offset))
+        if (box->containsCaretOffset(offset)) {
             // Return false for offsets inside composed characters.
-            return m_offset == 0 || m_offset == textRenderer->nextOffset(textRenderer->previousOffset(m_offset));
+            return !offset || offset == textRenderer->nextOffset(textRenderer->previousOffset(offset));
+        }
     }
 
     return false;
@@ -945,22 +975,20 @@ bool Position::inRenderedText() const
 
 bool Position::isRenderedCharacter() const
 {
-    if (isNull() || !deprecatedNode()->isTextNode())
-        return false;
-
-    RenderObject* renderer = deprecatedNode()->renderer();
-    if (!renderer)
+    RenderObject* renderer = this->renderer();
+    if (!renderer || !renderer->isText())
         return false;
 
     RenderText* textRenderer = toRenderText(renderer);
+    int offset = m_offset - textRenderer->textStartOffset();
     for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
-        if (m_offset < static_cast<int>(box->start()) && !textRenderer->containsReversedText()) {
+        if (offset < static_cast<int>(box->start()) && !textRenderer->containsReversedText()) {
             // The offset we're looking for is before this node
             // this means the offset must be in content that is
             // not rendered. Return false.
             return false;
         }
-        if (m_offset >= static_cast<int>(box->start()) && m_offset < static_cast<int>(box->start() + box->len()))
+        if (offset >= static_cast<int>(box->start()) && offset < static_cast<int>(box->start() + box->len()))
             return true;
     }
 
@@ -969,14 +997,11 @@ bool Position::isRenderedCharacter() const
 
 bool Position::rendersInDifferentPosition(const Position &pos) const
 {
-    if (isNull() || pos.isNull())
-        return false;
-
-    RenderObject* renderer = deprecatedNode()->renderer();
+    RenderObject* renderer = this->renderer();
     if (!renderer)
         return false;
 
-    RenderObject* posRenderer = pos.deprecatedNode()->renderer();
+    RenderObject* posRenderer = pos.renderer();
     if (!posRenderer)
         return false;
 
@@ -1157,7 +1182,7 @@ static Position upstreamIgnoringEditingBoundaries(Position position)
 void Position::getInlineBoxAndOffset(EAffinity affinity, TextDirection primaryDirection, InlineBox*& inlineBox, int& caretOffset) const
 {
     caretOffset = deprecatedEditingOffset();
-    RenderObject* renderer = deprecatedNode()->renderer();
+    RenderObject* renderer = this->renderer();
 
     if (!renderer->isText()) {
         inlineBox = 0;
@@ -1186,6 +1211,16 @@ void Position::getInlineBoxAndOffset(EAffinity affinity, TextDirection primaryDi
         InlineTextBox* box;
         InlineTextBox* candidate = 0;
 
+        if (textRenderer->isTextFragment() && toRenderTextFragment(textRenderer)->firstLetter()) {
+            if (caretOffset) {
+                caretOffset -= textRenderer->textStartOffset();
+            } else {
+                textRenderer = toRenderTextFragment(textRenderer)->firstRenderTextInFirstLetter();
+                if (!textRenderer)
+                    return;
+            }
+        }
+
         for (box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
             int caretMinOffset = box->caretMinOffset();
             int caretMaxOffset = box->caretMaxOffset();