[Editing][CodeHealth] Move Position::up/downstream implementation to VisibleUnit.cpp

Source/core/editing/Position.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 497 matching lines @@
 template <typename Strategy>
 bool PositionAlgorithm<Strategy>::atEndOfTree() const
 {
     if (isNull())
         return true;
     // TODO(yosin) We should use |Strategy::lastOffsetForEditing()| instead of
     // DOM tree version.
     return !Strategy::parent(*anchorNode()) && m_offset >= EditingStrategy::lastOffsetForEditing(anchorNode());
 }
 
-// Whether or not [node, 0] and [node, lastOffsetForEditing(node)] are their own VisiblePositions.
-// If true, adjacent candidates are visually distinct.
-// FIXME: Disregard nodes with layoutObjects that have no height, as we do in isCandidate.
-// FIXME: Share code with isCandidate, if possible.
-static bool endsOfNodeAreVisuallyDistinctPositions(Node* node)
+template <typename Strategy>
+PositionAlgorithm<Strategy> PositionAlgorithm<Strategy>::upstream(EditingBoundaryCrossingRule rule) const
 {
-    if (!node || !node->layoutObject())
-        return false;
-
-    if (!node->layoutObject()->isInline())
-        return true;
-
-    // Don't include inline tables.
-    if (isHTMLTableElement(*node))
-        return false;
-
-    // A Marquee elements are moving so we should assume their ends are always
-    // visibily distinct.
-    if (isHTMLMarqueeElement(*node))
-        return true;
-
-    // There is a VisiblePosition inside an empty inline-block container.
-    return node->layoutObject()->isReplaced() && canHaveChildrenForEditing(node) && toLayoutBox(node->layoutObject())->size().height() != 0 && !node->hasChildren();
+    return mostForwardCaretPosition(*this, rule);
 }
 
 template <typename Strategy>
-static Node* enclosingVisualBoundary(Node* node)
-{
-    while (node && !endsOfNodeAreVisuallyDistinctPositions(node))
-        node = Strategy::parent(*node);
-
-    return node;
-}
-
-// upstream() and downstream() want to return positions that are either in a
-// text node or at just before a non-text node.  This method checks for that.
-template <typename Strategy>
-static bool isStreamer(const PositionIteratorAlgorithm<Strategy>& pos)
-{
-    if (!pos.node())
-        return true;
-
-    if (isAtomicNode(pos.node()))
-        return true;
-
-    return pos.atStartOfNode();
-}
-
-// This function and downstream() are used for moving back and forth between visually equivalent candidates.
-// For example, for the text node "foo     bar" where whitespace is collapsible, there are two candidates
-// that map to the VisiblePosition between 'b' and the space.  This function will return the left candidate
-// and downstream() will return the right one.
-// Also, upstream() will return [boundary, 0] for any of the positions from [boundary, 0] to the first candidate
-// in boundary, where endsOfNodeAreVisuallyDistinctPositions(boundary) is true.
-template <typename Strategy>
-PositionAlgorithm<Strategy> PositionAlgorithm<Strategy>::upstream(EditingBoundaryCrossingRule rule) const
-{
-    TRACE_EVENT0("blink", "Position::upstream");
-
-    Node* startNode = anchorNode();
-    if (!startNode)
-        return PositionAlgorithm<Strategy>();
-
-    // iterate backward from there, looking for a qualified position
-    Node* boundary = enclosingVisualBoundary<Strategy>(startNode);
-    // FIXME: PositionIterator should respect Before and After positions.
-    PositionIteratorAlgorithm<Strategy> lastVisible(isAfterAnchor() ? editingPositionOf(m_anchorNode.get(), Strategy::caretMaxOffset(*m_anchorNode)) : PositionAlgorithm<Strategy>(*this));
-    PositionIteratorAlgorithm<Strategy> currentPos = lastVisible;
-    bool startEditable = startNode->hasEditableStyle();
-    Node* lastNode = startNode;
-    bool boundaryCrossed = false;
-    for (; !currentPos.atStart(); currentPos.decrement()) {
-        Node* currentNode = currentPos.node();
-        // Don't check for an editability change if we haven't moved to a different node,
-        // to avoid the expense of computing hasEditableStyle().
-        if (currentNode != lastNode) {
-            // Don't change editability.
-            bool currentEditable = currentNode->hasEditableStyle();
-            if (startEditable != currentEditable) {
-                if (rule == CannotCrossEditingBoundary)
-                    break;
-                boundaryCrossed = true;
-            }
-            lastNode = currentNode;
-        }
-
-        // If we've moved to a position that is visually distinct, return the last saved position. There
-        // is code below that terminates early if we're *about* to move to a visually distinct position.
-        if (endsOfNodeAreVisuallyDistinctPositions(currentNode) && currentNode != boundary)
-            return lastVisible.deprecatedComputePosition();
-
-        // skip position in non-laid out or invisible node
-        LayoutObject* layoutObject = currentNode->layoutObject();
-        if (!layoutObject || layoutObject->style()->visibility() != VISIBLE)
-            continue;
-
-        if (rule == CanCrossEditingBoundary && boundaryCrossed) {
-            lastVisible = currentPos;
-            break;
-        }
-
-        // track last visible streamer position
-        if (isStreamer<Strategy>(currentPos))
-            lastVisible = currentPos;
-
-        // Don't move past a position that is visually distinct.  We could rely on code above to terminate and
-        // return lastVisible on the next iteration, but we terminate early to avoid doing a nodeIndex() call.
-        if (endsOfNodeAreVisuallyDistinctPositions(currentNode) && currentPos.atStartOfNode())
-            return lastVisible.deprecatedComputePosition();
-
-        // Return position after tables and nodes which have content that can be ignored.
-        if (Strategy::editingIgnoresContent(currentNode) || isRenderedHTMLTableElement(currentNode)) {
-            if (currentPos.atEndOfNode())
-                return afterNode(currentNode);
-            continue;
-        }
-
-        // return current position if it is in laid out text
-        if (layoutObject->isText() && toLayoutText(layoutObject)->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
-                // layout 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 >= layoutObject->caretMaxOffset());
-                return PositionAlgorithm<Strategy>(currentNode, layoutObject->caretMaxOffset());
-            }
-
-            unsigned textOffset = currentPos.offsetInLeafNode();
-            LayoutText* textLayoutObject = toLayoutText(layoutObject);
-            InlineTextBox* lastTextBox = textLayoutObject->lastTextBox();
-            for (InlineTextBox* box = textLayoutObject->firstTextBox(); box; box = box->nextTextBox()) {
-                if (textOffset <= box->start() + box->len()) {
-                    if (textOffset > box->start())
-                        return currentPos.computePosition();
-                    continue;
-                }
-
-                if (box == lastTextBox || textOffset != box->start() + box->len() + 1)
-                    continue;
-
-                // The text continues on the next line only if the last text box is not on this line and
-                // none of the boxes on this line have a larger start offset.
-
-                bool continuesOnNextLine = true;
-                InlineBox* otherBox = box;
-                while (continuesOnNextLine) {
-                    otherBox = otherBox->nextLeafChild();
-                    if (!otherBox)
-                        break;
-                    if (otherBox == lastTextBox || (otherBox->layoutObject() == textLayoutObject && toInlineTextBox(otherBox)->start() > textOffset))
-                        continuesOnNextLine = false;
-                }
-
-                otherBox = box;
-                while (continuesOnNextLine) {
-                    otherBox = otherBox->prevLeafChild();
-                    if (!otherBox)
-                        break;
-                    if (otherBox == lastTextBox || (otherBox->layoutObject() == textLayoutObject && toInlineTextBox(otherBox)->start() > textOffset))
-                        continuesOnNextLine = false;
-                }
-
-                if (continuesOnNextLine)
-                    return currentPos.computePosition();
-            }
-        }
-    }
-    return lastVisible.deprecatedComputePosition();
-}
-
-// This function and upstream() are used for moving back and forth between visually equivalent candidates.
-// For example, for the text node "foo     bar" where whitespace is collapsible, there are two candidates
-// that map to the VisiblePosition between 'b' and the space.  This function will return the right candidate
-// and upstream() will return the left one.
-// Also, downstream() will return the last position in the last atomic node in boundary for all of the positions
-// in boundary after the last candidate, where endsOfNodeAreVisuallyDistinctPositions(boundary).
-// FIXME: This function should never be called when the line box tree is dirty. See https://bugs.webkit.org/show_bug.cgi?id=97264
-template <typename Strategy>
 PositionAlgorithm<Strategy> PositionAlgorithm<Strategy>::downstream(EditingBoundaryCrossingRule rule) const
 {
-    TRACE_EVENT0("blink", "Position::downstream");
-
-    Node* startNode = anchorNode();
-    if (!startNode)
-        return PositionAlgorithm<Strategy>();
-
-    // iterate forward from there, looking for a qualified position
-    Node* boundary = enclosingVisualBoundary<Strategy>(startNode);
-    // FIXME: PositionIterator should respect Before and After positions.
-    PositionIteratorAlgorithm<Strategy> lastVisible(isAfterAnchor() ? editingPositionOf(m_anchorNode.get(), Strategy::caretMaxOffset(*m_anchorNode)) : PositionAlgorithm<Strategy>(*this));
-    PositionIteratorAlgorithm<Strategy> currentPos = lastVisible;
-    bool startEditable = startNode->hasEditableStyle();
-    Node* lastNode = startNode;
-    bool boundaryCrossed = false;
-    for (; !currentPos.atEnd(); currentPos.increment()) {
-        Node* currentNode = currentPos.node();
-        // Don't check for an editability change if we haven't moved to a different node,
-        // to avoid the expense of computing hasEditableStyle().
-        if (currentNode != lastNode) {
-            // Don't change editability.
-            bool currentEditable = currentNode->hasEditableStyle();
-            if (startEditable != currentEditable) {
-                if (rule == CannotCrossEditingBoundary)
-                    break;
-                boundaryCrossed = true;
-            }
-
-            lastNode = currentNode;
-        }
-
-        // stop before going above the body, up into the head
-        // return the last visible streamer position
-        if (isHTMLBodyElement(*currentNode) && currentPos.atEndOfNode())
-            break;
-
-        // Do not move to a visually distinct position.
-        if (endsOfNodeAreVisuallyDistinctPositions(currentNode) && currentNode != boundary)
-            return lastVisible.deprecatedComputePosition();
-        // Do not move past a visually disinct position.
-        // Note: The first position after the last in a node whose ends are visually distinct
-        // positions will be [boundary->parentNode(), originalBlock->nodeIndex() + 1].
-        if (boundary && Strategy::parent(*boundary) == currentNode)
-            return lastVisible.deprecatedComputePosition();
-
-        // skip position in non-laid out or invisible node
-        LayoutObject* layoutObject = currentNode->layoutObject();
-        if (!layoutObject || layoutObject->style()->visibility() != VISIBLE)
-            continue;
-
-        if (rule == CanCrossEditingBoundary && boundaryCrossed) {
-            lastVisible = currentPos;
-            break;
-        }
-
-        // track last visible streamer position
-        if (isStreamer<Strategy>(currentPos))
-            lastVisible = currentPos;
-
-        // Return position before tables and nodes which have content that can be ignored.
-        if (Strategy::editingIgnoresContent(currentNode) || isRenderedHTMLTableElement(currentNode)) {
-            if (currentPos.offsetInLeafNode() <= layoutObject->caretMinOffset())
-                return editingPositionOf(currentNode, layoutObject->caretMinOffset());
-            continue;
-        }
-
-        // return current position if it is in laid out text
-        if (layoutObject->isText() && toLayoutText(layoutObject)->firstTextBox()) {
-            if (currentNode != startNode) {
-                ASSERT(currentPos.atStartOfNode());
-                return PositionAlgorithm<Strategy>(currentNode, layoutObject->caretMinOffset());
-            }
-
-            unsigned textOffset = currentPos.offsetInLeafNode();
-            LayoutText* textLayoutObject = toLayoutText(layoutObject);
-            InlineTextBox* lastTextBox = textLayoutObject->lastTextBox();
-            for (InlineTextBox* box = textLayoutObject->firstTextBox(); box; box = box->nextTextBox()) {
-                if (textOffset <= box->end()) {
-                    if (textOffset >= box->start())
-                        return currentPos.computePosition();
-                    continue;
-                }
-
-                if (box == lastTextBox || textOffset != box->start() + box->len())
-                    continue;
-
-                // The text continues on the next line only if the last text box is not on this line and
-                // none of the boxes on this line have a larger start offset.
-
-                bool continuesOnNextLine = true;
-                InlineBox* otherBox = box;
-                while (continuesOnNextLine) {
-                    otherBox = otherBox->nextLeafChild();
-                    if (!otherBox)
-                        break;
-                    if (otherBox == lastTextBox || (otherBox->layoutObject() == textLayoutObject && toInlineTextBox(otherBox)->start() >= textOffset))
-                        continuesOnNextLine = false;
-                }
-
-                otherBox = box;
-                while (continuesOnNextLine) {
-                    otherBox = otherBox->prevLeafChild();
-                    if (!otherBox)
-                        break;
-                    if (otherBox == lastTextBox || (otherBox->layoutObject() == textLayoutObject && toInlineTextBox(otherBox)->start() >= textOffset))
-                        continuesOnNextLine = false;
-                }
-
-                if (continuesOnNextLine)
-                    return currentPos.computePosition();
-            }
-        }
-    }
-
-    return lastVisible.deprecatedComputePosition();
+    return mostBackwardCaretPosition(*this, rule);
 }
 
 static int boundingBoxLogicalHeight(LayoutObject *o, const IntRect &rect)
 {
     return o->style()->isHorizontalWritingMode() ? rect.height() : rect.width();
 }
 
 // TODO(yosin) We should move |hasRenderedNonAnonymousDescendantsWithHeight|
 // to "VisibleUnits.cpp" to reduce |LayoutObject| dependency in "Position.cpp"
 bool hasRenderedNonAnonymousDescendantsWithHeight(LayoutObject* layoutObject)
@@ skipping 537 matching lines @@
 
 void showTree(const blink::Position* pos)
 {
     if (pos)
         pos->showTreeForThis();
     else
         fprintf(stderr, "Cannot showTree for (nil)\n");
 }
 
 #endif