WebCore/editing/InsertLineBreakCommand.cpp

   1 /*
   2  * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
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   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "InsertLineBreakCommand.h"
  28
  29 #include "CSSMutableStyleDeclaration.h"
  30 #include "Document.h"
  31 #include "Element.h"
  32 #include "Frame.h"
  33 #include "Text.h"
  34 #include "VisiblePosition.h"
  35 #include "Range.h"
  36 #include "htmlediting.h"
  37 #include "HTMLNames.h"
  38 #include "visible_units.h"
  39
  40 namespace WebCore {
  41
  42 using namespace HTMLNames;
  43
  44 InsertLineBreakCommand::InsertLineBreakCommand(Document* document)
  45     : CompositeEditCommand(document)
  46 {
  47 }
  48
  49 bool InsertLineBreakCommand::preservesTypingStyle() const
  50 {
  51     return true;
  52 }
  53
  54 void InsertLineBreakCommand::insertNodeAfterPosition(Node *node, const Position &pos)
  55 {
  56     // Insert the BR after the caret position. In the case the
  57     // position is a block, do an append. We don't want to insert
  58     // the BR *after* the block.
  59     Node *cb = pos.node()->enclosingBlockFlowElement();
  60     if (cb == pos.node())
  61         appendNode(node, cb);
  62     else
  63         insertNodeAfter(node, pos.node());
  64 }
  65
  66 void InsertLineBreakCommand::insertNodeBeforePosition(Node *node, const Position &pos)
  67 {
  68     // Insert the BR after the caret position. In the case the
  69     // position is a block, do an append. We don't want to insert
  70     // the BR *before* the block.
  71     Node *cb = pos.node()->enclosingBlockFlowElement();
  72     if (cb == pos.node())
  73         appendNode(node, cb);
  74     else
  75         insertNodeBefore(node, pos.node());
  76 }
  77
  78 // Whether we should insert a break element or a '\n'.
  79 bool InsertLineBreakCommand::shouldUseBreakElement(const Position& insertionPos)
  80 {
  81     // An editing position like [input, 0] actually refers to the position before
  82     // the input element, and in that case we need to check the input element's
  83     // parent's renderer.
  84     Position p(rangeCompliantEquivalent(insertionPos));
  85     return p.node()->renderer() && !p.node()->renderer()->style()->preserveNewline();
  86 }
  87
  88 void InsertLineBreakCommand::doApply()
  89 {
  90     deleteSelection();
  91     Selection selection = endingSelection();
  92     if (selection.isNone())
  93         return;
  94
  95     VisiblePosition caret(selection.visibleStart());
  96     Position pos(caret.deepEquivalent());
  97
  98     pos = positionAvoidingSpecialElementBoundary(pos);
  99
 100     pos = positionOutsideTabSpan(pos);
 101
 102     RefPtr<Node> nodeToInsert;
 103     if (shouldUseBreakElement(pos))
 104         nodeToInsert = createBreakElement(document());
 105     else
 106         nodeToInsert = document()->createTextNode("\n");
 107
 108     // FIXME: Need to merge text nodes when inserting just after or before text.
 109
 110     if (isEndOfParagraph(caret) && !lineBreakExistsAtPosition(caret)) {
 111         bool needExtraLineBreak = !pos.node()->hasTagName(hrTag) && !pos.node()->hasTagName(tableTag);
 112
 113         insertNodeAt(nodeToInsert.get(), pos);
 114
 115         if (needExtraLineBreak)
 116             insertNodeBefore(nodeToInsert->cloneNode(false).get(), nodeToInsert.get());
 117
 118         VisiblePosition endingPosition(Position(nodeToInsert.get(), 0));
 119         setEndingSelection(Selection(endingPosition));
 120     } else if (pos.offset() <= caretMinOffset(pos.node())) {
 121         insertNodeAt(nodeToInsert.get(), pos);
 122
 123         // Insert an extra br or '\n' if the just inserted one collapsed.
 124         if (!isStartOfParagraph(VisiblePosition(Position(nodeToInsert.get(), 0))))
 125             insertNodeBefore(nodeToInsert->cloneNode(false).get(), nodeToInsert.get());
 126
 127         setEndingSelection(Selection(positionAfterNode(nodeToInsert.get()), DOWNSTREAM));
 128     } else if (pos.offset() >= caretMaxOffset(pos.node())) {
 129         insertNodeAt(nodeToInsert.get(), pos);
 130         setEndingSelection(Selection(positionAfterNode(nodeToInsert.get()), DOWNSTREAM));
 131     } else {
 132         // Split a text node
 133         ASSERT(pos.node()->isTextNode());
 134
 135         // Do the split
 136         ExceptionCode ec = 0;
 137         Text *textNode = static_cast<Text *>(pos.node());
 138         RefPtr<Text> textBeforeNode = document()->createTextNode(textNode->substringData(0, selection.start().offset(), ec));
 139         deleteTextFromNode(textNode, 0, pos.offset());
 140         insertNodeBefore(textBeforeNode.get(), textNode);
 141         insertNodeBefore(nodeToInsert.get(), textNode);
 142         Position endingPosition = Position(textNode, 0);
 143
 144         // Handle whitespace that occurs after the split
 145         updateLayout();
 146         if (!endingPosition.isRenderedCharacter()) {
 147             Position positionBeforeTextNode(positionBeforeNode(textNode));
 148             // Clear out all whitespace and insert one non-breaking space
 149             deleteInsignificantTextDownstream(endingPosition);
 150             ASSERT(!textNode->renderer() || textNode->renderer()->style()->collapseWhiteSpace());
 151             // Deleting insignificant whitespace will remove textNode if it contains nothing but insignificant whitespace.
 152             if (textNode->inDocument())
 153                 insertTextIntoNode(textNode, 0, nonBreakingSpaceString());
 154             else {
 155                 RefPtr<Text> nbspNode = document()->createTextNode(nonBreakingSpaceString());
 156                 insertNodeAt(nbspNode.get(), positionBeforeTextNode);
 157                 endingPosition = Position(nbspNode.get(), 0);
 158             }
 159         }
 160
 161         setEndingSelection(Selection(endingPosition, DOWNSTREAM));
 162     }
 163
 164     // Handle the case where there is a typing style.
 165
 166     CSSMutableStyleDeclaration* typingStyle = document()->frame()->typingStyle();
 167
 168     if (typingStyle && typingStyle->length() > 0) {
 169         // Apply the typing style to the inserted line break, so that if the selection
 170         // leaves and then comes back, new input will have the right style.
 171         // FIXME: We shouldn't always apply the typing style to the line break here,
 172         // see <rdar://problem/5794462>.
 173         applyStyle(typingStyle, Position(nodeToInsert.get(), 0),
 174                                 Position(nodeToInsert.get(), maxDeepOffset(nodeToInsert.get())));
 175         // Even though this applyStyle operates on a Range, it still sets an endingSelection().
 176         // It tries to set a Selection around the content it operated on. So, that Selection
 177         // will either (a) select the line break we inserted, or it will (b) be a caret just
 178         // before the line break (if the line break is at the end of a block it isn't selectable).
 179         // So, this next call sets the endingSelection() to a caret just after the line break
 180         // that we inserted, or just before it if it's at the end of a block.
 181         setEndingSelection(endingSelection().visibleEnd());
 182     }
 183
 184     rebalanceWhitespace();
 185 }
 186
 187 }