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
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
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
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "InsertParagraphSeparatorCommand.h"
28
29#include "CSSPropertyNames.h"
30#include "Document.h"
31#include "EditingStyle.h"
32#include "HTMLElement.h"
33#include "HTMLNames.h"
34#include "InsertLineBreakCommand.h"
35#include "RenderObject.h"
36#include "Text.h"
37#include "htmlediting.h"
38#include "visible_units.h"
39
40namespace WebCore {
41
42using namespace HTMLNames;
43
44// When inserting a new line, we want to avoid nesting empty divs if we can.  Otherwise, when
45// pasting, it's easy to have each new line be a div deeper than the previous.  E.g., in the case
46// below, we want to insert at ^ instead of |.
47// <div>foo<div>bar</div>|</div>^
48static Element* highestVisuallyEquivalentDivBelowRoot(Element* startBlock)
49{
50    Element* curBlock = startBlock;
51    // We don't want to return a root node (if it happens to be a div, e.g., in a document fragment) because there are no
52    // siblings for us to append to.
53    while (!curBlock->nextSibling() && curBlock->parentElement()->hasTagName(divTag) && curBlock->parentElement()->parentElement()) {
54        NamedNodeMap* attributes = curBlock->parentElement()->attributes(true);
55        if (attributes && !attributes->isEmpty())
56            break;
57        curBlock = curBlock->parentElement();
58    }
59    return curBlock;
60}
61
62InsertParagraphSeparatorCommand::InsertParagraphSeparatorCommand(Document *document, bool mustUseDefaultParagraphElement)
63    : CompositeEditCommand(document)
64    , m_mustUseDefaultParagraphElement(mustUseDefaultParagraphElement)
65{
66}
67
68bool InsertParagraphSeparatorCommand::preservesTypingStyle() const
69{
70    return true;
71}
72
73void InsertParagraphSeparatorCommand::calculateStyleBeforeInsertion(const Position &pos)
74{
75    // It is only important to set a style to apply later if we're at the boundaries of
76    // a paragraph. Otherwise, content that is moved as part of the work of the command
77    // will lend their styles to the new paragraph without any extra work needed.
78    VisiblePosition visiblePos(pos, VP_DEFAULT_AFFINITY);
79    if (!isStartOfParagraph(visiblePos) && !isEndOfParagraph(visiblePos))
80        return;
81
82    ASSERT(pos.isNotNull());
83    m_style = EditingStyle::create(pos);
84    m_style->mergeTypingStyle(pos.anchorNode()->document());
85}
86
87void InsertParagraphSeparatorCommand::applyStyleAfterInsertion(Node* originalEnclosingBlock)
88{
89    // Not only do we break out of header tags, but we also do not preserve the typing style,
90    // in order to match other browsers.
91    if (originalEnclosingBlock->hasTagName(h1Tag) ||
92        originalEnclosingBlock->hasTagName(h2Tag) ||
93        originalEnclosingBlock->hasTagName(h3Tag) ||
94        originalEnclosingBlock->hasTagName(h4Tag) ||
95        originalEnclosingBlock->hasTagName(h5Tag))
96        return;
97
98    if (!m_style)
99        return;
100
101    m_style->prepareToApplyAt(endingSelection().start());
102    if (!m_style->isEmpty())
103        applyStyle(m_style.get());
104}
105
106bool InsertParagraphSeparatorCommand::shouldUseDefaultParagraphElement(Node* enclosingBlock) const
107{
108    if (m_mustUseDefaultParagraphElement)
109        return true;
110
111    // Assumes that if there was a range selection, it was already deleted.
112    if (!isEndOfBlock(endingSelection().visibleStart()))
113        return false;
114
115    return enclosingBlock->hasTagName(h1Tag) ||
116           enclosingBlock->hasTagName(h2Tag) ||
117           enclosingBlock->hasTagName(h3Tag) ||
118           enclosingBlock->hasTagName(h4Tag) ||
119           enclosingBlock->hasTagName(h5Tag);
120}
121
122void InsertParagraphSeparatorCommand::getAncestorsInsideBlock(const Node* insertionNode, Element* outerBlock, Vector<Element*>& ancestors)
123{
124    ancestors.clear();
125
126    // Build up list of ancestors elements between the insertion node and the outer block.
127    if (insertionNode != outerBlock) {
128        for (Element* n = insertionNode->parentElement(); n && n != outerBlock; n = n->parentElement())
129            ancestors.append(n);
130    }
131}
132
133PassRefPtr<Element> InsertParagraphSeparatorCommand::cloneHierarchyUnderNewBlock(const Vector<Element*>& ancestors, PassRefPtr<Element> blockToInsert)
134{
135    // Make clones of ancestors in between the start node and the start block.
136    RefPtr<Element> parent = blockToInsert;
137    for (size_t i = ancestors.size(); i != 0; --i) {
138        RefPtr<Element> child = ancestors[i - 1]->cloneElementWithoutChildren();
139        appendNode(child, parent);
140        parent = child.release();
141    }
142
143    return parent.release();
144}
145
146void InsertParagraphSeparatorCommand::doApply()
147{
148    bool splitText = false;
149    if (!endingSelection().isNonOrphanedCaretOrRange())
150        return;
151
152    Position insertionPosition = endingSelection().start();
153
154    EAffinity affinity = endingSelection().affinity();
155
156    // Delete the current selection.
157    if (endingSelection().isRange()) {
158        calculateStyleBeforeInsertion(insertionPosition);
159        deleteSelection(false, true);
160        insertionPosition = endingSelection().start();
161        affinity = endingSelection().affinity();
162    }
163
164    // FIXME: The parentAnchoredEquivalent conversion needs to be moved into enclosingBlock.
165    Node* startBlockNode = enclosingBlock(insertionPosition.parentAnchoredEquivalent().containerNode());
166    Position canonicalPos = VisiblePosition(insertionPosition).deepEquivalent();
167    Element* startBlock = static_cast<Element*>(startBlockNode);
168    if (!startBlockNode
169            || !startBlockNode->isElementNode()
170            || !startBlock->parentNode()
171            || isTableCell(startBlock)
172            || startBlock->hasTagName(formTag)
173            // FIXME: If the node is hidden, we don't have a canonical position so we will do the wrong thing for tables and <hr>. https://bugs.webkit.org/show_bug.cgi?id=40342
174            || (!canonicalPos.isNull() && canonicalPos.deprecatedNode()->renderer() && canonicalPos.deprecatedNode()->renderer()->isTable())
175            || (!canonicalPos.isNull() && canonicalPos.deprecatedNode()->hasTagName(hrTag))) {
176        applyCommandToComposite(InsertLineBreakCommand::create(document()));
177        return;
178    }
179
180    // Use the leftmost candidate.
181    insertionPosition = insertionPosition.upstream();
182    if (!insertionPosition.isCandidate())
183        insertionPosition = insertionPosition.downstream();
184
185    // Adjust the insertion position after the delete
186    insertionPosition = positionAvoidingSpecialElementBoundary(insertionPosition);
187    VisiblePosition visiblePos(insertionPosition, affinity);
188    calculateStyleBeforeInsertion(insertionPosition);
189
190    //---------------------------------------------------------------------
191    // Handle special case of typing return on an empty list item
192    if (breakOutOfEmptyListItem())
193        return;
194
195    //---------------------------------------------------------------------
196    // Prepare for more general cases.
197
198    bool isFirstInBlock = isStartOfBlock(visiblePos);
199    bool isLastInBlock = isEndOfBlock(visiblePos);
200    bool nestNewBlock = false;
201
202    // Create block to be inserted.
203    RefPtr<Element> blockToInsert;
204    if (startBlock == startBlock->rootEditableElement()) {
205        blockToInsert = createDefaultParagraphElement(document());
206        nestNewBlock = true;
207    } else if (shouldUseDefaultParagraphElement(startBlock))
208        blockToInsert = createDefaultParagraphElement(document());
209    else
210        blockToInsert = startBlock->cloneElementWithoutChildren();
211
212    //---------------------------------------------------------------------
213    // Handle case when position is in the last visible position in its block,
214    // including when the block is empty.
215    if (isLastInBlock) {
216        if (nestNewBlock) {
217            if (isFirstInBlock && !lineBreakExistsAtVisiblePosition(visiblePos)) {
218                // The block is empty.  Create an empty block to
219                // represent the paragraph that we're leaving.
220                RefPtr<Element> extraBlock = createDefaultParagraphElement(document());
221                appendNode(extraBlock, startBlock);
222                appendBlockPlaceholder(extraBlock);
223            }
224            appendNode(blockToInsert, startBlock);
225        } else {
226            // We can get here if we pasted a copied portion of a blockquote with a newline at the end and are trying to paste it
227            // into an unquoted area. We then don't want the newline within the blockquote or else it will also be quoted.
228            if (Node* highestBlockquote = highestEnclosingNodeOfType(canonicalPos, &isMailBlockquote))
229                startBlock = static_cast<Element*>(highestBlockquote);
230
231            // Most of the time we want to stay at the nesting level of the startBlock (e.g., when nesting within lists).  However,
232            // for div nodes, this can result in nested div tags that are hard to break out of.
233            Element* siblingNode = startBlock;
234            if (blockToInsert->hasTagName(divTag))
235                siblingNode = highestVisuallyEquivalentDivBelowRoot(startBlock);
236            insertNodeAfter(blockToInsert, siblingNode);
237        }
238
239        // Recreate the same structure in the new paragraph.
240
241        Vector<Element*> ancestors;
242        getAncestorsInsideBlock(positionOutsideTabSpan(insertionPosition).deprecatedNode(), startBlock, ancestors);
243        RefPtr<Element> parent = cloneHierarchyUnderNewBlock(ancestors, blockToInsert);
244
245        appendBlockPlaceholder(parent);
246
247        setEndingSelection(VisibleSelection(firstPositionInNode(parent.get()), DOWNSTREAM));
248        return;
249    }
250
251
252    //---------------------------------------------------------------------
253    // Handle case when position is in the first visible position in its block, and
254    // similar case where previous position is in another, presumeably nested, block.
255    if (isFirstInBlock || !inSameBlock(visiblePos, visiblePos.previous())) {
256        Node *refNode;
257
258        insertionPosition = positionOutsideTabSpan(insertionPosition);
259
260        if (isFirstInBlock && !nestNewBlock)
261            refNode = startBlock;
262        else if (insertionPosition.deprecatedNode() == startBlock && nestNewBlock) {
263            refNode = startBlock->childNode(insertionPosition.deprecatedEditingOffset());
264            ASSERT(refNode); // must be true or we'd be in the end of block case
265        } else
266            refNode = insertionPosition.deprecatedNode();
267
268        // find ending selection position easily before inserting the paragraph
269        insertionPosition = insertionPosition.downstream();
270
271        insertNodeBefore(blockToInsert, refNode);
272
273        // Recreate the same structure in the new paragraph.
274
275        Vector<Element*> ancestors;
276        getAncestorsInsideBlock(positionAvoidingSpecialElementBoundary(positionOutsideTabSpan(insertionPosition)).deprecatedNode(), startBlock, ancestors);
277
278        appendBlockPlaceholder(cloneHierarchyUnderNewBlock(ancestors, blockToInsert));
279
280        // In this case, we need to set the new ending selection.
281        setEndingSelection(VisibleSelection(insertionPosition, DOWNSTREAM));
282        return;
283    }
284
285    //---------------------------------------------------------------------
286    // Handle the (more complicated) general case,
287
288    // All of the content in the current block after visiblePos is
289    // about to be wrapped in a new paragraph element.  Add a br before
290    // it if visiblePos is at the start of a paragraph so that the
291    // content will move down a line.
292    if (isStartOfParagraph(visiblePos)) {
293        RefPtr<Element> br = createBreakElement(document());
294        insertNodeAt(br.get(), insertionPosition);
295        insertionPosition = positionInParentAfterNode(br.get());
296    }
297
298    // Move downstream. Typing style code will take care of carrying along the
299    // style of the upstream position.
300    insertionPosition = insertionPosition.downstream();
301
302    // At this point, the insertionPosition's node could be a container, and we want to make sure we include
303    // all of the correct nodes when building the ancestor list.  So this needs to be the deepest representation of the position
304    // before we walk the DOM tree.
305    insertionPosition = positionOutsideTabSpan(VisiblePosition(insertionPosition).deepEquivalent());
306
307    // Make sure we do not cause a rendered space to become unrendered.
308    // FIXME: We need the affinity for pos, but pos.downstream() does not give it
309    Position leadingWhitespace = insertionPosition.leadingWhitespacePosition(VP_DEFAULT_AFFINITY);
310    // FIXME: leadingWhitespacePosition is returning the position before preserved newlines for positions
311    // after the preserved newline, causing the newline to be turned into a nbsp.
312    if (leadingWhitespace.isNotNull() && leadingWhitespace.deprecatedNode()->isTextNode()) {
313        Text* textNode = static_cast<Text*>(leadingWhitespace.deprecatedNode());
314        ASSERT(!textNode->renderer() || textNode->renderer()->style()->collapseWhiteSpace());
315        replaceTextInNode(textNode, leadingWhitespace.deprecatedEditingOffset(), 1, nonBreakingSpaceString());
316    }
317
318    // Split at pos if in the middle of a text node.
319    if (insertionPosition.deprecatedNode()->isTextNode()) {
320        Text* textNode = static_cast<Text*>(insertionPosition.deprecatedNode());
321        bool atEnd = (unsigned)insertionPosition.deprecatedEditingOffset() >= textNode->length();
322        if (insertionPosition.deprecatedEditingOffset() > 0 && !atEnd) {
323            splitTextNode(textNode, insertionPosition.deprecatedEditingOffset());
324            insertionPosition.moveToOffset(0);
325            visiblePos = VisiblePosition(insertionPosition);
326            splitText = true;
327        }
328    }
329
330    // Put the added block in the tree.
331    if (nestNewBlock)
332        appendNode(blockToInsert.get(), startBlock);
333    else
334        insertNodeAfter(blockToInsert.get(), startBlock);
335
336    updateLayout();
337
338    // If the paragraph separator was inserted at the end of a paragraph, an empty line must be
339    // created.  All of the nodes, starting at visiblePos, are about to be added to the new paragraph
340    // element.  If the first node to be inserted won't be one that will hold an empty line open, add a br.
341    if (isEndOfParagraph(visiblePos) && !lineBreakExistsAtVisiblePosition(visiblePos))
342        appendNode(createBreakElement(document()).get(), blockToInsert.get());
343
344    // Move the start node and the siblings of the start node.
345    if (VisiblePosition(insertionPosition) != VisiblePosition(positionBeforeNode(blockToInsert.get()))) {
346        Node* n;
347        if (insertionPosition.containerNode() == startBlock)
348            n = insertionPosition.computeNodeAfterPosition();
349        else {
350            splitTreeToNode(insertionPosition.containerNode(), startBlock);
351
352            for (n = startBlock->firstChild(); n; n = n->nextSibling()) {
353                if (comparePositions(VisiblePosition(insertionPosition), positionBeforeNode(n)) <= 0)
354                    break;
355            }
356        }
357
358        while (n && n != blockToInsert) {
359            Node *next = n->nextSibling();
360            removeNode(n);
361            appendNode(n, blockToInsert);
362            n = next;
363        }
364    }
365
366    // Handle whitespace that occurs after the split
367    if (splitText) {
368        updateLayout();
369        if (insertionPosition.anchorType() == Position::PositionIsOffsetInAnchor)
370            insertionPosition.moveToOffset(0);
371        if (!insertionPosition.isRenderedCharacter()) {
372            // Clear out all whitespace and insert one non-breaking space
373            ASSERT(!insertionPosition.deprecatedNode()->renderer() || insertionPosition.deprecatedNode()->renderer()->style()->collapseWhiteSpace());
374            deleteInsignificantTextDownstream(insertionPosition);
375            if (insertionPosition.deprecatedNode()->isTextNode())
376                insertTextIntoNode(static_cast<Text*>(insertionPosition.deprecatedNode()), 0, nonBreakingSpaceString());
377        }
378    }
379
380    setEndingSelection(VisibleSelection(firstPositionInNode(blockToInsert.get()), DOWNSTREAM));
381    applyStyleAfterInsertion(startBlock);
382}
383
384} // namespace WebCore
385