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 "InsertLineBreakCommand.h"
28
29#include "Document.h"
30#include "EditingStyle.h"
31#include "Frame.h"
32#include "FrameSelection.h"
33#include "HTMLElement.h"
34#include "HTMLNames.h"
35#include "Range.h"
36#include "RenderObject.h"
37#include "Text.h"
38#include "VisiblePosition.h"
39#include "VisibleUnits.h"
40#include "htmlediting.h"
41
42namespace WebCore {
43
44using namespace HTMLNames;
45
46InsertLineBreakCommand::InsertLineBreakCommand(Document* document)
47    : CompositeEditCommand(document)
48{
49}
50
51bool InsertLineBreakCommand::preservesTypingStyle() const
52{
53    return true;
54}
55
56void InsertLineBreakCommand::insertNodeAfterPosition(Node* node, const Position& pos)
57{
58    // Insert the BR after the caret position. In the case the
59    // position is a block, do an append. We don't want to insert
60    // the BR *after* the block.
61    Element* cb = deprecatedEnclosingBlockFlowElement(pos.deprecatedNode());
62    if (cb == pos.deprecatedNode())
63        appendNode(node, cb);
64    else
65        insertNodeAfter(node, pos.deprecatedNode());
66}
67
68void InsertLineBreakCommand::insertNodeBeforePosition(Node* node, const Position& pos)
69{
70    // Insert the BR after the caret position. In the case the
71    // position is a block, do an append. We don't want to insert
72    // the BR *before* the block.
73    Element* cb = deprecatedEnclosingBlockFlowElement(pos.deprecatedNode());
74    if (cb == pos.deprecatedNode())
75        appendNode(node, cb);
76    else
77        insertNodeBefore(node, pos.deprecatedNode());
78}
79
80// Whether we should insert a break element or a '\n'.
81bool InsertLineBreakCommand::shouldUseBreakElement(const Position& insertionPos)
82{
83    // An editing position like [input, 0] actually refers to the position before
84    // the input element, and in that case we need to check the input element's
85    // parent's renderer.
86    Position p(insertionPos.parentAnchoredEquivalent());
87    return p.deprecatedNode()->renderer() && !p.deprecatedNode()->renderer()->style()->preserveNewline();
88}
89
90void InsertLineBreakCommand::doApply()
91{
92    deleteSelection();
93    VisibleSelection selection = endingSelection();
94    if (!selection.isNonOrphanedCaretOrRange())
95        return;
96
97    VisiblePosition caret(selection.visibleStart());
98    // FIXME: If the node is hidden, we should still be able to insert text.
99    // For now, we return to avoid a crash.  https://bugs.webkit.org/show_bug.cgi?id=40342
100    if (caret.isNull())
101        return;
102
103    Position pos(caret.deepEquivalent());
104
105    pos = positionAvoidingSpecialElementBoundary(pos);
106
107    pos = positionOutsideTabSpan(pos);
108
109    RefPtr<Node> nodeToInsert;
110    if (shouldUseBreakElement(pos))
111        nodeToInsert = createBreakElement(document());
112    else
113        nodeToInsert = document()->createTextNode("\n");
114
115    // FIXME: Need to merge text nodes when inserting just after or before text.
116
117    if (isEndOfParagraph(caret) && !lineBreakExistsAtVisiblePosition(caret)) {
118        bool needExtraLineBreak = !pos.deprecatedNode()->hasTagName(hrTag) && !pos.deprecatedNode()->hasTagName(tableTag);
119
120        insertNodeAt(nodeToInsert.get(), pos);
121
122        if (needExtraLineBreak)
123            insertNodeBefore(nodeToInsert->cloneNode(false), nodeToInsert);
124
125        VisiblePosition endingPosition(positionBeforeNode(nodeToInsert.get()));
126        setEndingSelection(VisibleSelection(endingPosition, endingSelection().isDirectional()));
127    } else if (pos.deprecatedEditingOffset() <= caretMinOffset(pos.deprecatedNode())) {
128        insertNodeAt(nodeToInsert.get(), pos);
129
130        // Insert an extra br or '\n' if the just inserted one collapsed.
131        if (!isStartOfParagraph(positionBeforeNode(nodeToInsert.get())))
132            insertNodeBefore(nodeToInsert->cloneNode(false).get(), nodeToInsert.get());
133
134        setEndingSelection(VisibleSelection(positionInParentAfterNode(nodeToInsert.get()), DOWNSTREAM, endingSelection().isDirectional()));
135    // If we're inserting after all of the rendered text in a text node, or into a non-text node,
136    // a simple insertion is sufficient.
137    } else if (pos.deprecatedEditingOffset() >= caretMaxOffset(pos.deprecatedNode()) || !pos.deprecatedNode()->isTextNode()) {
138        insertNodeAt(nodeToInsert.get(), pos);
139        setEndingSelection(VisibleSelection(positionInParentAfterNode(nodeToInsert.get()), DOWNSTREAM, endingSelection().isDirectional()));
140    } else if (pos.deprecatedNode()->isTextNode()) {
141        // Split a text node
142        Text* textNode = toText(pos.deprecatedNode());
143        splitTextNode(textNode, pos.deprecatedEditingOffset());
144        insertNodeBefore(nodeToInsert, textNode);
145        Position endingPosition = firstPositionInNode(textNode);
146
147        // Handle whitespace that occurs after the split
148        document()->updateLayoutIgnorePendingStylesheets();
149        if (!endingPosition.isRenderedCharacter()) {
150            Position positionBeforeTextNode(positionInParentBeforeNode(textNode));
151            // Clear out all whitespace and insert one non-breaking space
152            deleteInsignificantTextDownstream(endingPosition);
153            ASSERT(!textNode->renderer() || textNode->renderer()->style()->collapseWhiteSpace());
154            // Deleting insignificant whitespace will remove textNode if it contains nothing but insignificant whitespace.
155            if (textNode->inDocument())
156                insertTextIntoNode(textNode, 0, nonBreakingSpaceString());
157            else {
158                RefPtr<Text> nbspNode = document()->createTextNode(nonBreakingSpaceString());
159                insertNodeAt(nbspNode.get(), positionBeforeTextNode);
160                endingPosition = firstPositionInNode(nbspNode.get());
161            }
162        }
163
164        setEndingSelection(VisibleSelection(endingPosition, DOWNSTREAM, endingSelection().isDirectional()));
165    }
166
167    // Handle the case where there is a typing style.
168
169    RefPtr<EditingStyle> typingStyle = document()->frame()->selection()->typingStyle();
170
171    if (typingStyle && !typingStyle->isEmpty()) {
172        // Apply the typing style to the inserted line break, so that if the selection
173        // leaves and then comes back, new input will have the right style.
174        // FIXME: We shouldn't always apply the typing style to the line break here,
175        // see <rdar://problem/5794462>.
176        applyStyle(typingStyle.get(), firstPositionInOrBeforeNode(nodeToInsert.get()), lastPositionInOrAfterNode(nodeToInsert.get()));
177        // Even though this applyStyle operates on a Range, it still sets an endingSelection().
178        // It tries to set a VisibleSelection around the content it operated on. So, that VisibleSelection
179        // will either (a) select the line break we inserted, or it will (b) be a caret just
180        // before the line break (if the line break is at the end of a block it isn't selectable).
181        // So, this next call sets the endingSelection() to a caret just after the line break
182        // that we inserted, or just before it if it's at the end of a block.
183        setEndingSelection(endingSelection().visibleEnd());
184    }
185
186    rebalanceWhitespace();
187}
188
189}
190