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