1/*
2 * Copyright (C) 2008 Apple 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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "config.h"
30#include "core/rendering/RenderLineBoxList.h"
31
32#include "core/paint/InlinePainter.h"
33#include "core/rendering/HitTestResult.h"
34#include "core/rendering/InlineTextBox.h"
35#include "core/rendering/PaintInfo.h"
36#include "core/rendering/RenderInline.h"
37#include "core/rendering/RenderView.h"
38#include "core/rendering/RootInlineBox.h"
39
40namespace blink {
41
42#if ENABLE(ASSERT)
43RenderLineBoxList::~RenderLineBoxList()
44{
45    ASSERT(!m_firstLineBox);
46    ASSERT(!m_lastLineBox);
47}
48#endif
49
50void RenderLineBoxList::appendLineBox(InlineFlowBox* box)
51{
52    checkConsistency();
53
54    if (!m_firstLineBox)
55        m_firstLineBox = m_lastLineBox = box;
56    else {
57        m_lastLineBox->setNextLineBox(box);
58        box->setPreviousLineBox(m_lastLineBox);
59        m_lastLineBox = box;
60    }
61
62    checkConsistency();
63}
64
65void RenderLineBoxList::deleteLineBoxTree()
66{
67    InlineFlowBox* line = m_firstLineBox;
68    InlineFlowBox* nextLine;
69    while (line) {
70        nextLine = line->nextLineBox();
71        line->deleteLine();
72        line = nextLine;
73    }
74    m_firstLineBox = m_lastLineBox = 0;
75}
76
77void RenderLineBoxList::extractLineBox(InlineFlowBox* box)
78{
79    checkConsistency();
80
81    m_lastLineBox = box->prevLineBox();
82    if (box == m_firstLineBox)
83        m_firstLineBox = 0;
84    if (box->prevLineBox())
85        box->prevLineBox()->setNextLineBox(0);
86    box->setPreviousLineBox(0);
87    for (InlineFlowBox* curr = box; curr; curr = curr->nextLineBox())
88        curr->setExtracted();
89
90    checkConsistency();
91}
92
93void RenderLineBoxList::attachLineBox(InlineFlowBox* box)
94{
95    checkConsistency();
96
97    if (m_lastLineBox) {
98        m_lastLineBox->setNextLineBox(box);
99        box->setPreviousLineBox(m_lastLineBox);
100    } else
101        m_firstLineBox = box;
102    InlineFlowBox* last = box;
103    for (InlineFlowBox* curr = box; curr; curr = curr->nextLineBox()) {
104        curr->setExtracted(false);
105        last = curr;
106    }
107    m_lastLineBox = last;
108
109    checkConsistency();
110}
111
112void RenderLineBoxList::removeLineBox(InlineFlowBox* box)
113{
114    checkConsistency();
115
116    if (box == m_firstLineBox)
117        m_firstLineBox = box->nextLineBox();
118    if (box == m_lastLineBox)
119        m_lastLineBox = box->prevLineBox();
120    if (box->nextLineBox())
121        box->nextLineBox()->setPreviousLineBox(box->prevLineBox());
122    if (box->prevLineBox())
123        box->prevLineBox()->setNextLineBox(box->nextLineBox());
124
125    checkConsistency();
126}
127
128void RenderLineBoxList::deleteLineBoxes()
129{
130    if (m_firstLineBox) {
131        InlineFlowBox* next;
132        for (InlineFlowBox* curr = m_firstLineBox; curr; curr = next) {
133            next = curr->nextLineBox();
134            curr->destroy();
135        }
136        m_firstLineBox = 0;
137        m_lastLineBox = 0;
138    }
139}
140
141void RenderLineBoxList::dirtyLineBoxes()
142{
143    for (InlineFlowBox* curr = firstLineBox(); curr; curr = curr->nextLineBox())
144        curr->dirtyLineBoxes();
145}
146
147bool RenderLineBoxList::rangeIntersectsRect(RenderBoxModelObject* renderer, LayoutUnit logicalTop, LayoutUnit logicalBottom, const LayoutRect& rect, const LayoutPoint& offset) const
148{
149    RenderBox* block;
150    if (renderer->isBox())
151        block = toRenderBox(renderer);
152    else
153        block = renderer->containingBlock();
154    LayoutUnit physicalStart = block->flipForWritingMode(logicalTop);
155    LayoutUnit physicalEnd = block->flipForWritingMode(logicalBottom);
156    LayoutUnit physicalExtent = absoluteValue(physicalEnd - physicalStart);
157    physicalStart = std::min(physicalStart, physicalEnd);
158
159    if (renderer->style()->isHorizontalWritingMode()) {
160        physicalStart += offset.y();
161        if (physicalStart >= rect.maxY() || physicalStart + physicalExtent <= rect.y())
162            return false;
163    } else {
164        physicalStart += offset.x();
165        if (physicalStart >= rect.maxX() || physicalStart + physicalExtent <= rect.x())
166            return false;
167    }
168
169    return true;
170}
171
172bool RenderLineBoxList::anyLineIntersectsRect(RenderBoxModelObject* renderer, const LayoutRect& rect, const LayoutPoint& offset) const
173{
174    // We can check the first box and last box and avoid painting/hit testing if we don't
175    // intersect.  This is a quick short-circuit that we can take to avoid walking any lines.
176    // FIXME: This check is flawed in the following extremely obscure way:
177    // if some line in the middle has a huge overflow, it might actually extend below the last line.
178    RootInlineBox& firstRootBox = firstLineBox()->root();
179    RootInlineBox& lastRootBox = lastLineBox()->root();
180    LayoutUnit firstLineTop = firstLineBox()->logicalTopVisualOverflow(firstRootBox.lineTop());
181    LayoutUnit lastLineBottom = lastLineBox()->logicalBottomVisualOverflow(lastRootBox.lineBottom());
182
183    return rangeIntersectsRect(renderer, firstLineTop, lastLineBottom, rect, offset);
184}
185
186bool RenderLineBoxList::lineIntersectsDirtyRect(RenderBoxModelObject* renderer, InlineFlowBox* box, const PaintInfo& paintInfo, const LayoutPoint& offset) const
187{
188    RootInlineBox& root = box->root();
189    LayoutUnit logicalTop = std::min<LayoutUnit>(box->logicalTopVisualOverflow(root.lineTop()), root.selectionTop());
190    LayoutUnit logicalBottom = box->logicalBottomVisualOverflow(root.lineBottom());
191
192    return rangeIntersectsRect(renderer, logicalTop, logicalBottom, paintInfo.rect, offset);
193}
194
195bool RenderLineBoxList::hitTest(RenderBoxModelObject* renderer, const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction) const
196{
197    if (hitTestAction != HitTestForeground)
198        return false;
199
200    ASSERT(renderer->isRenderBlock() || (renderer->isRenderInline() && renderer->hasLayer())); // The only way an inline could hit test like this is if it has a layer.
201
202    // If we have no lines then we have no work to do.
203    if (!firstLineBox())
204        return false;
205
206    LayoutPoint point = locationInContainer.point();
207    LayoutRect rect = firstLineBox()->isHorizontal() ?
208        IntRect(point.x(), point.y() - locationInContainer.topPadding(), 1, locationInContainer.topPadding() + locationInContainer.bottomPadding() + 1) :
209        IntRect(point.x() - locationInContainer.leftPadding(), point.y(), locationInContainer.rightPadding() + locationInContainer.leftPadding() + 1, 1);
210
211    if (!anyLineIntersectsRect(renderer, rect, accumulatedOffset))
212        return false;
213
214    // See if our root lines contain the point.  If so, then we hit test
215    // them further.  Note that boxes can easily overlap, so we can't make any assumptions
216    // based off positions of our first line box or our last line box.
217    for (InlineFlowBox* curr = lastLineBox(); curr; curr = curr->prevLineBox()) {
218        RootInlineBox& root = curr->root();
219        if (rangeIntersectsRect(renderer, curr->logicalTopVisualOverflow(root.lineTop()), curr->logicalBottomVisualOverflow(root.lineBottom()), rect, accumulatedOffset)) {
220            bool inside = curr->nodeAtPoint(request, result, locationInContainer, accumulatedOffset, root.lineTop(), root.lineBottom());
221            if (inside) {
222                renderer->updateHitTestResult(result, locationInContainer.point() - toLayoutSize(accumulatedOffset));
223                return true;
224            }
225        }
226    }
227
228    return false;
229}
230
231void RenderLineBoxList::dirtyLinesFromChangedChild(RenderObject* container, RenderObject* child)
232{
233    if (!container->parent() || (container->isRenderBlock() && (container->selfNeedsLayout() || !container->isRenderBlockFlow())))
234        return;
235
236    RenderInline* inlineContainer = container->isRenderInline() ? toRenderInline(container) : 0;
237    InlineBox* firstBox = inlineContainer ? inlineContainer->firstLineBoxIncludingCulling() : firstLineBox();
238
239    // If we have no first line box, then just bail early.
240    if (!firstBox) {
241        // For an empty inline, go ahead and propagate the check up to our parent, unless the parent
242        // is already dirty.
243        if (container->isInline() && !container->ancestorLineBoxDirty()) {
244            container->parent()->dirtyLinesFromChangedChild(container);
245            container->setAncestorLineBoxDirty(); // Mark the container to avoid dirtying the same lines again across multiple destroy() calls of the same subtree.
246        }
247        return;
248    }
249
250    // Try to figure out which line box we belong in.  First try to find a previous
251    // line box by examining our siblings.  If we didn't find a line box, then use our
252    // parent's first line box.
253    RootInlineBox* box = 0;
254    RenderObject* curr = 0;
255    ListHashSet<RenderObject*, 16> potentialLineBreakObjects;
256    potentialLineBreakObjects.add(child);
257    for (curr = child->previousSibling(); curr; curr = curr->previousSibling()) {
258        potentialLineBreakObjects.add(curr);
259
260        if (curr->isFloatingOrOutOfFlowPositioned())
261            continue;
262
263        if (curr->isReplaced()) {
264            InlineBox* wrapper = toRenderBox(curr)->inlineBoxWrapper();
265            if (wrapper)
266                box = &wrapper->root();
267        } else if (curr->isText()) {
268            InlineTextBox* textBox = toRenderText(curr)->lastTextBox();
269            if (textBox)
270                box = &textBox->root();
271        } else if (curr->isRenderInline()) {
272            InlineBox* lastSiblingBox = toRenderInline(curr)->lastLineBoxIncludingCulling();
273            if (lastSiblingBox)
274                box = &lastSiblingBox->root();
275        }
276
277        if (box)
278            break;
279    }
280    if (!box) {
281        if (inlineContainer && !inlineContainer->alwaysCreateLineBoxes()) {
282            // https://bugs.webkit.org/show_bug.cgi?id=60778
283            // We may have just removed a <br> with no line box that was our first child. In this case
284            // we won't find a previous sibling, but firstBox can be pointing to a following sibling.
285            // This isn't good enough, since we won't locate the root line box that encloses the removed
286            // <br>. We have to just over-invalidate a bit and go up to our parent.
287            if (!inlineContainer->ancestorLineBoxDirty()) {
288                inlineContainer->parent()->dirtyLinesFromChangedChild(inlineContainer);
289                inlineContainer->setAncestorLineBoxDirty(); // Mark the container to avoid dirtying the same lines again across multiple destroy() calls of the same subtree.
290            }
291            return;
292        }
293        box = &firstBox->root();
294    }
295
296    // If we found a line box, then dirty it.
297    if (box) {
298        RootInlineBox* adjacentBox;
299        box->markDirty();
300
301        // dirty the adjacent lines that might be affected
302        // NOTE: we dirty the previous line because RootInlineBox objects cache
303        // the address of the first object on the next line after a BR, which we may be
304        // invalidating here.  For more info, see how RenderBlock::layoutInlineChildren
305        // calls setLineBreakInfo with the result of findNextLineBreak.  findNextLineBreak,
306        // despite the name, actually returns the first RenderObject after the BR.
307        // <rdar://problem/3849947> "Typing after pasting line does not appear until after window resize."
308        adjacentBox = box->prevRootBox();
309        if (adjacentBox)
310            adjacentBox->markDirty();
311        adjacentBox = box->nextRootBox();
312        // If |child| or any of its immediately previous siblings with culled lineboxes is the object after a line-break in |box| or the linebox after it
313        // then that means |child| actually sits on the linebox after |box| (or is its line-break object) and so we need to dirty it as well.
314        if (adjacentBox && (potentialLineBreakObjects.contains(box->lineBreakObj()) || potentialLineBreakObjects.contains(adjacentBox->lineBreakObj()) || child->isBR() || isIsolated(container->style()->unicodeBidi())))
315            adjacentBox->markDirty();
316    }
317}
318
319#if ENABLE(ASSERT)
320
321void RenderLineBoxList::checkConsistency() const
322{
323#ifdef CHECK_CONSISTENCY
324    const InlineFlowBox* prev = 0;
325    for (const InlineFlowBox* child = m_firstLineBox; child != 0; child = child->nextLineBox()) {
326        ASSERT(child->prevLineBox() == prev);
327        prev = child;
328    }
329    ASSERT(prev == m_lastLineBox);
330#endif
331}
332
333#endif
334
335}
336