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      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 "RenderLineBoxList.h"
     31 
     32 #include "InlineTextBox.h"
     33 #include "RenderArena.h"
     34 #include "RenderInline.h"
     35 #include "RenderView.h"
     36 #include "RootInlineBox.h"
     37 
     38 using namespace std;
     39 
     40 namespace WebCore {
     41 
     42 #ifndef NDEBUG
     43 RenderLineBoxList::~RenderLineBoxList()
     44 {
     45     ASSERT(!m_firstLineBox);
     46     ASSERT(!m_lastLineBox);
     47 }
     48 #endif
     49 
     50 void 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 
     65 void RenderLineBoxList::deleteLineBoxTree(RenderArena* arena)
     66 {
     67     InlineFlowBox* line = m_firstLineBox;
     68     InlineFlowBox* nextLine;
     69     while (line) {
     70         nextLine = line->nextFlowBox();
     71         line->deleteLine(arena);
     72         line = nextLine;
     73     }
     74     m_firstLineBox = m_lastLineBox = 0;
     75 }
     76 
     77 void RenderLineBoxList::extractLineBox(InlineFlowBox* box)
     78 {
     79     checkConsistency();
     80 
     81     m_lastLineBox = box->prevFlowBox();
     82     if (box == m_firstLineBox)
     83         m_firstLineBox = 0;
     84     if (box->prevLineBox())
     85         box->prevLineBox()->setNextLineBox(0);
     86     box->setPreviousLineBox(0);
     87     for (InlineRunBox* curr = box; curr; curr = curr->nextLineBox())
     88         curr->setExtracted();
     89 
     90     checkConsistency();
     91 }
     92 
     93 void 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->nextFlowBox()) {
    104         curr->setExtracted(false);
    105         last = curr;
    106     }
    107     m_lastLineBox = last;
    108 
    109     checkConsistency();
    110 }
    111 
    112 void RenderLineBoxList::removeLineBox(InlineFlowBox* box)
    113 {
    114     checkConsistency();
    115 
    116     if (box == m_firstLineBox)
    117         m_firstLineBox = box->nextFlowBox();
    118     if (box == m_lastLineBox)
    119         m_lastLineBox = box->prevFlowBox();
    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 
    128 void RenderLineBoxList::deleteLineBoxes(RenderArena* arena)
    129 {
    130     if (m_firstLineBox) {
    131         InlineRunBox* next;
    132         for (InlineRunBox* curr = m_firstLineBox; curr; curr = next) {
    133             next = curr->nextLineBox();
    134             curr->destroy(arena);
    135         }
    136         m_firstLineBox = 0;
    137         m_lastLineBox = 0;
    138     }
    139 }
    140 
    141 void RenderLineBoxList::dirtyLineBoxes()
    142 {
    143     for (InlineRunBox* curr = firstLineBox(); curr; curr = curr->nextLineBox())
    144         curr->dirtyLineBoxes();
    145 }
    146 
    147 void RenderLineBoxList::paint(RenderBoxModelObject* renderer, RenderObject::PaintInfo& paintInfo, int tx, int ty) const
    148 {
    149     // Only paint during the foreground/selection phases.
    150     if (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseSelection && paintInfo.phase != PaintPhaseOutline
    151         && paintInfo.phase != PaintPhaseSelfOutline && paintInfo.phase != PaintPhaseChildOutlines && paintInfo.phase != PaintPhaseTextClip
    152         && paintInfo.phase != PaintPhaseMask)
    153         return;
    154 
    155     ASSERT(renderer->isRenderBlock() || (renderer->isRenderInline() && renderer->hasLayer())); // The only way an inline could paint like this is if it has a layer.
    156 
    157     // If we have no lines then we have no work to do.
    158     if (!firstLineBox())
    159         return;
    160 
    161     // We can check the first box and last box and avoid painting if we don't
    162     // intersect.  This is a quick short-circuit that we can take to avoid walking any lines.
    163     // FIXME: This check is flawed in the following extremely obscure way:
    164     // if some line in the middle has a huge overflow, it might actually extend below the last line.
    165     int yPos = firstLineBox()->topVisibleOverflow() - renderer->maximalOutlineSize(paintInfo.phase);
    166     int h = renderer->maximalOutlineSize(paintInfo.phase) + lastLineBox()->bottomVisibleOverflow() - yPos;
    167     yPos += ty;
    168     if (yPos >= paintInfo.rect.bottom() || yPos + h <= paintInfo.rect.y())
    169         return;
    170 
    171     RenderObject::PaintInfo info(paintInfo);
    172     ListHashSet<RenderInline*> outlineObjects;
    173     info.outlineObjects = &outlineObjects;
    174 
    175     // See if our root lines intersect with the dirty rect.  If so, then we paint
    176     // them.  Note that boxes can easily overlap, so we can't make any assumptions
    177     // based off positions of our first line box or our last line box.
    178     RenderView* v = renderer->view();
    179     bool usePrintRect = !v->printRect().isEmpty();
    180     for (InlineFlowBox* curr = firstLineBox(); curr; curr = curr->nextFlowBox()) {
    181         if (usePrintRect) {
    182             // FIXME: This is a feeble effort to avoid splitting a line across two pages.
    183             // It is utterly inadequate, and this should not be done at paint time at all.
    184             // The whole way objects break across pages needs to be redone.
    185             // Try to avoid splitting a line vertically, but only if it's less than the height
    186             // of the entire page.
    187             if (curr->bottomVisibleOverflow() - curr->topVisibleOverflow() <= v->printRect().height()) {
    188                 if (ty + curr->bottomVisibleOverflow() > v->printRect().bottom()) {
    189                     if (ty + curr->topVisibleOverflow() < v->truncatedAt())
    190                         v->setBestTruncatedAt(ty + curr->root()->topVisibleOverflow(), renderer);
    191                     // If we were able to truncate, don't paint.
    192                     if (ty + curr->topVisibleOverflow() >= v->truncatedAt())
    193                         break;
    194                 }
    195             }
    196         }
    197 
    198         int top = min(curr->topVisibleOverflow(), curr->root()->selectionTop()) - renderer->maximalOutlineSize(info.phase);
    199         int bottom = curr->bottomVisibleOverflow() + renderer->maximalOutlineSize(info.phase);
    200         h = bottom - top;
    201         yPos = ty + top;
    202         v->setMinimumColumnHeight(h);
    203         if (yPos < info.rect.bottom() && yPos + h > info.rect.y())
    204             curr->paint(info, tx, ty);
    205     }
    206 
    207     if (info.phase == PaintPhaseOutline || info.phase == PaintPhaseSelfOutline || info.phase == PaintPhaseChildOutlines) {
    208         ListHashSet<RenderInline*>::iterator end = info.outlineObjects->end();
    209         for (ListHashSet<RenderInline*>::iterator it = info.outlineObjects->begin(); it != end; ++it) {
    210             RenderInline* flow = *it;
    211             flow->paintOutline(info.context, tx, ty);
    212         }
    213         info.outlineObjects->clear();
    214     }
    215 }
    216 
    217 
    218 bool RenderLineBoxList::hitTest(RenderBoxModelObject* renderer, const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty, HitTestAction hitTestAction) const
    219 {
    220     if (hitTestAction != HitTestForeground)
    221         return false;
    222 
    223     ASSERT(renderer->isRenderBlock() || (renderer->isRenderInline() && renderer->hasLayer())); // The only way an inline could hit test like this is if it has a layer.
    224 
    225     // If we have no lines then we have no work to do.
    226     if (!firstLineBox())
    227         return false;
    228 
    229     // We can check the first box and last box and avoid hit testing if we don't
    230     // contain the point.  This is a quick short-circuit that we can take to avoid walking any lines.
    231     // FIXME: This check is flawed in the following extremely obscure way:
    232     // if some line in the middle has a huge overflow, it might actually extend below the last line.
    233     if ((y >= ty + lastLineBox()->root()->bottomVisibleOverflow()) || (y < ty + firstLineBox()->root()->topVisibleOverflow()))
    234         return false;
    235 
    236     // See if our root lines contain the point.  If so, then we hit test
    237     // them further.  Note that boxes can easily overlap, so we can't make any assumptions
    238     // based off positions of our first line box or our last line box.
    239     for (InlineFlowBox* curr = lastLineBox(); curr; curr = curr->prevFlowBox()) {
    240         if (y >= ty + curr->root()->topVisibleOverflow() && y < ty + curr->root()->bottomVisibleOverflow()) {
    241             bool inside = curr->nodeAtPoint(request, result, x, y, tx, ty);
    242             if (inside) {
    243                 renderer->updateHitTestResult(result, IntPoint(x - tx, y - ty));
    244                 return true;
    245             }
    246         }
    247     }
    248 
    249     return false;
    250 }
    251 
    252 void RenderLineBoxList::dirtyLinesFromChangedChild(RenderObject* container, RenderObject* child)
    253 {
    254     if (!container->parent() || (container->isRenderBlock() && (container->selfNeedsLayout() || !container->isBlockFlow())))
    255         return;
    256 
    257     // If we have no first line box, then just bail early.
    258     if (!firstLineBox()) {
    259         // For an empty inline, go ahead and propagate the check up to our parent, unless the parent
    260         // is already dirty.
    261         if (container->isInline() && !container->parent()->selfNeedsLayout())
    262             container->parent()->dirtyLinesFromChangedChild(container);
    263         return;
    264     }
    265 
    266     // Try to figure out which line box we belong in.  First try to find a previous
    267     // line box by examining our siblings.  If we didn't find a line box, then use our
    268     // parent's first line box.
    269     RootInlineBox* box = 0;
    270     RenderObject* curr = 0;
    271     for (curr = child->previousSibling(); curr; curr = curr->previousSibling()) {
    272         if (curr->isFloatingOrPositioned())
    273             continue;
    274 
    275         if (curr->isReplaced()) {
    276             InlineBox* wrapper = toRenderBox(curr)->inlineBoxWrapper();
    277             if (wrapper)
    278                 box = wrapper->root();
    279         } else if (curr->isText()) {
    280             InlineTextBox* textBox = toRenderText(curr)->lastTextBox();
    281             if (textBox)
    282                 box = textBox->root();
    283         } else if (curr->isRenderInline()) {
    284             InlineRunBox* runBox = toRenderInline(curr)->lastLineBox();
    285             if (runBox)
    286                 box = runBox->root();
    287         }
    288 
    289         if (box)
    290             break;
    291     }
    292     if (!box)
    293         box = firstLineBox()->root();
    294 
    295     // If we found a line box, then dirty it.
    296     if (box) {
    297         RootInlineBox* adjacentBox;
    298         box->markDirty();
    299 
    300         // dirty the adjacent lines that might be affected
    301         // NOTE: we dirty the previous line because RootInlineBox objects cache
    302         // the address of the first object on the next line after a BR, which we may be
    303         // invalidating here.  For more info, see how RenderBlock::layoutInlineChildren
    304         // calls setLineBreakInfo with the result of findNextLineBreak.  findNextLineBreak,
    305         // despite the name, actually returns the first RenderObject after the BR.
    306         // <rdar://problem/3849947> "Typing after pasting line does not appear until after window resize."
    307         adjacentBox = box->prevRootBox();
    308         if (adjacentBox)
    309             adjacentBox->markDirty();
    310         if (child->isBR() || (curr && curr->isBR())) {
    311             adjacentBox = box->nextRootBox();
    312             if (adjacentBox)
    313                 adjacentBox->markDirty();
    314         }
    315     }
    316 }
    317 
    318 #ifndef NDEBUG
    319 
    320 void RenderLineBoxList::checkConsistency() const
    321 {
    322 #ifdef CHECK_CONSISTENCY
    323     const InlineFlowBox* prev = 0;
    324     for (const InlineFlowBox* child = m_firstLineBox; child != 0; child = child->nextFlowBox()) {
    325         ASSERT(child->prevFlowBox() == prev);
    326         prev = child;
    327     }
    328     ASSERT(prev == m_lastLineBox);
    329 #endif
    330 }
    331 
    332 #endif
    333 
    334 }
    335