| /* |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "core/rendering/FastTextAutosizer.h" |
| |
| #include "core/dom/Document.h" |
| #include "core/frame/FrameView.h" |
| #include "core/frame/LocalFrame.h" |
| #include "core/frame/Settings.h" |
| #include "core/page/Page.h" |
| #include "core/rendering/InlineIterator.h" |
| #include "core/rendering/RenderBlock.h" |
| #include "core/rendering/RenderListItem.h" |
| #include "core/rendering/RenderListMarker.h" |
| #include "core/rendering/RenderTableCell.h" |
| #include "core/rendering/RenderView.h" |
| |
| using namespace std; |
| |
| namespace WebCore { |
| |
| static const RenderObject* parentElementRenderer(const RenderObject* renderer) |
| { |
| // At style recalc, the renderer's parent may not be attached, |
| // so we need to obtain this from the DOM tree. |
| |
| const Node* node = renderer->node(); |
| if (!node) |
| return 0; |
| |
| while ((node = node->parentNode())) { |
| if (node->isElementNode()) |
| return node->renderer(); |
| } |
| return 0; |
| } |
| |
| static const Vector<QualifiedName>& formInputTags() |
| { |
| // Returns the tags for the form input elements. |
| DEFINE_STATIC_LOCAL(Vector<QualifiedName>, formInputTags, ()); |
| if (formInputTags.isEmpty()) { |
| formInputTags.append(HTMLNames::inputTag); |
| formInputTags.append(HTMLNames::buttonTag); |
| formInputTags.append(HTMLNames::selectTag); |
| } |
| return formInputTags; |
| } |
| |
| static bool isAutosizingContainer(const RenderObject* renderer) |
| { |
| // "Autosizing containers" are the smallest unit for which we can |
| // enable/disable Text Autosizing. |
| // - Must not be inline, as different multipliers on one line looks terrible. |
| // Exceptions are inline-block and alike elements (inline-table, -webkit-inline-*), |
| // as they often contain entire multi-line columns of text. |
| // - Must not be list items, as items in the same list should look consistent (*). |
| // - Must not be normal list items, as items in the same list should look |
| // consistent, unless they are floating or position:absolute/fixed. |
| Node* node = renderer->generatingNode(); |
| if ((node && !node->hasChildren()) |
| || !renderer->isRenderBlock() |
| || (renderer->isInline() && !renderer->style()->isDisplayReplacedType())) |
| return false; |
| if (renderer->isListItem()) |
| return renderer->isFloating() || renderer->isOutOfFlowPositioned(); |
| // Avoid creating containers for text within text controls, buttons, or <select> buttons. |
| Node* parentNode = renderer->parent() ? renderer->parent()->generatingNode() : 0; |
| if (parentNode && parentNode->isElementNode() && formInputTags().contains(toElement(parentNode)->tagQName())) |
| return false; |
| |
| return true; |
| } |
| |
| static RenderObject* nextInPreOrderSkippingDescendantsOfContainers(const RenderObject* current, const RenderObject* stayWithin) |
| { |
| if (current == stayWithin || !isAutosizingContainer(current)) |
| return current->nextInPreOrder(stayWithin); |
| return current->nextInPreOrderAfterChildren(stayWithin); |
| } |
| |
| static bool isIndependentDescendant(const RenderBlock* renderer) |
| { |
| ASSERT(isAutosizingContainer(renderer)); |
| |
| // "Autosizing clusters" are special autosizing containers within which we |
| // want to enforce a uniform text size multiplier, in the hopes of making |
| // the major sections of the page look internally consistent. |
| // All their descendants (including other autosizing containers) must share |
| // the same multiplier, except for subtrees which are themselves clusters, |
| // and some of their descendant containers might not be autosized at all |
| // (for example if their height is constrained). |
| // Additionally, clusterShouldBeAutosized requires each cluster to contain a |
| // minimum amount of text, without which it won't be autosized. |
| // |
| // Clusters are chosen using very similar criteria to CSS flow roots, aka |
| // block formatting contexts (http://w3.org/TR/css3-box/#flow-root), since |
| // flow roots correspond to box containers that behave somewhat |
| // independently from their parent (for example they don't overlap floats). |
| // The definition of a flow root also conveniently includes most of the |
| // ways that a box and its children can have significantly different width |
| // from the box's parent (we want to avoid having significantly different |
| // width blocks within a cluster, since the narrower blocks would end up |
| // larger than would otherwise be necessary). |
| RenderBlock* containingBlock = renderer->containingBlock(); |
| return renderer->isRenderView() |
| || renderer->isFloating() |
| || renderer->isOutOfFlowPositioned() |
| || renderer->isTableCell() |
| || renderer->isTableCaption() |
| || renderer->isFlexibleBoxIncludingDeprecated() |
| || renderer->hasColumns() |
| || (containingBlock && containingBlock->isHorizontalWritingMode() != renderer->isHorizontalWritingMode()) |
| || renderer->style()->isDisplayReplacedType() |
| || renderer->isTextArea() |
| || renderer->style()->userModify() != READ_ONLY; |
| // FIXME: Tables need special handling to multiply all their columns by |
| // the same amount even if they're different widths; so do hasColumns() |
| // containers, and probably flexboxes... |
| } |
| |
| static bool containerIsRowOfLinks(const RenderObject* container) |
| { |
| // A "row of links" is a container for which holds: |
| // 1. it should not contain non-link text elements longer than 3 characters |
| // 2. it should contain min. 3 inline links and all links should |
| // have the same specified font size |
| // 3. it should not contain <br> elements |
| // 4. it should contain only inline elements unless they are containers, |
| // children of link elements or children of sub-containers. |
| int linkCount = 0; |
| RenderObject* renderer = container->nextInPreOrder(container); |
| float matchingFontSize = -1; |
| |
| while (renderer) { |
| if (!isAutosizingContainer(renderer)) { |
| if (renderer->isText() && toRenderText(renderer)->text().impl()->stripWhiteSpace()->length() > 3) |
| return false; |
| if (!renderer->isInline()) |
| return false; |
| if (renderer->isBR()) |
| return false; |
| } |
| if (renderer->style()->isLink()) { |
| if (matchingFontSize < 0) { |
| matchingFontSize = renderer->style()->specifiedFontSize(); |
| } else { |
| if (matchingFontSize != renderer->style()->specifiedFontSize()) |
| return false; |
| } |
| |
| linkCount++; |
| // Skip traversing descendants of the link. |
| renderer = renderer->nextInPreOrderAfterChildren(container); |
| } else { |
| renderer = nextInPreOrderSkippingDescendantsOfContainers(renderer, container); |
| } |
| } |
| |
| return (linkCount >= 3); |
| } |
| |
| static bool contentHeightIsConstrained(const RenderBlock* container) |
| { |
| // FIXME: Propagate constrainedness down the tree, to avoid inefficiently walking back up from each box. |
| // FIXME: This code needs to take into account vertical writing modes. |
| // FIXME: Consider additional heuristics, such as ignoring fixed heights if the content is already overflowing before autosizing kicks in. |
| for (; container; container = container->containingBlock()) { |
| RenderStyle* style = container->style(); |
| if (style->overflowY() >= OSCROLL) |
| return false; |
| if (style->height().isSpecified() || style->maxHeight().isSpecified() || container->isOutOfFlowPositioned()) { |
| // Some sites (e.g. wikipedia) set their html and/or body elements to height:100%, |
| // without intending to constrain the height of the content within them. |
| return !container->isRoot() && !container->isBody(); |
| } |
| if (container->isFloating()) |
| return false; |
| } |
| return false; |
| } |
| |
| static bool containerContainsOneOfTags(const RenderBlock* container, const Vector<QualifiedName>& tags) |
| { |
| const RenderObject* renderer = container; |
| while (renderer) { |
| const Node* rendererNode = renderer->node(); |
| if (rendererNode && rendererNode->isElementNode()) { |
| if (tags.contains(toElement(rendererNode)->tagQName())) |
| return true; |
| } |
| renderer = nextInPreOrderSkippingDescendantsOfContainers(renderer, container); |
| } |
| |
| return false; |
| } |
| |
| static bool containerShouldBeAutosized(const RenderBlock* container) |
| { |
| if (containerContainsOneOfTags(container, formInputTags())) |
| return false; |
| |
| if (containerIsRowOfLinks(container)) |
| return false; |
| |
| // Don't autosize block-level text that can't wrap (as it's likely to |
| // expand sideways and break the page's layout). |
| if (!container->style()->autoWrap()) |
| return false; |
| |
| return !contentHeightIsConstrained(container); |
| } |
| |
| FastTextAutosizer::FastTextAutosizer(const Document* document) |
| : m_document(document) |
| , m_frameWidth(0) |
| , m_layoutWidth(0) |
| , m_baseMultiplier(0) |
| , m_pageAutosizingStatus(PageAutosizingStatusUnknown) |
| , m_firstBlock(0) |
| #ifndef NDEBUG |
| , m_renderViewInfoPrepared(false) |
| , m_blocksThatHaveBegunLayout() |
| #endif |
| , m_superclusters() |
| , m_clusterStack() |
| , m_fingerprintMapper() |
| { |
| } |
| |
| void FastTextAutosizer::record(const RenderBlock* block) |
| { |
| if (!enabled()) |
| return; |
| |
| ASSERT(!m_blocksThatHaveBegunLayout.contains(block)); |
| |
| if (!isFingerprintingCandidate(block)) |
| return; |
| |
| if (Fingerprint fingerprint = computeFingerprint(block)) |
| m_fingerprintMapper.addTentativeClusterRoot(block, fingerprint); |
| } |
| |
| void FastTextAutosizer::destroy(const RenderBlock* block) |
| { |
| if (!enabled()) |
| return; |
| ASSERT(!m_blocksThatHaveBegunLayout.contains(block)); |
| |
| m_fingerprintMapper.remove(block); |
| } |
| |
| void FastTextAutosizer::prepareClusterStack(const RenderObject* renderer) |
| { |
| if (!renderer) |
| return; |
| prepareClusterStack(renderer->parent()); |
| |
| if (renderer->isRenderBlock()) { |
| const RenderBlock* block = toRenderBlock(renderer); |
| #ifndef NDEBUG |
| m_blocksThatHaveBegunLayout.add(block); |
| #endif |
| if (Cluster* cluster = maybeCreateCluster(block)) |
| m_clusterStack.append(adoptPtr(cluster)); |
| } |
| } |
| |
| void FastTextAutosizer::beginLayout(RenderBlock* block) |
| { |
| ASSERT(enabled() && m_pageAutosizingStatus == PageNeedsAutosizing); |
| #ifndef NDEBUG |
| m_blocksThatHaveBegunLayout.add(block); |
| #endif |
| |
| if (!m_firstBlock) { |
| m_firstBlock = block; |
| prepareClusterStack(block->parent()); |
| } else if (block == currentCluster()->m_root) { |
| // Ignore beginLayout on the same block twice. |
| // This can happen with paginated overflow. |
| return; |
| } |
| |
| if (Cluster* cluster = maybeCreateCluster(block)) { |
| m_clusterStack.append(adoptPtr(cluster)); |
| if (block->isTable()) |
| inflateTable(toRenderTable(block)); |
| } |
| |
| if (block->childrenInline() && block->firstChild()) |
| inflate(block); |
| } |
| |
| void FastTextAutosizer::inflateListItem(RenderListItem* listItem, RenderListMarker* listItemMarker) |
| { |
| if (!enabled() || m_pageAutosizingStatus != PageNeedsAutosizing) |
| return; |
| ASSERT(listItem && listItemMarker); |
| #ifndef NDEBUG |
| m_blocksThatHaveBegunLayout.add(listItem); |
| #endif |
| // Force the LI to be inside the DBCAT when computing the multiplier. |
| // This guarantees that the DBCAT has entered layout, so we can ask for its width. |
| // It also makes sense because the list marker is autosized like a text node. |
| float multiplier = clusterMultiplier(currentCluster()); |
| |
| applyMultiplier(listItem, multiplier); |
| applyMultiplier(listItemMarker, multiplier); |
| } |
| |
| void FastTextAutosizer::inflateTable(RenderTable* table) |
| { |
| ASSERT(table); |
| ASSERT(table->containingBlock()); |
| |
| Cluster* cluster = currentCluster(); |
| ASSERT(cluster->m_root->isTable()); |
| |
| // Pre-inflate cells that have enough text so that their inflated preferred widths will be used |
| // for column sizing. |
| // The multiplier used for cell descendants represents the maximum we can ever inflate |
| // descendants without overflowing the cell width computed by the table layout. Therefore, |
| // descendants of cells cannot use a multiplier higher than the table's multiplier. |
| float multiplier = clusterMultiplier(cluster); |
| for (RenderObject* section = table->firstChild(); section; section = section->nextSibling()) { |
| if (!section->isTableSection()) |
| continue; |
| for (RenderObject* row = section->firstChild(); row; row = row->nextSibling()) { |
| if (!row->isTableRow()) |
| continue; |
| for (RenderObject* cell = row->firstChild(); cell; cell = cell->nextSibling()) { |
| if (!cell->isTableCell()) |
| continue; |
| RenderTableCell* renderTableCell = toRenderTableCell(cell); |
| |
| bool shouldAutosize; |
| if (!containerShouldBeAutosized(renderTableCell)) |
| shouldAutosize = false; |
| else if (Supercluster* supercluster = getSupercluster(renderTableCell)) |
| shouldAutosize = anyClusterHasEnoughTextToAutosize(supercluster->m_roots, table); |
| else |
| shouldAutosize = clusterWouldHaveEnoughTextToAutosize(renderTableCell, table); |
| |
| if (shouldAutosize) { |
| for (RenderObject* child = cell; child; child = child->nextInPreOrder(cell)) { |
| if (child->isText()) { |
| applyMultiplier(child, multiplier); |
| applyMultiplier(child->parent(), multiplier); // Parent handles line spacing. |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| void FastTextAutosizer::endLayout(RenderBlock* block) |
| { |
| ASSERT(enabled() && m_pageAutosizingStatus == PageNeedsAutosizing); |
| |
| if (block == m_firstBlock) { |
| m_firstBlock = 0; |
| m_pageAutosizingStatus = PageAutosizingStatusUnknown; |
| m_clusterStack.clear(); |
| m_superclusters.clear(); |
| #ifndef NDEBUG |
| m_blocksThatHaveBegunLayout.clear(); |
| #endif |
| } else if (currentCluster()->m_root == block) { |
| m_clusterStack.removeLast(); |
| } |
| } |
| |
| void FastTextAutosizer::inflate(RenderBlock* block) |
| { |
| Cluster* cluster = currentCluster(); |
| float multiplier = 0; |
| for (RenderObject* descendant = nextChildSkippingChildrenOfBlocks(block, block); descendant; descendant = nextChildSkippingChildrenOfBlocks(descendant, block)) { |
| if (descendant->isText()) { |
| // We only calculate this multiplier on-demand to ensure the parent block of this text |
| // has entered layout. |
| if (!multiplier) |
| multiplier = cluster->m_autosize ? clusterMultiplier(cluster) : 1.0f; |
| applyMultiplier(descendant, multiplier); |
| applyMultiplier(descendant->parent(), multiplier); // Parent handles line spacing. |
| } |
| } |
| } |
| |
| bool FastTextAutosizer::enabled() |
| { |
| if (!m_document->settings() || !m_document->page() || m_document->printing()) |
| return false; |
| |
| return m_document->settings()->textAutosizingEnabled(); |
| } |
| |
| void FastTextAutosizer::updateRenderViewInfo() |
| { |
| RenderView* renderView = toRenderView(m_document->renderer()); |
| bool horizontalWritingMode = isHorizontalWritingMode(renderView->style()->writingMode()); |
| |
| LocalFrame* mainFrame = m_document->page()->mainFrame(); |
| IntSize frameSize = m_document->settings()->textAutosizingWindowSizeOverride(); |
| if (frameSize.isEmpty()) |
| frameSize = mainFrame->view()->unscaledVisibleContentSize(IncludeScrollbars); |
| m_frameWidth = horizontalWritingMode ? frameSize.width() : frameSize.height(); |
| |
| IntSize layoutSize = m_document->page()->mainFrame()->view()->layoutSize(); |
| m_layoutWidth = horizontalWritingMode ? layoutSize.width() : layoutSize.height(); |
| |
| // Compute the base font scale multiplier based on device and accessibility settings. |
| m_baseMultiplier = m_document->settings()->accessibilityFontScaleFactor(); |
| // If the page has a meta viewport or @viewport, don't apply the device scale adjustment. |
| const ViewportDescription& viewportDescription = m_document->page()->mainFrame()->document()->viewportDescription(); |
| if (!viewportDescription.isSpecifiedByAuthor()) { |
| float deviceScaleAdjustment = m_document->settings()->deviceScaleAdjustment(); |
| m_baseMultiplier *= deviceScaleAdjustment; |
| } |
| |
| m_pageAutosizingStatus = m_frameWidth && (m_baseMultiplier * (static_cast<float>(m_layoutWidth) / m_frameWidth) > 1.0f) |
| ? PageNeedsAutosizing : PageDoesNotNeedAutosizing; |
| |
| #ifndef NDEBUG |
| m_renderViewInfoPrepared = true; |
| #endif |
| } |
| |
| bool FastTextAutosizer::isFingerprintingCandidate(const RenderBlock* block) |
| { |
| // FIXME: move the logic out of TextAutosizer.cpp into this class. |
| return block->isRenderView() |
| || (isAutosizingContainer(block) |
| && (isIndependentDescendant(block) |
| || mightBeWiderOrNarrowerDescendant(block))); |
| } |
| |
| bool FastTextAutosizer::clusterWouldHaveEnoughTextToAutosize(const RenderBlock* root, const RenderBlock* widthProvider) |
| { |
| Cluster hypotheticalCluster(root, true, 0); |
| return clusterHasEnoughTextToAutosize(&hypotheticalCluster, widthProvider); |
| } |
| |
| bool FastTextAutosizer::clusterHasEnoughTextToAutosize(Cluster* cluster, const RenderBlock* widthProvider) |
| { |
| if (cluster->m_hasEnoughTextToAutosize != UnknownAmountOfText) |
| return cluster->m_hasEnoughTextToAutosize == HasEnoughText; |
| |
| const RenderBlock* root = cluster->m_root; |
| if (!widthProvider) |
| widthProvider = clusterWidthProvider(root); |
| |
| // TextAreas and user-modifiable areas get a free pass to autosize regardless of text content. |
| if (root->isTextArea() || (root->style() && root->style()->userModify() != READ_ONLY)) { |
| cluster->m_hasEnoughTextToAutosize = HasEnoughText; |
| return true; |
| } |
| |
| if (!containerShouldBeAutosized(root)) { |
| cluster->m_hasEnoughTextToAutosize = NotEnoughText; |
| return false; |
| } |
| |
| // 4 lines of text is considered enough to autosize. |
| float minimumTextLengthToAutosize = widthFromBlock(widthProvider) * 4; |
| |
| float length = 0; |
| RenderObject* descendant = root->nextInPreOrder(root); |
| while (descendant) { |
| if (descendant->isRenderBlock()) { |
| RenderBlock* block = toRenderBlock(descendant); |
| if (isAutosizingContainer(block)) { |
| // Note: Ideally we would check isWiderOrNarrowerDescendant here but we only know that |
| // after the block has entered layout, which may not be the case. |
| bool isAutosizingClusterRoot = isIndependentDescendant(block) || block->isTable(); |
| if ((isAutosizingClusterRoot && !block->isTableCell()) |
| || !containerShouldBeAutosized(block)) { |
| descendant = descendant->nextInPreOrderAfterChildren(root); |
| continue; |
| } |
| } |
| } else if (descendant->isText()) { |
| // Note: Using text().stripWhiteSpace().length() instead of renderedTextLength() because |
| // the lineboxes will not be built until layout. These values can be different. |
| // Note: This is an approximation assuming each character is 1em wide. |
| length += toRenderText(descendant)->text().stripWhiteSpace().length() * descendant->style()->specifiedFontSize(); |
| |
| if (length >= minimumTextLengthToAutosize) { |
| cluster->m_hasEnoughTextToAutosize = HasEnoughText; |
| return true; |
| } |
| } |
| descendant = descendant->nextInPreOrder(root); |
| } |
| |
| cluster->m_hasEnoughTextToAutosize = NotEnoughText; |
| return false; |
| } |
| |
| FastTextAutosizer::Fingerprint FastTextAutosizer::getFingerprint(const RenderObject* renderer) |
| { |
| Fingerprint result = m_fingerprintMapper.get(renderer); |
| if (!result) { |
| result = computeFingerprint(renderer); |
| m_fingerprintMapper.add(renderer, result); |
| } |
| return result; |
| } |
| |
| FastTextAutosizer::Fingerprint FastTextAutosizer::computeFingerprint(const RenderObject* renderer) |
| { |
| Node* node = renderer->generatingNode(); |
| if (!node || !node->isElementNode()) |
| return 0; |
| |
| FingerprintSourceData data; |
| |
| // FIXME: Instead of computing and caching parent fingerprints on demand, |
| // consider maintaining a fingerprint stack during the style recalc |
| // tree walk (similar to the cluster stack used during layout). |
| |
| if (const RenderObject* parent = parentElementRenderer(renderer)) |
| data.m_parentHash = getFingerprint(parent); |
| |
| data.m_qualifiedNameHash = QualifiedNameHash::hash(toElement(node)->tagQName()); |
| |
| if (RenderStyle* style = renderer->style()) { |
| data.m_packedStyleProperties = style->direction(); |
| data.m_packedStyleProperties |= (style->position() << 1); |
| data.m_packedStyleProperties |= (style->floating() << 4); |
| data.m_packedStyleProperties |= (style->display() << 6); |
| data.m_packedStyleProperties |= (style->width().type() << 11); |
| // packedStyleProperties effectively using 15 bits now. |
| |
| // consider for adding: writing mode, padding. |
| |
| data.m_width = style->width().getFloatValue(); |
| } |
| |
| // Use nodeIndex as a rough approximation of column number |
| // (it's too early to call RenderTableCell::col). |
| // FIXME: account for colspan |
| if (renderer->isTableCell()) |
| data.m_column = renderer->node()->nodeIndex(); |
| |
| return StringHasher::computeHash<UChar>( |
| static_cast<const UChar*>(static_cast<const void*>(&data)), |
| sizeof data / sizeof(UChar)); |
| } |
| |
| FastTextAutosizer::Cluster* FastTextAutosizer::maybeCreateCluster(const RenderBlock* block) |
| { |
| if (!isAutosizingContainer(block)) |
| return 0; |
| |
| Cluster* parentCluster = m_clusterStack.isEmpty() ? 0 : currentCluster(); |
| ASSERT(parentCluster || block->isRenderView()); |
| |
| // Create clusters to suppress / unsuppress autosizing based on containerShouldBeAutosized. |
| bool containerCanAutosize = containerShouldBeAutosized(block); |
| bool parentClusterCanAutosize = parentCluster && parentCluster->m_autosize; |
| bool createClusterThatMightAutosize = block->isRenderView() |
| || mightBeWiderOrNarrowerDescendant(block) |
| || isIndependentDescendant(block) |
| || block->isTable(); |
| |
| // If the container would not alter the m_autosize bit, it doesn't need to be a cluster. |
| if (!createClusterThatMightAutosize && containerCanAutosize == parentClusterCanAutosize) |
| return 0; |
| |
| return new Cluster(block, containerCanAutosize, parentCluster, getSupercluster(block)); |
| } |
| |
| FastTextAutosizer::Supercluster* FastTextAutosizer::getSupercluster(const RenderBlock* block) |
| { |
| Fingerprint fingerprint = m_fingerprintMapper.get(block); |
| if (!fingerprint) |
| return 0; |
| |
| BlockSet* roots = &m_fingerprintMapper.getTentativeClusterRoots(fingerprint); |
| if (!roots || roots->size() < 2 || !roots->contains(block)) |
| return 0; |
| |
| SuperclusterMap::AddResult addResult = m_superclusters.add(fingerprint, PassOwnPtr<Supercluster>()); |
| if (!addResult.isNewEntry) |
| return addResult.storedValue->value.get(); |
| |
| Supercluster* supercluster = new Supercluster(roots); |
| addResult.storedValue->value = adoptPtr(supercluster); |
| return supercluster; |
| } |
| |
| const RenderBlock* FastTextAutosizer::deepestCommonAncestor(BlockSet& blocks) |
| { |
| // Find the lowest common ancestor of blocks. |
| // Note: this could be improved to not be O(b*h) for b blocks and tree height h. |
| HashCountedSet<const RenderBlock*> ancestors; |
| for (BlockSet::iterator it = blocks.begin(); it != blocks.end(); ++it) { |
| for (const RenderBlock* block = (*it); block; block = block->containingBlock()) { |
| ancestors.add(block); |
| // The first ancestor that has all of the blocks as children wins. |
| if (ancestors.count(block) == blocks.size()) |
| return block; |
| } |
| } |
| ASSERT_NOT_REACHED(); |
| return 0; |
| } |
| |
| float FastTextAutosizer::clusterMultiplier(Cluster* cluster) |
| { |
| ASSERT(m_renderViewInfoPrepared); |
| if (!cluster->m_multiplier) { |
| if (cluster->m_root->isTable() |
| || isIndependentDescendant(cluster->m_root) |
| || isWiderOrNarrowerDescendant(cluster)) { |
| |
| if (cluster->m_supercluster) { |
| cluster->m_multiplier = superclusterMultiplier(cluster); |
| } else if (clusterHasEnoughTextToAutosize(cluster)) { |
| cluster->m_multiplier = multiplierFromBlock(clusterWidthProvider(cluster->m_root)); |
| // Do not inflate table descendants above the table's multiplier. See inflateTable(...) for details. |
| if (cluster->m_hasTableAncestor) |
| cluster->m_multiplier = min(cluster->m_multiplier, clusterMultiplier(cluster->m_parent)); |
| } else { |
| cluster->m_multiplier = 1.0f; |
| } |
| } else { |
| cluster->m_multiplier = cluster->m_parent ? clusterMultiplier(cluster->m_parent) : 1.0f; |
| } |
| } |
| ASSERT(cluster->m_multiplier); |
| return cluster->m_multiplier; |
| } |
| |
| bool FastTextAutosizer::anyClusterHasEnoughTextToAutosize(const BlockSet* roots, const RenderBlock* widthProvider) |
| { |
| for (BlockSet::iterator it = roots->begin(); it != roots->end(); ++it) { |
| if (clusterWouldHaveEnoughTextToAutosize(*it, widthProvider)) |
| return true; |
| } |
| return false; |
| } |
| |
| float FastTextAutosizer::superclusterMultiplier(Cluster* cluster) |
| { |
| Supercluster* supercluster = cluster->m_supercluster; |
| if (!supercluster->m_multiplier) { |
| const BlockSet* roots = supercluster->m_roots; |
| const RenderBlock* widthProvider; |
| |
| if (cluster->m_root->isTableCell()) { |
| widthProvider = clusterWidthProvider(cluster->m_root); |
| } else { |
| BlockSet widthProviders; |
| for (BlockSet::iterator it = roots->begin(); it != roots->end(); ++it) |
| widthProviders.add(clusterWidthProvider(*it)); |
| widthProvider = deepestCommonAncestor(widthProviders); |
| } |
| |
| supercluster->m_multiplier = anyClusterHasEnoughTextToAutosize(roots, widthProvider) |
| ? multiplierFromBlock(widthProvider) : 1.0f; |
| } |
| ASSERT(supercluster->m_multiplier); |
| return supercluster->m_multiplier; |
| } |
| |
| const RenderBlock* FastTextAutosizer::clusterWidthProvider(const RenderBlock* root) |
| { |
| if (root->isTable() || root->isTableCell()) |
| return root; |
| |
| return deepestBlockContainingAllText(root); |
| } |
| |
| float FastTextAutosizer::widthFromBlock(const RenderBlock* block) |
| { |
| if (block->isTable()) { |
| RenderBlock* containingBlock = block->containingBlock(); |
| ASSERT(block->containingBlock()); |
| if (block->style()->logicalWidth().isSpecified()) |
| return floatValueForLength(block->style()->logicalWidth(), containingBlock->contentLogicalWidth().toFloat()); |
| return containingBlock->contentLogicalWidth().toFloat(); |
| } |
| return block->contentLogicalWidth().toFloat(); |
| } |
| |
| float FastTextAutosizer::multiplierFromBlock(const RenderBlock* block) |
| { |
| // If block->needsLayout() is false, it does not need to be in m_blocksThatHaveBegunLayout. |
| // This can happen during layout of a positioned object if the cluster's DBCAT is deeper |
| // than the positioned object's containing block, and wasn't marked as needing layout. |
| ASSERT(m_blocksThatHaveBegunLayout.contains(block) || !block->needsLayout()); |
| |
| // Block width, in CSS pixels. |
| float blockWidth = widthFromBlock(block); |
| float multiplier = m_frameWidth ? min(blockWidth, static_cast<float>(m_layoutWidth)) / m_frameWidth : 1.0f; |
| |
| return max(m_baseMultiplier * multiplier, 1.0f); |
| } |
| |
| const RenderBlock* FastTextAutosizer::deepestBlockContainingAllText(Cluster* cluster) |
| { |
| if (!cluster->m_deepestBlockContainingAllText) |
| cluster->m_deepestBlockContainingAllText = deepestBlockContainingAllText(cluster->m_root); |
| |
| return cluster->m_deepestBlockContainingAllText; |
| } |
| |
| // FIXME: Refactor this to look more like FastTextAutosizer::deepestCommonAncestor. This is copied |
| // from TextAutosizer::findDeepestBlockContainingAllText. |
| const RenderBlock* FastTextAutosizer::deepestBlockContainingAllText(const RenderBlock* root) |
| { |
| size_t firstDepth = 0; |
| const RenderObject* firstTextLeaf = findTextLeaf(root, firstDepth, First); |
| if (!firstTextLeaf) |
| return root; |
| |
| size_t lastDepth = 0; |
| const RenderObject* lastTextLeaf = findTextLeaf(root, lastDepth, Last); |
| ASSERT(lastTextLeaf); |
| |
| // Equalize the depths if necessary. Only one of the while loops below will get executed. |
| const RenderObject* firstNode = firstTextLeaf; |
| const RenderObject* lastNode = lastTextLeaf; |
| while (firstDepth > lastDepth) { |
| firstNode = firstNode->parent(); |
| --firstDepth; |
| } |
| while (lastDepth > firstDepth) { |
| lastNode = lastNode->parent(); |
| --lastDepth; |
| } |
| |
| // Go up from both nodes until the parent is the same. Both pointers will point to the LCA then. |
| while (firstNode != lastNode) { |
| firstNode = firstNode->parent(); |
| lastNode = lastNode->parent(); |
| } |
| |
| if (firstNode->isRenderBlock()) |
| return toRenderBlock(firstNode); |
| |
| // containingBlock() should never leave the cluster, since it only skips ancestors when finding |
| // the container of position:absolute/fixed blocks, and those cannot exist between a cluster and |
| // its text node's lowest common ancestor as isAutosizingCluster would have made them into their |
| // own independent cluster. |
| const RenderBlock* containingBlock = firstNode->containingBlock(); |
| ASSERT(containingBlock->isDescendantOf(root)); |
| |
| return containingBlock; |
| } |
| |
| const RenderObject* FastTextAutosizer::findTextLeaf(const RenderObject* parent, size_t& depth, TextLeafSearch firstOrLast) |
| { |
| // List items are treated as text due to the marker. |
| // The actual renderer for the marker (RenderListMarker) may not be in the tree yet since it is added during layout. |
| if (parent->isListItem()) |
| return parent; |
| |
| if (parent->isEmpty()) |
| return parent->isText() ? parent : 0; |
| |
| ++depth; |
| const RenderObject* child = (firstOrLast == First) ? parent->firstChild() : parent->lastChild(); |
| while (child) { |
| // Note: At this point clusters may not have been created for these blocks so we cannot rely |
| // on m_clusters. Instead, we use a best-guess about whether the block will become a cluster. |
| if (!isAutosizingContainer(child) || !isIndependentDescendant(toRenderBlock(child))) { |
| const RenderObject* leaf = findTextLeaf(child, depth, firstOrLast); |
| if (leaf) |
| return leaf; |
| } |
| child = (firstOrLast == First) ? child->nextSibling() : child->previousSibling(); |
| } |
| --depth; |
| |
| return 0; |
| } |
| |
| void FastTextAutosizer::applyMultiplier(RenderObject* renderer, float multiplier) |
| { |
| ASSERT(renderer); |
| RenderStyle* currentStyle = renderer->style(); |
| if (currentStyle->textAutosizingMultiplier() == multiplier) |
| return; |
| |
| // We need to clone the render style to avoid breaking style sharing. |
| RefPtr<RenderStyle> style = RenderStyle::clone(currentStyle); |
| style->setTextAutosizingMultiplier(multiplier); |
| style->setUnique(); |
| renderer->setStyleInternal(style.release()); |
| } |
| |
| bool FastTextAutosizer::mightBeWiderOrNarrowerDescendant(const RenderBlock* block) |
| { |
| // FIXME: This heuristic may need to be expanded to other ways a block can be wider or narrower |
| // than its parent containing block. |
| return block->style() && block->style()->width().isSpecified(); |
| } |
| |
| bool FastTextAutosizer::isWiderOrNarrowerDescendant(Cluster* cluster) |
| { |
| if (!cluster->m_parent || !mightBeWiderOrNarrowerDescendant(cluster->m_root)) |
| return true; |
| |
| const RenderBlock* parentDeepestBlockContainingAllText = deepestBlockContainingAllText(cluster->m_parent); |
| ASSERT(m_blocksThatHaveBegunLayout.contains(cluster->m_root)); |
| ASSERT(m_blocksThatHaveBegunLayout.contains(parentDeepestBlockContainingAllText)); |
| |
| float contentWidth = cluster->m_root->contentLogicalWidth().toFloat(); |
| float clusterTextWidth = parentDeepestBlockContainingAllText->contentLogicalWidth().toFloat(); |
| |
| // Clusters with a root that is wider than the deepestBlockContainingAllText of their parent |
| // autosize independently of their parent. |
| if (contentWidth > clusterTextWidth) |
| return true; |
| |
| // Clusters with a root that is significantly narrower than the deepestBlockContainingAllText of |
| // their parent autosize independently of their parent. |
| static float narrowWidthDifference = 200; |
| if (clusterTextWidth - contentWidth > narrowWidthDifference) |
| return true; |
| |
| return false; |
| } |
| |
| FastTextAutosizer::Cluster* FastTextAutosizer::currentCluster() const |
| { |
| ASSERT(!m_clusterStack.isEmpty()); |
| return m_clusterStack.last().get(); |
| } |
| |
| #ifndef NDEBUG |
| void FastTextAutosizer::FingerprintMapper::assertMapsAreConsistent() |
| { |
| // For each fingerprint -> block mapping in m_blocksForFingerprint we should have an associated |
| // map from block -> fingerprint in m_fingerprints. |
| ReverseFingerprintMap::iterator end = m_blocksForFingerprint.end(); |
| for (ReverseFingerprintMap::iterator fingerprintIt = m_blocksForFingerprint.begin(); fingerprintIt != end; ++fingerprintIt) { |
| Fingerprint fingerprint = fingerprintIt->key; |
| BlockSet* blocks = fingerprintIt->value.get(); |
| for (BlockSet::iterator blockIt = blocks->begin(); blockIt != blocks->end(); ++blockIt) { |
| const RenderBlock* block = (*blockIt); |
| ASSERT(m_fingerprints.get(block) == fingerprint); |
| } |
| } |
| } |
| #endif |
| |
| void FastTextAutosizer::FingerprintMapper::add(const RenderObject* renderer, Fingerprint fingerprint) |
| { |
| remove(renderer); |
| |
| m_fingerprints.set(renderer, fingerprint); |
| #ifndef NDEBUG |
| assertMapsAreConsistent(); |
| #endif |
| } |
| |
| void FastTextAutosizer::FingerprintMapper::addTentativeClusterRoot(const RenderBlock* block, Fingerprint fingerprint) |
| { |
| add(block, fingerprint); |
| |
| ReverseFingerprintMap::AddResult addResult = m_blocksForFingerprint.add(fingerprint, PassOwnPtr<BlockSet>()); |
| if (addResult.isNewEntry) |
| addResult.storedValue->value = adoptPtr(new BlockSet); |
| addResult.storedValue->value->add(block); |
| #ifndef NDEBUG |
| assertMapsAreConsistent(); |
| #endif |
| } |
| |
| void FastTextAutosizer::FingerprintMapper::remove(const RenderObject* renderer) |
| { |
| Fingerprint fingerprint = m_fingerprints.take(renderer); |
| if (!fingerprint || !renderer->isRenderBlock()) |
| return; |
| |
| ReverseFingerprintMap::iterator blocksIter = m_blocksForFingerprint.find(fingerprint); |
| if (blocksIter == m_blocksForFingerprint.end()) |
| return; |
| |
| BlockSet& blocks = *blocksIter->value; |
| blocks.remove(toRenderBlock(renderer)); |
| if (blocks.isEmpty()) |
| m_blocksForFingerprint.remove(blocksIter); |
| #ifndef NDEBUG |
| assertMapsAreConsistent(); |
| #endif |
| } |
| |
| FastTextAutosizer::Fingerprint FastTextAutosizer::FingerprintMapper::get(const RenderObject* renderer) |
| { |
| return m_fingerprints.get(renderer); |
| } |
| |
| FastTextAutosizer::BlockSet& FastTextAutosizer::FingerprintMapper::getTentativeClusterRoots(Fingerprint fingerprint) |
| { |
| return *m_blocksForFingerprint.get(fingerprint); |
| } |
| |
| RenderObject* FastTextAutosizer::nextChildSkippingChildrenOfBlocks(const RenderObject* current, const RenderObject* stayWithin) |
| { |
| if (current == stayWithin || !current->isRenderBlock()) |
| return current->nextInPreOrder(stayWithin); |
| return current->nextInPreOrderAfterChildren(stayWithin); |
| } |
| |
| FastTextAutosizer::LayoutScope::LayoutScope(RenderBlock* block) |
| : m_textAutosizer(block->document().fastTextAutosizer()) |
| , m_block(block) |
| { |
| if (!m_textAutosizer) |
| return; |
| |
| if (!m_textAutosizer->enabled()) { |
| m_textAutosizer = 0; |
| return; |
| } |
| |
| if (m_textAutosizer->m_pageAutosizingStatus == PageAutosizingStatusUnknown) |
| m_textAutosizer->updateRenderViewInfo(); |
| |
| if (m_textAutosizer->m_pageAutosizingStatus == PageNeedsAutosizing) |
| m_textAutosizer->beginLayout(m_block); |
| else |
| m_textAutosizer = 0; |
| } |
| |
| FastTextAutosizer::LayoutScope::~LayoutScope() |
| { |
| if (m_textAutosizer) |
| m_textAutosizer->endLayout(m_block); |
| } |
| |
| } // namespace WebCore |