| /* |
| * Copyright (C) 1999 Lars Knoll (knoll@kde.org) |
| * (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com) |
| * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com) |
| * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved. |
| * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org> |
| * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org> |
| * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/) |
| * Copyright (c) 2011, Code Aurora Forum. All rights reserved. |
| * Copyright (C) Research In Motion Limited 2011. All rights reserved. |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| */ |
| |
| #include "core/css/resolver/StyleAdjuster.h" |
| |
| #include "core/HTMLNames.h" |
| #include "core/SVGNames.h" |
| #include "core/dom/ContainerNode.h" |
| #include "core/dom/Document.h" |
| #include "core/dom/Element.h" |
| #include "core/frame/FrameView.h" |
| #include "core/frame/Settings.h" |
| #include "core/frame/UseCounter.h" |
| #include "core/html/HTMLIFrameElement.h" |
| #include "core/html/HTMLInputElement.h" |
| #include "core/html/HTMLPlugInElement.h" |
| #include "core/html/HTMLTableCellElement.h" |
| #include "core/html/HTMLTextAreaElement.h" |
| #include "core/layout/LayoutTheme.h" |
| #include "core/style/ComputedStyle.h" |
| #include "core/style/ComputedStyleConstants.h" |
| #include "core/svg/SVGSVGElement.h" |
| #include "platform/Length.h" |
| #include "platform/transforms/TransformOperations.h" |
| #include "wtf/Assertions.h" |
| |
| namespace blink { |
| |
| using namespace HTMLNames; |
| |
| static EDisplay equivalentBlockDisplay(EDisplay display) |
| { |
| switch (display) { |
| case BLOCK: |
| case TABLE: |
| case BOX: |
| case FLEX: |
| case GRID: |
| case LIST_ITEM: |
| return display; |
| case INLINE_TABLE: |
| return TABLE; |
| case INLINE_BOX: |
| return BOX; |
| case INLINE_FLEX: |
| return FLEX; |
| case INLINE_GRID: |
| return GRID; |
| |
| case INLINE: |
| case INLINE_BLOCK: |
| case TABLE_ROW_GROUP: |
| case TABLE_HEADER_GROUP: |
| case TABLE_FOOTER_GROUP: |
| case TABLE_ROW: |
| case TABLE_COLUMN_GROUP: |
| case TABLE_COLUMN: |
| case TABLE_CELL: |
| case TABLE_CAPTION: |
| return BLOCK; |
| case NONE: |
| ASSERT_NOT_REACHED(); |
| return NONE; |
| } |
| ASSERT_NOT_REACHED(); |
| return BLOCK; |
| } |
| |
| static bool isOutermostSVGElement(const Element* element) |
| { |
| return element && element->isSVGElement() && toSVGElement(*element).isOutermostSVGSVGElement(); |
| } |
| |
| // CSS requires text-decoration to be reset at each DOM element for |
| // inline blocks, inline tables, shadow DOM crossings, floating elements, |
| // and absolute or relatively positioned elements. Outermost <svg> roots are |
| // considered to be atomic inline-level. |
| static bool doesNotInheritTextDecoration(const ComputedStyle& style, const Element* element) |
| { |
| return style.display() == INLINE_TABLE |
| || style.display() == INLINE_BLOCK || style.display() == INLINE_BOX || isAtShadowBoundary(element) |
| || style.isFloating() || style.hasOutOfFlowPosition() || isOutermostSVGElement(element); |
| } |
| |
| // FIXME: This helper is only needed because pseudoStyleForElement passes a null |
| // element to adjustComputedStyle, so we can't just use element->isInTopLayer(). |
| static bool isInTopLayer(const Element* element, const ComputedStyle& style) |
| { |
| return (element && element->isInTopLayer()) || style.styleType() == PseudoIdBackdrop; |
| } |
| |
| static bool parentStyleForcesZIndexToCreateStackingContext(const ComputedStyle& parentStyle) |
| { |
| return parentStyle.isDisplayFlexibleOrGridBox(); |
| } |
| |
| void StyleAdjuster::adjustStyleForEditing(ComputedStyle& style) |
| { |
| if (style.userModify() != READ_WRITE_PLAINTEXT_ONLY) |
| return; |
| // Collapsing whitespace is harmful in plain-text editing. |
| if (style.whiteSpace() == NORMAL) |
| style.setWhiteSpace(PRE_WRAP); |
| else if (style.whiteSpace() == NOWRAP) |
| style.setWhiteSpace(PRE); |
| else if (style.whiteSpace() == PRE_LINE) |
| style.setWhiteSpace(PRE_WRAP); |
| } |
| |
| static void adjustStyleForFirstLetter(ComputedStyle& style) |
| { |
| if (style.styleType() != PseudoIdFirstLetter) |
| return; |
| |
| // Force inline display (except for floating first-letters). |
| style.setDisplay(style.isFloating() ? BLOCK : INLINE); |
| |
| // CSS2 says first-letter can't be positioned. |
| style.setPosition(StaticPosition); |
| } |
| |
| void StyleAdjuster::adjustStyleForAlignment(ComputedStyle& style, const ComputedStyle& parentStyle) |
| { |
| // To avoid needing to copy the RareNonInheritedData, we repurpose the 'auto' flag |
| // to not just mean 'auto' prior to running the StyleAdjuster but also mean 'normal' |
| // after running it. |
| |
| // If the inherited value of justify-items includes the 'legacy' keyword, 'auto' |
| // computes to the the inherited value. |
| // Otherwise, 'auto' computes to 'normal'. |
| if (style.justifyItemsPosition() == ItemPositionAuto) { |
| if (parentStyle.justifyItemsPositionType() == LegacyPosition) |
| style.setJustifyItems(parentStyle.justifyItems()); |
| } |
| |
| // The 'auto' keyword computes the computed value of justify-items on the parent (minus |
| // any legacy keywords), or 'normal' if the box has no parent. |
| if (style.justifySelfPosition() == ItemPositionAuto) { |
| if (parentStyle.justifyItemsPositionType() == LegacyPosition) |
| style.setJustifySelfPosition(parentStyle.justifyItemsPosition()); |
| else if (parentStyle.justifyItemsPosition() != ItemPositionAuto) |
| style.setJustifySelf(parentStyle.justifyItems()); |
| } |
| |
| // The 'auto' keyword computes the computed value of align-items on the parent |
| // or 'normal' if the box has no parent. |
| if (style.alignSelfPosition() == ItemPositionAuto && parentStyle.alignItemsPosition() != ComputedStyle::initialDefaultAlignment().position()) |
| style.setAlignSelf(parentStyle.alignItems()); |
| } |
| |
| static void adjustStyleForHTMLElement(ComputedStyle& style, HTMLElement& element) |
| { |
| // <div> and <span> are the most common elements on the web, we skip all the work for them. |
| if (isHTMLDivElement(element) || isHTMLSpanElement(element)) |
| return; |
| |
| if (isHTMLTableCellElement(element)) { |
| if (style.whiteSpace() == KHTML_NOWRAP) { |
| // Figure out if we are really nowrapping or if we should just |
| // use normal instead. If the width of the cell is fixed, then |
| // we don't actually use NOWRAP. |
| if (style.width().isFixed()) |
| style.setWhiteSpace(NORMAL); |
| else |
| style.setWhiteSpace(NOWRAP); |
| } |
| return; |
| } |
| |
| if (isHTMLTableElement(element)) { |
| // Tables never support the -webkit-* values for text-align and will reset back to the default. |
| if (style.textAlign() == WEBKIT_LEFT || style.textAlign() == WEBKIT_CENTER || style.textAlign() == WEBKIT_RIGHT) |
| style.setTextAlign(TASTART); |
| return; |
| } |
| |
| if (isHTMLFrameElement(element) || isHTMLFrameSetElement(element)) { |
| // Frames and framesets never honor position:relative or position:absolute. This is necessary to |
| // fix a crash where a site tries to position these objects. They also never honor display. |
| style.setPosition(StaticPosition); |
| style.setDisplay(BLOCK); |
| return; |
| } |
| |
| if (isHTMLFrameElementBase(element)) { |
| // Frames cannot overflow (they are always the size we ask them to be). |
| // Some compositing code paths may try to draw scrollbars anyhow. |
| style.setOverflowX(OverflowVisible); |
| style.setOverflowY(OverflowVisible); |
| return; |
| } |
| |
| if (isHTMLRTElement(element)) { |
| // Ruby text does not support float or position. This might change with evolution of the specification. |
| style.setPosition(StaticPosition); |
| style.setFloating(EFloat::NoFloat); |
| return; |
| } |
| |
| if (isHTMLMarqueeElement(element)) { |
| // For now, <marquee> requires an overflow clip to work properly. |
| style.setOverflowX(OverflowHidden); |
| style.setOverflowY(OverflowHidden); |
| return; |
| } |
| |
| if (isHTMLTextAreaElement(element)) { |
| // Textarea considers overflow visible as auto. |
| style.setOverflowX(style.overflowX() == OverflowVisible ? OverflowAuto : style.overflowX()); |
| style.setOverflowY(style.overflowY() == OverflowVisible ? OverflowAuto : style.overflowY()); |
| return; |
| } |
| |
| if (isHTMLPlugInElement(element)) { |
| style.setRequiresAcceleratedCompositingForExternalReasons(toHTMLPlugInElement(element).shouldAccelerate()); |
| return; |
| } |
| } |
| |
| static void adjustOverflow(ComputedStyle& style) |
| { |
| ASSERT(style.overflowX() != OverflowVisible || style.overflowY() != OverflowVisible); |
| |
| if (style.display() == TABLE || style.display() == INLINE_TABLE) { |
| // Tables only support overflow:hidden and overflow:visible and ignore anything else, |
| // see http://dev.w3.org/csswg/css2/visufx.html#overflow. As a table is not a block |
| // container box the rules for resolving conflicting x and y values in CSS Overflow Module |
| // Level 3 do not apply. Arguably overflow-x and overflow-y aren't allowed on tables but |
| // all UAs allow it. |
| if (style.overflowX() != OverflowHidden) |
| style.setOverflowX(OverflowVisible); |
| if (style.overflowY() != OverflowHidden) |
| style.setOverflowY(OverflowVisible); |
| // If we are left with conflicting overflow values for the x and y axes on a table then resolve |
| // both to OverflowVisible. This is interoperable behaviour but is not specced anywhere. |
| if (style.overflowX() == OverflowVisible) |
| style.setOverflowY(OverflowVisible); |
| else if (style.overflowY() == OverflowVisible) |
| style.setOverflowX(OverflowVisible); |
| } else if (style.overflowX() == OverflowVisible && style.overflowY() != OverflowVisible) { |
| // If either overflow value is not visible, change to auto. |
| // FIXME: Once we implement pagination controls, overflow-x should default to hidden |
| // if overflow-y is set to -webkit-paged-x or -webkit-page-y. For now, we'll let it |
| // default to auto so we can at least scroll through the pages. |
| style.setOverflowX(OverflowAuto); |
| } else if (style.overflowY() == OverflowVisible && style.overflowX() != OverflowVisible) { |
| style.setOverflowY(OverflowAuto); |
| } |
| |
| // Menulists should have visible overflow |
| if (style.appearance() == MenulistPart) { |
| style.setOverflowX(OverflowVisible); |
| style.setOverflowY(OverflowVisible); |
| } |
| } |
| |
| static void adjustStyleForDisplay(ComputedStyle& style, const ComputedStyle& parentStyle, Document* document) |
| { |
| if (style.display() == BLOCK && !style.isFloating()) |
| return; |
| |
| // FIXME: Don't support this mutation for pseudo styles like first-letter or first-line, since it's not completely |
| // clear how that should work. |
| if (style.display() == INLINE && style.styleType() == PseudoIdNone && style.getWritingMode() != parentStyle.getWritingMode()) |
| style.setDisplay(INLINE_BLOCK); |
| |
| // After performing the display mutation, check table rows. We do not honor position: relative table rows or cells. |
| // This has been established for position: relative in CSS2.1 (and caused a crash in containingBlock() |
| // on some sites). |
| if ((style.display() == TABLE_HEADER_GROUP || style.display() == TABLE_ROW_GROUP |
| || style.display() == TABLE_FOOTER_GROUP || style.display() == TABLE_ROW) |
| && style.position() == RelativePosition) |
| style.setPosition(StaticPosition); |
| |
| // Cannot support position: sticky for table columns and column groups because current code is only doing |
| // background painting through columns / column groups |
| if ((style.display() == TABLE_COLUMN_GROUP || style.display() == TABLE_COLUMN) |
| && style.position() == StickyPosition) |
| style.setPosition(StaticPosition); |
| |
| // writing-mode does not apply to table row groups, table column groups, table rows, and table columns. |
| // FIXME: Table cells should be allowed to be perpendicular or flipped with respect to the table, though. |
| if (style.display() == TABLE_COLUMN || style.display() == TABLE_COLUMN_GROUP || style.display() == TABLE_FOOTER_GROUP |
| || style.display() == TABLE_HEADER_GROUP || style.display() == TABLE_ROW || style.display() == TABLE_ROW_GROUP |
| || style.display() == TABLE_CELL) |
| style.setWritingMode(parentStyle.getWritingMode()); |
| |
| // FIXME: Since we don't support block-flow on flexible boxes yet, disallow setting |
| // of block-flow to anything other than TopToBottomWritingMode. |
| // https://bugs.webkit.org/show_bug.cgi?id=46418 - Flexible box support. |
| if (style.getWritingMode() != TopToBottomWritingMode && (style.display() == BOX || style.display() == INLINE_BOX)) |
| style.setWritingMode(TopToBottomWritingMode); |
| |
| if (parentStyle.isDisplayFlexibleOrGridBox()) { |
| style.setFloating(EFloat::NoFloat); |
| style.setDisplay(equivalentBlockDisplay(style.display())); |
| |
| // We want to count vertical percentage paddings/margins on flex items because our current |
| // behavior is different from the spec and we want to gather compatibility data. |
| if (style.paddingBefore().isPercentOrCalc() || style.paddingAfter().isPercentOrCalc()) |
| UseCounter::count(document, UseCounter::FlexboxPercentagePaddingVertical); |
| if (style.marginBefore().isPercentOrCalc() || style.marginAfter().isPercentOrCalc()) |
| UseCounter::count(document, UseCounter::FlexboxPercentageMarginVertical); |
| } |
| } |
| |
| void StyleAdjuster::adjustComputedStyle(ComputedStyle& style, const ComputedStyle& parentStyle, Element* element) |
| { |
| if (style.display() != NONE) { |
| if (element && element->isHTMLElement()) |
| adjustStyleForHTMLElement(style, toHTMLElement(*element)); |
| |
| // Per the spec, position 'static' and 'relative' in the top layer compute to 'absolute'. |
| if (isInTopLayer(element, style) && (style.position() == StaticPosition || style.position() == RelativePosition)) |
| style.setPosition(AbsolutePosition); |
| |
| // Absolute/fixed positioned elements, floating elements and the document element need block-like outside display. |
| if (style.hasOutOfFlowPosition() || style.isFloating() || (element && element->document().documentElement() == element)) |
| style.setDisplay(equivalentBlockDisplay(style.display())); |
| |
| // We don't adjust the first letter style earlier because we may change the display setting in |
| // adjustStyeForTagName() above. |
| adjustStyleForFirstLetter(style); |
| |
| adjustStyleForDisplay(style, parentStyle, element ? &element->document() : 0); |
| |
| // Paint containment forces a block formatting context, so we must coerce from inline. |
| // https://drafts.csswg.org/css-containment/#containment-paint |
| if (style.containsPaint() && style.display() == INLINE) |
| style.setDisplay(BLOCK); |
| } else { |
| adjustStyleForFirstLetter(style); |
| } |
| |
| if (element && element->hasCompositorProxy()) |
| style.setHasCompositorProxy(true); |
| |
| // Make sure our z-index value is only applied if the object is positioned. |
| if (style.position() == StaticPosition && !parentStyleForcesZIndexToCreateStackingContext(parentStyle)) { |
| style.setIsStackingContext(false); |
| // TODO(alancutter): Avoid altering z-index here. |
| if (!style.hasAutoZIndex()) |
| style.setZIndex(0); |
| } else if (!style.hasAutoZIndex()) { |
| style.setIsStackingContext(true); |
| } |
| |
| if (style.overflowX() != OverflowVisible || style.overflowY() != OverflowVisible) |
| adjustOverflow(style); |
| |
| if (doesNotInheritTextDecoration(style, element)) |
| style.clearAppliedTextDecorations(); |
| else |
| style.restoreParentTextDecorations(parentStyle); |
| style.applyTextDecorations(); |
| |
| // Cull out any useless layers and also repeat patterns into additional layers. |
| style.adjustBackgroundLayers(); |
| style.adjustMaskLayers(); |
| |
| // Let the theme also have a crack at adjusting the style. |
| if (style.hasAppearance()) |
| LayoutTheme::theme().adjustStyle(style, element); |
| |
| // If we have first-letter pseudo style, transitions, or animations, do not share this style. |
| if (style.hasPseudoStyle(PseudoIdFirstLetter) || style.transitions() || style.animations()) |
| style.setUnique(); |
| |
| adjustStyleForEditing(style); |
| |
| bool isSVGElement = element && element->isSVGElement(); |
| if (isSVGElement) { |
| // Only the root <svg> element in an SVG document fragment tree honors css position |
| if (!(isSVGSVGElement(*element) && element->parentNode() && !element->parentNode()->isSVGElement())) |
| style.setPosition(ComputedStyle::initialPosition()); |
| |
| // SVG text layout code expects us to be a block-level style element. |
| if ((isSVGForeignObjectElement(*element) || isSVGTextElement(*element)) && style.isDisplayInlineType()) |
| style.setDisplay(BLOCK); |
| |
| // Columns don't apply to svg text elements. |
| if (isSVGTextElement(*element)) |
| style.clearMultiCol(); |
| } |
| adjustStyleForAlignment(style, parentStyle); |
| } |
| |
| } // namespace blink |
