2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 * (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
4 * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
5 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
6 * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
7 * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
8 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
9 * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
10 * Copyright (C) Research In Motion Limited 2011. All rights reserved.
11 * Copyright (C) 2013 Google Inc. All rights reserved.
13 * This library is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU Library General Public
15 * License as published by the Free Software Foundation; either
16 * version 2 of the License, or (at your option) any later version.
18 * This library is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * Library General Public License for more details.
23 * You should have received a copy of the GNU Library General Public License
24 * along with this library; see the file COPYING.LIB. If not, write to
25 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
26 * Boston, MA 02110-1301, USA.
30 #include "core/css/resolver/StyleAdjuster.h"
32 #include "core/HTMLNames.h"
33 #include "core/SVGNames.h"
34 #include "core/dom/ContainerNode.h"
35 #include "core/dom/Document.h"
36 #include "core/dom/Element.h"
37 #include "core/dom/NodeRenderStyle.h"
38 #include "core/html/HTMLIFrameElement.h"
39 #include "core/html/HTMLInputElement.h"
40 #include "core/html/HTMLPlugInElement.h"
41 #include "core/html/HTMLTableCellElement.h"
42 #include "core/html/HTMLTextAreaElement.h"
43 #include "core/frame/FrameView.h"
44 #include "core/frame/Settings.h"
45 #include "core/rendering/RenderTheme.h"
46 #include "core/rendering/style/GridPosition.h"
47 #include "core/rendering/style/RenderStyle.h"
48 #include "core/rendering/style/RenderStyleConstants.h"
49 #include "core/svg/SVGSVGElement.h"
50 #include "platform/Length.h"
51 #include "platform/transforms/TransformOperations.h"
52 #include "wtf/Assertions.h"
56 using namespace HTMLNames;
58 // FIXME: This is duplicated with StyleResolver.cpp
59 // Perhaps this should move onto ElementResolveContext or even Element?
60 static inline bool isAtShadowBoundary(const Element* element)
64 ContainerNode* parentNode = element->parentNode();
65 return parentNode && parentNode->isShadowRoot();
69 static void addIntrinsicMargins(RenderStyle* style)
71 // Intrinsic margin value.
72 const int intrinsicMargin = 2 * style->effectiveZoom();
74 // FIXME: Using width/height alone and not also dealing with min-width/max-width is flawed.
75 // FIXME: Using "quirk" to decide the margin wasn't set is kind of lame.
76 if (style->width().isIntrinsicOrAuto()) {
77 if (style->marginLeft().quirk())
78 style->setMarginLeft(Length(intrinsicMargin, Fixed));
79 if (style->marginRight().quirk())
80 style->setMarginRight(Length(intrinsicMargin, Fixed));
83 if (style->height().isAuto()) {
84 if (style->marginTop().quirk())
85 style->setMarginTop(Length(intrinsicMargin, Fixed));
86 if (style->marginBottom().quirk())
87 style->setMarginBottom(Length(intrinsicMargin, Fixed));
91 static EDisplay equivalentBlockDisplay(EDisplay display, bool isFloating, bool strictParsing)
102 // It is a WinIE bug that floated list items lose their bullets, so we'll emulate the quirk, but only in quirks mode.
103 if (!strictParsing && isFloating)
117 case TABLE_ROW_GROUP:
118 case TABLE_HEADER_GROUP:
119 case TABLE_FOOTER_GROUP:
121 case TABLE_COLUMN_GROUP:
127 ASSERT_NOT_REACHED();
130 ASSERT_NOT_REACHED();
134 // CSS requires text-decoration to be reset at each DOM element for tables,
135 // inline blocks, inline tables, shadow DOM crossings, floating elements,
136 // and absolute or relatively positioned elements.
137 static bool doesNotInheritTextDecoration(const RenderStyle* style, const Element* e)
139 return style->display() == TABLE || style->display() == INLINE_TABLE
140 || style->display() == INLINE_BLOCK || style->display() == INLINE_BOX || isAtShadowBoundary(e)
141 || style->isFloating() || style->hasOutOfFlowPosition();
144 // FIXME: This helper is only needed because pseudoStyleForElement passes a null
145 // element to adjustRenderStyle, so we can't just use element->isInTopLayer().
146 static bool isInTopLayer(const Element* element, const RenderStyle* style)
148 return (element && element->isInTopLayer()) || (style && style->styleType() == BACKDROP);
151 static bool isDisplayFlexibleBox(EDisplay display)
153 return display == FLEX || display == INLINE_FLEX;
156 static bool isDisplayGridBox(EDisplay display)
158 return display == GRID || display == INLINE_GRID;
161 static bool parentStyleForcesZIndexToCreateStackingContext(const RenderStyle* parentStyle)
163 return isDisplayFlexibleBox(parentStyle->display()) || isDisplayGridBox(parentStyle->display());
166 static bool hasWillChangeThatCreatesStackingContext(const RenderStyle* style)
168 for (size_t i = 0; i < style->willChangeProperties().size(); ++i) {
169 switch (style->willChangeProperties()[i]) {
170 case CSSPropertyOpacity:
171 case CSSPropertyTransform:
172 case CSSPropertyWebkitTransform:
173 case CSSPropertyTransformStyle:
174 case CSSPropertyWebkitTransformStyle:
175 case CSSPropertyPerspective:
176 case CSSPropertyWebkitPerspective:
177 case CSSPropertyWebkitMask:
178 case CSSPropertyWebkitMaskBoxImage:
179 case CSSPropertyWebkitClipPath:
180 case CSSPropertyWebkitBoxReflect:
181 case CSSPropertyWebkitFilter:
182 case CSSPropertyZIndex:
183 case CSSPropertyPosition:
185 case CSSPropertyMixBlendMode:
186 case CSSPropertyIsolation:
187 if (RuntimeEnabledFeatures::cssCompositingEnabled())
197 void StyleAdjuster::adjustRenderStyle(RenderStyle* style, RenderStyle* parentStyle, Element *e, const CachedUAStyle* cachedUAStyle)
201 // Cache our original display.
202 style->setOriginalDisplay(style->display());
204 if (style->display() != NONE) {
206 adjustStyleForTagName(style, parentStyle, *e);
208 // Per the spec, position 'static' and 'relative' in the top layer compute to 'absolute'.
209 if (isInTopLayer(e, style) && (style->position() == StaticPosition || style->position() == RelativePosition))
210 style->setPosition(AbsolutePosition);
212 // Absolute/fixed positioned elements, floating elements and the document element need block-like outside display.
213 if (style->hasOutOfFlowPosition() || style->isFloating() || (e && e->document().documentElement() == e))
214 style->setDisplay(equivalentBlockDisplay(style->display(), style->isFloating(), !m_useQuirksModeStyles));
216 adjustStyleForDisplay(style, parentStyle);
219 // Make sure our z-index value is only applied if the object is positioned.
220 if (style->position() == StaticPosition && !parentStyleForcesZIndexToCreateStackingContext(parentStyle))
221 style->setHasAutoZIndex();
223 // Auto z-index becomes 0 for the root element and transparent objects. This prevents
224 // cases where objects that should be blended as a single unit end up with a non-transparent
225 // object wedged in between them. Auto z-index also becomes 0 for objects that specify transforms/masks/reflections.
226 if (style->hasAutoZIndex() && ((e && e->document().documentElement() == e)
227 || style->opacity() < 1.0f
228 || style->hasTransformRelatedProperty()
231 || style->boxReflect()
232 || style->hasFilter()
233 || style->hasBlendMode()
234 || style->hasIsolation()
235 || style->position() == StickyPosition
236 || style->position() == FixedPosition
237 || isInTopLayer(e, style)
238 || hasWillChangeThatCreatesStackingContext(style)))
241 // will-change:transform should result in the same rendering behavior as having a transform,
242 // including the creation of a containing block for fixed position descendants.
243 if (!style->hasTransform() && (style->willChangeProperties().contains(CSSPropertyWebkitTransform) || style->willChangeProperties().contains(CSSPropertyTransform))) {
244 bool makeIdentity = true;
245 style->setTransform(TransformOperations(makeIdentity));
248 if (doesNotInheritTextDecoration(style, e))
249 style->clearAppliedTextDecorations();
251 style->applyTextDecorations();
253 if (style->overflowX() != OVISIBLE || style->overflowY() != OVISIBLE)
254 adjustOverflow(style);
256 // Cull out any useless layers and also repeat patterns into additional layers.
257 style->adjustBackgroundLayers();
258 style->adjustMaskLayers();
260 // Let the theme also have a crack at adjusting the style.
261 if (style->hasAppearance())
262 RenderTheme::theme().adjustStyle(style, e, cachedUAStyle);
264 // If we have first-letter pseudo style, transitions, or animations, do not share this style.
265 if (style->hasPseudoStyle(FIRST_LETTER) || style->transitions() || style->animations())
268 // FIXME: when dropping the -webkit prefix on transform-style, we should also have opacity < 1 cause flattening.
269 if (style->preserves3D() && (style->overflowX() != OVISIBLE
270 || style->overflowY() != OVISIBLE
271 || style->hasFilter()))
272 style->setTransformStyle3D(TransformStyle3DFlat);
274 if (e && e->isSVGElement()) {
275 // Only the root <svg> element in an SVG document fragment tree honors css position
276 if (!(isSVGSVGElement(*e) && e->parentNode() && !e->parentNode()->isSVGElement()))
277 style->setPosition(RenderStyle::initialPosition());
279 // SVG text layout code expects us to be a block-level style element.
280 if ((isSVGForeignObjectElement(*e) || isSVGTextElement(*e)) && style->isDisplayInlineType())
281 style->setDisplay(BLOCK);
284 if (e && e->renderStyle() && e->renderStyle()->textAutosizingMultiplier() != 1) {
285 // Preserve the text autosizing multiplier on style recalc.
286 // (The autosizer will update it during layout if it needs to be changed.)
287 style->setTextAutosizingMultiplier(e->renderStyle()->textAutosizingMultiplier());
292 void StyleAdjuster::adjustStyleForTagName(RenderStyle* style, RenderStyle* parentStyle, Element& element)
294 // <div> and <span> are the most common elements on the web, we skip all the work for them.
295 if (isHTMLDivElement(element) || isHTMLSpanElement(element))
298 if (isHTMLTableCellElement(element)) {
299 // If we have a <td> that specifies a float property, in quirks mode we just drop the float property.
300 // FIXME: Why is this only <td> and not <th>?
301 if (element.hasTagName(tdTag) && m_useQuirksModeStyles) {
302 style->setDisplay(TABLE_CELL);
303 style->setFloating(NoFloat);
305 // FIXME: We shouldn't be overriding start/-webkit-auto like this. Do it in html.css instead.
306 // Table headers with a text-align of -webkit-auto will change the text-align to center.
307 if (element.hasTagName(thTag) && style->textAlign() == TASTART)
308 style->setTextAlign(CENTER);
309 if (style->whiteSpace() == KHTML_NOWRAP) {
310 // Figure out if we are really nowrapping or if we should just
311 // use normal instead. If the width of the cell is fixed, then
312 // we don't actually use NOWRAP.
313 if (style->width().isFixed())
314 style->setWhiteSpace(NORMAL);
316 style->setWhiteSpace(NOWRAP);
321 if (isHTMLTableElement(element)) {
322 // Sites commonly use display:inline/block on <td>s and <table>s. In quirks mode we force
323 // these tags to retain their display types.
324 if (m_useQuirksModeStyles)
325 style->setDisplay(style->isDisplayInlineType() ? INLINE_TABLE : TABLE);
326 // Tables never support the -webkit-* values for text-align and will reset back to the default.
327 if (style->textAlign() == WEBKIT_LEFT || style->textAlign() == WEBKIT_CENTER || style->textAlign() == WEBKIT_RIGHT)
328 style->setTextAlign(TASTART);
332 if (isHTMLFrameElement(element) || isHTMLFrameSetElement(element)) {
333 // Frames and framesets never honor position:relative or position:absolute. This is necessary to
334 // fix a crash where a site tries to position these objects. They also never honor display.
335 style->setPosition(StaticPosition);
336 style->setDisplay(BLOCK);
340 if (isHTMLRTElement(element)) {
341 // Ruby text does not support float or position. This might change with evolution of the specification.
342 style->setPosition(StaticPosition);
343 style->setFloating(NoFloat);
347 if (isHTMLLegendElement(element)) {
348 style->setDisplay(BLOCK);
352 if (isHTMLMarqueeElement(element)) {
353 // For now, <marquee> requires an overflow clip to work properly.
354 style->setOverflowX(OHIDDEN);
355 style->setOverflowY(OHIDDEN);
359 if (element.isFormControlElement()) {
360 if (isHTMLTextAreaElement(element)) {
361 // Textarea considers overflow visible as auto.
362 style->setOverflowX(style->overflowX() == OVISIBLE ? OAUTO : style->overflowX());
363 style->setOverflowY(style->overflowY() == OVISIBLE ? OAUTO : style->overflowY());
366 // Important: Intrinsic margins get added to controls before the theme has adjusted the style,
367 // since the theme will alter fonts and heights/widths.
369 // Don't apply intrinsic margins to image buttons. The designer knows how big the images are,
370 // so we have to treat all image buttons as though they were explicitly sized.
371 if (style->fontSize() >= 11 && (!isHTMLInputElement(element) || !toHTMLInputElement(element).isImageButton()))
372 addIntrinsicMargins(style);
376 if (isHTMLPlugInElement(element)) {
377 style->setRequiresAcceleratedCompositingForExternalReasons(toHTMLPlugInElement(element).shouldAccelerate());
382 void StyleAdjuster::adjustOverflow(RenderStyle* style)
384 ASSERT(style->overflowX() != OVISIBLE || style->overflowY() != OVISIBLE);
386 // If either overflow value is not visible, change to auto.
387 if (style->overflowX() == OVISIBLE && style->overflowY() != OVISIBLE) {
388 // FIXME: Once we implement pagination controls, overflow-x should default to hidden
389 // if overflow-y is set to -webkit-paged-x or -webkit-page-y. For now, we'll let it
390 // default to auto so we can at least scroll through the pages.
391 style->setOverflowX(OAUTO);
392 } else if (style->overflowY() == OVISIBLE && style->overflowX() != OVISIBLE) {
393 style->setOverflowY(OAUTO);
396 // Table rows, sections and the table itself will support overflow:hidden and will ignore scroll/auto.
397 // FIXME: Eventually table sections will support auto and scroll.
398 if (style->display() == TABLE || style->display() == INLINE_TABLE
399 || style->display() == TABLE_ROW_GROUP || style->display() == TABLE_ROW) {
400 if (style->overflowX() != OVISIBLE && style->overflowX() != OHIDDEN)
401 style->setOverflowX(OVISIBLE);
402 if (style->overflowY() != OVISIBLE && style->overflowY() != OHIDDEN)
403 style->setOverflowY(OVISIBLE);
406 // Menulists should have visible overflow
407 if (style->appearance() == MenulistPart) {
408 style->setOverflowX(OVISIBLE);
409 style->setOverflowY(OVISIBLE);
413 void StyleAdjuster::adjustStyleForDisplay(RenderStyle* style, RenderStyle* parentStyle)
415 if (style->display() == BLOCK && !style->isFloating())
418 // FIXME: Don't support this mutation for pseudo styles like first-letter or first-line, since it's not completely
419 // clear how that should work.
420 if (style->display() == INLINE && style->styleType() == NOPSEUDO && style->writingMode() != parentStyle->writingMode())
421 style->setDisplay(INLINE_BLOCK);
423 // After performing the display mutation, check table rows. We do not honor position: relative table rows or cells.
424 // This has been established for position: relative in CSS2.1 (and caused a crash in containingBlock()
426 if ((style->display() == TABLE_HEADER_GROUP || style->display() == TABLE_ROW_GROUP
427 || style->display() == TABLE_FOOTER_GROUP || style->display() == TABLE_ROW)
428 && style->position() == RelativePosition)
429 style->setPosition(StaticPosition);
431 // Cannot support position: sticky for table columns and column groups because current code is only doing
432 // background painting through columns / column groups
433 if ((style->display() == TABLE_COLUMN_GROUP || style->display() == TABLE_COLUMN)
434 && style->position() == StickyPosition)
435 style->setPosition(StaticPosition);
437 // writing-mode does not apply to table row groups, table column groups, table rows, and table columns.
438 // FIXME: Table cells should be allowed to be perpendicular or flipped with respect to the table, though.
439 if (style->display() == TABLE_COLUMN || style->display() == TABLE_COLUMN_GROUP || style->display() == TABLE_FOOTER_GROUP
440 || style->display() == TABLE_HEADER_GROUP || style->display() == TABLE_ROW || style->display() == TABLE_ROW_GROUP
441 || style->display() == TABLE_CELL)
442 style->setWritingMode(parentStyle->writingMode());
444 // FIXME: Since we don't support block-flow on flexible boxes yet, disallow setting
445 // of block-flow to anything other than TopToBottomWritingMode.
446 // https://bugs.webkit.org/show_bug.cgi?id=46418 - Flexible box support.
447 if (style->writingMode() != TopToBottomWritingMode && (style->display() == BOX || style->display() == INLINE_BOX))
448 style->setWritingMode(TopToBottomWritingMode);
450 if (isDisplayFlexibleBox(parentStyle->display()) || isDisplayGridBox(parentStyle->display())) {
451 style->setFloating(NoFloat);
452 style->setDisplay(equivalentBlockDisplay(style->display(), style->isFloating(), !m_useQuirksModeStyles));