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 "HTMLNames.h"
34 #include "core/dom/ContainerNode.h"
35 #include "core/dom/Document.h"
36 #include "core/dom/Element.h"
37 #include "core/html/HTMLIFrameElement.h"
38 #include "core/html/HTMLInputElement.h"
39 #include "core/html/HTMLTextAreaElement.h"
40 #include "core/frame/FrameView.h"
41 #include "core/frame/Settings.h"
42 #include "core/rendering/Pagination.h"
43 #include "core/rendering/RenderTheme.h"
44 #include "core/rendering/style/GridPosition.h"
45 #include "core/rendering/style/RenderStyle.h"
46 #include "core/rendering/style/RenderStyleConstants.h"
47 #include "platform/Length.h"
48 #include "wtf/Assertions.h"
52 using namespace HTMLNames;
54 // FIXME: This is duplicated with StyleResolver.cpp
55 // Perhaps this should move onto ElementResolveContext or even Element?
56 static inline bool isAtShadowBoundary(const Element* element)
60 ContainerNode* parentNode = element->parentNode();
61 return parentNode && parentNode->isShadowRoot();
65 static void addIntrinsicMargins(RenderStyle* style)
67 // Intrinsic margin value.
68 const int intrinsicMargin = 2 * style->effectiveZoom();
70 // FIXME: Using width/height alone and not also dealing with min-width/max-width is flawed.
71 // FIXME: Using "quirk" to decide the margin wasn't set is kind of lame.
72 if (style->width().isIntrinsicOrAuto()) {
73 if (style->marginLeft().quirk())
74 style->setMarginLeft(Length(intrinsicMargin, Fixed));
75 if (style->marginRight().quirk())
76 style->setMarginRight(Length(intrinsicMargin, Fixed));
79 if (style->height().isAuto()) {
80 if (style->marginTop().quirk())
81 style->setMarginTop(Length(intrinsicMargin, Fixed));
82 if (style->marginBottom().quirk())
83 style->setMarginBottom(Length(intrinsicMargin, Fixed));
87 static EDisplay equivalentBlockDisplay(EDisplay display, bool isFloating, bool strictParsing)
98 // It is a WinIE bug that floated list items lose their bullets, so we'll emulate the quirk, but only in quirks mode.
99 if (!strictParsing && isFloating)
113 case TABLE_ROW_GROUP:
114 case TABLE_HEADER_GROUP:
115 case TABLE_FOOTER_GROUP:
117 case TABLE_COLUMN_GROUP:
123 ASSERT_NOT_REACHED();
126 ASSERT_NOT_REACHED();
130 // CSS requires text-decoration to be reset at each DOM element for tables,
131 // inline blocks, inline tables, shadow DOM crossings, floating elements,
132 // and absolute or relatively positioned elements.
133 static bool doesNotInheritTextDecoration(const RenderStyle* style, const Element* e)
135 return style->display() == TABLE || style->display() == INLINE_TABLE
136 || style->display() == INLINE_BLOCK || style->display() == INLINE_BOX || isAtShadowBoundary(e)
137 || style->isFloating() || style->hasOutOfFlowPosition();
140 // FIXME: This helper is only needed because pseudoStyleForElement passes a null
141 // element to adjustRenderStyle, so we can't just use element->isInTopLayer().
142 static bool isInTopLayer(const Element* element, const RenderStyle* style)
144 return (element && element->isInTopLayer()) || (style && style->styleType() == BACKDROP);
147 static bool isDisplayFlexibleBox(EDisplay display)
149 return display == FLEX || display == INLINE_FLEX;
152 static bool isDisplayGridBox(EDisplay display)
154 return display == GRID || display == INLINE_GRID;
157 static bool parentStyleForcesZIndexToCreateStackingContext(const RenderStyle* parentStyle)
159 return isDisplayFlexibleBox(parentStyle->display()) || isDisplayGridBox(parentStyle->display());
162 void StyleAdjuster::adjustRenderStyle(RenderStyle* style, RenderStyle* parentStyle, Element *e)
166 // Cache our original display.
167 style->setOriginalDisplay(style->display());
169 if (style->display() != NONE) {
170 // If we have a <td> that specifies a float property, in quirks mode we just drop the float
172 // Sites also commonly use display:inline/block on <td>s and <table>s. In quirks mode we force
173 // these tags to retain their display types.
174 if (m_useQuirksModeStyles && e) {
175 if (e->hasTagName(tdTag)) {
176 style->setDisplay(TABLE_CELL);
177 style->setFloating(NoFloat);
178 } else if (e->hasTagName(tableTag)) {
179 style->setDisplay(style->isDisplayInlineType() ? INLINE_TABLE : TABLE);
183 if (e && (e->hasTagName(tdTag) || e->hasTagName(thTag))) {
184 if (style->whiteSpace() == KHTML_NOWRAP) {
185 // Figure out if we are really nowrapping or if we should just
186 // use normal instead. If the width of the cell is fixed, then
187 // we don't actually use NOWRAP.
188 if (style->width().isFixed())
189 style->setWhiteSpace(NORMAL);
191 style->setWhiteSpace(NOWRAP);
195 // Tables never support the -webkit-* values for text-align and will reset back to the default.
196 if (e && e->hasTagName(tableTag) && (style->textAlign() == WEBKIT_LEFT || style->textAlign() == WEBKIT_CENTER || style->textAlign() == WEBKIT_RIGHT))
197 style->setTextAlign(TASTART);
199 // Frames and framesets never honor position:relative or position:absolute. This is necessary to
200 // fix a crash where a site tries to position these objects. They also never honor display.
201 if (e && (e->hasTagName(frameTag) || e->hasTagName(framesetTag))) {
202 style->setPosition(StaticPosition);
203 style->setDisplay(BLOCK);
206 // Ruby text does not support float or position. This might change with evolution of the specification.
207 if (e && e->hasTagName(rtTag)) {
208 style->setPosition(StaticPosition);
209 style->setFloating(NoFloat);
212 // FIXME: We shouldn't be overriding start/-webkit-auto like this. Do it in html.css instead.
213 // Table headers with a text-align of -webkit-auto will change the text-align to center.
214 if (e && e->hasTagName(thTag) && style->textAlign() == TASTART)
215 style->setTextAlign(CENTER);
217 if (e && e->hasTagName(legendTag))
218 style->setDisplay(BLOCK);
220 // Per the spec, position 'static' and 'relative' in the top layer compute to 'absolute'.
221 if (isInTopLayer(e, style) && (style->position() == StaticPosition || style->position() == RelativePosition))
222 style->setPosition(AbsolutePosition);
224 // Absolute/fixed positioned elements, floating elements and the document element need block-like outside display.
225 if (style->hasOutOfFlowPosition() || style->isFloating() || (e && e->document().documentElement() == e))
226 style->setDisplay(equivalentBlockDisplay(style->display(), style->isFloating(), !m_useQuirksModeStyles));
228 // FIXME: Don't support this mutation for pseudo styles like first-letter or first-line, since it's not completely
229 // clear how that should work.
230 if (style->display() == INLINE && style->styleType() == NOPSEUDO && style->writingMode() != parentStyle->writingMode())
231 style->setDisplay(INLINE_BLOCK);
233 // After performing the display mutation, check table rows. We do not honor position:relative or position:sticky on
234 // table rows or cells. This has been established for position:relative in CSS2.1 (and caused a crash in containingBlock()
236 if ((style->display() == TABLE_HEADER_GROUP || style->display() == TABLE_ROW_GROUP
237 || style->display() == TABLE_FOOTER_GROUP || style->display() == TABLE_ROW)
238 && style->hasInFlowPosition())
239 style->setPosition(StaticPosition);
241 // writing-mode does not apply to table row groups, table column groups, table rows, and table columns.
242 // FIXME: Table cells should be allowed to be perpendicular or flipped with respect to the table, though.
243 if (style->display() == TABLE_COLUMN || style->display() == TABLE_COLUMN_GROUP || style->display() == TABLE_FOOTER_GROUP
244 || style->display() == TABLE_HEADER_GROUP || style->display() == TABLE_ROW || style->display() == TABLE_ROW_GROUP
245 || style->display() == TABLE_CELL)
246 style->setWritingMode(parentStyle->writingMode());
248 // FIXME: Since we don't support block-flow on flexible boxes yet, disallow setting
249 // of block-flow to anything other than TopToBottomWritingMode.
250 // https://bugs.webkit.org/show_bug.cgi?id=46418 - Flexible box support.
251 if (style->writingMode() != TopToBottomWritingMode && (style->display() == BOX || style->display() == INLINE_BOX))
252 style->setWritingMode(TopToBottomWritingMode);
254 if (isDisplayFlexibleBox(parentStyle->display()) || isDisplayGridBox(parentStyle->display())) {
255 style->setFloating(NoFloat);
256 style->setDisplay(equivalentBlockDisplay(style->display(), style->isFloating(), !m_useQuirksModeStyles));
260 // Make sure our z-index value is only applied if the object is positioned.
261 if (style->position() == StaticPosition && !parentStyleForcesZIndexToCreateStackingContext(parentStyle))
262 style->setHasAutoZIndex();
264 // Auto z-index becomes 0 for the root element and transparent objects. This prevents
265 // cases where objects that should be blended as a single unit end up with a non-transparent
266 // object wedged in between them. Auto z-index also becomes 0 for objects that specify transforms/masks/reflections.
267 if (style->hasAutoZIndex() && ((e && e->document().documentElement() == e)
268 || style->opacity() < 1.0f
269 || style->hasTransformRelatedProperty()
272 || style->boxReflect()
273 || style->hasFilter()
274 || style->hasBlendMode()
275 || style->hasIsolation()
276 || style->position() == StickyPosition
277 || (style->position() == FixedPosition && e && e->document().settings() && e->document().settings()->fixedPositionCreatesStackingContext())
278 || isInTopLayer(e, style)
279 || style->hasFlowFrom()
283 // Textarea considers overflow visible as auto.
284 if (e && e->hasTagName(textareaTag)) {
285 style->setOverflowX(style->overflowX() == OVISIBLE ? OAUTO : style->overflowX());
286 style->setOverflowY(style->overflowY() == OVISIBLE ? OAUTO : style->overflowY());
289 // For now, <marquee> requires an overflow clip to work properly.
290 if (e && e->hasTagName(marqueeTag)) {
291 style->setOverflowX(OHIDDEN);
292 style->setOverflowY(OHIDDEN);
295 if (doesNotInheritTextDecoration(style, e))
296 style->setTextDecorationsInEffect(style->textDecoration());
298 style->addToTextDecorationsInEffect(style->textDecoration());
300 // If either overflow value is not visible, change to auto.
301 if (style->overflowX() == OVISIBLE && style->overflowY() != OVISIBLE) {
302 // FIXME: Once we implement pagination controls, overflow-x should default to hidden
303 // if overflow-y is set to -webkit-paged-x or -webkit-page-y. For now, we'll let it
304 // default to auto so we can at least scroll through the pages.
305 style->setOverflowX(OAUTO);
306 } else if (style->overflowY() == OVISIBLE && style->overflowX() != OVISIBLE) {
307 style->setOverflowY(OAUTO);
310 // Call setStylesForPaginationMode() if a pagination mode is set for any non-root elements. If these
311 // styles are specified on a root element, then they will be incorporated in
312 // StyleAdjuster::styleForDocument().
313 if ((style->overflowY() == OPAGEDX || style->overflowY() == OPAGEDY) && !(e && (e->hasTagName(htmlTag) || e->hasTagName(bodyTag))))
314 Pagination::setStylesForPaginationMode(WebCore::paginationModeForRenderStyle(style), style);
316 // Table rows, sections and the table itself will support overflow:hidden and will ignore scroll/auto.
317 // FIXME: Eventually table sections will support auto and scroll.
318 if (style->display() == TABLE || style->display() == INLINE_TABLE
319 || style->display() == TABLE_ROW_GROUP || style->display() == TABLE_ROW) {
320 if (style->overflowX() != OVISIBLE && style->overflowX() != OHIDDEN)
321 style->setOverflowX(OVISIBLE);
322 if (style->overflowY() != OVISIBLE && style->overflowY() != OHIDDEN)
323 style->setOverflowY(OVISIBLE);
326 // Menulists should have visible overflow
327 if (style->appearance() == MenulistPart) {
328 style->setOverflowX(OVISIBLE);
329 style->setOverflowY(OVISIBLE);
332 // Cull out any useless layers and also repeat patterns into additional layers.
333 style->adjustBackgroundLayers();
334 style->adjustMaskLayers();
336 // Important: Intrinsic margins get added to controls before the theme has adjusted the style, since the theme will
337 // alter fonts and heights/widths.
338 if (e && e->isFormControlElement() && style->fontSize() >= 11) {
339 // Don't apply intrinsic margins to image buttons. The designer knows how big the images are,
340 // so we have to treat all image buttons as though they were explicitly sized.
341 if (!e->hasTagName(inputTag) || !toHTMLInputElement(e)->isImageButton())
342 addIntrinsicMargins(style);
345 // Let the theme also have a crack at adjusting the style.
346 if (style->hasAppearance())
347 RenderTheme::theme().adjustStyle(style, e, m_cachedUAStyle);
349 // If we have first-letter pseudo style, do not share this style.
350 if (style->hasPseudoStyle(FIRST_LETTER))
353 // FIXME: when dropping the -webkit prefix on transform-style, we should also have opacity < 1 cause flattening.
354 if (style->preserves3D() && (style->overflowX() != OVISIBLE
355 || style->overflowY() != OVISIBLE
356 || style->hasFilter()))
357 style->setTransformStyle3D(TransformStyle3DFlat);
359 adjustGridItemPosition(style, parentStyle);
361 if (e && e->isSVGElement()) {
362 // Spec: http://www.w3.org/TR/SVG/masking.html#OverflowProperty
363 if (style->overflowY() == OSCROLL)
364 style->setOverflowY(OHIDDEN);
365 else if (style->overflowY() == OAUTO)
366 style->setOverflowY(OVISIBLE);
368 if (style->overflowX() == OSCROLL)
369 style->setOverflowX(OHIDDEN);
370 else if (style->overflowX() == OAUTO)
371 style->setOverflowX(OVISIBLE);
373 // Only the root <svg> element in an SVG document fragment tree honors css position
374 if (!(e->hasTagName(SVGNames::svgTag) && e->parentNode() && !e->parentNode()->isSVGElement()))
375 style->setPosition(RenderStyle::initialPosition());
377 // RenderSVGRoot handles zooming for the whole SVG subtree, so foreignObject content should
378 // not be scaled again.
379 if (e->hasTagName(SVGNames::foreignObjectTag))
380 style->setEffectiveZoom(RenderStyle::initialZoom());
382 // SVG text layout code expects us to be a block-level style element.
383 if ((e->hasTagName(SVGNames::foreignObjectTag) || e->hasTagName(SVGNames::textTag)) && style->isDisplayInlineType())
384 style->setDisplay(BLOCK);
388 void StyleAdjuster::adjustGridItemPosition(RenderStyle* style, RenderStyle* parentStyle) const
390 const GridPosition& columnStartPosition = style->gridColumnStart();
391 const GridPosition& columnEndPosition = style->gridColumnEnd();
392 const GridPosition& rowStartPosition = style->gridRowStart();
393 const GridPosition& rowEndPosition = style->gridRowEnd();
395 // If opposing grid-placement properties both specify a grid span, they both compute to ‘auto’.
396 if (columnStartPosition.isSpan() && columnEndPosition.isSpan()) {
397 style->setGridColumnStart(GridPosition());
398 style->setGridColumnEnd(GridPosition());
401 if (rowStartPosition.isSpan() && rowEndPosition.isSpan()) {
402 style->setGridRowStart(GridPosition());
403 style->setGridRowEnd(GridPosition());
406 // Unknown named grid area compute to 'auto'.
407 const NamedGridAreaMap& map = parentStyle->namedGridArea();
409 #define CLEAR_UNKNOWN_NAMED_AREA(prop, Prop) \
410 if (prop.isNamedGridArea() && !map.contains(prop.namedGridLine())) \
411 style->setGrid##Prop(GridPosition());
413 CLEAR_UNKNOWN_NAMED_AREA(columnStartPosition, ColumnStart);
414 CLEAR_UNKNOWN_NAMED_AREA(columnEndPosition, ColumnEnd);
415 CLEAR_UNKNOWN_NAMED_AREA(rowStartPosition, RowStart);
416 CLEAR_UNKNOWN_NAMED_AREA(rowEndPosition, RowEnd);