1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611
|
/*
* CSS Media Query Evaluator
*
* Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
* Copyright (C) 2013 Apple Inc. All rights reserved.
* Copyright (C) 2013 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 APPLE COMPUTER, INC. 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/css/MediaQueryEvaluator.h"
#include "core/CSSValueKeywords.h"
#include "core/MediaFeatureNames.h"
#include "core/MediaFeatures.h"
#include "core/MediaTypeNames.h"
#include "core/css/CSSAspectRatioValue.h"
#include "core/css/CSSHelper.h"
#include "core/css/CSSPrimitiveValue.h"
#include "core/css/CSSToLengthConversionData.h"
#include "core/css/MediaList.h"
#include "core/css/MediaQuery.h"
#include "core/css/MediaValuesDynamic.h"
#include "core/css/resolver/MediaQueryResult.h"
#include "core/dom/NodeRenderStyle.h"
#include "core/frame/FrameHost.h"
#include "core/frame/FrameView.h"
#include "core/frame/LocalFrame.h"
#include "core/frame/Settings.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/rendering/RenderView.h"
#include "core/rendering/compositing/RenderLayerCompositor.h"
#include "core/rendering/style/RenderStyle.h"
#include "platform/PlatformScreen.h"
#include "platform/geometry/FloatRect.h"
#include "wtf/HashMap.h"
namespace WebCore {
using namespace MediaFeatureNames;
enum MediaFeaturePrefix { MinPrefix, MaxPrefix, NoPrefix };
typedef bool (*EvalFunc)(const MediaQueryExpValue&, MediaFeaturePrefix, const MediaValues&);
typedef HashMap<StringImpl*, EvalFunc> FunctionMap;
static FunctionMap* gFunctionMap;
MediaQueryEvaluator::MediaQueryEvaluator(bool mediaFeatureResult)
: m_expectedResult(mediaFeatureResult)
{
}
MediaQueryEvaluator::MediaQueryEvaluator(const String& acceptedMediaType, bool mediaFeatureResult)
: m_mediaType(acceptedMediaType)
, m_expectedResult(mediaFeatureResult)
{
}
MediaQueryEvaluator::MediaQueryEvaluator(const char* acceptedMediaType, bool mediaFeatureResult)
: m_mediaType(acceptedMediaType)
, m_expectedResult(mediaFeatureResult)
{
}
MediaQueryEvaluator::MediaQueryEvaluator(const String& acceptedMediaType, LocalFrame* frame)
: m_mediaType(acceptedMediaType)
, m_expectedResult(false) // Doesn't matter when we have m_frame and m_style.
, m_mediaValues(MediaValues::createDynamicIfFrameExists(frame))
{
}
MediaQueryEvaluator::MediaQueryEvaluator(const String& acceptedMediaType, const MediaValues& mediaValues)
: m_mediaType(acceptedMediaType)
, m_expectedResult(false) // Doesn't matter when we have mediaValues.
, m_mediaValues(mediaValues.copy())
{
}
MediaQueryEvaluator::~MediaQueryEvaluator()
{
}
bool MediaQueryEvaluator::mediaTypeMatch(const String& mediaTypeToMatch) const
{
return mediaTypeToMatch.isEmpty()
|| equalIgnoringCase(mediaTypeToMatch, MediaTypeNames::all)
|| equalIgnoringCase(mediaTypeToMatch, m_mediaType);
}
bool MediaQueryEvaluator::mediaTypeMatchSpecific(const char* mediaTypeToMatch) const
{
// Like mediaTypeMatch, but without the special cases for "" and "all".
ASSERT(mediaTypeToMatch);
ASSERT(mediaTypeToMatch[0] != '\0');
ASSERT(!equalIgnoringCase(mediaTypeToMatch, MediaTypeNames::all));
return equalIgnoringCase(mediaTypeToMatch, m_mediaType);
}
static bool applyRestrictor(MediaQuery::Restrictor r, bool value)
{
return r == MediaQuery::Not ? !value : value;
}
bool MediaQueryEvaluator::eval(const MediaQuerySet* querySet, MediaQueryResultList* viewportDependentMediaQueryResults) const
{
if (!querySet)
return true;
const WillBeHeapVector<OwnPtrWillBeMember<MediaQuery> >& queries = querySet->queryVector();
if (!queries.size())
return true; // Empty query list evaluates to true.
// Iterate over queries, stop if any of them eval to true (OR semantics).
bool result = false;
for (size_t i = 0; i < queries.size() && !result; ++i) {
MediaQuery* query = queries[i].get();
if (mediaTypeMatch(query->mediaType())) {
const ExpressionHeapVector& expressions = query->expressions();
// Iterate through expressions, stop if any of them eval to false (AND semantics).
size_t j = 0;
for (; j < expressions.size(); ++j) {
bool exprResult = eval(expressions.at(j).get());
if (viewportDependentMediaQueryResults && expressions.at(j)->isViewportDependent())
viewportDependentMediaQueryResults->append(adoptRefWillBeNoop(new MediaQueryResult(*expressions.at(j), exprResult)));
if (!exprResult)
break;
}
// Assume true if we are at the end of the list, otherwise assume false.
result = applyRestrictor(query->restrictor(), expressions.size() == j);
} else {
result = applyRestrictor(query->restrictor(), false);
}
}
return result;
}
template<typename T>
bool compareValue(T a, T b, MediaFeaturePrefix op)
{
switch (op) {
case MinPrefix:
return a >= b;
case MaxPrefix:
return a <= b;
case NoPrefix:
return a == b;
}
return false;
}
static bool compareAspectRatioValue(const MediaQueryExpValue& value, int width, int height, MediaFeaturePrefix op)
{
if (value.isRatio)
return compareValue(width * static_cast<int>(value.denominator), height * static_cast<int>(value.numerator), op);
return false;
}
static bool numberValue(const MediaQueryExpValue& value, float& result)
{
if (value.isValue && value.unit == CSSPrimitiveValue::CSS_NUMBER) {
result = value.value;
return true;
}
return false;
}
static bool colorMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
float number;
int bitsPerComponent = mediaValues.colorBitsPerComponent();
if (value.isValid())
return numberValue(value, number) && compareValue(bitsPerComponent, static_cast<int>(number), op);
return bitsPerComponent != 0;
}
static bool colorIndexMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues&)
{
// FIXME: We currently assume that we do not support indexed displays, as it is unknown
// how to retrieve the information if the display mode is indexed. This matches Firefox.
if (!value.isValid())
return false;
// Acording to spec, if the device does not use a color lookup table, the value is zero.
float number;
return numberValue(value, number) && compareValue(0, static_cast<int>(number), op);
}
static bool monochromeMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
if (!mediaValues.monochromeBitsPerComponent()) {
if (value.isValid()) {
float number;
return numberValue(value, number) && compareValue(0, static_cast<int>(number), op);
}
return false;
}
return colorMediaFeatureEval(value, op, mediaValues);
}
static bool orientationMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
int width = mediaValues.viewportWidth();
int height = mediaValues.viewportHeight();
if (value.isID) {
if (width > height) // Square viewport is portrait.
return CSSValueLandscape == value.id;
return CSSValuePortrait == value.id;
}
// Expression (orientation) evaluates to true if width and height >= 0.
return height >= 0 && width >= 0;
}
static bool aspectRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
if (value.isValid())
return compareAspectRatioValue(value, mediaValues.viewportWidth(), mediaValues.viewportHeight(), op);
// ({,min-,max-}aspect-ratio)
// assume if we have a device, its aspect ratio is non-zero.
return true;
}
static bool deviceAspectRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
if (value.isValid())
return compareAspectRatioValue(value, mediaValues.deviceWidth(), mediaValues.deviceHeight(), op);
// ({,min-,max-}device-aspect-ratio)
// assume if we have a device, its aspect ratio is non-zero.
return true;
}
static bool evalResolution(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
// According to MQ4, only 'screen', 'print' and 'speech' may match.
// FIXME: What should speech match? https://www.w3.org/Style/CSS/Tracker/issues/348
float actualResolution = 0;
// This checks the actual media type applied to the document, and we know
// this method only got called if this media type matches the one defined
// in the query. Thus, if if the document's media type is "print", the
// media type of the query will either be "print" or "all".
if (mediaValues.screenMediaType()) {
actualResolution = clampTo<float>(mediaValues.devicePixelRatio());
} else if (mediaValues.printMediaType()) {
// The resolution of images while printing should not depend on the DPI
// of the screen. Until we support proper ways of querying this info
// we use 300px which is considered minimum for current printers.
actualResolution = 300 / cssPixelsPerInch;
}
if (!value.isValid())
return !!actualResolution;
if (!value.isValue)
return false;
if (value.unit == CSSPrimitiveValue::CSS_NUMBER)
return compareValue(actualResolution, clampTo<float>(value.value), op);
if (!CSSPrimitiveValue::isResolution(value.unit))
return false;
double canonicalFactor = CSSPrimitiveValue::conversionToCanonicalUnitsScaleFactor(value.unit);
double dppxFactor = CSSPrimitiveValue::conversionToCanonicalUnitsScaleFactor(CSSPrimitiveValue::CSS_DPPX);
float valueInDppx = clampTo<float>(value.value * (canonicalFactor / dppxFactor));
if (CSSPrimitiveValue::isDotsPerCentimeter(value.unit)) {
// To match DPCM to DPPX values, we limit to 2 decimal points.
// The http://dev.w3.org/csswg/css3-values/#absolute-lengths recommends
// "that the pixel unit refer to the whole number of device pixels that best
// approximates the reference pixel". With that in mind, allowing 2 decimal
// point precision seems appropriate.
return compareValue(
floorf(0.5 + 100 * actualResolution) / 100,
floorf(0.5 + 100 * valueInDppx) / 100, op);
}
return compareValue(actualResolution, valueInDppx, op);
}
static bool devicePixelRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
UseCounter::count(mediaValues.document(), UseCounter::PrefixedDevicePixelRatioMediaFeature);
return (!value.isValid() || value.unit == CSSPrimitiveValue::CSS_NUMBER) && evalResolution(value, op, mediaValues);
}
static bool resolutionMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& MediaValues)
{
return (!value.isValid() || CSSPrimitiveValue::isResolution(value.unit)) && evalResolution(value, op, MediaValues);
}
static bool gridMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues&)
{
// if output device is bitmap, grid: 0 == true
// assume we have bitmap device
float number;
if (value.isValid() && numberValue(value, number))
return compareValue(static_cast<int>(number), 0, op);
return false;
}
static bool computeLength(const MediaQueryExpValue& value, const MediaValues& mediaValues, int& result)
{
if (!value.isValue)
return false;
if (value.unit == CSSPrimitiveValue::CSS_NUMBER) {
result = clampTo<int>(value.value);
return !mediaValues.strictMode() || !result;
}
if (CSSPrimitiveValue::isLength(value.unit))
return mediaValues.computeLength(value.value, value.unit, result);
return false;
}
static bool deviceHeightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
if (value.isValid()) {
int length;
return computeLength(value, mediaValues, length) && compareValue(static_cast<int>(mediaValues.deviceHeight()), length, op);
}
// ({,min-,max-}device-height)
// assume if we have a device, assume non-zero
return true;
}
static bool deviceWidthMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
if (value.isValid()) {
int length;
return computeLength(value, mediaValues, length) && compareValue(static_cast<int>(mediaValues.deviceWidth()), length, op);
}
// ({,min-,max-}device-width)
// assume if we have a device, assume non-zero
return true;
}
static bool heightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
int height = mediaValues.viewportHeight();
if (value.isValid()) {
int length;
return computeLength(value, mediaValues, length) && compareValue(height, length, op);
}
return height;
}
static bool widthMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
int width = mediaValues.viewportWidth();
if (value.isValid()) {
int length;
return computeLength(value, mediaValues, length) && compareValue(width, length, op);
}
return width;
}
// Rest of the functions are trampolines which set the prefix according to the media feature expression used.
static bool minColorMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return colorMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxColorMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return colorMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minColorIndexMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return colorIndexMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxColorIndexMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return colorIndexMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minMonochromeMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return monochromeMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxMonochromeMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return monochromeMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minAspectRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return aspectRatioMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxAspectRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return aspectRatioMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minDeviceAspectRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return deviceAspectRatioMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxDeviceAspectRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return deviceAspectRatioMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minDevicePixelRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
UseCounter::count(mediaValues.document(), UseCounter::PrefixedMinDevicePixelRatioMediaFeature);
return devicePixelRatioMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxDevicePixelRatioMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
UseCounter::count(mediaValues.document(), UseCounter::PrefixedMaxDevicePixelRatioMediaFeature);
return devicePixelRatioMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minHeightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return heightMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxHeightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return heightMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minWidthMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return widthMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxWidthMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return widthMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minDeviceHeightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return deviceHeightMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxDeviceHeightMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return deviceHeightMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minDeviceWidthMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return deviceWidthMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxDeviceWidthMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return deviceWidthMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool minResolutionMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return resolutionMediaFeatureEval(value, MinPrefix, mediaValues);
}
static bool maxResolutionMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
return resolutionMediaFeatureEval(value, MaxPrefix, mediaValues);
}
static bool transform3dMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix op, const MediaValues& mediaValues)
{
UseCounter::count(mediaValues.document(), UseCounter::PrefixedTransform3dMediaFeature);
bool returnValueIfNoParameter;
int have3dRendering;
bool threeDEnabled = mediaValues.threeDEnabled();
returnValueIfNoParameter = threeDEnabled;
have3dRendering = threeDEnabled ? 1 : 0;
if (value.isValid()) {
float number;
return numberValue(value, number) && compareValue(have3dRendering, static_cast<int>(number), op);
}
return returnValueIfNoParameter;
}
static bool hoverMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
MediaValues::PointerDeviceType pointer = mediaValues.pointer();
// If we're on a port that hasn't explicitly opted into providing pointer device information
// (or otherwise can't be confident in the pointer hardware available), then behave exactly
// as if this feature feature isn't supported.
if (pointer == MediaValues::UnknownPointer)
return false;
float number = 1;
if (value.isValid()) {
if (!numberValue(value, number))
return false;
}
return (pointer == MediaValues::NoPointer && !number)
|| (pointer == MediaValues::TouchPointer && !number)
|| (pointer == MediaValues::MousePointer && number == 1);
}
static bool pointerMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
MediaValues::PointerDeviceType pointer = mediaValues.pointer();
// If we're on a port that hasn't explicitly opted into providing pointer device information
// (or otherwise can't be confident in the pointer hardware available), then behave exactly
// as if this feature feature isn't supported.
if (pointer == MediaValues::UnknownPointer)
return false;
if (!value.isValid())
return pointer != MediaValues::NoPointer;
if (!value.isID)
return false;
return (pointer == MediaValues::NoPointer && value.id == CSSValueNone)
|| (pointer == MediaValues::TouchPointer && value.id == CSSValueCoarse)
|| (pointer == MediaValues::MousePointer && value.id == CSSValueFine);
}
static bool scanMediaFeatureEval(const MediaQueryExpValue& value, MediaFeaturePrefix, const MediaValues& mediaValues)
{
if (!mediaValues.scanMediaType())
return false;
if (!value.isValid())
return true;
if (!value.isID)
return false;
// If a platform interface supplies progressive/interlace info for TVs in the
// future, it needs to be handled here. For now, assume a modern TV with
// progressive display.
return (value.id == CSSValueProgressive);
}
static void createFunctionMap()
{
// Create the table.
gFunctionMap = new FunctionMap;
#define ADD_TO_FUNCTIONMAP(name) \
gFunctionMap->set(name##MediaFeature.impl(), name##MediaFeatureEval);
CSS_MEDIAQUERY_NAMES_FOR_EACH_MEDIAFEATURE(ADD_TO_FUNCTIONMAP);
#undef ADD_TO_FUNCTIONMAP
}
bool MediaQueryEvaluator::eval(const MediaQueryExp* expr) const
{
if (!m_mediaValues || !m_mediaValues->hasValues())
return m_expectedResult;
if (!gFunctionMap)
createFunctionMap();
// Call the media feature evaluation function. Assume no prefix and let
// trampoline functions override the prefix if prefix is used.
EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());
if (func)
return func(expr->expValue(), NoPrefix, *m_mediaValues);
return false;
}
} // namespace
|