void reportMediaQueryWarningIfNeeded(Document* document, const MediaQuerySet* mediaQuerySet)
{
if (!mediaQuerySet || !document)
return;
auto& mediaQueries = mediaQuerySet->queryVector();
const size_t queryCount = mediaQueries.size();
if (!queryCount)
return;
for (size_t i = 0; i < queryCount; ++i) {
const MediaQuery* query = mediaQueries[i].get();
String mediaType = query->mediaType();
if (!query->ignored() && !equalIgnoringCase(mediaType, "print")) {
auto& expressions = query->expressions();
for (size_t j = 0; j < expressions.size(); ++j) {
const MediaQueryExp* exp = expressions.at(j).get();
if (exp->mediaFeature() == MediaFeatureNames::resolutionMediaFeature || exp->mediaFeature() == MediaFeatureNames::max_resolutionMediaFeature || exp->mediaFeature() == MediaFeatureNames::min_resolutionMediaFeature) {
CSSValue* cssValue = exp->value();
if (cssValue && cssValue->isPrimitiveValue()) {
CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(cssValue);
if (primitiveValue->isDotsPerInch() || primitiveValue->isDotsPerCentimeter())
addResolutionWarningMessageToConsole(document, mediaQuerySet->mediaText(), primitiveValue);
}
}
}
}
}
}
static bool evalResolution(CSSValue* value, Frame* frame, MediaFeaturePrefix op)
{
// 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".
String mediaType = frame->view()->mediaType();
if (equalIgnoringCase(mediaType, "screen"))
actualResolution = clampTo<float>(frame->devicePixelRatio());
else if (equalIgnoringCase(mediaType, "print")) {
// 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)
return !!actualResolution;
if (!value->isPrimitiveValue())
return false;
CSSPrimitiveValue* resolution = toCSSPrimitiveValue(value);
if (resolution->isNumber())
return compareValue(actualResolution, resolution->getFloatValue(), op);
if (!resolution->isResolution())
return false;
if (resolution->isDotsPerCentimeter()) {
// 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 * resolution->getFloatValue(CSSPrimitiveValue::CSS_DPPX)) / 100, op);
}
return compareValue(actualResolution, resolution->getFloatValue(CSSPrimitiveValue::CSS_DPPX), op);
}
static void addResolutionWarningMessageToConsole(Document& document, const String& serializedExpression, const CSSPrimitiveValue& value)
{
static NeverDestroyed<String> mediaQueryMessage(ASCIILiteral("Consider using 'dppx' units instead of '%replacementUnits%', as in CSS '%replacementUnits%' means dots-per-CSS-%lengthUnit%, not dots-per-physical-%lengthUnit%, so does not correspond to the actual '%replacementUnits%' of a screen. In media query expression: "));
static NeverDestroyed<String> mediaValueDPI(ASCIILiteral("dpi"));
static NeverDestroyed<String> mediaValueDPCM(ASCIILiteral("dpcm"));
static NeverDestroyed<String> lengthUnitInch(ASCIILiteral("inch"));
static NeverDestroyed<String> lengthUnitCentimeter(ASCIILiteral("centimeter"));
String message;
if (value.isDotsPerInch())
message = mediaQueryMessage.get().replace("%replacementUnits%", mediaValueDPI).replace("%lengthUnit%", lengthUnitInch);
else if (value.isDotsPerCentimeter())
message = mediaQueryMessage.get().replace("%replacementUnits%", mediaValueDPCM).replace("%lengthUnit%", lengthUnitCentimeter);
else
ASSERT_NOT_REACHED();
message.append(serializedExpression);
document.addConsoleMessage(MessageSource::CSS, MessageLevel::Debug, message);
}