ladybird/Userland/Libraries/LibWeb/CSS/MediaQuery.cpp
sin-ack 3f3f45580a Everywhere: Add sv suffix to strings relying on StringView(char const*)
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).

No functional changes.
2022-07-12 23:11:35 +02:00

504 lines
17 KiB
C++

/*
* Copyright (c) 2021, Sam Atkins <atkinssj@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibWeb/CSS/MediaQuery.h>
#include <LibWeb/CSS/Serialize.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/HTML/Window.h>
namespace Web::CSS {
NonnullRefPtr<MediaQuery> MediaQuery::create_not_all()
{
auto media_query = new MediaQuery;
media_query->m_negated = true;
media_query->m_media_type = MediaType::All;
return adopt_ref(*media_query);
}
String MediaFeatureValue::to_string() const
{
return m_value.visit(
[](ValueID const& ident) { return String { string_from_value_id(ident) }; },
[](Length const& length) { return length.to_string(); },
[](Ratio const& ratio) { return ratio.to_string(); },
[](Resolution const& resolution) { return resolution.to_string(); },
[](float number) { return String::number(number); });
}
bool MediaFeatureValue::is_same_type(MediaFeatureValue const& other) const
{
return m_value.visit(
[&](ValueID const&) { return other.is_ident(); },
[&](Length const&) { return other.is_length(); },
[&](Ratio const&) { return other.is_ratio(); },
[&](Resolution const&) { return other.is_resolution(); },
[&](float) { return other.is_number(); });
}
String MediaFeature::to_string() const
{
auto comparison_string = [](Comparison comparison) -> StringView {
switch (comparison) {
case Comparison::Equal:
return "="sv;
case Comparison::LessThan:
return "<"sv;
case Comparison::LessThanOrEqual:
return "<="sv;
case Comparison::GreaterThan:
return ">"sv;
case Comparison::GreaterThanOrEqual:
return ">="sv;
}
VERIFY_NOT_REACHED();
};
switch (m_type) {
case Type::IsTrue:
return string_from_media_feature_id(m_id);
case Type::ExactValue:
return String::formatted("{}:{}", string_from_media_feature_id(m_id), m_value->to_string());
case Type::MinValue:
return String::formatted("min-{}:{}", string_from_media_feature_id(m_id), m_value->to_string());
case Type::MaxValue:
return String::formatted("max-{}:{}", string_from_media_feature_id(m_id), m_value->to_string());
case Type::Range:
if (!m_range->right_comparison.has_value())
return String::formatted("{} {} {}", m_range->left_value.to_string(), comparison_string(m_range->left_comparison), string_from_media_feature_id(m_id));
return String::formatted("{} {} {} {} {}", m_range->left_value.to_string(), comparison_string(m_range->left_comparison), string_from_media_feature_id(m_id), comparison_string(*m_range->right_comparison), m_range->right_value->to_string());
}
VERIFY_NOT_REACHED();
}
bool MediaFeature::evaluate(HTML::Window const& window) const
{
auto maybe_queried_value = window.query_media_feature(m_id);
if (!maybe_queried_value.has_value())
return false;
auto queried_value = maybe_queried_value.release_value();
switch (m_type) {
case Type::IsTrue:
if (queried_value.is_number())
return queried_value.number() != 0;
if (queried_value.is_length())
return queried_value.length().raw_value() != 0;
// FIXME: I couldn't figure out from the spec how ratios should be evaluated in a boolean context.
if (queried_value.is_ratio())
return !queried_value.ratio().is_degenerate();
if (queried_value.is_resolution())
return queried_value.resolution().to_dots_per_pixel() != 0;
if (queried_value.is_ident()) {
// NOTE: It is not technically correct to always treat `no-preference` as false, but every
// media-feature that accepts it as a value treats it as false, so good enough. :^)
// If other features gain this property for other identifiers in the future, we can
// add more robust handling for them then.
return queried_value.ident() != ValueID::None
&& queried_value.ident() != ValueID::NoPreference;
}
return false;
case Type::ExactValue:
return compare(window, *m_value, Comparison::Equal, queried_value);
case Type::MinValue:
return compare(window, queried_value, Comparison::GreaterThanOrEqual, *m_value);
case Type::MaxValue:
return compare(window, queried_value, Comparison::LessThanOrEqual, *m_value);
case Type::Range:
if (!compare(window, m_range->left_value, m_range->left_comparison, queried_value))
return false;
if (m_range->right_comparison.has_value())
if (!compare(window, queried_value, *m_range->right_comparison, *m_range->right_value))
return false;
return true;
}
VERIFY_NOT_REACHED();
}
bool MediaFeature::compare(HTML::Window const& window, MediaFeatureValue left, Comparison comparison, MediaFeatureValue right)
{
if (!left.is_same_type(right))
return false;
if (left.is_ident()) {
if (comparison == Comparison::Equal)
return left.ident() == right.ident();
return false;
}
if (left.is_number()) {
switch (comparison) {
case Comparison::Equal:
return left.number() == right.number();
case Comparison::LessThan:
return left.number() < right.number();
case Comparison::LessThanOrEqual:
return left.number() <= right.number();
case Comparison::GreaterThan:
return left.number() > right.number();
case Comparison::GreaterThanOrEqual:
return left.number() >= right.number();
}
VERIFY_NOT_REACHED();
}
if (left.is_length()) {
float left_px;
float right_px;
// Save ourselves some work if neither side is a relative length.
if (left.length().is_absolute() && right.length().is_absolute()) {
left_px = left.length().absolute_length_to_px();
right_px = right.length().absolute_length_to_px();
} else {
Gfx::IntRect viewport_rect { 0, 0, window.inner_width(), window.inner_height() };
auto const& initial_font = window.associated_document().style_computer().initial_font();
Gfx::FontPixelMetrics const& initial_font_metrics = initial_font.pixel_metrics();
float initial_font_size = initial_font.presentation_size();
left_px = left.length().to_px(viewport_rect, initial_font_metrics, initial_font_size, initial_font_size);
right_px = right.length().to_px(viewport_rect, initial_font_metrics, initial_font_size, initial_font_size);
}
switch (comparison) {
case Comparison::Equal:
return left_px == right_px;
case Comparison::LessThan:
return left_px < right_px;
case Comparison::LessThanOrEqual:
return left_px <= right_px;
case Comparison::GreaterThan:
return left_px > right_px;
case Comparison::GreaterThanOrEqual:
return left_px >= right_px;
}
VERIFY_NOT_REACHED();
}
if (left.is_ratio()) {
auto left_decimal = left.ratio().value();
auto right_decimal = right.ratio().value();
switch (comparison) {
case Comparison::Equal:
return left_decimal == right_decimal;
case Comparison::LessThan:
return left_decimal < right_decimal;
case Comparison::LessThanOrEqual:
return left_decimal <= right_decimal;
case Comparison::GreaterThan:
return left_decimal > right_decimal;
case Comparison::GreaterThanOrEqual:
return left_decimal >= right_decimal;
}
VERIFY_NOT_REACHED();
}
if (left.is_resolution()) {
auto left_dppx = left.resolution().to_dots_per_pixel();
auto right_dppx = right.resolution().to_dots_per_pixel();
switch (comparison) {
case Comparison::Equal:
return left_dppx == right_dppx;
case Comparison::LessThan:
return left_dppx < right_dppx;
case Comparison::LessThanOrEqual:
return left_dppx <= right_dppx;
case Comparison::GreaterThan:
return left_dppx > right_dppx;
case Comparison::GreaterThanOrEqual:
return left_dppx >= right_dppx;
}
VERIFY_NOT_REACHED();
}
VERIFY_NOT_REACHED();
}
NonnullOwnPtr<MediaCondition> MediaCondition::from_general_enclosed(GeneralEnclosed&& general_enclosed)
{
auto result = new MediaCondition;
result->type = Type::GeneralEnclosed;
result->general_enclosed = move(general_enclosed);
return adopt_own(*result);
}
NonnullOwnPtr<MediaCondition> MediaCondition::from_feature(MediaFeature&& feature)
{
auto result = new MediaCondition;
result->type = Type::Single;
result->feature = move(feature);
return adopt_own(*result);
}
NonnullOwnPtr<MediaCondition> MediaCondition::from_not(NonnullOwnPtr<MediaCondition>&& condition)
{
auto result = new MediaCondition;
result->type = Type::Not;
result->conditions.append(move(condition));
return adopt_own(*result);
}
NonnullOwnPtr<MediaCondition> MediaCondition::from_and_list(NonnullOwnPtrVector<MediaCondition>&& conditions)
{
auto result = new MediaCondition;
result->type = Type::And;
result->conditions = move(conditions);
return adopt_own(*result);
}
NonnullOwnPtr<MediaCondition> MediaCondition::from_or_list(NonnullOwnPtrVector<MediaCondition>&& conditions)
{
auto result = new MediaCondition;
result->type = Type::Or;
result->conditions = move(conditions);
return adopt_own(*result);
}
String MediaCondition::to_string() const
{
StringBuilder builder;
builder.append('(');
switch (type) {
case Type::Single:
builder.append(feature->to_string());
break;
case Type::Not:
builder.append("not "sv);
builder.append(conditions.first().to_string());
break;
case Type::And:
builder.join(" and "sv, conditions);
break;
case Type::Or:
builder.join(" or "sv, conditions);
break;
case Type::GeneralEnclosed:
builder.append(general_enclosed->to_string());
break;
}
builder.append(')');
return builder.to_string();
}
MatchResult MediaCondition::evaluate(HTML::Window const& window) const
{
switch (type) {
case Type::Single:
return as_match_result(feature->evaluate(window));
case Type::Not:
return negate(conditions.first().evaluate(window));
case Type::And:
return evaluate_and(conditions, [&](auto& child) { return child.evaluate(window); });
case Type::Or:
return evaluate_or(conditions, [&](auto& child) { return child.evaluate(window); });
case Type::GeneralEnclosed:
return general_enclosed->evaluate();
}
VERIFY_NOT_REACHED();
}
String MediaQuery::to_string() const
{
StringBuilder builder;
if (m_negated)
builder.append("not "sv);
if (m_negated || m_media_type != MediaType::All || !m_media_condition) {
builder.append(CSS::to_string(m_media_type));
if (m_media_condition)
builder.append(" and "sv);
}
if (m_media_condition) {
builder.append(m_media_condition->to_string());
}
return builder.to_string();
}
bool MediaQuery::evaluate(HTML::Window const& window)
{
auto matches_media = [](MediaType media) -> MatchResult {
switch (media) {
case MediaType::All:
return MatchResult::True;
case MediaType::Print:
// FIXME: Enable for printing, when we have printing!
return MatchResult::False;
case MediaType::Screen:
// FIXME: Disable for printing, when we have printing!
return MatchResult::True;
// Deprecated, must never match:
case MediaType::TTY:
case MediaType::TV:
case MediaType::Projection:
case MediaType::Handheld:
case MediaType::Braille:
case MediaType::Embossed:
case MediaType::Aural:
case MediaType::Speech:
return MatchResult::False;
}
VERIFY_NOT_REACHED();
};
MatchResult result = matches_media(m_media_type);
if ((result == MatchResult::True) && m_media_condition)
result = m_media_condition->evaluate(window);
if (m_negated)
result = negate(result);
m_matches = result == MatchResult::True;
return m_matches;
}
// https://www.w3.org/TR/cssom-1/#serialize-a-media-query-list
String serialize_a_media_query_list(NonnullRefPtrVector<MediaQuery> const& media_queries)
{
// 1. If the media query list is empty, then return the empty string.
if (media_queries.is_empty())
return "";
// 2. Serialize each media query in the list of media queries, in the same order as they
// appear in the media query list, and then serialize the list.
StringBuilder builder;
builder.join(", "sv, media_queries);
return builder.to_string();
}
bool is_media_feature_name(StringView name)
{
// MEDIAQUERIES-4 - https://www.w3.org/TR/mediaqueries-4/#media-descriptor-table
if (name.equals_ignoring_case("any-hover"sv))
return true;
if (name.equals_ignoring_case("any-pointer"sv))
return true;
if (name.equals_ignoring_case("aspect-ratio"sv))
return true;
if (name.equals_ignoring_case("color"sv))
return true;
if (name.equals_ignoring_case("color-gamut"sv))
return true;
if (name.equals_ignoring_case("color-index"sv))
return true;
if (name.equals_ignoring_case("device-aspect-ratio"sv))
return true;
if (name.equals_ignoring_case("device-height"sv))
return true;
if (name.equals_ignoring_case("device-width"sv))
return true;
if (name.equals_ignoring_case("grid"sv))
return true;
if (name.equals_ignoring_case("height"sv))
return true;
if (name.equals_ignoring_case("hover"sv))
return true;
if (name.equals_ignoring_case("monochrome"sv))
return true;
if (name.equals_ignoring_case("orientation"sv))
return true;
if (name.equals_ignoring_case("overflow-block"sv))
return true;
if (name.equals_ignoring_case("overflow-inline"sv))
return true;
if (name.equals_ignoring_case("pointer"sv))
return true;
if (name.equals_ignoring_case("resolution"sv))
return true;
if (name.equals_ignoring_case("scan"sv))
return true;
if (name.equals_ignoring_case("update"sv))
return true;
if (name.equals_ignoring_case("width"sv))
return true;
// MEDIAQUERIES-5 - https://www.w3.org/TR/mediaqueries-5/#media-descriptor-table
if (name.equals_ignoring_case("prefers-color-scheme"sv))
return true;
// FIXME: Add other level 5 feature names
return false;
}
Optional<MediaQuery::MediaType> media_type_from_string(StringView name)
{
if (name.equals_ignoring_case("all"sv))
return MediaQuery::MediaType::All;
if (name.equals_ignoring_case("aural"sv))
return MediaQuery::MediaType::Aural;
if (name.equals_ignoring_case("braille"sv))
return MediaQuery::MediaType::Braille;
if (name.equals_ignoring_case("embossed"sv))
return MediaQuery::MediaType::Embossed;
if (name.equals_ignoring_case("handheld"sv))
return MediaQuery::MediaType::Handheld;
if (name.equals_ignoring_case("print"sv))
return MediaQuery::MediaType::Print;
if (name.equals_ignoring_case("projection"sv))
return MediaQuery::MediaType::Projection;
if (name.equals_ignoring_case("screen"sv))
return MediaQuery::MediaType::Screen;
if (name.equals_ignoring_case("speech"sv))
return MediaQuery::MediaType::Speech;
if (name.equals_ignoring_case("tty"sv))
return MediaQuery::MediaType::TTY;
if (name.equals_ignoring_case("tv"sv))
return MediaQuery::MediaType::TV;
return {};
}
StringView to_string(MediaQuery::MediaType media_type)
{
switch (media_type) {
case MediaQuery::MediaType::All:
return "all"sv;
case MediaQuery::MediaType::Aural:
return "aural"sv;
case MediaQuery::MediaType::Braille:
return "braille"sv;
case MediaQuery::MediaType::Embossed:
return "embossed"sv;
case MediaQuery::MediaType::Handheld:
return "handheld"sv;
case MediaQuery::MediaType::Print:
return "print"sv;
case MediaQuery::MediaType::Projection:
return "projection"sv;
case MediaQuery::MediaType::Screen:
return "screen"sv;
case MediaQuery::MediaType::Speech:
return "speech"sv;
case MediaQuery::MediaType::TTY:
return "tty"sv;
case MediaQuery::MediaType::TV:
return "tv"sv;
}
VERIFY_NOT_REACHED();
}
}