LibWeb: Allow setting shorthand CSS properties via CSSStyleDeclaration

We now expand shorthands into their respective longhand values when
assigning to a shorthand named property on a CSSStyleDeclaration.

We also make sure that shorthands can be round-tripped by correctly
routing named property access through the getPropertyValue() AO,
and expanding it to handle shorthands as well.

A lot of WPT tests for CSS parsing rely on these mechanisms and should
now start working. :^)

Note that multi-level recursive shorthands like `border` don't work
100% correctly yet. We're going to need a bunch more logic to properly
serialize e.g `border-width` or `border` itself.
This commit is contained in:
Andreas Kling 2024-09-21 20:11:03 +02:00 committed by Andreas Kling
parent 6fe43e9f73
commit e40ad73ae7
Notes: github-actions[bot] 2024-09-22 07:46:48 +00:00
3 changed files with 138 additions and 13 deletions

View file

@ -0,0 +1,46 @@
Setting flex: 'none'; becomes...
flex-basis: 'auto'
flex-grow: '0'
flex-shrink: '0'
flex: '0 0 auto'
e.style.length: 3
> [0] flex-grow
> [1] flex-shrink
> [2] flex-basis
Setting flex: 'auto 1 2'; becomes...
flex-basis: 'auto'
flex-grow: '1'
flex-shrink: '2'
flex: '1 2 auto'
e.style.length: 3
> [0] flex-grow
> [1] flex-shrink
> [2] flex-basis
Setting flex: ''; becomes...
flex-basis: ''
flex-grow: ''
flex-shrink: ''
flex: ''
e.style.length: 0
Setting border: '1px solid red'; becomes...
border-width: '1px 1px 1px 1px'
border-style: 'solid solid solid solid'
border-color: 'rgb(255, 0, 0) rgb(255, 0, 0) rgb(255, 0, 0) rgb(255, 0, 0)'
border: ''
e.style.length: 12
> [0] border-top-width
> [1] border-right-width
> [2] border-bottom-width
> [3] border-left-width
> [4] border-top-style
> [5] border-right-style
> [6] border-bottom-style
> [7] border-left-style
> [8] border-top-color
> [9] border-right-color
> [10] border-bottom-color
> [11] border-left-color

View file

@ -0,0 +1,38 @@
<script src="../include.js"></script>
<script>
function testFlexValue(value) {
let e = document.createElement("div");
e.style.flex = value;
println("Setting flex: '" + value + "'; becomes...");
println(" flex-basis: '" + e.style.flexBasis + "'");
println(" flex-grow: '" + e.style.flexGrow + "'");
println(" flex-shrink: '" + e.style.flexShrink + "'");
println(" flex: '" + e.style.flex + "'");
println(" e.style.length: " + e.style.length);
for (let p = 0; p < e.style.length; ++p) {
println(" > [" + p + "] " + e.style[p]);
}
println("");
}
function testBorderValue(value) {
let e = document.createElement("div");
e.style.border = value;
println("Setting border: '" + value + "'; becomes...");
println(" border-width: '" + e.style.getPropertyValue('border-width') + "'");
println(" border-style: '" + e.style.borderStyle + "'");
println(" border-color: '" + e.style.borderColor + "'");
println(" border: '" + e.style.border + "'");
println(" e.style.length: " + e.style.length);
for (let p = 0; p < e.style.length; ++p) {
println(" > [" + p + "] " + e.style[p]);
}
println("");
}
test(() => {
testFlexValue("none");
testFlexValue("auto 1 2");
testFlexValue("");
testBorderValue("1px solid red");
});
</script>

View file

@ -1,5 +1,5 @@
/* /*
* Copyright (c) 2018-2023, Andreas Kling <kling@serenityos.org> * Copyright (c) 2018-2024, Andreas Kling <andreas@ladybird.org>
* *
* SPDX-License-Identifier: BSD-2-Clause * SPDX-License-Identifier: BSD-2-Clause
*/ */
@ -9,6 +9,7 @@
#include <LibWeb/Bindings/Intrinsics.h> #include <LibWeb/Bindings/Intrinsics.h>
#include <LibWeb/CSS/CSSStyleDeclaration.h> #include <LibWeb/CSS/CSSStyleDeclaration.h>
#include <LibWeb/CSS/Parser/Parser.h> #include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/StyleComputer.h>
#include <LibWeb/CSS/StyleValues/ImageStyleValue.h> #include <LibWeb/CSS/StyleValues/ImageStyleValue.h>
#include <LibWeb/DOM/Document.h> #include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/Element.h> #include <LibWeb/DOM/Element.h>
@ -130,15 +131,23 @@ WebIDL::ExceptionOr<void> PropertyOwningCSSStyleDeclaration::set_property(Proper
// 7. Let updated be false. // 7. Let updated be false.
bool updated = false; bool updated = false;
// FIXME: 8. If property is a shorthand property, then for each longhand property longhand that property maps to, in canonical order, follow these substeps: // 8. If property is a shorthand property,
// FIXME: 1. Let longhand result be the result of set the CSS declaration longhand with the appropriate value(s) from component value list, if (property_is_shorthand(property_id)) {
// with the important flag set if priority is not the empty string, and unset otherwise, and with the list of declarations being the declarations. // then for each longhand property longhand that property maps to, in canonical order, follow these substeps:
// FIXME: 2. If longhand result is true, let updated be true. StyleComputer::for_each_property_expanding_shorthands(property_id, *component_value_list, StyleComputer::AllowUnresolved::Yes, [this, &updated, priority](PropertyID longhand_property_id, CSSStyleValue const& longhand_value) {
// 1. Let longhand result be the result of set the CSS declaration longhand with the appropriate value(s) from component value list,
// 9. Otherwise, let updated be the result of set the CSS declaration property with value component value list, // with the important flag set if priority is not the empty string, and unset otherwise, and with the list of declarations being the declarations.
// with the important flag set if priority is not the empty string, and unset otherwise, // 2. If longhand result is true, let updated be true.
// and with the list of declarations being the declarations. updated |= set_a_css_declaration(longhand_property_id, longhand_value, !priority.is_empty() ? Important::Yes : Important::No);
updated = set_a_css_declaration(property_id, component_value_list.release_nonnull(), !priority.is_empty() ? Important::Yes : Important::No); });
}
// 9. Otherwise,
else {
// let updated be the result of set the CSS declaration property with value component value list,
// with the important flag set if priority is not the empty string, and unset otherwise,
// and with the list of declarations being the declarations.
updated = set_a_css_declaration(property_id, *component_value_list, !priority.is_empty() ? Important::Yes : Important::No);
}
// 10. If updated is true, update style attribute for the CSS declaration block. // 10. If updated is true, update style attribute for the CSS declaration block.
if (updated) if (updated)
@ -222,11 +231,45 @@ bool PropertyOwningCSSStyleDeclaration::set_a_css_declaration(PropertyID propert
return true; return true;
} }
// https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-getpropertyvalue
String CSSStyleDeclaration::get_property_value(StringView property_name) const String CSSStyleDeclaration::get_property_value(StringView property_name) const
{ {
auto property_id = property_id_from_string(property_name); auto property_id = property_id_from_string(property_name);
if (!property_id.has_value()) if (!property_id.has_value())
return {}; return {};
// 2. If property is a shorthand property, then follow these substeps:
if (property_is_shorthand(property_id.value())) {
// 1. Let list be a new empty array.
StringBuilder list;
Optional<Important> last_important_flag;
// 2. For each longhand property longhand that property maps to, in canonical order, follow these substeps:
for (auto longhand_property_id : longhands_for_shorthand(property_id.value())) {
// 1. If longhand is a case-sensitive match for a property name of a CSS declaration in the declarations, let declaration be that CSS declaration, or null otherwise.
auto declaration = property(longhand_property_id);
// 2. If declaration is null, then return the empty string.
if (!declaration.has_value())
return {};
// 3. Append the declaration to list.
if (!list.is_empty())
list.append(' ');
list.append(declaration->value->to_string());
if (last_important_flag.has_value() && declaration->important != *last_important_flag)
return {};
last_important_flag = declaration->important;
}
// 3. If important flags of all declarations in list are same, then return the serialization of list.
return list.to_string_without_validation();
// 4. Return the empty string.
// NOTE: This is handled by the loop.
}
auto maybe_property = property(property_id.value()); auto maybe_property = property(property_id.value());
if (!maybe_property.has_value()) if (!maybe_property.has_value())
return {}; return {};
@ -424,9 +467,7 @@ JS::ThrowCompletionOr<JS::Value> CSSStyleDeclaration::internal_get(JS::PropertyK
auto property_id = property_id_from_name(name.to_string()); auto property_id = property_id_from_name(name.to_string());
if (property_id == CSS::PropertyID::Invalid) if (property_id == CSS::PropertyID::Invalid)
return Base::internal_get(name, receiver, cacheable_metadata, phase); return Base::internal_get(name, receiver, cacheable_metadata, phase);
if (auto maybe_property = property(property_id); maybe_property.has_value()) return JS::PrimitiveString::create(vm(), get_property_value(string_from_property_id(property_id)));
return { JS::PrimitiveString::create(vm(), maybe_property->value->to_string()) };
return { JS::PrimitiveString::create(vm(), String {}) };
} }
JS::ThrowCompletionOr<bool> CSSStyleDeclaration::internal_set(JS::PropertyKey const& name, JS::Value value, JS::Value receiver, JS::CacheablePropertyMetadata* cacheable_metadata) JS::ThrowCompletionOr<bool> CSSStyleDeclaration::internal_set(JS::PropertyKey const& name, JS::Value value, JS::Value receiver, JS::CacheablePropertyMetadata* cacheable_metadata)