From 0ab31d8c84c57039a50eb0e8e0a3ed668ab422fe Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 26 Sep 2021 19:06:17 +0200
Subject: [PATCH] LibWeb: Support simplest form of
 CSSStyleDeclaration.setProperty()

This patch adds the setProperty(name, value) API to CSSStyleDeclaration.
Setting an invalid or empty value will cause the property to be removed
from the declaration.

Note that this only works on mutable declarations (i.e element.style)
and not on resolved declarations (i.e window.getComputedStyle(element)).
---
 .../Bindings/CSSStyleDeclarationWrapperCustom.cpp |  3 ++-
 .../Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp  | 15 +++++++++++++--
 .../Libraries/LibWeb/CSS/CSSStyleDeclaration.h    |  2 ++
 .../Libraries/LibWeb/CSS/CSSStyleDeclaration.idl  |  2 ++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/Userland/Libraries/LibWeb/Bindings/CSSStyleDeclarationWrapperCustom.cpp b/Userland/Libraries/LibWeb/Bindings/CSSStyleDeclarationWrapperCustom.cpp
index d5e572fcf3f..66bd50f446f 100644
--- a/Userland/Libraries/LibWeb/Bindings/CSSStyleDeclarationWrapperCustom.cpp
+++ b/Userland/Libraries/LibWeb/Bindings/CSSStyleDeclarationWrapperCustom.cpp
@@ -44,7 +44,8 @@ bool CSSStyleDeclarationWrapper::internal_set(JS::PropertyName const& name, JS::
     if (vm().exception())
         return false;
 
-    return impl().set_property(property_id, css_text);
+    impl().set_property(property_id, css_text);
+    return true;
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
index dae3a69a597..0635a4c2e3e 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.cpp
@@ -64,9 +64,12 @@ Optional<StyleProperty> PropertyOwningCSSStyleDeclaration::property(PropertyID p
 bool PropertyOwningCSSStyleDeclaration::set_property(PropertyID property_id, StringView css_text)
 {
     auto new_value = parse_css_value(CSS::ParsingContext {}, css_text, property_id);
-    // FIXME: What are we supposed to do if we can't parse it?
-    if (!new_value)
+    if (!new_value) {
+        m_properties.remove_all_matching([&](auto& entry) {
+            return entry.property_id == property_id;
+        });
         return false;
+    }
 
     ScopeGuard style_invalidation_guard = [&] {
         auto& declaration = verify_cast<CSS::ElementInlineCSSStyleDeclaration>(*this);
@@ -102,4 +105,12 @@ String CSSStyleDeclaration::get_property_value(StringView property_name) const
     return maybe_property->value->to_string();
 }
 
+void CSSStyleDeclaration::set_property(StringView property_name, StringView css_text)
+{
+    auto property_id = property_id_from_string(property_name);
+    if (property_id == CSS::PropertyID::Invalid)
+        return;
+    set_property(property_id, css_text);
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
index 17bfcb26c1c..37a32c9f6a7 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
@@ -34,6 +34,8 @@ public:
     virtual Optional<StyleProperty> property(PropertyID) const = 0;
     virtual bool set_property(PropertyID, StringView css_text) = 0;
 
+    void set_property(StringView property_name, StringView css_text);
+
     String get_property_value(StringView property) const;
 
 protected:
diff --git a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
index 743f2151ad2..bce8af29f36 100644
--- a/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
+++ b/Userland/Libraries/LibWeb/CSS/CSSStyleDeclaration.idl
@@ -6,4 +6,6 @@ interface CSSStyleDeclaration {
 
     CSSOMString getPropertyValue(CSSOMString property);
 
+    [CEReactions] undefined setProperty(CSSOMString property, [LegacyNullToEmptyString] CSSOMString value);
+
 };