add HTMLStyleElement.get_sheet

src/browser/State.zig

@@ -30,6 +30,7 @@ const Env = @import("env.zig").Env;
 const parser = @import("netsurf.zig");
 const DataSet = @import("html/DataSet.zig");
 const ShadowRoot = @import("dom/shadow_root.zig").ShadowRoot;
+const StyleSheet = @import("cssom/stylesheet.zig").StyleSheet;
 const CSSStyleDeclaration = @import("cssom/css_style_declaration.zig").CSSStyleDeclaration;
 
 // for HTMLScript (but probably needs to be added to more)
@@ -39,10 +40,17 @@ onerror: ?Env.Function = null,
 // for HTMLElement
 style: CSSStyleDeclaration = .empty,
 dataset: ?DataSet = null,
+template_content: ?*parser.DocumentFragment = null,
+
+// For dom/element
+shadow_root: ?*ShadowRoot = null,
 
 // for html/document
 ready_state: ReadyState = .loading,
 
+// for html/HTMLStyleElement
+style_sheet: ?*StyleSheet = null,
+
 // for dom/document
 active_element: ?*parser.Element = null,
 
@@ -61,10 +69,6 @@ active_element: ?*parser.Element = null,
 // default (by returning selectedIndex == 0).
 explicit_index_set: bool = false,
 
-template_content: ?*parser.DocumentFragment = null,
-
-shadow_root: ?*ShadowRoot = null,
-
 const ReadyState = enum {
     loading,
     interactive,

src/browser/html/elements.zig

@@ -29,6 +29,7 @@ const Node = @import("../dom/node.zig").Node;
 const Element = @import("../dom/element.zig").Element;
 const DataSet = @import("DataSet.zig");
 
+const StyleSheet = @import("../cssom/stylesheet.zig").StyleSheet;
 const CSSStyleDeclaration = @import("../cssom/css_style_declaration.zig").CSSStyleDeclaration;
 
 // HTMLElement interfaces
@@ -1012,6 +1013,18 @@ pub const HTMLStyleElement = struct {
     pub const Self = parser.Style;
     pub const prototype = *HTMLElement;
     pub const subtype = .node;
+
+    pub fn get_sheet(self: *parser.Style, page: *Page) !*StyleSheet {
+        const state = try page.getOrCreateNodeState(@alignCast(@ptrCast(self)));
+        if (state.style_sheet) |ss| {
+            return ss;
+        }
+
+        const ss = try page.arena.create(StyleSheet);
+        ss.* = .{};
+        state.style_sheet = ss;
+        return ss;
+    }
 };
 
 pub const HTMLTableElement = struct {
@@ -1453,6 +1466,18 @@ test "Browser.HTML.HTMLTemplateElement" {
     }, .{});
 }
 
+test "Browser.HTML.HTMLStyleElement" {
+    var runner = try testing.jsRunner(testing.tracking_allocator, .{ .html = "" });
+    defer runner.deinit();
+
+    try runner.testCases(&.{
+        .{ "let s = document.createElement('style')", null },
+        .{ "s.sheet.type", "text/css" },
+        .{ "s.sheet == s.sheet", "true" },
+        .{ "document.createElement('style').sheet == s.sheet", "false" },
+    }, .{});
+}
+
 const Check = struct {
     input: []const u8,
     expected: ?[]const u8 = null, // Needed when input != expected