Merge pull request #1579 from egrs/style-element-sheet

return CSSStyleSheet from HTMLStyleElement.sheet

src/browser/tests/element/html/style.html

@@ -3,7 +3,46 @@
 
 <script id="sheet">
   {
+    // Disconnected style element should have no sheet
     testing.expectEqual(null, document.createElement('style').sheet);
+
+    // Connected style element should have a CSSStyleSheet
+    const style = document.createElement('style');
+    document.head.appendChild(style);
+    testing.expectEqual(true, style.sheet instanceof CSSStyleSheet);
+
+    // Same sheet instance on repeated access
+    testing.expectEqual(true, style.sheet === style.sheet);
+
+    // Non-CSS type should have no sheet
+    const lessStyle = document.createElement('style');
+    lessStyle.type = 'text/less';
+    document.head.appendChild(lessStyle);
+    testing.expectEqual(null, lessStyle.sheet);
+
+    // Empty type attribute is valid (defaults to text/css per spec)
+    const emptyType = document.createElement('style');
+    emptyType.setAttribute('type', '');
+    document.head.appendChild(emptyType);
+    testing.expectEqual(true, emptyType.sheet instanceof CSSStyleSheet);
+
+    // Case-insensitive type check
+    const upperType = document.createElement('style');
+    upperType.type = 'TEXT/CSS';
+    document.head.appendChild(upperType);
+    testing.expectEqual(true, upperType.sheet instanceof CSSStyleSheet);
+
+    // Disconnection clears sheet
+    const tempStyle = document.createElement('style');
+    document.head.appendChild(tempStyle);
+    testing.expectEqual(true, tempStyle.sheet instanceof CSSStyleSheet);
+    document.head.removeChild(tempStyle);
+    testing.expectEqual(null, tempStyle.sheet);
+
+    // ownerNode points back to the style element
+    const ownStyle = document.createElement('style');
+    document.head.appendChild(ownStyle);
+    testing.expectEqual(true, ownStyle.sheet.ownerNode === ownStyle);
   }
 </script>
 

src/browser/webapi/css/CSSStyleSheet.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const js = @import("../../js/js.zig");
 const Page = @import("../../Page.zig");
+const Element = @import("../Element.zig");
 const CSSRuleList = @import("CSSRuleList.zig");
 const CSSRule = @import("CSSRule.zig");
 
@@ -11,14 +12,18 @@ _title: []const u8 = "",
 _disabled: bool = false,
 _css_rules: ?*CSSRuleList = null,
 _owner_rule: ?*CSSRule = null,
+_owner_node: ?*Element = null,
 
 pub fn init(page: *Page) !*CSSStyleSheet {
     return page._factory.create(CSSStyleSheet{});
 }
 
-pub fn getOwnerNode(self: *const CSSStyleSheet) ?*CSSStyleSheet {
-    _ = self;
-    return null;
+pub fn initWithOwner(owner: *Element, page: *Page) !*CSSStyleSheet {
+    return page._factory.create(CSSStyleSheet{ ._owner_node = owner });
+}
+
+pub fn getOwnerNode(self: *const CSSStyleSheet) ?*Element {
+    return self._owner_node;
 }
 
 pub fn getHref(self: *const CSSStyleSheet) ?[]const u8 {

src/browser/webapi/element/html/Style.zig

@@ -16,6 +16,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+const std = @import("std");
 const js = @import("../../../js/js.zig");
 const Page = @import("../../../Page.zig");
 
@@ -25,6 +26,7 @@ const HtmlElement = @import("../Html.zig");
 
 const Style = @This();
 _proto: *HtmlElement,
+_sheet: ?*CSSStyleSheet = null,
 
 pub fn asElement(self: *Style) *Element {
     return self._proto._proto;
@@ -75,9 +77,24 @@ pub fn setDisabled(self: *Style, disabled: bool, page: *Page) !void {
 }
 
 const CSSStyleSheet = @import("../../css/CSSStyleSheet.zig");
-pub fn getSheet(_: *const Style) ?*CSSStyleSheet {
-    // TODO?
+pub fn getSheet(self: *Style, page: *Page) !?*CSSStyleSheet {
+    // Per spec, sheet is null for disconnected elements or non-CSS types.
+    // Valid types: absent (defaults to "text/css"), empty string, or
+    // case-insensitive match for "text/css".
+    if (!self.asNode().isConnected()) {
+        self._sheet = null;
         return null;
+    }
+    const t = self.getType();
+    if (t.len != 0 and !std.ascii.eqlIgnoreCase(t, "text/css")) {
+        self._sheet = null;
+        return null;
+    }
+
+    if (self._sheet) |sheet| return sheet;
+    const sheet = try CSSStyleSheet.initWithOwner(self.asElement(), page);
+    self._sheet = sheet;
+    return sheet;
 }
 
 pub const JsApi = struct {