Files
browser/src/browser/webapi/css/CSSStyleDeclaration.zig
2026-02-19 14:49:49 +01:00

346 lines
12 KiB
Zig

// Copyright (C) 2023-2025 Lightpanda (Selecy SAS)
//
// Francis Bouvier <francis@lightpanda.io>
// Pierre Tachoire <pierre@lightpanda.io>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// 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 log = @import("../../../log.zig");
const String = @import("../../../string.zig").String;
const CssParser = @import("../../css/Parser.zig");
const js = @import("../../js/js.zig");
const Page = @import("../../Page.zig");
const Element = @import("../Element.zig");
const CSSStyleDeclaration = @This();
_element: ?*Element = null,
_properties: std.DoublyLinkedList = .{},
_is_computed: bool = false,
pub fn init(element: ?*Element, is_computed: bool, page: *Page) !*CSSStyleDeclaration {
const self = try page._factory.create(CSSStyleDeclaration{
._element = element,
._is_computed = is_computed,
});
// Parse the element's existing style attribute into _properties so that
// subsequent JS reads and writes see all CSS properties, not just newly
// added ones. Computed styles have no inline attribute to parse.
if (!is_computed) {
if (element) |el| {
if (el.getAttributeSafe(comptime .wrap("style"))) |attr_value| {
var it = CssParser.parseDeclarationsList(attr_value);
while (it.next()) |declaration| {
try self.setPropertyImpl(declaration.name, declaration.value, declaration.important, page);
}
}
}
}
return self;
}
pub fn length(self: *const CSSStyleDeclaration) u32 {
return @intCast(self._properties.len());
}
pub fn item(self: *const CSSStyleDeclaration, index: u32) []const u8 {
var i: u32 = 0;
var node = self._properties.first;
while (node) |n| {
if (i == index) {
const prop = Property.fromNodeLink(n);
return prop._name.str();
}
i += 1;
node = n.next;
}
return "";
}
pub fn getPropertyValue(self: *const CSSStyleDeclaration, property_name: []const u8, page: *Page) []const u8 {
const normalized = normalizePropertyName(property_name, &page.buf);
const prop = self.findProperty(normalized) orelse {
// Only return default values for computed styles
if (self._is_computed) {
return getDefaultPropertyValue(self, normalized);
}
return "";
};
return prop._value.str();
}
pub fn getPropertyPriority(self: *const CSSStyleDeclaration, property_name: []const u8, page: *Page) []const u8 {
const normalized = normalizePropertyName(property_name, &page.buf);
const prop = self.findProperty(normalized) orelse return "";
return if (prop._important) "important" else "";
}
pub fn setProperty(self: *CSSStyleDeclaration, property_name: []const u8, value: []const u8, priority_: ?[]const u8, page: *Page) !void {
// Validate priority
const priority = priority_ orelse "";
const important = if (priority.len > 0) blk: {
if (!std.ascii.eqlIgnoreCase(priority, "important")) {
return;
}
break :blk true;
} else false;
try self.setPropertyImpl(property_name, value, important, page);
try self.syncStyleAttribute(page);
}
fn setPropertyImpl(self: *CSSStyleDeclaration, property_name: []const u8, value: []const u8, important: bool, page: *Page) !void {
if (value.len == 0) {
_ = try self.removePropertyImpl(property_name, page);
return;
}
const normalized = normalizePropertyName(property_name, &page.buf);
// Find existing property
if (self.findProperty(normalized)) |existing| {
existing._value = try String.init(page.arena, value, .{});
existing._important = important;
return;
}
// Create new property
const prop = try page._factory.create(Property{
._node = .{},
._name = try String.init(page.arena, normalized, .{}),
._value = try String.init(page.arena, value, .{}),
._important = important,
});
self._properties.append(&prop._node);
}
pub fn removeProperty(self: *CSSStyleDeclaration, property_name: []const u8, page: *Page) ![]const u8 {
const result = try self.removePropertyImpl(property_name, page);
try self.syncStyleAttribute(page);
return result;
}
fn removePropertyImpl(self: *CSSStyleDeclaration, property_name: []const u8, page: *Page) ![]const u8 {
const normalized = normalizePropertyName(property_name, &page.buf);
const prop = self.findProperty(normalized) orelse return "";
// the value might not be on the heap (it could be inlined in the small string
// optimization), so we need to dupe it.
const old_value = try page.call_arena.dupe(u8, prop._value.str());
self._properties.remove(&prop._node);
page._factory.destroy(prop);
return old_value;
}
// Serialize current properties back to the element's style attribute so that
// DOM serialization (outerHTML, getAttribute) reflects JS-modified styles.
fn syncStyleAttribute(self: *CSSStyleDeclaration, page: *Page) !void {
const element = self._element orelse return;
const css_text = try self.getCssText(page);
try element.setAttributeSafe(String.wrap("style"), String.wrap(css_text), page);
}
pub fn getFloat(self: *const CSSStyleDeclaration, page: *Page) []const u8 {
return self.getPropertyValue("float", page);
}
pub fn setFloat(self: *CSSStyleDeclaration, value_: ?[]const u8, page: *Page) !void {
try self.setPropertyImpl("float", value_ orelse "", false, page);
try self.syncStyleAttribute(page);
}
pub fn getCssText(self: *const CSSStyleDeclaration, page: *Page) ![]const u8 {
if (self._element == null) return "";
var buf = std.Io.Writer.Allocating.init(page.call_arena);
try self.format(&buf.writer);
return buf.written();
}
pub fn setCssText(self: *CSSStyleDeclaration, text: []const u8, page: *Page) !void {
if (self._element == null) return;
// Clear existing properties
var node = self._properties.first;
while (node) |n| {
const next = n.next;
const prop = Property.fromNodeLink(n);
self._properties.remove(n);
page._factory.destroy(prop);
node = next;
}
// Parse and set new properties
var it = CssParser.parseDeclarationsList(text);
while (it.next()) |declaration| {
try self.setPropertyImpl(declaration.name, declaration.value, declaration.important, page);
}
try self.syncStyleAttribute(page);
}
pub fn format(self: *const CSSStyleDeclaration, writer: *std.Io.Writer) !void {
const node = self._properties.first orelse return;
try Property.fromNodeLink(node).format(writer);
var next = node.next;
while (next) |n| {
try writer.writeByte(' ');
try Property.fromNodeLink(n).format(writer);
next = n.next;
}
}
fn findProperty(self: *const CSSStyleDeclaration, name: []const u8) ?*Property {
var node = self._properties.first;
while (node) |n| {
const prop = Property.fromNodeLink(n);
if (prop._name.eqlSlice(name)) {
return prop;
}
node = n.next;
}
return null;
}
fn normalizePropertyName(name: []const u8, buf: []u8) []const u8 {
if (name.len > buf.len) {
log.info(.dom, "css.long.name", .{ .name = name });
return name;
}
return std.ascii.lowerString(buf, name);
}
fn getDefaultPropertyValue(self: *const CSSStyleDeclaration, normalized_name: []const u8) []const u8 {
if (std.mem.eql(u8, normalized_name, "visibility")) {
return "visible";
}
if (std.mem.eql(u8, normalized_name, "opacity")) {
return "1";
}
if (std.mem.eql(u8, normalized_name, "display")) {
const element = self._element orelse return "";
return getDefaultDisplay(element);
}
if (std.mem.eql(u8, normalized_name, "color")) {
const element = self._element orelse return "";
return getDefaultColor(element);
}
if (std.mem.eql(u8, normalized_name, "background-color")) {
// transparent
return "rgba(0, 0, 0, 0)";
}
return "";
}
fn getDefaultDisplay(element: *const Element) []const u8 {
switch (element._type) {
.html => |html| {
return switch (html._type) {
.anchor, .br, .span, .label, .time, .font, .mod, .quote => "inline",
.body, .div, .dl, .p, .heading, .form, .button, .canvas, .dialog, .embed, .head, .html, .hr, .iframe, .img, .input, .li, .link, .meta, .ol, .option, .script, .select, .slot, .style, .template, .textarea, .title, .ul, .media, .area, .base, .datalist, .directory, .fieldset, .legend, .map, .meter, .object, .optgroup, .output, .param, .picture, .pre, .progress, .source, .table, .table_caption, .table_cell, .table_col, .table_row, .table_section, .track => "block",
.generic, .custom, .unknown, .data => blk: {
const tag = element.getTagNameLower();
if (isInlineTag(tag)) break :blk "inline";
break :blk "block";
},
};
},
.svg => return "inline",
}
}
fn isInlineTag(tag_name: []const u8) bool {
const inline_tags = [_][]const u8{
"abbr", "b", "bdi", "bdo", "cite", "code", "dfn",
"em", "i", "kbd", "mark", "q", "s", "samp",
"small", "span", "strong", "sub", "sup", "time", "u",
"var", "wbr",
};
for (inline_tags) |inline_tag| {
if (std.mem.eql(u8, tag_name, inline_tag)) {
return true;
}
}
return false;
}
fn getDefaultColor(element: *const Element) []const u8 {
switch (element._type) {
.html => |html| {
return switch (html._type) {
.anchor => "rgb(0, 0, 238)", // blue
else => "rgb(0, 0, 0)",
};
},
.svg => return "rgb(0, 0, 0)",
}
}
pub const Property = struct {
_name: String,
_value: String,
_important: bool = false,
_node: std.DoublyLinkedList.Node,
fn fromNodeLink(n: *std.DoublyLinkedList.Node) *Property {
return @alignCast(@fieldParentPtr("_node", n));
}
pub fn format(self: *const Property, writer: *std.Io.Writer) !void {
try self._name.format(writer);
try writer.writeAll(": ");
try self._value.format(writer);
if (self._important) {
try writer.writeAll(" !important");
}
try writer.writeByte(';');
}
};
pub const JsApi = struct {
pub const bridge = js.Bridge(CSSStyleDeclaration);
pub const Meta = struct {
pub const name = "CSSStyleDeclaration";
pub const prototype_chain = bridge.prototypeChain();
pub var class_id: bridge.ClassId = undefined;
};
pub const cssText = bridge.accessor(CSSStyleDeclaration.getCssText, CSSStyleDeclaration.setCssText, .{});
pub const length = bridge.accessor(CSSStyleDeclaration.length, null, .{});
pub const item = bridge.function(_item, .{});
fn _item(self: *const CSSStyleDeclaration, index: i32) []const u8 {
if (index < 0) {
return "";
}
return self.item(@intCast(index));
}
pub const getPropertyValue = bridge.function(CSSStyleDeclaration.getPropertyValue, .{});
pub const getPropertyPriority = bridge.function(CSSStyleDeclaration.getPropertyPriority, .{});
pub const setProperty = bridge.function(CSSStyleDeclaration.setProperty, .{});
pub const removeProperty = bridge.function(CSSStyleDeclaration.removeProperty, .{});
pub const cssFloat = bridge.accessor(CSSStyleDeclaration.getFloat, CSSStyleDeclaration.setFloat, .{});
};