Merge pull request #915 from lightpanda-io/css_tweaks

Tweak cssom

Author: karlseguin

src/browser/State.zig

@@ -30,8 +30,8 @@ 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;
+const StyleSheet = @import("cssom/StyleSheet.zig");
+const CSSStyleDeclaration = @import("cssom/CSSStyleDeclaration.zig");
 
 // for HTMLScript (but probably needs to be added to more)
 onload: ?Env.Function = null,

src/browser/cssom/CSSParser.zig

@@ -0,0 +1,289 @@
+// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <[email protected]>
+// Pierre Tachoire <[email protected]>
+//
+// 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 Allocator = std.mem.Allocator;
+
+const CSSConstants = struct {
+    const IMPORTANT = "!important";
+    const URL_PREFIX = "url(";
+};
+
+const CSSParserState = enum {
+    seek_name,
+    in_name,
+    seek_colon,
+    seek_value,
+    in_value,
+    in_quoted_value,
+    in_single_quoted_value,
+    in_url,
+    in_important,
+};
+
+const CSSDeclaration = struct {
+    name: []const u8,
+    value: []const u8,
+    is_important: bool,
+};
+
+const CSSParser = @This();
+state: CSSParserState,
+name_start: usize,
+name_end: usize,
+value_start: usize,
+position: usize,
+paren_depth: usize,
+escape_next: bool,
+
+pub fn init() CSSParser {
+    return .{
+        .state = .seek_name,
+        .name_start = 0,
+        .name_end = 0,
+        .value_start = 0,
+        .position = 0,
+        .paren_depth = 0,
+        .escape_next = false,
+    };
+}
+
+pub fn parseDeclarations(arena: Allocator, text: []const u8) ![]CSSDeclaration {
+    var parser = init();
+    var declarations: std.ArrayListUnmanaged(CSSDeclaration) = .empty;
+
+    while (parser.position < text.len) {
+        const c = text[parser.position];
+
+        switch (parser.state) {
+            .seek_name => {
+                if (!std.ascii.isWhitespace(c)) {
+                    parser.name_start = parser.position;
+                    parser.state = .in_name;
+                    continue;
+                }
+            },
+            .in_name => {
+                if (c == ':') {
+                    parser.name_end = parser.position;
+                    parser.state = .seek_value;
+                } else if (std.ascii.isWhitespace(c)) {
+                    parser.name_end = parser.position;
+                    parser.state = .seek_colon;
+                }
+            },
+            .seek_colon => {
+                if (c == ':') {
+                    parser.state = .seek_value;
+                } else if (!std.ascii.isWhitespace(c)) {
+                    parser.state = .seek_name;
+                    continue;
+                }
+            },
+            .seek_value => {
+                if (!std.ascii.isWhitespace(c)) {
+                    parser.value_start = parser.position;
+                    if (c == '"') {
+                        parser.state = .in_quoted_value;
+                    } else if (c == '\'') {
+                        parser.state = .in_single_quoted_value;
+                    } else if (c == 'u' and parser.position + CSSConstants.URL_PREFIX.len <= text.len and std.mem.startsWith(u8, text[parser.position..], CSSConstants.URL_PREFIX)) {
+                        parser.state = .in_url;
+                        parser.paren_depth = 1;
+                        parser.position += 3;
+                    } else {
+                        parser.state = .in_value;
+                        continue;
+                    }
+                }
+            },
+            .in_value => {
+                if (parser.escape_next) {
+                    parser.escape_next = false;
+                } else if (c == '\\') {
+                    parser.escape_next = true;
+                } else if (c == '(') {
+                    parser.paren_depth += 1;
+                } else if (c == ')' and parser.paren_depth > 0) {
+                    parser.paren_depth -= 1;
+                } else if (c == ';' and parser.paren_depth == 0) {
+                    try parser.finishDeclaration(arena, &declarations, text);
+                    parser.state = .seek_name;
+                }
+            },
+            .in_quoted_value => {
+                if (parser.escape_next) {
+                    parser.escape_next = false;
+                } else if (c == '\\') {
+                    parser.escape_next = true;
+                } else if (c == '"') {
+                    parser.state = .in_value;
+                }
+            },
+            .in_single_quoted_value => {
+                if (parser.escape_next) {
+                    parser.escape_next = false;
+                } else if (c == '\\') {
+                    parser.escape_next = true;
+                } else if (c == '\'') {
+                    parser.state = .in_value;
+                }
+            },
+            .in_url => {
+                if (parser.escape_next) {
+                    parser.escape_next = false;
+                } else if (c == '\\') {
+                    parser.escape_next = true;
+                } else if (c == '(') {
+                    parser.paren_depth += 1;
+                } else if (c == ')') {
+                    parser.paren_depth -= 1;
+                    if (parser.paren_depth == 0) {
+                        parser.state = .in_value;
+                    }
+                }
+            },
+            .in_important => {},
+        }
+
+        parser.position += 1;
+    }
+
+    try parser.finalize(arena, &declarations, text);
+
+    return declarations.items;
+}
+
+fn finishDeclaration(self: *CSSParser, arena: Allocator, declarations: *std.ArrayListUnmanaged(CSSDeclaration), text: []const u8) !void {
+    const name = std.mem.trim(u8, text[self.name_start..self.name_end], &std.ascii.whitespace);
+    if (name.len == 0) return;
+
+    const raw_value = text[self.value_start..self.position];
+    const value = std.mem.trim(u8, raw_value, &std.ascii.whitespace);
+
+    var final_value = value;
+    var is_important = false;
+
+    if (std.mem.endsWith(u8, value, CSSConstants.IMPORTANT)) {
+        is_important = true;
+        final_value = std.mem.trimRight(u8, value[0 .. value.len - CSSConstants.IMPORTANT.len], &std.ascii.whitespace);
+    }
+
+    try declarations.append(arena, .{
+        .name = name,
+        .value = final_value,
+        .is_important = is_important,
+    });
+}
+
+fn finalize(self: *CSSParser, arena: Allocator, declarations: *std.ArrayListUnmanaged(CSSDeclaration), text: []const u8) !void {
+    if (self.state != .in_value) {
+        return;
+    }
+    return self.finishDeclaration(arena, declarations, text);
+}
+
+const testing = @import("../../testing.zig");
+test "CSSParser - Simple property" {
+    defer testing.reset();
+
+    const text = "color: red;";
+    const allocator = testing.arena_allocator;
+
+    const declarations = try CSSParser.parseDeclarations(allocator, text);
+
+    try testing.expectEqual(1, declarations.len);
+    try testing.expectEqual("color", declarations[0].name);
+    try testing.expectEqual("red", declarations[0].value);
+    try testing.expectEqual(false, declarations[0].is_important);
+}
+
+test "CSSParser - Property with !important" {
+    defer testing.reset();
+    const text = "margin: 10px !important;";
+    const allocator = testing.arena_allocator;
+
+    const declarations = try CSSParser.parseDeclarations(allocator, text);
+
+    try testing.expectEqual(1, declarations.len);
+    try testing.expectEqual("margin", declarations[0].name);
+    try testing.expectEqual("10px", declarations[0].value);
+    try testing.expectEqual(true, declarations[0].is_important);
+}
+
+test "CSSParser - Multiple properties" {
+    defer testing.reset();
+    const text = "color: red; font-size: 12px; margin: 5px !important;";
+    const allocator = testing.arena_allocator;
+
+    const declarations = try CSSParser.parseDeclarations(allocator, text);
+
+    try testing.expect(declarations.len == 3);
+
+    try testing.expectEqual("color", declarations[0].name);
+    try testing.expectEqual("red", declarations[0].value);
+    try testing.expectEqual(false, declarations[0].is_important);
+
+    try testing.expectEqual("font-size", declarations[1].name);
+    try testing.expectEqual("12px", declarations[1].value);
+    try testing.expectEqual(false, declarations[1].is_important);
+
+    try testing.expectEqual("margin", declarations[2].name);
+    try testing.expectEqual("5px", declarations[2].value);
+    try testing.expectEqual(true, declarations[2].is_important);
+}
+
+test "CSSParser - Quoted value with semicolon" {
+    defer testing.reset();
+    const text = "content: \"Hello; world!\";";
+    const allocator = testing.arena_allocator;
+
+    const declarations = try CSSParser.parseDeclarations(allocator, text);
+
+    try testing.expectEqual(1, declarations.len);
+    try testing.expectEqual("content", declarations[0].name);
+    try testing.expectEqual("\"Hello; world!\"", declarations[0].value);
+    try testing.expectEqual(false, declarations[0].is_important);
+}
+
+test "CSSParser - URL value" {
+    defer testing.reset();
+    const text = "background-image: url(\"test.png\");";
+    const allocator = testing.arena_allocator;
+
+    const declarations = try CSSParser.parseDeclarations(allocator, text);
+
+    try testing.expectEqual(1, declarations.len);
+    try testing.expectEqual("background-image", declarations[0].name);
+    try testing.expectEqual("url(\"test.png\")", declarations[0].value);
+    try testing.expectEqual(false, declarations[0].is_important);
+}
+
+test "CSSParser - Whitespace handling" {
+    defer testing.reset();
+    const text = "  color  :  purple  ;  margin  :  10px  ;  ";
+    const allocator = testing.arena_allocator;
+
+    const declarations = try CSSParser.parseDeclarations(allocator, text);
+
+    try testing.expectEqual(2, declarations.len);
+    try testing.expectEqual("color", declarations[0].name);
+    try testing.expectEqual("purple", declarations[0].value);
+    try testing.expectEqual("margin", declarations[1].name);
+    try testing.expectEqual("10px", declarations[1].value);
+}

src/browser/cssom/css_rule.zig renamed to src/browser/cssom/CSSRule.zig

@@ -18,19 +18,18 @@
 
 const std = @import("std");
 
-const CSSStyleSheet = @import("css_stylesheet.zig").CSSStyleSheet;
+const CSSStyleSheet = @import("CSSStyleSheet.zig");
 
 pub const Interfaces = .{
     CSSRule,
     CSSImportRule,
 };
 
 // https://developer.mozilla.org/en-US/docs/Web/API/CSSRule
-pub const CSSRule = struct {
-    css_text: []const u8,
-    parent_rule: ?*CSSRule = null,
-    parent_stylesheet: ?*CSSStyleSheet = null,
-};
+const CSSRule = @This();
+css_text: []const u8,
+parent_rule: ?*CSSRule = null,
+parent_stylesheet: ?*CSSStyleSheet = null,
 
 pub const CSSImportRule = struct {
     pub const prototype = *CSSRule;

src/browser/cssom/css_rule_list.zig renamed to src/browser/cssom/CSSRuleList.zig

@@ -18,33 +18,33 @@
 
 const std = @import("std");
 
-const StyleSheet = @import("stylesheet.zig").StyleSheet;
-const CSSRule = @import("css_rule.zig").CSSRule;
-const CSSImportRule = @import("css_rule.zig").CSSImportRule;
+const CSSRule = @import("CSSRule.zig");
+const StyleSheet = @import("StyleSheet.zig").StyleSheet;
 
-pub const CSSRuleList = struct {
-    list: std.ArrayListUnmanaged([]const u8),
+const CSSImportRule = CSSRule.CSSImportRule;
 
-    pub fn constructor() CSSRuleList {
-        return .{ .list = .empty };
-    }
+const CSSRuleList = @This();
+list: std.ArrayListUnmanaged([]const u8),
 
-    pub fn _item(self: *CSSRuleList, _index: u32) ?CSSRule {
-        const index: usize = @intCast(_index);
+pub fn constructor() CSSRuleList {
+    return .{ .list = .empty };
+}
 
-        if (index > self.list.items.len) {
-            return null;
-        }
+pub fn _item(self: *CSSRuleList, _index: u32) ?CSSRule {
+    const index: usize = @intCast(_index);
 
-        // todo: for now, just return null.
-        // this depends on properly parsing CSSRule
+    if (index > self.list.items.len) {
         return null;
     }
 
-    pub fn get_length(self: *CSSRuleList) u32 {
-        return @intCast(self.list.items.len);
-    }
-};
+    // todo: for now, just return null.
+    // this depends on properly parsing CSSRule
+    return null;
+}
+
+pub fn get_length(self: *CSSRuleList) u32 {
+    return @intCast(self.list.items.len);
+}
 
 const testing = @import("../../testing.zig");
 test "Browser.CSS.CSSRuleList" {