add TreeWalker

Author: mookums

src/browser/dom/document.zig

@@ -30,6 +30,9 @@ const css = @import("css.zig");
 
 const Element = @import("element.zig").Element;
 const ElementUnion = @import("element.zig").Union;
+const TreeWalker = @import("tree_walker.zig").TreeWalker;
+
+const Env = @import("../env.zig").Env;
 
 const DOMImplementation = @import("implementation.zig").DOMImplementation;
 
@@ -238,6 +241,10 @@ pub const Document = struct {
     pub fn _replaceChildren(self: *parser.Document, nodes: []const Node.NodeOrText) !void {
         return Node.replaceChildren(parser.documentToNode(self), nodes);
     }
+
+    pub fn _createTreeWalker(_: *parser.Document, root: *parser.Node, what_to_show: ?u32, filter: ?Env.Callback) TreeWalker {
+        return TreeWalker.init(root, what_to_show, filter);
+    }
 };
 
 const testing = @import("../../testing.zig");

src/browser/dom/dom.zig

@@ -26,6 +26,7 @@ const Node = @import("node.zig");
 const MutationObserver = @import("mutation_observer.zig");
 const IntersectionObserver = @import("intersection_observer.zig");
 const DOMParser = @import("dom_parser.zig").DOMParser;
+const TreeWalker = @import("tree_walker.zig").TreeWalker;
 
 pub const Interfaces = .{
     DOMException,
@@ -39,4 +40,5 @@ pub const Interfaces = .{
     MutationObserver.Interfaces,
     IntersectionObserver.Interfaces,
     DOMParser,
+    TreeWalker,
 };

src/browser/dom/tree_walker.zig

@@ -0,0 +1,94 @@
+// 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 parser = @import("../netsurf.zig");
+
+const NodeFilter = @import("node_filter.zig").NodeFilter;
+const Env = @import("../env.zig").Env;
+
+// https://developer.mozilla.org/en-US/docs/Web/API/TreeWalker
+pub const TreeWalker = struct {
+    root: *parser.Node,
+    current_node: *parser.Node,
+    what_to_show: u32,
+    filter: ?Env.Callback,
+
+    pub fn init(node: *parser.Node, what_to_show: ?u32, filter: ?Env.Callback) TreeWalker {
+        return .{
+            .root = node,
+            .current_node = node,
+            .what_to_show = what_to_show orelse NodeFilter._SHOW_ALL,
+            .filter = filter,
+        };
+    }
+
+    pub fn get_root(self: *TreeWalker) *parser.Node {
+        return self.root;
+    }
+
+    pub fn get_currentNode(self: *TreeWalker) *parser.Node {
+        return self.current_node;
+    }
+
+    pub fn get_whatToShow(self: *TreeWalker) u32 {
+        return self.what_to_show;
+    }
+
+    pub fn get_filter(self: *TreeWalker) ?Env.Callback {
+        return self.filter;
+    }
+
+    pub fn _firstChild(self: *TreeWalker) ?*parser.Node {
+        const first_child = parser.nodeFirstChild(self.current_node) catch return null;
+        self.current_node = first_child orelse return null;
+        return first_child;
+    }
+
+    pub fn _lastChild(self: *TreeWalker) ?*parser.Node {
+        const last_child = parser.nodeLastChild(self.current_node) catch return null;
+        self.current_node = last_child orelse return null;
+        return last_child;
+    }
+
+    pub fn _nextNode(self: *TreeWalker) ?*parser.Node {
+        return self._firstChild();
+    }
+
+    pub fn _nextSibling(self: *TreeWalker) ?*parser.Node {
+        const next_sibling = parser.nodeNextSibling(self.current_node) catch return null;
+        self.current_node = next_sibling orelse return null;
+        return next_sibling;
+    }
+
+    pub fn _parentNode(self: *TreeWalker) ?*parser.Node {
+        const parent = parser.nodeParentNode(self.current_node) catch return null;
+        self.current_node = parent orelse return null;
+        return parent;
+    }
+
+    pub fn _previousNode(self: *TreeWalker) ?*parser.Node {
+        return self._parentNode();
+    }
+
+    pub fn _previousSibling(self: *TreeWalker) ?*parser.Node {
+        const previous_sibling = parser.nodePreviousSibling(self.current_node) catch return null;
+        self.current_node = previous_sibling orelse return null;
+        return previous_sibling;
+    }
+};