NodeIterator

src/browser/dom/document.zig

@@ -33,6 +33,7 @@ const Element = @import("element.zig").Element;
 const ElementUnion = @import("element.zig").Union;
 const TreeWalker = @import("tree_walker.zig").TreeWalker;
 const CSSStyleSheet = @import("../cssom/css_stylesheet.zig").CSSStyleSheet;
+const NodeIterator = @import("node_iterator.zig").NodeIterator;
 const Range = @import("range.zig").Range;
 
 const Env = @import("../env.zig").Env;
@@ -265,6 +266,10 @@ pub const Document = struct {
         return try TreeWalker.init(root, what_to_show, filter);
     }
 
+    pub fn _createNodeIterator(_: *parser.Document, root: *parser.Node, what_to_show: ?u32, filter: ?TreeWalker.TreeWalkerOpts) !NodeIterator {
+        return try NodeIterator.init(root, what_to_show, filter);
+    }
+
     pub fn getActiveElement(self: *parser.Document, page: *Page) !?*parser.Element {
         if (page.getNodeState(@alignCast(@ptrCast(self)))) |state| {
             if (state.active_element) |ae| {

src/browser/dom/dom.zig

@@ -28,6 +28,7 @@ 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;
+const NodeIterator = @import("node_iterator.zig").NodeIterator;
 const NodeFilter = @import("node_filter.zig").NodeFilter;
 const PerformanceObserver = @import("performance_observer.zig").PerformanceObserver;
 
@@ -46,6 +47,7 @@ pub const Interfaces = .{
     IntersectionObserver.Interfaces,
     DOMParser,
     TreeWalker,
+    NodeIterator,
     NodeFilter,
     @import("performance.zig").Interfaces,
     PerformanceObserver,

src/browser/dom/node_filter.zig

@@ -22,6 +22,7 @@ pub const NodeFilter = struct {
     pub const _FILTER_ACCEPT: u16 = 1;
     pub const _FILTER_REJECT: u16 = 2;
     pub const _FILTER_SKIP: u16 = 3;
+
     pub const _SHOW_ALL: u32 = std.math.maxInt(u32);
     pub const _SHOW_ELEMENT: u32 = 0b1;
     pub const _SHOW_ATTRIBUTE: u32 = 0b10;

src/browser/dom/node_iterator.zig

@@ -0,0 +1,213 @@
+// 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 parser = @import("../netsurf.zig");
+const Env = @import("../env.zig").Env;
+const TreeWalker = @import("tree_walker.zig").TreeWalker;
+
+// https://developer.mozilla.org/en-US/docs/Web/API/NodeIterator
+pub const NodeIterator = struct {
+    walker: TreeWalker,
+    pointer_before_current: bool = true,
+
+    pub fn init(node: *parser.Node, what_to_show: ?u32, filter: ?TreeWalker.TreeWalkerOpts) !NodeIterator {
+        return .{ .walker = try TreeWalker.init(node, what_to_show, filter) };
+    }
+
+    pub fn get_filter(self: *const NodeIterator) ?Env.Function {
+        return self.walker.filter;
+    }
+
+    pub fn get_pointerBeforeReferenceNode(self: *const NodeIterator) bool {
+        return self.pointer_before_current;
+    }
+
+    pub fn get_referenceNode(self: *const NodeIterator) *parser.Node {
+        return self.walker.current_node;
+    }
+
+    pub fn get_root(self: *const NodeIterator) *parser.Node {
+        return self.walker.root;
+    }
+
+    pub fn get_whatToShow(self: *const NodeIterator) u32 {
+        return self.walker.what_to_show;
+    }
+
+    pub fn _nextNode(self: *NodeIterator) !?*parser.Node {
+        if (self.pointer_before_current) { // Unlike TreeWalker, NodeIterator starts at the first node
+            self.pointer_before_current = false;
+            if (.accept == try self.walker.verify(self.walker.current_node)) {
+                return self.walker.current_node;
+            }
+        }
+
+        if (try self.firstChild(self.walker.current_node)) |child| {
+            self.walker.current_node = child;
+            return child;
+        }
+
+        var current = self.walker.current_node;
+        while (current != self.walker.root) {
+            if (try self.walker.nextSibling(current)) |sibling| {
+                self.walker.current_node = sibling;
+                return sibling;
+            }
+
+            current = (try parser.nodeParentNode(current)) orelse break;
+        }
+
+        return null;
+    }
+
+    pub fn _previousNode(self: *NodeIterator) !?*parser.Node {
+        if (!self.pointer_before_current) {
+            self.pointer_before_current = true;
+            if (.accept == try self.walker.verify(self.walker.current_node)) {
+                return self.walker.current_node; // Still need to verify as last may be first as well
+            }
+        }
+        if (self.walker.current_node == self.walker.root) return null;
+
+        var current = self.walker.current_node;
+        while (try parser.nodePreviousSibling(current)) |previous| {
+            current = previous;
+
+            switch (try self.walker.verify(current)) {
+                .accept => {
+                    // Get last child if it has one.
+                    if (try self.lastChild(current)) |child| {
+                        self.walker.current_node = child;
+                        return child;
+                    }
+
+                    // Otherwise, this node is our previous one.
+                    self.walker.current_node = current;
+                    return current;
+                },
+                .reject, .skip => {
+                    // Get last child if it has one.
+                    if (try self.lastChild(current)) |child| {
+                        self.walker.current_node = child;
+                        return child;
+                    }
+                },
+            }
+        }
+
+        if (current != self.walker.root) {
+            if (try self.walker.parentNode(current)) |parent| {
+                self.walker.current_node = parent;
+                return parent;
+            }
+        }
+
+        return null;
+    }
+
+    fn firstChild(self: *const NodeIterator, node: *parser.Node) !?*parser.Node {
+        const children = try parser.nodeGetChildNodes(node);
+        const child_count = try parser.nodeListLength(children);
+
+        for (0..child_count) |i| {
+            const index: u32 = @intCast(i);
+            const child = (try parser.nodeListItem(children, index)) orelse return null;
+
+            switch (try self.walker.verify(child)) {
+                .accept => return child, // NOTE: Skip and reject are equivalent for NodeIterator, this is different from TreeWalker
+                .reject, .skip => if (try self.firstChild(child)) |gchild| return gchild,
+            }
+        }
+
+        return null;
+    }
+
+    fn lastChild(self: *const NodeIterator, node: *parser.Node) !?*parser.Node {
+        const children = try parser.nodeGetChildNodes(node);
+        const child_count = try parser.nodeListLength(children);
+
+        var index: u32 = child_count;
+        while (index > 0) {
+            index -= 1;
+            const child = (try parser.nodeListItem(children, index)) orelse return null;
+
+            switch (try self.walker.verify(child)) {
+                .accept => return child, // NOTE: Skip and reject are equivalent for NodeIterator, this is different from TreeWalker
+                .reject, .skip => if (try self.lastChild(child)) |gchild| return gchild,
+            }
+        }
+
+        return null;
+    }
+};
+
+const testing = @import("../../testing.zig");
+test "Browser.DOM.NodeFilter" {
+    var runner = try testing.jsRunner(testing.tracking_allocator, .{});
+    defer runner.deinit();
+
+    try runner.testCases(&.{
+        .{
+            \\ const nodeIterator = document.createNodeIterator(
+            \\   document.body,
+            \\   NodeFilter.SHOW_ELEMENT,
+            \\   {
+            \\     acceptNode(node) {
+            \\       return NodeFilter.FILTER_ACCEPT;
+            \\     },
+            \\   },
+            \\ );
+            \\ nodeIterator.nextNode().nodeName;
+            ,
+            "BODY",
+        },
+        .{ "nodeIterator.nextNode().nodeName", "DIV" },
+        .{ "nodeIterator.nextNode().nodeName", "A" },
+        .{ "nodeIterator.previousNode().nodeName", "A" }, // pointer_before_current flips
+        .{ "nodeIterator.nextNode().nodeName", "A" }, // pointer_before_current flips
+        .{ "nodeIterator.previousNode().nodeName", "A" }, // pointer_before_current flips
+        .{ "nodeIterator.previousNode().nodeName", "DIV" },
+        .{ "nodeIterator.previousNode().nodeName", "BODY" },
+        .{ "nodeIterator.previousNode()", "null" }, // Not HEAD since body is root
+        .{ "nodeIterator.previousNode()", "null" }, // Keeps returning null
+        .{ "nodeIterator.nextNode().nodeName", "BODY" },
+
+        .{ "nodeIterator.nextNode().nodeName", null },
+        .{ "nodeIterator.nextNode().nodeName", null },
+        .{ "nodeIterator.nextNode().nodeName", null },
+        .{ "nodeIterator.nextNode().nodeName", "SPAN" },
+        .{ "nodeIterator.nextNode().nodeName", "P" },
+        .{ "nodeIterator.nextNode()", "null" }, // Just the last one
+        .{ "nodeIterator.nextNode()", "null" }, // Keeps returning null
+        .{ "nodeIterator.previousNode().nodeName", "P" },
+    }, .{});
+
+    try runner.testCases(&.{
+        .{
+            \\ const notationIterator = document.createNodeIterator(
+            \\   document.body,
+            \\   NodeFilter.SHOW_NOTATION,
+            \\ );
+            \\ notationIterator.nextNode();
+            ,
+            "null",
+        },
+        .{ "notationIterator.previousNode()", "null" },
+    }, .{});
+}

src/browser/dom/tree_walker.zig

@@ -55,7 +55,7 @@ pub const TreeWalker = struct {
 
     const VerifyResult = enum { accept, skip, reject };
 
-    fn verify(self: *const TreeWalker, node: *parser.Node) !VerifyResult {
+    pub fn verify(self: *const TreeWalker, node: *parser.Node) !VerifyResult {
         const node_type = try parser.nodeType(node);
         const what_to_show = self.what_to_show;
 
@@ -77,7 +77,7 @@ pub const TreeWalker = struct {
 
         // Verify that we aren't filtering it out.
         if (self.filter) |f| {
-            const filter = try f.call(u32, .{node});
+            const filter = try f.call(u16, .{node});
             return switch (filter) {
                 NodeFilter._FILTER_ACCEPT => .accept,
                 NodeFilter._FILTER_REJECT => .reject,
@@ -144,7 +144,7 @@ pub const TreeWalker = struct {
         return null;
     }
 
-    fn nextSibling(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
+    pub fn nextSibling(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
         var current = node;
 
         while (true) {
@@ -174,7 +174,7 @@ pub const TreeWalker = struct {
         return null;
     }
 
-    fn parentNode(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
+    pub fn parentNode(self: *const TreeWalker, node: *parser.Node) !?*parser.Node {
         if (self.root == node) return null;
 
         var current = node;
@@ -245,6 +245,8 @@ pub const TreeWalker = struct {
     }
 
     pub fn _previousNode(self: *TreeWalker) !?*parser.Node {
+        if (self.current_node == self.root) return null;
+
         var current = self.current_node;
         while (try parser.nodePreviousSibling(current)) |previous| {
             current = previous;

src/browser/html/window.zig

@@ -360,7 +360,7 @@ const TimerCallback = struct {
         }
 
         call catch {
-            log.debug(.user_script, "callback error", .{
+            log.warn(.user_script, "callback error", .{
                 .err = result.exception,
                 .stack = result.stack,
                 .source = "window timeout",