events: add EventTargetBase

EventTargetBase implements event target vtable for pure zig struct

src/html/window.zig

@@ -1,6 +1,9 @@
 const std = @import("std");
 
 const parser = @import("../netsurf.zig");
+const c = @cImport({
+    @cInclude("events/event_target.h");
+});
 
 const EventTarget = @import("../dom/event_target.zig").EventTarget;
 
@@ -10,6 +13,9 @@ pub const Window = struct {
     pub const prototype = *EventTarget;
     pub const mem_guarantied = true;
 
+    // Extend libdom event target for pure zig struct.
+    base: parser.EventTargetTBase = parser.EventTargetTBase{},
+
     document: ?*parser.Document = null,
     target: []const u8,
 
@@ -42,6 +48,4 @@ pub const Window = struct {
     pub fn get_name(self: *Window) []const u8 {
         return self.target;
     }
-
-    // TODO we need to re-implement EventTarget interface.
 };

src/netsurf.zig

@@ -3,6 +3,7 @@ const std = @import("std");
 const c = @cImport({
     @cInclude("dom/dom.h");
     @cInclude("dom/bindings/hubbub/parser.h");
+    @cInclude("events/event_target.h");
 });
 
 const Callback = @import("jsruntime").Callback;
@@ -622,6 +623,33 @@ pub fn eventTargetDispatchEvent(et: *EventTarget, event: *Event) !bool {
     return res;
 }
 
+// EventTargetBase is used to implement EventTarget for pure zig struct.
+pub const EventTargetTBase = struct {
+    const Self = @This();
+
+    vtable: ?*const c.struct_dom_event_target_vtable = &c.struct_dom_event_target_vtable{
+        .dispatch_event = dispatch_event,
+        .remove_event_listener = remove_event_listener,
+        .add_event_listener = add_event_listener,
+    },
+    eti: c.dom_event_target_internal = c.dom_event_target_internal{ .listeners = null },
+
+    pub fn add_event_listener(et: [*c]c.dom_event_target, t: [*c]c.dom_string, l: ?*c.struct_dom_event_listener, capture: bool) callconv(.C) c.dom_exception {
+        const self = @as(*Self, @ptrCast(et));
+        return c._dom_event_target_add_event_listener(&self.eti, t, l, capture);
+    }
+
+    pub fn dispatch_event(et: [*c]c.dom_event_target, evt: ?*c.struct_dom_event, res: [*c]bool) callconv(.C) c.dom_exception {
+        const self = @as(*Self, @ptrCast(et));
+        return c._dom_event_target_dispatch(et, &self.eti, evt, c.DOM_BUBBLING_PHASE, res);
+    }
+
+    pub fn remove_event_listener(et: [*c]c.dom_event_target, t: [*c]c.dom_string, l: ?*c.struct_dom_event_listener, capture: bool) callconv(.C) c.dom_exception {
+        const self = @as(*Self, @ptrCast(et));
+        return c._dom_event_target_add_event_listener(&self.eti, t, l, capture);
+    }
+};
+
 // NodeType
 
 pub const NodeType = enum(u4) {

src/run_tests.zig

@@ -6,6 +6,7 @@ const generate = @import("generate.zig");
 
 const parser = @import("netsurf.zig");
 const apiweb = @import("apiweb.zig");
+const Window = @import("html/window.zig").Window;
 
 const documentTestExecFn = @import("dom/document.zig").testExecFn;
 const HTMLDocumentTestExecFn = @import("html/document.zig").testExecFn;
@@ -135,3 +136,13 @@ test "run browser tests" {
 
     try dump.HTMLFileTestFn(out);
 }
+
+test "Window is a libdom event target" {
+    var window = Window.create(null);
+
+    const event = try parser.eventCreate();
+    try parser.eventInit(event, "foo", .{});
+
+    const et = @as(*parser.EventTarget, @ptrCast(&window));
+    _ = try parser.eventTargetDispatchEvent(et, event);
+}