Merge pull request #180 from lightpanda-io/eventtarget

Enforce EventTarget casting by using EventTargetTBase if available
This commit is contained in:
Pierre Tachoire
2024-02-15 16:48:07 +01:00
committed by GitHub
2 changed files with 38 additions and 3 deletions

View File

@@ -474,10 +474,20 @@ fn eventListenerGetData(lst: *EventListener) ?*anyopaque {
pub const EventTarget = c.dom_event_target; pub const EventTarget = c.dom_event_target;
fn eventTargetVtable(et: *EventTarget) c.dom_event_target_vtable { fn eventTargetVtable(et: *EventTarget) c.dom_event_target_vtable {
return getVtable(c.dom_event_target_vtable, EventTarget, et); // retrieve the vtable
const vtable = et.*.vtable.?;
// align correctly the vtable
const vtable_aligned: *align(@alignOf([*c]c.dom_event_target_vtable)) const anyopaque = @alignCast(vtable);
// convert the vtable to it's actual type and return it
return @as([*c]const c.dom_event_target_vtable, @ptrCast(vtable_aligned)).*;
} }
pub inline fn toEventTarget(comptime T: type, v: *T) *EventTarget { pub inline fn toEventTarget(comptime T: type, v: *T) *EventTarget {
if (comptime eventTargetTBaseFieldName(T)) |field| {
const et_aligned: *align(@alignOf(EventTarget)) EventTargetTBase = @alignCast(&@field(v, field));
return @as(*EventTarget, @ptrCast(et_aligned));
}
const et_aligned: *align(@alignOf(EventTarget)) T = @alignCast(v); const et_aligned: *align(@alignOf(EventTarget)) T = @alignCast(v);
return @as(*EventTarget, @ptrCast(et_aligned)); return @as(*EventTarget, @ptrCast(et_aligned));
} }
@@ -628,8 +638,22 @@ pub fn eventTargetDispatchEvent(et: *EventTarget, event: *Event) !bool {
return res; return res;
} }
pub fn eventTargetTBaseFieldName(comptime T: type) ?[]const u8 {
std.debug.assert(@inComptime());
switch (@typeInfo(T)) {
.Struct => |ti| {
for (ti.fields) |f| {
if (f.type == EventTargetTBase) return f.name;
}
},
else => {},
}
return null;
}
// EventTargetBase is used to implement EventTarget for pure zig struct. // EventTargetBase is used to implement EventTarget for pure zig struct.
pub const EventTargetTBase = struct { pub const EventTargetTBase = extern struct {
const Self = @This(); const Self = @This();
vtable: ?*const c.struct_dom_event_target_vtable = &c.struct_dom_event_target_vtable{ vtable: ?*const c.struct_dom_event_target_vtable = &c.struct_dom_event_target_vtable{

View File

@@ -143,6 +143,17 @@ test "Window is a libdom event target" {
const event = try parser.eventCreate(); const event = try parser.eventCreate();
try parser.eventInit(event, "foo", .{}); try parser.eventInit(event, "foo", .{});
const et = @as(*parser.EventTarget, @ptrCast(&window)); const et = parser.toEventTarget(Window, &window);
_ = try parser.eventTargetDispatchEvent(et, event);
}
test "DocumentHTML is a libdom event target" {
doc = try parser.documentHTMLParseFromStr("<body></body>");
parser.documentHTMLClose(doc) catch {};
const event = try parser.eventCreate();
try parser.eventInit(event, "foo", .{});
const et = parser.toEventTarget(parser.DocumentHTML, doc);
_ = try parser.eventTargetDispatchEvent(et, event); _ = try parser.eventTargetDispatchEvent(et, event);
} }