Add further HMTL element prototype hierarchy. Add HTMLImageElement.width getter/setter that interacts with layout.

This commit is contained in:
Josh Matthews 2012-08-21 22:42:38 -07:00
parent bfec29d86f
commit 07c17fdef4
13 changed files with 250 additions and 211 deletions

@ -1 +1 @@
Subproject commit 1a01c0063a4f0cd5ceaf04fbd84a59699f668a02
Subproject commit 9bf630c5f2035a29e7ccee0ca94e9c4568815f7b

View file

@ -136,7 +136,7 @@ struct Content<C:Compositor> {
#debug["js_scripts: %?", js_scripts];
let document = Document(root, css_rules);
let window = Window(root);
let window = Window();
self.relayout(document, &url);
self.document = some(@document);
self.window = some(@window);

View file

@ -16,9 +16,9 @@ import std::arc::arc;
import style::Stylesheet;
struct Window {
let root: Node;
new(root: Node) {
self.root = root;
let unused: int;
new() {
self.unused = 0;
}
}
@ -81,6 +81,7 @@ fn define_bindings(compartment: bare_compartment, doc: @Document,
bindings::window::init(compartment, win);
bindings::document::init(compartment, doc);
bindings::node::init(compartment);
bindings::element::init(compartment);
}
enum ElementKind {

View file

@ -10,10 +10,10 @@ import js::crust::{JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub, JS_
import result::{result, ok, err};
import ptr::null;
import libc::c_uint;
import utils::{DOMString, domstring_to_jsval, rust_box, squirrel_away, str,
Document_class};
import utils::{DOMString, domstring_to_jsval, rust_box, squirrel_away, str};
import bindings::node::create;
import base::{Document, Node};
import base::Document;
import option::{some, none};
enum DOMException {
INVALID_CHARACTER_ERR
@ -60,8 +60,6 @@ enum Element = int;
return 1;
}*/
// Unfortunately duplicated in document and window.
// Generalizing it triggers a trans bug
extern fn getDocumentElement(cx: *JSContext, obj: *JSObject, _id: jsid, rval: *mut jsval) -> JSBool unsafe {
let node = (*unwrap(obj)).payload.root;
*rval = RUST_OBJECT_TO_JSVAL(node::create(cx, node).ptr);
@ -83,50 +81,7 @@ extern fn finalize(_fop: *JSFreeOp, obj: *JSObject) {
}
fn init(compartment: bare_compartment, doc: @Document) {
fn DocumentProto_class(compartment: bare_compartment) -> JSClass {
{name: compartment.add_name(~"DOMDocumentPrototype"),
flags: 0,
addProperty: JS_PropertyStub,
delProperty: JS_PropertyStub,
getProperty: JS_PropertyStub,
setProperty: JS_StrictPropertyStub,
enumerate: JS_EnumerateStub,
resolve: JS_ResolveStub,
convert: JS_ConvertStub,
finalize: null(),
checkAccess: null(),
call: null(),
construct: null(),
hasInstance: utils::has_instance,
trace: null(),
reserved: (null(), null(), null(), null(), null(), // 05
null(), null(), null(), null(), null(), // 10
null(), null(), null(), null(), null(), // 15
null(), null(), null(), null(), null(), // 20
null(), null(), null(), null(), null(), // 25
null(), null(), null(), null(), null(), // 30
null(), null(), null(), null(), null(), // 35
null(), null(), null(), null(), null())} // 40
};
compartment.register_class(DocumentProto_class);
compartment.register_class(|c| Document_class(c, ~"DOMDocument",
finalize));
//TODO error checking
let obj = result::unwrap(
compartment.new_object(~"DOMDocumentPrototype",
null(),
compartment.global_obj.ptr));
/*let methods = ~[
{name: compartment.add_name("getDocumentURI"),
call: getDocumentURI,
nargs: 0,
flags: 0}];
vec::as_buf(methods, |fns| {
JS_DefineFunctions(compartment.cx.ptr, obj.ptr, fns);
});*/
let obj = utils::define_empty_prototype(~"Document", none, compartment);
let attrs = @~[
{name: compartment.add_name(~"documentElement"),
@ -139,13 +94,10 @@ fn init(compartment: bare_compartment, doc: @Document) {
JS_DefineProperties(compartment.cx.ptr, obj.ptr, specs);
});
compartment.define_property(~"Document", RUST_OBJECT_TO_JSVAL(obj.ptr),
JS_PropertyStub, JS_StrictPropertyStub,
JSPROP_ENUMERATE);
compartment.register_class(utils::instance_jsclass(~"DocumentInstance", finalize));
let instance = result::unwrap(
//compartment.new_object(Document_class, null(), compartment.global_obj.ptr));
compartment.new_object_with_proto(~"DOMDocument", ~"DOMDocumentPrototype",
compartment.new_object_with_proto(~"DocumentInstance", ~"Document",
compartment.global_obj.ptr));
unsafe {

View file

@ -0,0 +1,145 @@
import js::rust::{bare_compartment, methods, jsobj};
import js::{JS_ARGV, JSCLASS_HAS_RESERVED_SLOTS, JSPROP_ENUMERATE, JSPROP_SHARED, JSVAL_NULL,
JS_THIS_OBJECT, JS_SET_RVAL};
import js::jsapi::{JSContext, jsval, JSObject, JSBool, jsid, JSClass, JSFreeOp, JSPropertySpec};
import js::jsapi::bindgen::{JS_ValueToString, JS_GetStringCharsZAndLength, JS_ReportError,
JS_GetReservedSlot, JS_SetReservedSlot, JS_NewStringCopyN,
JS_DefineFunctions, JS_DefineProperty, JS_GetContextPrivate};
import js::jsapi::bindgen::*;
import js::glue::bindgen::*;
import js::crust::{JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub, JS_ConvertStub};
import dom::base::{Node, Element};
import utils::{rust_box, squirrel_away_unique, get_compartment, domstring_to_jsval, str};
import libc::c_uint;
import ptr::null;
import node::unwrap;
import dom::base::{HTMLImageElement, HTMLScriptElement, HTMLHeadElement, HTMLDivElement,
UnknownElement};
import gfx::geometry::{au_to_px, px_to_au};
extern fn finalize(_fop: *JSFreeOp, obj: *JSObject) {
#debug("element finalize!");
unsafe {
let val = JS_GetReservedSlot(obj, 0);
let _node: ~Node = unsafe::reinterpret_cast(RUST_JSVAL_TO_PRIVATE(val));
}
}
fn init(compartment: bare_compartment) {
let obj = utils::define_empty_prototype(~"Element", some(~"Node"), compartment);
let attrs = @~[
{name: compartment.add_name(~"tagName"),
tinyid: 0,
flags: 0,
getter: getTagName,
setter: null()}];
vec::push(compartment.global_props, attrs);
vec::as_buf(*attrs, |specs, _len| {
JS_DefineProperties(compartment.cx.ptr, obj.ptr, specs);
});
compartment.register_class(utils::instance_jsclass(~"GenericElementInstance",
finalize));
let _ = utils::define_empty_prototype(~"HTMLElement", some(~"Element"), compartment);
let _ = utils::define_empty_prototype(~"HTMLDivElement", some(~"HTMLElement"), compartment);
let _ = utils::define_empty_prototype(~"HTMLScriptElement", some(~"HTMLElement"), compartment);
let _ = utils::define_empty_prototype(~"HTMLHeadElement", some(~"HTMLElement"), compartment);
let obj = utils::define_empty_prototype(~"HTMLImageElement", some(~"HTMLElement"), compartment);
let attrs = @~[
{name: compartment.add_name(~"width"),
tinyid: 0,
flags: (JSPROP_SHARED | JSPROP_ENUMERATE) as u8,
getter: HTMLImageElement_getWidth,
setter: HTMLImageElement_setWidth}];
vec::push(compartment.global_props, attrs);
vec::as_buf(*attrs, |specs, _len| {
JS_DefineProperties(compartment.cx.ptr, obj.ptr, specs);
});
}
extern fn HTMLImageElement_getWidth(_cx: *JSContext, obj: *JSObject, _id: jsid,
rval: *mut jsval) -> JSBool unsafe {
let width = (*unwrap(obj)).payload.read(|nd| {
match nd.kind {
~Element(ed) => {
match ed.kind {
~HTMLImageElement(img) => img.size.width,
_ => fail ~"why is this not an image element?"
}
}
_ => fail ~"why is this not an element?"
}
});
*rval = RUST_INT_TO_JSVAL(
(au_to_px(width) & (i32::max_value as int)) as libc::c_int);
return 1;
}
extern fn HTMLImageElement_setWidth(_cx: *JSContext, obj: *JSObject, _id: jsid,
_strict: JSBool, vp: *jsval) -> JSBool unsafe {
let width = (*unwrap(obj)).payload.read(|nd| {
match nd.kind {
~Element(ed) => {
match ed.kind {
~HTMLImageElement(img) =>
img.size.width = px_to_au(RUST_JSVAL_TO_INT(*vp) as int),
_ => fail ~"why is this not an image element?"
}
}
_ => fail ~"why is this not an element?"
}
});
return 1;
}
extern fn getTagName(cx: *JSContext, obj: *JSObject, _id: jsid, rval: *mut jsval)
-> JSBool {
unsafe {
(*unwrap(obj)).payload.read(|nd| {
match nd.kind {
~Element(ed) => {
let s = str(copy ed.tag_name);
*rval = domstring_to_jsval(cx, s);
}
_ => {
//XXXjdm should probably read the spec to figure out what to do here
*rval = JSVAL_NULL;
}
}
});
}
return 1;
}
fn create(cx: *JSContext, node: Node) -> jsobj unsafe {
let proto = node.read(|nd| {
match nd.kind {
~Element(ed) => {
match ed.kind {
~HTMLDivElement(*) => ~"HTMLDivElement",
~HTMLHeadElement(*) => ~"HTMLHeadElement",
~HTMLImageElement(*) => ~"HTMLImageElement",
~HTMLScriptElement(*) => ~"HTMLScriptElement",
~UnknownElement(*) => ~"HTMLElement"
}
}
_ => fail ~"element::create only handles elements"
}
});
//XXXjdm the parent should probably be the node parent instead of the global
//TODO error checking
let compartment = utils::get_compartment(cx);
let obj = result::unwrap(
(*compartment).new_object_with_proto(~"GenericElementInstance", proto,
(*compartment).global_obj.ptr));
unsafe {
let raw_ptr: *libc::c_void = unsafe::reinterpret_cast(squirrel_away_unique(~node));
JS_SetReservedSlot(obj.ptr, 0, RUST_PRIVATE_TO_JSVAL(raw_ptr));
}
return obj;
}

View file

@ -9,78 +9,14 @@ import js::jsapi::bindgen::*;
import js::glue::bindgen::*;
import js::crust::{JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub, JS_ConvertStub};
import dom::base::{Node, Element};
import dom::base::{Node, Element, Text};
import utils::{rust_box, squirrel_away_unique, get_compartment, domstring_to_jsval, str};
import libc::c_uint;
import ptr::null;
extern fn finalize(_fop: *JSFreeOp, obj: *JSObject) {
#debug("node finalize!");
unsafe {
let val = JS_GetReservedSlot(obj, 0);
let _node: ~Node = unsafe::reinterpret_cast(RUST_JSVAL_TO_PRIVATE(val));
}
}
fn init(compartment: bare_compartment) {
fn NodeProto_class(compartment: bare_compartment) -> JSClass {
{name: compartment.add_name(~"NodePrototype"),
flags: 0,
addProperty: JS_PropertyStub,
delProperty: JS_PropertyStub,
getProperty: JS_PropertyStub,
setProperty: JS_StrictPropertyStub,
enumerate: JS_EnumerateStub,
resolve: JS_PropertyStub,
convert: JS_ConvertStub,
finalize: null(),
checkAccess: null(),
call: null(),
construct: null(),
hasInstance: utils::has_instance,
trace: null(),
reserved: (null(), null(), null(), null(), null(), // 05
null(), null(), null(), null(), null(), // 10
null(), null(), null(), null(), null(), // 15
null(), null(), null(), null(), null(), // 20
null(), null(), null(), null(), null(), // 25
null(), null(), null(), null(), null(), // 30
null(), null(), null(), null(), null(), // 35
null(), null(), null(), null(), null())} // 40
};
let obj = utils::define_empty_prototype(~"Node", none, compartment);
fn Node_class(compartment: bare_compartment) -> JSClass {
{name: compartment.add_name(~"Node"),
flags: JSCLASS_HAS_RESERVED_SLOTS(1),
addProperty: JS_PropertyStub,
delProperty: JS_PropertyStub,
getProperty: JS_PropertyStub,
setProperty: JS_StrictPropertyStub,
enumerate: JS_EnumerateStub,
resolve: JS_PropertyStub,
convert: JS_ConvertStub,
finalize: finalize,
checkAccess: null(),
call: null(),
construct: null(),
hasInstance: utils::has_instance,
trace: null(),
reserved: (null(), null(), null(), null(), null(), // 05
null(), null(), null(), null(), null(), // 10
null(), null(), null(), null(), null(), // 15
null(), null(), null(), null(), null(), // 20
null(), null(), null(), null(), null(), // 25
null(), null(), null(), null(), null(), // 30
null(), null(), null(), null(), null(), // 35
null(), null(), null(), null(), null())} // 40
};
compartment.register_class(NodeProto_class);
compartment.register_class(Node_class);
let obj = result::unwrap(
compartment.new_object(~"NodePrototype", null(),
compartment.global_obj.ptr));
let attrs = @~[
{name: compartment.add_name(~"firstChild"),
tinyid: 0,
@ -92,38 +28,25 @@ fn init(compartment: bare_compartment) {
tinyid: 0,
flags: 0,
getter: getNextSibling,
setter: null()},
{name: compartment.add_name(~"tagName"),
tinyid: 0,
flags: 0,
getter: getTagName,
setter: null()}];
vec::push(compartment.global_props, attrs);
vec::as_buf(*attrs, |specs, _len| {
JS_DefineProperties(compartment.cx.ptr, obj.ptr, specs);
});
compartment.define_property(~"Node", RUST_OBJECT_TO_JSVAL(obj.ptr),
JS_PropertyStub, JS_StrictPropertyStub,
JSPROP_ENUMERATE);
}
fn create(cx: *JSContext, node: Node) -> jsobj unsafe {
let compartment = get_compartment(cx);
do node.read |nd| {
match nd.kind {
~Element(ed) => {
element::create(cx, node)
}
//XXXjdm the parent should probably be the node parent instead of the global
//TODO error checking
let obj = result::unwrap(
(*compartment).new_object_with_proto(~"Node", ~"NodePrototype",
(*compartment).global_obj.ptr));
unsafe {
let raw_ptr: *libc::c_void = unsafe::reinterpret_cast(squirrel_away_unique(~node));
JS_SetReservedSlot(obj.ptr, 0, RUST_PRIVATE_TO_JSVAL(raw_ptr));
~Text(s) => {
fail ~"no text node bindings yet";
}
}
}
return obj;
}
unsafe fn unwrap(obj: *JSObject) -> *rust_box<Node> {
@ -164,21 +87,3 @@ extern fn getNextSibling(cx: *JSContext, obj: *JSObject, _id: jsid, rval: *mut j
}
return 1;
}
extern fn getTagName(cx: *JSContext, obj: *JSObject, _id: jsid, rval: *mut jsval) -> JSBool {
unsafe {
(*unwrap(obj)).payload.read(|nd| {
match nd.kind {
~Element(ed) => {
let s = str(copy ed.tag_name);
*rval = domstring_to_jsval(cx, s);
}
_ => {
//XXXjdm should probably read the spec to figure out what to do here
*rval = JSVAL_NULL;
}
}
});
}
return 1;
}

View file

@ -6,11 +6,11 @@ import js::jsapi::bindgen::{JS_ValueToString, JS_GetStringCharsZAndLength, JS_Re
JS_GetReservedSlot, JS_SetReservedSlot, JS_NewStringCopyN,
JS_DefineFunctions, JS_DefineProperty, JS_GetContextPrivate,
JS_GetClass, JS_GetPrototype};
import js::crust::{JS_ConvertStub, JS_PropertyStub, JS_StrictPropertyStub,
JS_EnumerateStub, JS_ConvertStub, JS_ResolveStub};
import js::glue::bindgen::*;
import ptr::null;
import result::{result, ok, err};
import js::crust::{JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub,
JS_ResolveStub, JS_ConvertStub};
enum DOMString {
str(~str),
@ -95,8 +95,37 @@ extern fn has_instance(_cx: *JSContext, obj: *JSObject, v: *jsval, bp: *mut JSBo
return 1;
}
fn Document_class(compartment: bare_compartment, name: ~str,
finalize: *u8) -> JSClass {
fn prototype_jsclass(name: ~str) -> fn(bare_compartment) -> JSClass {
return fn@(compartment: bare_compartment) -> JSClass {
{name: compartment.add_name(name),
flags: 0,
addProperty: JS_PropertyStub,
delProperty: JS_PropertyStub,
getProperty: JS_PropertyStub,
setProperty: JS_StrictPropertyStub,
enumerate: JS_EnumerateStub,
resolve: JS_PropertyStub,
convert: JS_ConvertStub,
finalize: null(),
checkAccess: null(),
call: null(),
construct: null(),
hasInstance: has_instance,
trace: null(),
reserved: (null(), null(), null(), null(), null(), // 05
null(), null(), null(), null(), null(), // 10
null(), null(), null(), null(), null(), // 15
null(), null(), null(), null(), null(), // 20
null(), null(), null(), null(), null(), // 25
null(), null(), null(), null(), null(), // 30
null(), null(), null(), null(), null(), // 35
null(), null(), null(), null(), null())} // 40
};
}
fn instance_jsclass(name: ~str, finalize: *u8)
-> fn(bare_compartment) -> JSClass {
return fn@(compartment: bare_compartment) -> JSClass {
{name: compartment.add_name(name),
flags: JSCLASS_HAS_RESERVED_SLOTS(1),
addProperty: JS_PropertyStub,
@ -110,7 +139,7 @@ fn Document_class(compartment: bare_compartment, name: ~str,
checkAccess: null(),
call: null(),
construct: null(),
hasInstance: null(),
hasInstance: has_instance,
trace: null(),
reserved: (null(), null(), null(), null(), null(), // 05
null(), null(), null(), null(), null(), // 10
@ -120,4 +149,24 @@ fn Document_class(compartment: bare_compartment, name: ~str,
null(), null(), null(), null(), null(), // 30
null(), null(), null(), null(), null(), // 35
null(), null(), null(), null(), null())} // 40
};
}
fn define_empty_prototype(name: ~str, proto: option<~str>, compartment: bare_compartment)
-> js::rust::jsobj {
compartment.register_class(utils::prototype_jsclass(name));
//TODO error checking
let obj = result::unwrap(
match proto {
some(s) => compartment.new_object_with_proto(name, s,
compartment.global_obj.ptr),
none => compartment.new_object(name, null(), compartment.global_obj.ptr)
});
compartment.define_property(name, RUST_OBJECT_TO_JSVAL(obj.ptr),
JS_PropertyStub, JS_StrictPropertyStub,
JSPROP_ENUMERATE);
compartment.stash_global_proto(name, obj);
return obj;
}

View file

@ -11,17 +11,10 @@ import js::crust::{JS_PropertyStub, JS_StrictPropertyStub, JS_EnumerateStub, JS_
import result::{result, ok, err};
import ptr::null;
import libc::c_uint;
import utils::{DOMString, domstring_to_jsval, rust_box, squirrel_away, str,
Document_class};
import utils::{rust_box, squirrel_away, jsval_to_str};
import bindings::node::create;
import base::{Node, Window};
enum DOMException {
INVALID_CHARACTER_ERR
}
enum Element = int;
extern fn alert(cx: *JSContext, argc: c_uint, vp: *jsval) -> JSBool {
unsafe {
let argv = JS_ARGV(cx, vp);
@ -35,15 +28,6 @@ extern fn alert(cx: *JSContext, argc: c_uint, vp: *jsval) -> JSBool {
1_i32
}
// Unfortunately duplicated in document and window.
// Generalizing it triggers a trans bug
extern fn getDocumentElement(cx: *JSContext, obj: *JSObject,
_id: jsid, rval: *mut jsval) -> JSBool unsafe {
let node = (*unwrap(obj)).payload.root;
*rval = RUST_OBJECT_TO_JSVAL(node::create(cx, node).ptr);
return 1;
}
unsafe fn unwrap(obj: *JSObject) -> *rust_box<Window> {
let val = JS_GetReservedSlot(obj, 0);
unsafe::reinterpret_cast(RUST_JSVAL_TO_PRIVATE(val))
@ -58,12 +42,12 @@ extern fn finalize(_fop: *JSFreeOp, obj: *JSObject) {
}
fn init(compartment: bare_compartment, win: @Window) {
compartment.register_class(|c| Document_class(c, ~"DOMWindow",
finalize));
let proto = utils::define_empty_prototype(~"Window", none, compartment);
compartment.register_class(utils::instance_jsclass(~"WindowInstance", finalize));
let obj = result::unwrap(
compartment.new_object(~"DOMWindow", null(), null()));
compartment.new_object_with_proto(~"WindowInstance",
~"Window", null()));
/* Define methods on a window */
let methods = ~[{name: compartment.add_name(~"alert"),
@ -72,25 +56,16 @@ fn init(compartment: bare_compartment, win: @Window) {
flags: 0}];
vec::as_buf(methods, |fns, _len| {
JS_DefineFunctions(compartment.cx.ptr, obj.ptr, fns);
JS_DefineFunctions(compartment.cx.ptr, proto.ptr, fns);
});
let attrs = @~[
{name: compartment.add_name(~"DOMWindow"),
tinyid: 0, // ???
flags: 0,
getter: getDocumentElement,
setter: null()}];
vec::push(compartment.global_props, attrs);
vec::as_buf(*attrs, |specs, _len| {
JS_DefineProperties(compartment.cx.ptr, obj.ptr, specs);
});
unsafe {
let raw_ptr: *libc::c_void = unsafe::reinterpret_cast(squirrel_away(win));
JS_SetReservedSlot(obj.ptr, 0, RUST_PRIVATE_TO_JSVAL(raw_ptr));
}
//TODO: All properties/methods on Window need to be available on the global
// object as well. We probably want a special JSClass with a resolve hook.
compartment.define_property(~"window", RUST_OBJECT_TO_JSVAL(obj.ptr),
JS_PropertyStub, JS_StrictPropertyStub,
JSPROP_ENUMERATE);

View file

@ -1,9 +1,9 @@
import geom::point::Point2D;
import geom::rect::Rect;
import geom::size::Size2D;
import num::Num;
import num::{Num, from_int};
enum au = int;
enum au = i32;
impl au : Num {
pure fn add(&&other: au) -> au { au(*self + *other) }
@ -13,8 +13,10 @@ impl au : Num {
pure fn modulo(&&other: au) -> au { au(*self % *other) }
pure fn neg() -> au { au(-*self) }
pure fn to_int() -> int { *self }
static pure fn from_int(n: int) -> au { au(n) }
pure fn to_int() -> int { *self as int }
static pure fn from_int(n: int) -> au {
au((n & (i32::max_value as int)) as i32)
}
}
fn box<A:copy Num>(x: A, y: A, w: A, h: A) -> Rect<A> {
@ -31,9 +33,9 @@ fn zero_size_au() -> Size2D<au> {
}
pure fn px_to_au(i: int) -> au {
au(i * 60)
from_int(i * 60)
}
pure fn au_to_px(au: au) -> int {
*au / 60
(*au / 60) as int
}

View file

@ -30,7 +30,7 @@ impl @Box : InlineLayout {
for tree::each_child(BTree, self) |kid| {
kid.bounds.origin = Point2D(au(x), au(y));
x += *kid.bounds.size.width;
current_height = int::max(current_height, *kid.bounds.size.height);
current_height = i32::max(current_height, *kid.bounds.size.height);
}
let height = match self.appearance.height {
@ -41,7 +41,7 @@ impl @Box : InlineLayout {
let width = match self.appearance.width {
Px(p) => px_to_au(p.to_int()),
Auto => au(int::max(x, *self.bounds.size.width)),
Auto => au(i32::max(x, *self.bounds.size.width)),
_ => fail ~"inhereit_width failed, width is neither a Px or auto"
};

View file

@ -26,6 +26,7 @@ mod dom {
mod style;
mod bindings {
mod document;
mod element;
mod utils;
mod node;
mod window;

View file

@ -0,0 +1,3 @@
<img src="test.jpeg" width="50" height="378"/>
<script src="test_image_getter.js"></script>

View file

@ -0,0 +1,6 @@
var elem = document.documentElement.firstChild;
debug(elem.tagName);
debug(elem instanceof HTMLImageElement);
debug(elem.width);
elem.width = 1000;
debug(elem.width);