Introduce trait Castable

This trait is used to hold onto the downcast and upcast functions of all
castable IDL interfaces. A castable IDL interface is one which either derives
from or is derived by other interfaces.

The deriving relation is represented by implementations of marker trait
DerivedFrom<T: Castable> generated in InheritTypes.

/^[ ]*use dom::bindings::codegen::InheritTypes::.*(Base|Cast|Derived)/ {
    /::[a-zA-Z]+(Base|Cast|Derived);/d
    s/([{ ])[a-zA-Z]+(Base|Cast|Derived), /\1/g
    s/([{ ])[a-zA-Z]+(Base|Cast|Derived), /\1/g
    s/, [a-zA-Z]+(Base|Cast|Derived)([},])/\2/g
    s/, [a-zA-Z]+(Base|Cast|Derived)([},])/\2/g
    /\{([a-zA-Z]+(Base|Cast|Derived))?\};$/d
    s/\{([a-zA-Z_]+)\};$/\1;/
}

s/([a-zA-Z]+)Cast::from_ref\(\&?\**([a-zA-Z_]+)(\.r\(\))?\)/\2.upcast::<\1>()/g
s/([a-zA-Z]+)Cast::from_ref\(\&?\**([a-zA-Z_]+)(\.[a-zA-Z_]+\(\))?\)/\2\3.upcast::<\1>()/g
s/\(([a-zA-Z]+)Cast::from_ref\)/\(Castable::upcast::<\1>\)/g

s/([a-zA-Z]+)Cast::from_root/Root::upcast::<\1>/g

s/([a-zA-Z]+)Cast::from_layout_js\(\&([a-zA-Z_.]+)\)/\2.upcast::<\1>()/g

s/([a-zA-Z]+)Cast::to_ref\(\&?\**([a-zA-Z_]+)(\.r\(\))?\)/\2.downcast::<\1>()/g
s/([a-zA-Z]+)Cast::to_ref\(\&?\**([a-zA-Z_]+)(\.[a-zA-Z_]+\(\))?\)/\2\3.downcast::<\1>()/g
s/\(([a-zA-Z]+)Cast::to_ref\)/\(Castable::downcast::<\1>\)/g

s/([a-zA-Z]+)Cast::to_root/Root::downcast::<\1>/g

s/([a-zA-Z]+)Cast::to_layout_js\(&?([a-zA-Z_.]+(\(\))?)\)/\2.downcast::<\1>()/g

s/\.is_document\(\)/.is::<Document>()/g
s/\.is_htmlanchorelement\(\)/.is::<HTMLAnchorElement>()/g
s/\.is_htmlappletelement\(\)/.is::<HTMLAppletElement>()/g
s/\.is_htmlareaelement\(\)/.is::<HTMLAreaElement>()/g
s/\.is_htmlbodyelement\(\)/.is::<HTMLBodyElement>()/g
s/\.is_htmlembedelement\(\)/.is::<HTMLEmbedElement>()/g
s/\.is_htmlfieldsetelement\(\)/.is::<HTMLFieldSetElement>()/g
s/\.is_htmlformelement\(\)/.is::<HTMLFormElement>()/g
s/\.is_htmlframesetelement\(\)/.is::<HTMLFrameSetElement>()/g
s/\.is_htmlhtmlelement\(\)/.is::<HTMLHtmlElement>()/g
s/\.is_htmlimageelement\(\)/.is::<HTMLImageElement>()/g
s/\.is_htmllegendelement\(\)/.is::<HTMLLegendElement>()/g
s/\.is_htmloptgroupelement\(\)/.is::<HTMLOptGroupElement>()/g
s/\.is_htmloptionelement\(\)/.is::<HTMLOptionElement>()/g
s/\.is_htmlscriptelement\(\)/.is::<HTMLScriptElement>()/g
s/\.is_htmltabledatacellelement\(\)/.is::<HTMLTableDataCellElement>()/g
s/\.is_htmltableheadercellelement\(\)/.is::<HTMLTableHeaderCellElement>()/g
s/\.is_htmltablerowelement\(\)/.is::<HTMLTableRowElement>()/g
s/\.is_htmltablesectionelement\(\)/.is::<HTMLTableSectionElement>()/g
s/\.is_htmltitleelement\(\)/.is::<HTMLTitleElement>()/g
This commit is contained in:
Anthony Ramine 2015-10-06 17:21:44 +02:00
parent bd363b009d
commit 13ea3ac413
82 changed files with 1124 additions and 1148 deletions

View file

@ -55,6 +55,7 @@ use libc;
use num::Float;
use num::traits::{Bounded, Zero};
use std::borrow::ToOwned;
use std::mem;
use std::rc::Rc;
use std::{char, ptr, slice};
use util::str::DOMString;
@ -106,6 +107,36 @@ pub trait IDLInterface {
fn derives(&'static DOMClass) -> bool;
}
/// A trait to hold the cast functions of IDL interfaces that either derive
/// or are derived from other interfaces.
pub trait Castable: IDLInterface + Reflectable + Sized {
/// Check whether a DOM object implements one of its deriving interfaces.
fn is<T>(&self) -> bool where T: DerivedFrom<Self> {
let class = unsafe {
get_dom_class(self.reflector().get_jsobject().get()).unwrap()
};
T::derives(class)
}
/// Cast a DOM object upwards to one of the interfaces it derives from.
fn upcast<T>(&self) -> &T where T: Castable, Self: DerivedFrom<T> {
unsafe { mem::transmute(self) }
}
/// Cast a DOM object downwards to one of the interfaces it might implement.
fn downcast<T>(&self) -> Option<&T> where T: DerivedFrom<Self> {
if self.is::<T>() {
Some(unsafe { mem::transmute(self) })
} else {
None
}
}
}
/// A trait to mark an IDL interface as deriving from another one.
#[rustc_on_unimplemented = "The IDL interface `{Self}` is not derived from `{T}`."]
pub trait DerivedFrom<T: Castable>: Castable {}
/// A trait to convert Rust types to `JSVal`s.
pub trait ToJSValConvertible {
/// Convert `self` to a `JSVal`. JSAPI failure causes a task failure.