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

1 files changed, 14 insertions, 13 deletions

diff --git a/components/script/dom/htmlanchorelement.rs b/components/script/dom/htmlanchorelement.rs
index 4e2c396b88e..dd1c88e16e6 100644
--- a/components/script/dom/htmlanchorelement.rs
+++ b/components/script/dom/htmlanchorelement.rs
@@ -10,8 +10,7 @@ use dom::bindings::codegen::Bindings::HTMLAnchorElementBinding;
 use dom::bindings::codegen::Bindings::HTMLAnchorElementBinding::HTMLAnchorElementMethods;
 use dom::bindings::codegen::Bindings::MouseEventBinding::MouseEventMethods;
 use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
-use dom::bindings::codegen::InheritTypes::{ElementCast, HTMLElementCast};
-use dom::bindings::codegen::InheritTypes::{HTMLImageElementDerived, MouseEventCast, NodeCast};
+use dom::bindings::conversions::Castable;
 use dom::bindings::js::{JS, MutNullableHeap, Root};
 use dom::document::Document;
 use dom::domtokenlist::DOMTokenList;
@@ -19,6 +18,8 @@ use dom::element::Element;
 use dom::event::Event;
 use dom::eventtarget::EventTarget;
 use dom::htmlelement::HTMLElement;
+use dom::htmlimageelement::HTMLImageElement;
+use dom::mouseevent::MouseEvent;
 use dom::node::{Node, document_from_node, window_from_node};
 use dom::virtualmethods::VirtualMethods;
 use num::ToPrimitive;
@@ -55,7 +56,7 @@ impl HTMLAnchorElement {
 
 impl VirtualMethods for HTMLAnchorElement {
     fn super_type(&self) -> Option<&VirtualMethods> {
-        let htmlelement: &HTMLElement = HTMLElementCast::from_ref(self);
+        let htmlelement: &HTMLElement = self.upcast::<HTMLElement>();
         Some(htmlelement as &VirtualMethods)
     }
 
@@ -70,20 +71,20 @@ impl VirtualMethods for HTMLAnchorElement {
 impl HTMLAnchorElementMethods for HTMLAnchorElement {
     // https://html.spec.whatwg.org/multipage/#dom-a-text
     fn Text(&self) -> DOMString {
-        let node = NodeCast::from_ref(self);
+        let node = self.upcast::<Node>();
         node.GetTextContent().unwrap()
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-a-text
     fn SetText(&self, value: DOMString) {
-        let node = NodeCast::from_ref(self);
+        let node = self.upcast::<Node>();
         node.SetTextContent(Some(value))
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-a-rellist
     fn RelList(&self) -> Root<DOMTokenList> {
         self.rel_list.or_init(|| {
-            DOMTokenList::new(ElementCast::from_ref(self), &atom!("rel"))
+            DOMTokenList::new(self.upcast::<Element>(), &atom!("rel"))
         })
     }
 
@@ -114,7 +115,7 @@ impl HTMLAnchorElementMethods for HTMLAnchorElement {
 
 impl Activatable for HTMLAnchorElement {
     fn as_element(&self) -> &Element {
-        ElementCast::from_ref(self)
+        self.upcast::<Element>()
     }
 
     fn is_instance_activatable(&self) -> bool {
@@ -123,7 +124,7 @@ impl Activatable for HTMLAnchorElement {
         // hyperlink"
         // https://html.spec.whatwg.org/multipage/#the-a-element
         // "The activation behaviour of a elements *that create hyperlinks*"
-        ElementCast::from_ref(self).has_attribute(&atom!("href"))
+        self.upcast::<Element>().has_attribute(&atom!("href"))
     }
 
 
@@ -145,13 +146,13 @@ impl Activatable for HTMLAnchorElement {
         }
         //TODO: Step 2. Check if browsing context is specified and act accordingly.
         //Step 3. Handle <img ismap/>.
-        let element = ElementCast::from_ref(self);
-        let mouse_event = MouseEventCast::to_ref(event).unwrap();
+        let element = self.upcast::<Element>();
+        let mouse_event = event.downcast::<MouseEvent>().unwrap();
         let mut ismap_suffix = None;
-        if let Some(element) = ElementCast::to_ref(target) {
-            if target.is_htmlimageelement() && element.has_attribute(&atom!("ismap")) {
+        if let Some(element) = target.downcast::<Element>() {
+            if target.is::<HTMLImageElement>() && element.has_attribute(&atom!("ismap")) {
 
-                let target_node = NodeCast::from_ref(element);
+                let target_node = element.upcast::<Node>();
                 let rect = window_from_node(target_node).r().content_box_query(
                     target_node.to_trusted_node_address());
                 ismap_suffix = Some(