Bug 1444686 part 1. Get rid of nsIDOMDataTransfer::Get/SetDropEffect. r=mystor

MozReview-Commit-ID: 6Kn9uuaQYI0

dom/events/DataTransfer.cpp

@@ -223,16 +223,7 @@ DataTransfer::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
   return DataTransferBinding::Wrap(aCx, this, aGivenProto);
 }
 
-NS_IMETHODIMP
-DataTransfer::GetDropEffect(nsAString& aDropEffect)
-{
-  nsString dropEffect;
-  GetDropEffect(dropEffect);
-  aDropEffect = dropEffect;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
+void
 DataTransfer::SetDropEffect(const nsAString& aDropEffect)
 {
   // the drop effect can only be 'none', 'copy', 'move' or 'link'.
@@ -246,8 +237,6 @@ DataTransfer::SetDropEffect(const nsAString& aDropEffect)
       break;
     }
   }
-
-  return NS_OK;
 }
 
 NS_IMETHODIMP

dom/events/DataTransfer.h

@@ -128,10 +128,38 @@ public:
   Constructor(const GlobalObject& aGlobal, const nsAString& aEventType,
               bool aIsExternal, ErrorResult& aRv);
 
-  void GetDropEffect(nsString& aDropEffect)
+  /**
+   * The actual effect that will be used, and should always be one of the
+   * possible values of effectAllowed.
+   *
+   * For dragstart, drag and dragleave events, the dropEffect is initialized
+   * to none. Any value assigned to the dropEffect will be set, but the value
+   * isn't used for anything.
+   *
+   * For the dragenter and dragover events, the dropEffect will be initialized
+   * based on what action the user is requesting. How this is determined is
+   * platform specific, but typically the user can press modifier keys to
+   * adjust which action is desired. Within an event handler for the dragenter
+   * and dragover events, the dropEffect should be modified if the action the
+   * user is requesting is not the one that is desired.
+   *
+   * For the drop and dragend events, the dropEffect will be initialized to
+   * the action that was desired, which will be the value that the dropEffect
+   * had after the last dragenter or dragover event.
+   *
+   * Possible values:
+   *  copy - a copy of the source item is made at the new location
+   *  move - an item is moved to a new location
+   *  link - a link is established to the source at the new location
+   *  none - the item may not be dropped
+   *
+   * Assigning any other value has no effect and retains the old value.
+   */
+  void GetDropEffect(nsAString& aDropEffect)
   {
     aDropEffect.AssignASCII(sEffects[mDropEffect]);
   }
+  void SetDropEffect(const nsAString& aDropEffect);
 
   void GetEffectAllowed(nsString& aEffectAllowed)
   {

dom/events/DragEvent.h

@@ -36,6 +36,11 @@ public:
     return DragEventBinding::Wrap(aCx, this, aGivenProto);
   }
 
+  DragEvent* AsDragEvent() override
+  {
+    return this;
+  }
+
   DataTransfer* GetDataTransfer();
 
   void InitDragEvent(const nsAString& aType,

dom/events/Event.h

@@ -30,6 +30,7 @@ namespace mozilla {
 namespace dom {
 
 class BeforeUnloadEvent;
+class DragEvent;
 class EventTarget;
 class EventMessageAutoOverride;
 // ExtendableEvent is a ServiceWorker event that is not
@@ -126,6 +127,12 @@ public:
     return nullptr;
   }
 
+  // DragEvent has a non-autogeneratable initDragEvent.
+  virtual DragEvent* AsDragEvent()
+  {
+    return nullptr;
+  }
+
   // nsIDOMEvent Interface
   NS_DECL_NSIDOMEVENT
 

dom/interfaces/events/nsIDOMDataTransfer.idl

@@ -11,35 +11,6 @@ interface nsIDOMFileList;
 [builtinclass, uuid(655078bf-1675-4aa0-a48d-a133e864ce57)]
 interface nsIDOMDataTransfer : nsISupports
 {
-  /**
-   * The actual effect that will be used, and should always be one of the
-   * possible values of effectAllowed.
-   *
-   * For dragstart, drag and dragleave events, the dropEffect is initialized
-   * to none. Any value assigned to the dropEffect will be set, but the value
-   * isn't used for anything.
-   *
-   * For the dragenter and dragover events, the dropEffect will be initialized
-   * based on what action the user is requesting. How this is determined is
-   * platform specific, but typically the user can press modifier keys to
-   * adjust which action is desired. Within an event handler for the dragenter
-   * and dragover events, the dropEffect should be modified if the action the
-   * user is requesting is not the one that is desired.
-   *
-   * For the drop and dragend events, the dropEffect will be initialized to
-   * the action that was desired, which will be the value that the dropEffect
-   * had after the last dragenter or dragover event.
-   *
-   * Possible values:
-   *  copy - a copy of the source item is made at the new location
-   *  move - an item is moved to a new location
-   *  link - a link is established to the source at the new location
-   *  none - the item may not be dropped
-   *
-   * Assigning any other value has no effect and retains the old value.
-   */
-  attribute DOMString dropEffect;
-
   /*
    * Specifies the effects that are allowed for this drag. You may set this in
    * the dragstart event to set the desired effects for the source, and within

layout/forms/nsFileControlFrame.cpp

@@ -11,8 +11,12 @@
 #include "nsIDocument.h"
 #include "mozilla/dom/NodeInfo.h"
 #include "mozilla/dom/Element.h"
-#include "mozilla/dom/DataTransfer.h"
 #include "mozilla/dom/DOMPrefs.h"
+#include "mozilla/dom/DOMStringList.h"
+#include "mozilla/dom/DataTransfer.h"
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/DragEvent.h"
+#include "mozilla/dom/FileList.h"
 #include "mozilla/dom/HTMLButtonElement.h"
 #include "mozilla/dom/HTMLInputElement.h"
 #include "mozilla/dom/MutationEventBinding.h"
@@ -21,10 +25,6 @@
 #include "nsContentCreatorFunctions.h"
 #include "nsContentUtils.h"
 #include "mozilla/EventStates.h"
-#include "mozilla/dom/DOMStringList.h"
-#include "mozilla/dom/Directory.h"
-#include "mozilla/dom/FileList.h"
-#include "nsIDOMDragEvent.h"
 #include "nsIDOMFileList.h"
 #include "nsTextNode.h"
 
@@ -238,19 +238,17 @@ nsFileControlFrame::DnDListener::HandleEvent(nsIDOMEvent* aEvent)
 {
   NS_ASSERTION(mFrame, "We should have been unregistered");
 
-  bool defaultPrevented = false;
-  aEvent->GetDefaultPrevented(&defaultPrevented);
-  if (defaultPrevented) {
+  Event* event = aEvent->InternalDOMEvent();
+  if (event->DefaultPrevented()) {
     return NS_OK;
   }
 
-  nsCOMPtr<nsIDOMDragEvent> dragEvent = do_QueryInterface(aEvent);
+  DragEvent* dragEvent = event->AsDragEvent();
   if (!dragEvent) {
     return NS_OK;
   }
 
-  nsCOMPtr<nsIDOMDataTransfer> dataTransfer;
-  dragEvent->GetDataTransfer(getter_AddRefs(dataTransfer));
+  RefPtr<DataTransfer> dataTransfer = dragEvent->GetDataTransfer();
   if (!IsValidDropData(dataTransfer)) {
     return NS_OK;
   }