/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"
#include "nsIPrincipal.idl"
#include "nsIContentSecurityPolicy.idl"

webidl DragEvent;
webidl DataTransfer;

[scriptable, uuid(69E14F91-2E09-4CA6-A511-A715C99A2804)]
interface nsIDroppedLinkItem : nsISupports
{
  /**
   * Returns the URL of the link.
   */
  readonly attribute AString url;

  /**
   * Returns the link name.
   */
  readonly attribute AString name;

  /**
   * Returns the MIME-Type.
   */
  readonly attribute AString type;
};

[scriptable, uuid(21B5C25A-28A9-47BD-8431-FA9116305DED)]
interface nsIDroppedLinkHandler : nsISupports
{
  /**
   * Determines if a link being dragged can be dropped and returns true if so.
   * aEvent should be a dragenter or dragover event.
   *
   * If aAllowSameDocument is false, drops are only allowed if the document
   * of the source of the drag is different from the destination. This check
   * includes any parent, sibling and child frames in the same content tree.
   * If true, the source is not checked.
   */
  boolean canDropLink(in DragEvent aEvent, in boolean aAllowSameDocument);

  /**
   * Given a drop event aEvent, determines links being dragged and returns
   * them. If links are returned the caller can, for instance, load them. If
   * the returned array is empty, there is no valid link to be dropped.
   *
   * A NS_ERROR_DOM_SECURITY_ERR error will be thrown and the event cancelled if
   * the receiving target should not load the uri for security reasons. This
   * will occur if any of the following conditions are true:
   *  - the source of the drag initiated a link for dragging that
   *    it itself cannot access. This prevents a source document from tricking
   *    the user into a dragging a chrome url, for example.
   *  - aDisallowInherit is true, and the URI being dropped would inherit the
   *    current document's security context (URI_INHERITS_SECURITY_CONTEXT).
   */
  Array<nsIDroppedLinkItem> dropLinks(in DragEvent aEvent,
                                      [optional] in boolean aDisallowInherit);

  /**
   * Given a drop event aEvent, validate the extra URIs for the event,
   * this is used when the caller extracts yet another URIs from the dropped
   * text, like home button that splits the text with "|".
   */
  void validateURIsForDrop(in DragEvent aEvent,
                           in Array<AString> aURIs,
                           [optional] in boolean aDisallowInherit);

  /**
   * Given a dataTransfer, allows caller to determine and verify links being
   * dragged. Since drag/drop performs a roundtrip of parent, child, parent,
   * it allows the parent to verify that the child did not modify links
   * being dropped.
   */
  Array<nsIDroppedLinkItem> queryLinks(in DataTransfer aDataTransfer);

  /**
   * Given a drop event aEvent, determines the triggering principal for the
   * event and returns it.
   */
  nsIPrincipal getTriggeringPrincipal(in DragEvent aEvent);

  /**
   * Given a drop event aEvent, determines the CSP for the event and returns it.
   */
  nsIContentSecurityPolicy getCsp(in DragEvent aEvent);
};