/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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 "nsITransferable.idl"



%{ C++
#include "mozilla/EventForwards.h"
#include "nsIWidget.h"
#include "nsSize.h"
#include "Units.h"

class nsIFrame;
class nsIWidget;

namespace mozilla {
namespace dom {
class BrowserParent;
} // namespace dom
} // namespace mozilla
%}

interface nsIPolicyContainer;
interface nsIFile;

[ptr] native BrowserParentPtr(mozilla::dom::BrowserParent);
native EventMessage(mozilla::EventMessage);
[ref] native LayoutDeviceIntPoint(mozilla::LayoutDeviceIntPoint);
[ptr] native nsIFramePtr(nsIFrame);
[ptr] native nsIWidgetPtr(nsIWidget);
[ref] native StringSet(const nsTHashSet<nsString>);
native nsSize(nsSize);

webidl DataTransfer;
webidl DragEvent;
webidl Element;
webidl WindowContext;
webidl Node;
webidl Selection;

[scriptable, builtinclass, uuid(25bce737-73f0-43c7-bc20-c71044a73c5a)]
interface nsIDragSession : nsISupports
{
  /**
    * Set the current state of the drag, whether it can be dropped or not.
    * usually the target "frame" sets this so the native system can render the correct feedback
    */
  attribute boolean canDrop;

  /**
   * Indicates if the drop event should be dispatched only to chrome.
   */
  attribute boolean onlyChromeDrop;

  /**
    * Sets the action (copy, move, link, et.c) for the current drag
    */
  attribute unsigned long dragAction;

  /**
    * Get the number of items that were dropped
    */
  readonly attribute unsigned long numDropItems;

  /**
    * The window context where the drag was started, which will be null if the
    * drag originated outside the application. Useful for determining if a drop
    * originated in the same window context.
    */
  [infallible]
  attribute WindowContext sourceWindowContext;

  /**
    * The top-level window context where the drag was started, which will be
    * null if the drag originated outside the application. Useful for
    * determining if a drop originated in the same top-level window context.
    */
  [infallible]
  attribute WindowContext sourceTopWindowContext;

  /**
    * The dom node that was originally dragged to start the session, which will be null if the
    * drag originated outside the application.
    */
  readonly attribute Node sourceNode;

  /**
   * Replace source node and selection with new ones.
   * If sourceNode is a native anonymous node, it may be replaced at reframing.
   * If sourceNode is disconnected from the document, we cannot dispatch
   * `dragend` event properly.
   * When this is called, sourceNode or aNewSourceNode should be a native
   * anonymous node.
   */
  [notxpcom, nostdcall] void updateSource(in Node aNewSourceNode,
                                          in Selection aNewSelection);

  /**
   * the triggering principal.  This may be different than sourceNode's
   * principal when sourceNode is xul:browser and the drag is
   * triggered in a browsing context inside it.
   */
  attribute nsIPrincipal triggeringPrincipal;

  /**
   * the triggering policyContainer.  This may be different than sourceNode's
   * policyContainer when sourceNode is xul:browser and the drag is
   * triggered in a browsing context inside it.
   */
  attribute nsIPolicyContainer policyContainer;

  /**
   * The data transfer object for the current drag.
   */
  [binaryname(DataTransferXPCOM)]
  attribute DataTransfer dataTransfer;
  [notxpcom, nostdcall] DataTransfer getDataTransfer();
  [notxpcom, nostdcall] void setDataTransfer(in DataTransfer aDataTransfer);

  /**
    * Get data from a Drag&Drop. Can be called while the drag is in process
    * or after the drop has completed.
    *
    * @param  aTransferable the transferable for the data to be put into
    * @param  aItemIndex which of multiple drag items, zero-based
    */
  void getData ( in nsITransferable aTransferable, in unsigned long aItemIndex ) ;

   /**
    * Check to set if any of the native data on the clipboard matches this data flavor
    */
  boolean isDataFlavorSupported ( in string aDataFlavor ) ;

  void userCancelled();

  void dragEventDispatchedToChildProcess();

  // Called when nsIDragSession implementation should update the UI for the
  // drag-and-drop based on the data got from the child process in response to
  // NS_DRAGDROP_OVER sent from parent process to child process.
  void updateDragEffect();

  // Change the drag image, using similar arguments as
  // nsIDragService::InvokeDragSessionWithImage.
  void updateDragImage(in Node aImage, in long aImageX, in long aImageY);

  /**
   * Tell Gecko that this session is generated for automated testing.
   * This should be called immediately after StartDragSession when testing.
   */
  [noscript] void InitForTests(in uint32_t aAllowedEffect);

  /**
   * Returns effects allowed at starting the session for tests.
   */
  [notxpcom, nostdcall] unsigned long getEffectAllowedForTests();

  /**
   * Returns true if current session was started with synthesized drag start.
   */
  [notxpcom, nostdcall] boolean isSynthesizedForTests();

  /**
   * Sets the drag end point.  Position is relative to screen in device coords.
   */
  void setDragEndPoint(in long aScreenX, in long aScreenY);

  /**
   * Sets drag end point of synthesized session when the test does not dispatch
   * "drop" event.  Position is relative to screen in CSS coordinates.
   */
  void setDragEndPointForTests(in float aScreenX, in float aScreenY);

  /**
   * Returns true if the session is for dragging text in a text in text control
   * element.
   */
  [notxpcom, nostdcall] boolean isDraggingTextInTextControl();

  /**
   * Called when HTMLEditor maybe deleted the source node from the document.
   *
   * @param aEditingHost    The editing host when the editor deletes selection.
   */
  [noscript] void maybeEditorDeletedSourceNode(in Element aEditingHost);

  /**
    * Sets the position for the Gecko-drawn dragged-contents image.
    * aX and aY are in LayoutDevice pixels.
    */
  [noscript] void dragMoved(in long aX, in long aY);

  /**
   * Fire a drag event at the source of the drag
   */
  [noscript, can_run_script]
  void fireDragEventAtSource(in EventMessage aEventMessage,
                             in unsigned long aKeyModifiers);

  [notxpcom, nostdcall] boolean maybeAddBrowser(in BrowserParentPtr aBP);
  [notxpcom, nostdcall] boolean removeAllBrowsers();

  /**
    * Tells the Drag Service to end a drag session.
    *
    * If aDoneDrag is true, the drag has finished, otherwise the drag has
    * just left the window.
    *
    * @param aDoneDrag       If true, reports the drag as complete.
    * @param aKeyModifiers   Key state to assume while ending the session.
    */
  [can_run_script]
  void endDragSession(in boolean aDoneDrag,
                      [optional] in unsigned long aKeyModifiers);

  /**
   * Tell the drag session for the given browser that it
   * should store the would-be target of the aEvent (a drop event) and delay
   * calls to EndDragSession.  This is used in the main process.
   *
   * @param aEvent The drag event
   */
  void sendStoreDropTargetAndDelayEndDragSession(
      in DragEvent aEvent);

  /**
   * After sendStoreDropTargetAndDelayEndDragSession, send a drop (if
   * aShouldDrop is true) or dragexit event to the recorded drop target and
   * then reissue any stored EndDragSession call.  This is used in the main
   * process.
   *
   * @param aShouldDrop  True to send drop event, false to send dragexit event
   */
  void sendDispatchToDropTargetAndResumeEndDragSession(
      in boolean aShouldDrop, in Array<nsIFile> aAllowedFiles);

  /**
   * Store aElement and aDocFrame as the future drop/dragexit context, and
   * delay calls to EndDragSession.  This is used in content processes.
   *
   * @param aElement        The element to drop onto
   * @param aDocFrame       The frame to dispatch to
   */
  [noscript] void storeDropTargetAndDelayEndDragSession(
      in Element aElement,
      in nsIFramePtr aDocFrame
  );

  /**
   * Issue drop or dragexit to the stored drop target (if any) and issue
   * any delayed call to EndDragSession.  This is used in content processes.
   *
   * @param aWidget           The widget on which the drop will happen
   * @param aPt               Screen coords of drop
   * @param aShouldDrop       If true, send a drop event.  Otherwise send dragexit.
   * @param aAllowedFilePaths Paths to the files that were allowed to be dropped.
   */
  [noscript, can_run_script]
  void dispatchToDropTargetAndResumeEndDragSession(
      in nsIWidgetPtr aWidget,
      [const] in LayoutDeviceIntPoint aPt,
      in boolean aShouldDrop,
      in StringSet aAllowedFilePaths);

  /**
   * Retrun true if nsIDragSession's data is updated.
   */
  [notxpcom, nostdcall] boolean mustUpdateDataTransfer(in EventMessage aMessage);
};