/* 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"

interface nsIAutoCompleteInput;
interface nsIDOMEvent;

[scriptable, uuid(ff9f8465-204a-47a6-b3c9-0628b3856684)]
interface nsIAutoCompleteController : nsISupports
{
  /*
   * Possible values for the searchStatus attribute
   */
  const unsigned short STATUS_NONE = 1;
  const unsigned short STATUS_SEARCHING = 2;
  const unsigned short STATUS_COMPLETE_NO_MATCH = 3;
  const unsigned short STATUS_COMPLETE_MATCH = 4;

  /*
   * The input widget that is currently being controlled.
   */
  attribute nsIAutoCompleteInput input;

  /*
   * State which indicates the status of possible ongoing searches
   */
  readonly attribute unsigned short searchStatus;

  /*
   * The number of matches
   */
  readonly attribute unsigned long matchCount;

  /*
   * Start a search on a string, assuming the input property is already set.
   */
  void startSearch(in AString searchString);

  /*
   * Stop all asynchronous searches
   */
  void stopSearch();

  /*
   * Notify the controller that the user has changed text in the textbox.
   * This includes all means of changing the text value, including typing a
   * character, backspacing, deleting, pasting, committing composition or
   * canceling composition.
   *
   * NOTE: handleText() must be called after composition actually ends, even if
   *       the composition is canceled and the textbox value isn't changed.
   *       Then, implementation of handleText() can access the editor when
   *       it's not in composing mode. DOM compositionend event is not good
   *       timing for calling handleText(). DOM input event immediately after
   *       DOM compositionend event is the best timing to call this.
   *
   * @return whether this handler started a new search.
   */
  boolean handleText();

  /*
   * Notify the controller that the user wishes to enter the current text. If
   * aIsPopupSelection is true, then a selection was made from the popup, so
   * fill this value into the input field before continuing. If false, just
   * use the current value of the input field.
   *
   * @param aIsPopupSelection
   *        Pass true if the selection was made from the popup.
   * @param aEvent
   *        The event that triggered the enter, like a key event if the user
   *        pressed the Return key or a click event if the user clicked a popup
   *        item.
   * @return Whether the controller wishes to prevent event propagation and
   *         default event.
   */
  boolean handleEnter(in boolean aIsPopupSelection,
                      [optional] in nsIDOMEvent aEvent);

  /*
   * Notify the controller that the user wishes to revert autocomplete
   *
   * @return Whether the controller wishes to prevent event propagation and
   *         default event.
   */
  boolean handleEscape();

  /*
   * Notify the controller that the user wishes to start composition
   *
   * NOTE: nsIAutoCompleteController implementation expects that this is called
   *       by DOM compositionstart handler.
   */
  void handleStartComposition();

  /*
   * Notify the controller that the user wishes to end composition
   *
   * NOTE: nsIAutoCompleteController implementation expects that this is called
   *       by DOM compositionend handler.
   */
  void handleEndComposition();

  /*
   * Handle tab. Just closes up.
   */
  void handleTab();

  /*
   * Notify the controller of the following key navigation events:
   *   up, down, left, right, page up, page down
   *
   * @return Whether the controller wishes to prevent event propagation and
   *         default event
   */
  boolean handleKeyNavigation(in unsigned long key);

  /*
   * Notify the controller that the user chose to delete the current
   * auto-complete result.
   *
   * @return Whether the controller removed a result item.
   */
  boolean handleDelete();

  /*
   * Get the value of the result at a given index in the last completed search
   */
  AString getValueAt(in long index);

  /*
   * Get the label of the result at a given index in the last completed search
   */
  AString getLabelAt(in long index);

  /*
   * Get the comment of the result at a given index in the last completed search
   */
  AString getCommentAt(in long index);

  /*
   * Get the style hint for the result at a given index in the last completed search
   */
  AString getStyleAt(in long index);

  /*
   * Get the url of the image of the result at a given index in the last completed search
   */
  AString getImageAt(in long index);

  /*
   * For the last completed search, get the final value that should be completed
   * when the user confirms the match at the given index
   */
  AString getFinalCompleteValueAt(in long index);

  /*
   * Get / set the current search string.  Note, setting will not start searching
   */
  attribute AString searchString;

  /*
   * Set the index of the result item that should be initially selected.
   * This should be used when a search wants to pre-select an element before
   * the user starts using results.
   *
   * @note Setting this is not the same as just setting selectedIndex in
   * nsIAutocompletePopup, since this will take care of updating any internal
   * tracking variables of features like completeSelectedIndex.
   */
  void setInitiallySelectedIndex(in long index);
};
