/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 "nsISimpleEnumerator.idl"

%{C++
#define NS_WINDOWMEDIATOR_CID \
{ 0x292e17c8, 0xccc1, 0x42e1, \
  { 0xac, 0x8b, 0xaf, 0x61, 0x7d, 0x54, 0x13, 0xb1 } }

#define NS_WINDOWMEDIATOR_CONTRACTID \
  "@mozilla.org/appshell/window-mediator;1"
%}

interface nsIXULWindow;
interface nsIWidget;
interface nsIDOMWindow;
interface nsIWindowMediatorListener;

[scriptable, uuid(292e17c8-ccc1-42e1-ac8b-af617d5413b1)]
interface nsIWindowMediator: nsISupports
{
  /** Return an enumerator which iterates over all windows of type aWindowType
    * from the oldest window to the youngest.
    * @param  aWindowType the returned enumerator will enumerate only
    *                     windows of this type. ("type" is the
    *                     |windowtype| attribute of the XML <window> element.)
    *                     If null, all windows will be enumerated.
    * @return an enumerator of nsIDOMWindows
    */
  nsISimpleEnumerator getEnumerator(in wstring aWindowType);

  /** Identical to getEnumerator except:
    * @return an enumerator of nsIXULWindows
  */
  nsISimpleEnumerator getXULWindowEnumerator(in wstring aWindowType);

  /** Return an enumerator which iterates over all windows of type aWindowType
    * in their z (front-to-back) order. Note this interface makes
    * no requirement that a window couldn't be revisited if windows
    * are re-ordered while z-order enumerators are active.
    * @param  aWindowType the returned enumerator will enumerate only
    *                     windows of this type. ("type" is the
    *                     |windowtype| attribute of the XML <window> element.)
    *                     If null, all windows will be enumerated.
    * @param  aFrontToBack if true, the enumerator enumerates windows in order
    *                      from front to back. back to front if false.
    * @return an enumerator of nsIDOMWindows
    */
  nsISimpleEnumerator getZOrderDOMWindowEnumerator(in wstring aWindowType,
                        in boolean aFrontToBack);

  /** Identical to getZOrderDOMWindowEnumerator except:
    * @return an enumerator of nsIXULWindows
    */
  nsISimpleEnumerator getZOrderXULWindowEnumerator(in wstring aWindowType,
                        in boolean aFrontToBack);

  /** This is a shortcut for simply fetching the first window in
    * front to back order.
    * @param  aWindowType return the topmost window of this type.
    *                     ("type" is the |windowtype| attribute of
    *                     the XML <window> element.)
    *                     If null, return the topmost window of any type.
    * @return the topmost window
    */
  nsIDOMWindow getMostRecentWindow(in wstring aWindowType);

  /** Add the window to the list of known windows. Listeners (see
    * addListener) will be notified through their onOpenWindow method.
    * @param aWindow the window to add
    */
  [noscript] void registerWindow(in nsIXULWindow aWindow);

  /** Remove the window from the list of known windows. Listeners (see
    * addListener) will be be notified through their onCloseWindow method.
    * @param aWindow the window to remove
    */
  [noscript] void unregisterWindow(in nsIXULWindow aWindow);

  /** Call this method when a window gains focus. It's a primitive means of
    * determining the most recent window. It's no longer necessary and it
    * really should be removed.
    * @param aWindow the window which has gained focus
    */
  [noscript] void updateWindowTimeStamp(in nsIXULWindow aWindow);

  /** Call this method when a window's title changes. Listeners (see
    * addListener) will be notified through their onWindowTitleChange method.
    * @param aWindow the window whose title has changed
    * @param inTitle the window's new title
    */
  [noscript] void updateWindowTitle(in nsIXULWindow aWindow,
                                    in wstring inTitle );

  /* z-ordering: */

  const unsigned long zLevelTop    = 1;
  const unsigned long zLevelBottom = 2;
  const unsigned long zLevelBelow  = 3; // below some window

  /** A window wants to be moved in z-order. Calculate whether and how
    * it should be constrained. Note this method is advisory only:
    * it changes nothing either in WindowMediator's internal state
    * or with the window.
    * Note it compares the nsIXULWindow to nsIWidgets. A pure interface
    * would use all nsIXULWindows. But we expect this to be called from
    * callbacks originating in native window code. They are expected to
    * hand us comparison values which are pulled from general storage
    * in the native widget, and may not correspond to an nsIWidget at all.
    * For that reason this interface requires only objects one step
    * removed from the native window (nsIWidgets), and its implementation
    * must be very understanding of what may be completely invalid
    * pointers in those parameters.
    *
    * @param inWindow the window in question
    * @param inPosition requested position
    *                   values: zLevelTop: topmost window. zLevelBottom: bottom.
    *                   zLevelBelow: below ioBelow. (the value of ioBelow will
    *                   be ignored for zLevelTop and Bottom.)
    * @param inBelow if inPosition==zLevelBelow, the window
    *                 below which inWindow wants to be placed. Otherwise this
    *                 variable is ignored.
    * @param outPosition constrained position, values like inPosition.
    * @param outBelow if outPosition==zLevelBelow, the window
    *                 below which inWindow should be placed. Otherwise this
    *                 this value will be null.
    * @return PR_TRUE if the position returned is different from
    *         the position given.
    */

  [noscript] boolean calculateZPosition(in nsIXULWindow   inWindow,
                                        in unsigned long  inPosition,
                                        in nsIWidget      inBelow,
                                        out unsigned long outPosition,
                                        out nsIWidget     outBelow);

  /** A window has been positioned behind another. Inform WindowMediator
    * @param inWindow the window in question
    * @param inPosition new position. values:
    *                   zLevelTop: topmost window.
    *                   zLevelBottom: bottom.
    *                   zLevelBelow: below inBelow. (inBelow is ignored
    *                                for other values of inPosition.)
    * @param inBelow the window inWindow is behind, if zLevelBelow
    */
  [noscript] void setZPosition(in nsIXULWindow inWindow,
                               in unsigned long inPosition,
                               in nsIXULWindow inBelow);

  /** Return the window's Z level (as defined in nsIXULWindow).
    * @param aWindow the window in question
    * @return aWindow's z level
    */
  [noscript] PRUint32 getZLevel(in nsIXULWindow aWindow);

  /** Set the window's Z level (as defined in nsIXULWindow). The implementation
    * will reposition the window as necessary to match its new Z level.
    * The implementation will assume a window's Z level to be
    * nsIXULWindow::normalZ until it has been informed of a different level.
    * @param aWindow the window in question
    * @param aZLevel the window's new Z level
    */
  [noscript] void setZLevel(in nsIXULWindow aWindow, in PRUint32 aZLevel);

  /** Register a listener for window status changes.
    * keeps strong ref? (to be decided)
    * @param aListener the listener to register
    */
  void addListener(in nsIWindowMediatorListener aListener);

  /** Unregister a listener of window status changes.
    * @param aListener the listener to unregister
    */
  void removeListener(in nsIWindowMediatorListener aListener);
};
