/* -*- Mode: C++; 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/. */

/**
 * nsIWindowProvider is a callback interface used by Gecko when it needs to
 * open a new window.  This interface can be implemented by Gecko consumers who
 * wish to provide a custom "new window" of their own (for example by returning
 * a new tab, an existing window, etc) instead of just having a real new
 * toplevel window open.
 */

#include "nsISupports.idl"

interface nsIDOMWindow;
interface nsIURI;

/**
 * The nsIWindowProvider interface exists so that the window watcher's default
 * behavior of opening a new window can be easly modified.  When the window
 * watcher needs to open a new window, it will first check with the
 * nsIWindowProvider it gets from the parent window.  If there is no provider
 * or the provider does not provide a window, the window watcher will proceed
 * to actually open a new window.
 */
[scriptable, uuid(f607bd66-08e5-4d2e-ad83-9f9f3ca17658)]
interface nsIWindowProvider : nsISupports
{
  /**
   * A method to request that this provider provide a window.  The window
   * returned need not to have the right name or parent set on it; setting
   * those is the caller's responsibility.  The provider can always return null
   * to have the caller create a brand-new window.
   *
   * @param aParent Must not be null.  This is the window that the caller wants
   *        to use as the parent for the new window.  Generally,
   *        nsIWindowProvider implementors can expect to be somehow related to
   *        aParent; the relationship may depend on the nsIWindowProvider
   *        implementation.
   *
   * @param aChromeFlags The chrome flags the caller will use to create a new
   *        window if this provider returns null.  See nsIWebBrowserChrome for
   *        the possible values of this field.
   *
   * @param aPositionSpecified Whether the attempt to create a window is trying
   *        to specify a position for the new window.
   *
   * @param aSizeSpecified Whether the attempt to create a window is trying to
   *        specify a size for the new window.
   *
   * @param aURI The URI to be loaded in the new window (may be NULL).  The
   *        nsIWindowProvider implementation must not load this URI into the
   *        window it returns.  This URI is provided solely to help the
   *        nsIWindowProvider implementation make decisions; the caller will
   *        handle loading the URI in the window returned if provideWindow
   *        returns a window.
   *
   *        When making decisions based on aURI, note that even when it's not
   *        null, aURI may not represent all relevant information about the
   *        load.  For example, the load may have extra load flags, POST data,
   *        etc.
   *
   * @param aName The name of the window being opened.  Setting the name on the
   *        return value of provideWindow will be handled by the caller; aName
   *        is provided solely to help the nsIWindowProvider implementation
   *        make decisions.
   *
   * @param aFeatures The feature string for the window being opened.  This may
   *        be empty.  The nsIWindowProvider implementation is allowed to apply
   *        the feature string to the window it returns in any way it sees fit.
   *        See the nsIWindowWatcher interface for details on feature strings.
   *
   * @param aWindowIsNew [out] Whether the window being returned was just
   *        created by the window provider implementation.  This can be used by
   *        callers to keep track of which windows were opened by the user as
   *        opposed to being opened programmatically.  This should be set to
   *        false if the window being returned existed before the
   *        provideWindow() call.  The value of this out parameter is
   *        meaningless if provideWindow() returns null.

   * @return A window the caller should use or null if the caller should just
   *         create a new window.  The returned window may be newly opened by
   *         the nsIWindowProvider implementation or may be a window that
   *         already existed.
   *
   * @throw NS_ERROR_ABORT if the caller should cease its attempt to open a new
   *                       window.
   *
   * @see nsIWindowWatcher for more information on aFeatures.
   * @see nsIWebBrowserChrome for more information on aChromeFlags.
   */
  nsIDOMWindow provideWindow(in nsIDOMWindow aParent,
                             in unsigned long aChromeFlags,
                             in boolean aCalledFromJS,
                             in boolean aPositionSpecified,
                             in boolean aSizeSpecified,
                             in nsIURI aURI,
                             in AString aName,
                             in AUTF8String aFeatures,
                             out boolean aWindowIsNew);
};
