widget/nsIScreenManager.idl
author Nicholas Nethercote <nnethercote@mozilla.com>
Wed, 25 Oct 2017 10:22:38 +1100
changeset 387909 3d0093f961eec929caa370444cd0f7fcbfbc82bc
parent 353219 9ad613f8801ae30eebd7717430bb1f5c36b5701e
child 496097 7b50fcb49160b13628afc13d8f17334cd01184ca
permissions -rw-r--r--
Bug 1410794 - Change some |string| occurrences in nsIPrefBranch.idl to |ACString|. r=erahm. This makes the code nicer. In particular, it removes many getter_Copies() calls. The patch also converts a lot of nsCStrings to nsAutoCString, which will avoid heap allocation in the common case. The patch also renames PREF_CopyCharPref() as PREF_GetCStringPref(), because it's actually getting a string, not a char, and that matches the existing GetCString() and GetDefaultCString() methods. Correspondingly, it also renames PREF_SetCharPref() as PREF_SetCStringPref(). The |aPrefName| arguments in nsIPrefBranch.idl remain as |string| because they almost always involve passing in C string literals, and passing "foo" is much nicer than passing NS_LITERAL_CSTRING("foo"). It's worth noting that early versions of this patch used |AUTF8String| instead of |ACString|. But it turns out that libpref stores prefs internally as Latin1. And |ACString| is compatible with Latin1 but |AUTF8String| isn't, because non-ASCII Latin1 strings are not valid UTF-8!

/* -*- 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 "nsIScreen.idl"

[scriptable, uuid(e8a96e60-6b61-4a14-bacc-53891604b502)]
interface nsIScreenManager : nsISupports
{
    //
    // Returns the screen that contains the rectangle. If the rect overlaps
    // multiple screens, it picks the screen with the greatest area of intersection.
    //
    // The coordinates are in pixels (not twips) and in screen coordinates.
    //
  nsIScreen screenForRect ( in long left, in long top, in long width, in long height ) ;

    // The screen with the menubar/taskbar. This shouldn't be needed very
    // often.
  readonly attribute nsIScreen primaryScreen;
};