widget/nsIScreenManager.idl

   1 /* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsISupports.idl"
   8 #include "nsIScreen.idl"
   9
  10 [scriptable, uuid(e8a96e60-6b61-4a14-bacc-53891604b502)]
  11 interface nsIScreenManager : nsISupports
  12 {
  13     //
  14     // Returns the screen that contains the rectangle. If the rect overlaps
  15     // multiple screens, it picks the screen with the greatest area of intersection.
  16     //
  17     // The coordinates are in pixels (not twips) and in screen coordinates.
  18     //
  19   nsIScreen screenForRect ( in long left, in long top, in long width, in long height ) ;
  20
  21     //
  22     // Returns the screen corresponding to the id. If no such screen exists,
  23     // this will throw NS_ERROR_FAILURE. The id is a unique numeric value
  24     // assigned to each screen, and is an attribute available on the nsIScreen
  25     // interface.
  26   nsIScreen screenForId ( in unsigned long id ) ;
  27
  28     // The screen with the menubar/taskbar. This shouldn't be needed very
  29     // often.
  30   readonly attribute nsIScreen primaryScreen;
  31
  32     // Holds the number of screens that are available
  33   readonly attribute unsigned long numberOfScreens;
  34
  35     // The default DPI scaling factor of the screen environment (number of
  36     // screen pixels corresponding to 1 CSS px, at the default zoom level).
  37     //
  38     // This is currently fixed at 1.0 on most platforms, but varies on Windows
  39     // if the "logical DPI" scaling option in the Display control panel is set
  40     // to a value other than 100% (e.g. 125% or 150% are increasingly common
  41     // defaults on laptops with high-dpi screens). See bug 851520.
  42     //
  43     // NOTE that on OS X, this does -not- reflect the "backing scale factor"
  44     // used to support Retina displays, which is a per-display property,
  45     // not a system-wide scaling factor. The default ratio of CSS pixels to
  46     // Cocoa points remains 1:1, even on a Retina screen where one Cocoa point
  47     // corresponds to two device pixels. (This is exposed via other APIs:
  48     // see window.devicePixelRatio).
  49     //
  50     // NOTE also that on Linux, this does -not- currently reflect changes
  51     // to the system-wide (X11 or Gtk2) DPI value, as Firefox does not yet
  52     // honor these settings. See bug 798362 and bug 712898.
  53   readonly attribute float systemDefaultScale;
  54
  55     // Returns the nsIScreen instance for the given native widget pointer;
  56     // the pointer is specific to the particular widget implementation,
  57     // and is generally of the same type that NS_NATIVE_WINDOW is.
  58   [noscript] nsIScreen screenForNativeWidget ( in voidPtr nativeWidget );
  59 };
  60
  61
  62 %{ C++
  63
  64 %}