Source code

Revision control

Other Tools

/* -*- 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"
%{C++
/**
* The display type of nsIScreen belongs to.
*/
enum class DisplayType: int32_t {
DISPLAY_PRIMARY, // primary screen
DISPLAY_EXTERNAL, // wired displays, such as HDMI, DisplayPort, etc.
DISPLAY_VIRTUAL // wireless displays, such as Chromecast, WiFi-Display, etc.
};
%}
[scriptable, uuid(826e80c8-d70f-42e2-8aa9-82c05f2a370a)]
interface nsIScreen : nsISupports
{
/**
* These report screen dimensions in (screen-specific) device pixels
*/
void GetRect(out long left, out long top, out long width, out long height);
void GetAvailRect(out long left, out long top, out long width, out long height);
/**
* And these report in desktop pixels
*/
void GetRectDisplayPix(out long left, out long top, out long width, out long height);
void GetAvailRectDisplayPix(out long left, out long top, out long width, out long height);
readonly attribute long pixelDepth;
readonly attribute long colorDepth;
/**
* The number of device pixels per desktop pixel for this screen (for
* hidpi configurations where there may be multiple device pixels per
* desktop px and/or per CSS px).
*
* This seems poorly named (something like devicePixelsPerDesktopPixel
* would be more accurate/explicit), but given that it is exposed to
* front-end code and may also be used by add-ons, it's probably not
* worth the disruption of changing it.
*
* Returns 1.0 if HiDPI mode is disabled or unsupported, or if the
* host OS uses device pixels as its desktop pixel units (e.g. Windows 7 or
* GTK/X11). Per-monitor DPI is available in Windows 8.1+, GTK/Wayland or
* macOS.
*/
readonly attribute double contentsScaleFactor;
/**
* The default number of device pixels per unscaled CSS pixel for this
* screen. This is probably what contentsScaleFactor originally meant
* to be, prior to confusion between CSS pixels and desktop pixel units.
*/
readonly attribute double defaultCSSScaleFactor;
/**
* The DPI of the screen.
*/
readonly attribute float dpi;
};