widget/nsIScreen.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
   9 %{C++
  10 #include "Units.h"
  11
  12 /**
  13  * The display type of nsIScreen belongs to.
  14  */
  15 enum class DisplayType: int32_t {
  16   DISPLAY_PRIMARY,  // primary screen
  17   DISPLAY_EXTERNAL, // wired displays, such as HDMI, DisplayPort, etc.
  18   DISPLAY_VIRTUAL   // wireless displays, such as Chromecast, WiFi-Display, etc.
  19 };
  20 %}
  21
  22 [scriptable, builtinclass, uuid(826e80c8-d70f-42e2-8aa9-82c05f2a370a)]
  23 interface nsIScreen : nsISupports
  24 {
  25   /**
  26    * These report screen dimensions in (screen-specific) device pixels
  27    */
  28   void GetRect(out long left, out long top, out long width, out long height);
  29   void GetAvailRect(out long left, out long top, out long width, out long height);
  30
  31 %{C++
  32   mozilla::LayoutDeviceIntRect GetRect() {
  33     int32_t left = 0, top = 0, width = 0, height = 0;
  34     GetRect(&left, &top, &width, &height);
  35     return {left, top, width, height};
  36   }
  37
  38   mozilla::LayoutDeviceIntRect GetAvailRect() {
  39     int32_t left = 0, top = 0, width = 0, height = 0;
  40     GetAvailRect(&left, &top, &width, &height);
  41     return {left, top, width, height};
  42   }
  43 %}
  44
  45   /**
  46    * And these report in desktop pixels
  47    */
  48   void GetRectDisplayPix(out long left, out long top, out long width, out long height);
  49   void GetAvailRectDisplayPix(out long left, out long top, out long width, out long height);
  50
  51 %{C++
  52   mozilla::DesktopIntRect GetRectDisplayPix() {
  53     int32_t left = 0, top = 0, width = 0, height = 0;
  54     GetRectDisplayPix(&left, &top, &width, &height);
  55     return {left, top, width, height};
  56   }
  57
  58   mozilla::DesktopIntRect GetAvailRectDisplayPix() {
  59     int32_t left = 0, top = 0, width = 0, height = 0;
  60     GetAvailRectDisplayPix(&left, &top, &width, &height);
  61     return {left, top, width, height};
  62   }
  63 %}
  64
  65   readonly attribute long pixelDepth;
  66   readonly attribute long colorDepth;
  67
  68   /**
  69    * The number of device pixels per desktop pixel for this screen (for
  70    * hidpi configurations where there may be multiple device pixels per
  71    * desktop px and/or per CSS px).
  72    *
  73    * This seems poorly named (something like devicePixelsPerDesktopPixel
  74    * would be more accurate/explicit), but given that it is exposed to
  75    * front-end code and may also be used by add-ons, it's probably not
  76    * worth the disruption of changing it.
  77    *
  78    * Returns 1.0 if HiDPI mode is disabled or unsupported, or if the
  79    * host OS uses device pixels as its desktop pixel units (e.g. Windows 7 or
  80    * GTK/X11). Per-monitor DPI is available in Windows 8.1+, GTK/Wayland or
  81    * macOS.
  82    */
  83   [infallible] readonly attribute double contentsScaleFactor;
  84
  85   /**
  86    * The default number of device pixels per unscaled CSS pixel for this
  87    * screen. This is probably what contentsScaleFactor originally meant
  88    * to be, prior to confusion between CSS pixels and desktop pixel units.
  89    */
  90   [infallible] readonly attribute double defaultCSSScaleFactor;
  91
  92 %{C++
  93
  94   mozilla::DesktopToLayoutDeviceScale GetDesktopToLayoutDeviceScale() {
  95     return mozilla::DesktopToLayoutDeviceScale(GetContentsScaleFactor());
  96   }
  97
  98   mozilla::CSSToLayoutDeviceScale GetCSSToLayoutDeviceScale() {
  99     return mozilla::CSSToLayoutDeviceScale(GetDefaultCSSScaleFactor());
 100   }
 101
 102   mozilla::CSSToDesktopScale GetCSSToDesktopScale() {
 103     return GetCSSToLayoutDeviceScale() / GetDesktopToLayoutDeviceScale();
 104   }
 105
 106 %}
 107   /**
 108    * The DPI of the screen.
 109    */
 110   readonly attribute float dpi;
 111 };