dom/base/WindowOrientationObserver.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   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 "WindowOrientationObserver.h"
   8
   9 #include "nsGlobalWindow.h"
  10 #include "mozilla/Hal.h"
  11
  12 using namespace mozilla::dom;
  13
  14 /**
  15  * This class is used by nsGlobalWindowInner to implement window.orientation
  16  * and window.onorientationchange. This class is defined in its own file
  17  * because Hal.h pulls in windows.h and can't be included from
  18  * nsGlobalWindow.cpp
  19  */
  20 WindowOrientationObserver::WindowOrientationObserver(
  21     nsGlobalWindowInner* aGlobalWindow)
  22     : mWindow(aGlobalWindow) {
  23   MOZ_ASSERT(aGlobalWindow);
  24   hal::RegisterScreenConfigurationObserver(this);
  25
  26   hal::ScreenConfiguration config;
  27   hal::GetCurrentScreenConfiguration(&config);
  28   mAngle = config.angle();
  29 }
  30
  31 WindowOrientationObserver::~WindowOrientationObserver() {
  32   hal::UnregisterScreenConfigurationObserver(this);
  33 }
  34
  35 void WindowOrientationObserver::Notify(
  36     const mozilla::hal::ScreenConfiguration& aConfiguration) {
  37   uint16_t currentAngle = aConfiguration.angle();
  38   if (mAngle != currentAngle && mWindow->IsCurrentInnerWindow()) {
  39     mAngle = currentAngle;
  40     mWindow->GetOuterWindow()->DispatchCustomEvent(u"orientationchange"_ns);
  41   }
  42 }
  43
  44 /* static */
  45 int16_t WindowOrientationObserver::OrientationAngle() {
  46   hal::ScreenConfiguration config;
  47   hal::GetCurrentScreenConfiguration(&config);
  48   int16_t angle = static_cast<int16_t>(config.angle());
  49   // config.angle() returns 0, 90, 180 or 270.
  50   // window.orientation returns -90, 0, 90 or 180.
  51   return angle <= 180 ? angle : angle - 360;
  52 }