widget/windows/ScreenHelperWin.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 "ScreenHelperWin.h"
   8
   9 #include "mozilla/Logging.h"
  10 #include "nsTArray.h"
  11 #include "WinUtils.h"
  12
  13 static mozilla::LazyLogModule sScreenLog("WidgetScreen");
  14
  15 namespace mozilla {
  16 namespace widget {
  17
  18 BOOL CALLBACK CollectMonitors(HMONITOR aMon, HDC, LPRECT, LPARAM ioParam) {
  19   auto screens = reinterpret_cast<nsTArray<RefPtr<Screen>>*>(ioParam);
  20   BOOL success = FALSE;
  21   MONITORINFOEX info;
  22   info.cbSize = sizeof(MONITORINFOEX);
  23   success = ::GetMonitorInfoW(aMon, &info);
  24   if (!success) {
  25     MOZ_LOG(sScreenLog, LogLevel::Error, ("GetMonitorInfoW failed"));
  26     return TRUE;  // continue the enumeration
  27   }
  28
  29   double scale = WinUtils::LogToPhysFactor(aMon);
  30   DesktopToLayoutDeviceScale contentsScaleFactor;
  31   if (WinUtils::IsPerMonitorDPIAware()) {
  32     contentsScaleFactor.scale = 1.0;
  33   } else {
  34     contentsScaleFactor.scale = scale;
  35   }
  36   CSSToLayoutDeviceScale defaultCssScaleFactor(scale);
  37   LayoutDeviceIntRect rect(info.rcMonitor.left, info.rcMonitor.top,
  38                            info.rcMonitor.right - info.rcMonitor.left,
  39                            info.rcMonitor.bottom - info.rcMonitor.top);
  40   LayoutDeviceIntRect availRect(info.rcWork.left, info.rcWork.top,
  41                                 info.rcWork.right - info.rcWork.left,
  42                                 info.rcWork.bottom - info.rcWork.top);
  43
  44   HDC hDC = CreateDC(nullptr, info.szDevice, nullptr, nullptr);
  45   if (!hDC) {
  46     MOZ_LOG(sScreenLog, LogLevel::Error, ("CollectMonitors CreateDC failed"));
  47     return TRUE;
  48   }
  49   uint32_t pixelDepth = ::GetDeviceCaps(hDC, BITSPIXEL);
  50   DeleteDC(hDC);
  51   if (pixelDepth == 32) {
  52     // If a device uses 32 bits per pixel, it's still only using 8 bits
  53     // per color component, which is what our callers want to know.
  54     // (Some devices report 32 and some devices report 24.)
  55     pixelDepth = 24;
  56   }
  57
  58   float dpi = WinUtils::MonitorDPI(aMon);
  59   MOZ_LOG(sScreenLog, LogLevel::Debug,
  60           ("New screen [%d %d %d %d (%d %d %d %d) %d %f %f %f]", rect.X(),
  61            rect.Y(), rect.Width(), rect.Height(), availRect.X(), availRect.Y(),
  62            availRect.Width(), availRect.Height(), pixelDepth,
  63            contentsScaleFactor.scale, defaultCssScaleFactor.scale, dpi));
  64   auto screen = new Screen(rect, availRect, pixelDepth, pixelDepth,
  65                            contentsScaleFactor, defaultCssScaleFactor, dpi);
  66   if (info.dwFlags & MONITORINFOF_PRIMARY) {
  67     // The primary monitor must be the first element of the screen list.
  68     screens->InsertElementAt(0, std::move(screen));
  69   } else {
  70     screens->AppendElement(std::move(screen));
  71   }
  72   return TRUE;
  73 }
  74
  75 void ScreenHelperWin::RefreshScreens() {
  76   MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refreshing screens"));
  77
  78   AutoTArray<RefPtr<Screen>, 4> screens;
  79   BOOL result = ::EnumDisplayMonitors(
  80       nullptr, nullptr, (MONITORENUMPROC)CollectMonitors, (LPARAM)&screens);
  81   if (!result) {
  82     NS_WARNING("Unable to EnumDisplayMonitors");
  83   }
  84   ScreenManager& screenManager = ScreenManager::GetSingleton();
  85   screenManager.Refresh(std::move(screens));
  86 }
  87
  88 }  // namespace widget
  89 }  // namespace mozilla