widget/ScreenManager.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 "ScreenManager.h"
   8
   9 #include "mozilla/ClearOnShutdown.h"
  10 #include "mozilla/dom/ContentParent.h"
  11 #include "mozilla/dom/DOMTypes.h"
  12 #include "mozilla/Logging.h"
  13 #include "mozilla/StaticPtr.h"
  14
  15 static mozilla::LazyLogModule sScreenLog("WidgetScreen");
  16
  17 namespace mozilla {
  18 namespace widget {
  19
  20 NS_IMPL_ISUPPORTS(ScreenManager, nsIScreenManager)
  21
  22 ScreenManager::ScreenManager() {}
  23
  24 ScreenManager::~ScreenManager() {}
  25
  26 static StaticRefPtr<ScreenManager> sSingleton;
  27
  28 ScreenManager& ScreenManager::GetSingleton() {
  29   if (!sSingleton) {
  30     sSingleton = new ScreenManager();
  31     ClearOnShutdown(&sSingleton);
  32   }
  33   return *sSingleton;
  34 }
  35
  36 already_AddRefed<ScreenManager> ScreenManager::GetAddRefedSingleton() {
  37   RefPtr<ScreenManager> sm = &GetSingleton();
  38   return sm.forget();
  39 }
  40
  41 void ScreenManager::SetHelper(UniquePtr<Helper> aHelper) {
  42   mHelper = std::move(aHelper);
  43 }
  44
  45 void ScreenManager::Refresh(nsTArray<RefPtr<Screen>>&& aScreens) {
  46   MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refresh screens"));
  47
  48   mScreenList = std::move(aScreens);
  49
  50   CopyScreensToAllRemotesIfIsParent();
  51 }
  52
  53 void ScreenManager::Refresh(nsTArray<mozilla::dom::ScreenDetails>&& aScreens) {
  54   MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refresh screens from IPC"));
  55
  56   mScreenList.Clear();
  57   for (auto& screen : aScreens) {
  58     mScreenList.AppendElement(new Screen(screen));
  59   }
  60
  61   CopyScreensToAllRemotesIfIsParent();
  62 }
  63
  64 template <class Range>
  65 void ScreenManager::CopyScreensToRemoteRange(Range aRemoteRange) {
  66   AutoTArray<dom::ScreenDetails, 4> screens;
  67   for (auto& screen : mScreenList) {
  68     screens.AppendElement(screen->ToScreenDetails());
  69   }
  70   for (auto cp : aRemoteRange) {
  71     MOZ_LOG(sScreenLog, LogLevel::Debug,
  72             ("Send screens to [Pid %d]", cp->Pid()));
  73     if (!cp->SendRefreshScreens(screens)) {
  74       MOZ_LOG(sScreenLog, LogLevel::Error,
  75               ("SendRefreshScreens to [Pid %d] failed", cp->Pid()));
  76     }
  77   }
  78 }
  79
  80 void ScreenManager::CopyScreensToRemote(dom::ContentParent* aContentParent) {
  81   MOZ_ASSERT(aContentParent);
  82   MOZ_ASSERT(XRE_IsParentProcess());
  83
  84   auto range = {aContentParent};
  85   CopyScreensToRemoteRange(range);
  86 }
  87
  88 void ScreenManager::CopyScreensToAllRemotesIfIsParent() {
  89   if (XRE_IsContentProcess()) {
  90     return;
  91   }
  92
  93   MOZ_LOG(sScreenLog, LogLevel::Debug, ("Refreshing all ContentParents"));
  94
  95   CopyScreensToRemoteRange(
  96       dom::ContentParent::AllProcesses(dom::ContentParent::eLive));
  97 }
  98
  99 // Returns the screen that contains the rectangle. If the rect overlaps
 100 // multiple screens, it picks the screen with the greatest area of intersection.
 101 //
 102 // The coordinates are in desktop pixels.
 103 //
 104 NS_IMETHODIMP
 105 ScreenManager::ScreenForRect(int32_t aX, int32_t aY, int32_t aWidth,
 106                              int32_t aHeight, nsIScreen** aOutScreen) {
 107   if (mScreenList.IsEmpty()) {
 108     MOZ_LOG(sScreenLog, LogLevel::Warning,
 109             ("No screen available. This can happen in xpcshell."));
 110     RefPtr<Screen> ret = new Screen(
 111         LayoutDeviceIntRect(), LayoutDeviceIntRect(), 0, 0,
 112         DesktopToLayoutDeviceScale(), CSSToLayoutDeviceScale(), 96 /* dpi */);
 113     ret.forget(aOutScreen);
 114     return NS_OK;
 115   }
 116
 117   // Optimize for the common case. If the number of screens is only
 118   // one then just return the primary screen.
 119   if (mScreenList.Length() == 1) {
 120     return GetPrimaryScreen(aOutScreen);
 121   }
 122
 123   // which screen should we return?
 124   Screen* which = mScreenList[0].get();
 125
 126   // walk the list of screens and find the one that has the most
 127   // surface area.
 128   uint32_t area = 0;
 129   DesktopIntRect windowRect(aX, aY, aWidth, aHeight);
 130   for (auto& screen : mScreenList) {
 131     int32_t x, y, width, height;
 132     x = y = width = height = 0;
 133     screen->GetRectDisplayPix(&x, &y, &width, &height);
 134     // calculate the surface area
 135     DesktopIntRect screenRect(x, y, width, height);
 136     screenRect.IntersectRect(screenRect, windowRect);
 137     uint32_t tempArea = screenRect.Area();
 138     if (tempArea > area) {
 139       which = screen.get();
 140       area = tempArea;
 141     }
 142   }
 143
 144   // If the rect intersects one or more screen,
 145   // return the screen that has the largest intersection.
 146   if (area > 0) {
 147     RefPtr<Screen> ret = which;
 148     ret.forget(aOutScreen);
 149     return NS_OK;
 150   }
 151
 152   // If the rect does not intersect a screen, find
 153   // a screen that is nearest to the rect.
 154   uint32_t distance = UINT32_MAX;
 155   for (auto& screen : mScreenList) {
 156     int32_t x, y, width, height;
 157     x = y = width = height = 0;
 158     screen->GetRectDisplayPix(&x, &y, &width, &height);
 159
 160     uint32_t distanceX = 0;
 161     if (aX > (x + width)) {
 162       distanceX = aX - (x + width);
 163     } else if ((aX + aWidth) < x) {
 164       distanceX = x - (aX + aWidth);
 165     }
 166
 167     uint32_t distanceY = 0;
 168     if (aY > (y + height)) {
 169       distanceY = aY - (y + height);
 170     } else if ((aY + aHeight) < y) {
 171       distanceY = y - (aY + aHeight);
 172     }
 173
 174     uint32_t tempDistance = distanceX * distanceX + distanceY * distanceY;
 175     if (tempDistance < distance) {
 176       which = screen.get();
 177       distance = tempDistance;
 178       if (distance == 0) {
 179         break;
 180       }
 181     }
 182   }
 183
 184   RefPtr<Screen> ret = which;
 185   ret.forget(aOutScreen);
 186   return NS_OK;
 187 }
 188
 189 // The screen with the menubar/taskbar. This shouldn't be needed very
 190 // often.
 191 //
 192 NS_IMETHODIMP
 193 ScreenManager::GetPrimaryScreen(nsIScreen** aPrimaryScreen) {
 194   if (mScreenList.IsEmpty()) {
 195     MOZ_LOG(sScreenLog, LogLevel::Warning,
 196             ("No screen available. This can happen in xpcshell."));
 197     RefPtr<Screen> ret = new Screen(
 198         LayoutDeviceIntRect(), LayoutDeviceIntRect(), 0, 0,
 199         DesktopToLayoutDeviceScale(), CSSToLayoutDeviceScale(), 96 /* dpi */);
 200     ret.forget(aPrimaryScreen);
 201     return NS_OK;
 202   }
 203
 204   RefPtr<Screen> ret = mScreenList[0];
 205   ret.forget(aPrimaryScreen);
 206   return NS_OK;
 207 }
 208
 209 }  // namespace widget
 210 }  // namespace mozilla