Bug 1216148 - Handle how geolocation acts when the app's visibility changes. r=kchen.

Add the wake lock api to geolocation.
If your app holds a lock, you can continue use geolocation service when your app is invisible.
Otherwise, your invisible app can't get any updated location.

dom/geolocation/nsGeolocation.cpp

@@ -20,15 +20,20 @@
 #include "nsContentUtils.h"
 #include "nsContentPermissionHelper.h"
 #include "nsIDocument.h"
+#include "nsIDOMEvent.h"
 #include "nsIObserverService.h"
 #include "nsPIDOMWindow.h"
 #include "nsThreadUtils.h"
+#include "mozilla/HalWakeLock.h"
+#include "mozilla/Hal.h"
 #include "mozilla/Services.h"
 #include "mozilla/unused.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/ClearOnShutdown.h"
+#include "mozilla/dom/Event.h"
 #include "mozilla/dom/PermissionMessageUtils.h"
 #include "mozilla/dom/SettingChangeNotificationBinding.h"
+#include "mozilla/dom/WakeLock.h"
 
 #include "nsJSUtils.h"
 #include "prdtoa.h"
@@ -66,6 +71,7 @@ class nsIPrincipal;
 using mozilla::Unused;          // <snicker>
 using namespace mozilla;
 using namespace mozilla::dom;
+using namespace mozilla::hal;
 
 class nsGeolocationRequest final
  : public nsIContentPermissionRequest
@@ -499,6 +505,10 @@ nsGeolocationRequest::Allow(JS::HandleValue aChoices)
     }
   }
 
+  if (mLocator->ContainsRequest(this)) {
+    return NS_OK;
+  }
+
   if (mIsWatchPositionRequest || !canUseCache) {
     // let the locator know we're pending
     // we will now be owned by the locator
@@ -1044,6 +1054,16 @@ nsGeolocationService::StartDevice(nsIPrincipal *aPrincipal)
   return NS_OK;
 }
 
+void
+nsGeolocationService::StopDisconnectTimer()
+{
+  if (mDisconnectTimer) {
+    mDisconnectTimer->Cancel();
+    mDisconnectTimer = nullptr;
+  }
+}
+
+
 void
 nsGeolocationService::SetDisconnectTimer()
 {
@@ -1096,10 +1116,7 @@ nsGeolocationService::UpdateAccuracy(bool aForceHigh)
 void
 nsGeolocationService::StopDevice()
 {
-  if(mDisconnectTimer) {
-    mDisconnectTimer->Cancel();
-    mDisconnectTimer = nullptr;
-  }
+  StopDisconnectTimer();
 
   if (XRE_IsContentProcess()) {
     ContentChild* cpc = ContentChild::GetSingleton();
@@ -1209,6 +1226,14 @@ Geolocation::Init(nsIDOMWindow* aContentDom)
     }
 
     mPrincipal = doc->NodePrincipal();
+
+    if (XRE_IsContentProcess()) {
+      doc->AddSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
+                                  /* listener */ this,
+                                  /* use capture */ true,
+                                  /* wants untrusted */ false);
+    }
+
   }
 
   // If no aContentDom was passed into us, we are being used
@@ -1221,6 +1246,58 @@ Geolocation::Init(nsIDOMWindow* aContentDom)
   return NS_OK;
 }
 
+bool
+Geolocation::ContainsRequest(nsGeolocationRequest* aRequest)
+{
+  if (aRequest->IsWatch()) {
+    if (mWatchingCallbacks.Contains(aRequest)) {
+	return true;
+    }
+  } else {
+    if (mPendingCallbacks.Contains(aRequest)) {
+        return true;
+    }
+  }
+  return false;
+}
+
+
+NS_IMETHODIMP
+Geolocation::HandleEvent(nsIDOMEvent* aEvent)
+{
+
+  nsAutoString type;
+  aEvent->GetType(type);
+  if (!type.EqualsLiteral("visibilitychange")) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIDocument> doc = do_QueryInterface(aEvent->InternalDOMEvent()->GetTarget());
+  MOZ_ASSERT(doc);
+
+  if (doc->Hidden()) {
+    WakeLockInformation info;
+    GetWakeLockInfo(NS_LITERAL_STRING("gps"), &info);
+
+    MOZ_ASSERT(XRE_IsContentProcess());
+    ContentChild* cpc = ContentChild::GetSingleton();
+    if (!info.lockingProcesses().Contains(cpc->GetID())) {
+      cpc->SendRemoveGeolocationListener();
+      mService->StopDisconnectTimer();
+    }
+  } else {
+    mService->SetDisconnectTimer();
+    for (uint32_t i = 0, length = mWatchingCallbacks.Length(); i < length; ++i) {
+      mWatchingCallbacks[i]->Allow(JS::UndefinedHandleValue);
+    }
+    for (uint32_t i = 0, length = mPendingCallbacks.Length(); i < length; ++i) {
+      mPendingCallbacks[i]->Allow(JS::UndefinedHandleValue);
+    }
+  }
+
+  return NS_OK;
+}
+
 void
 Geolocation::Shutdown()
 {
@@ -1228,6 +1305,18 @@ Geolocation::Shutdown()
   mPendingCallbacks.Clear();
   mWatchingCallbacks.Clear();
 
+  if (XRE_IsContentProcess()) {
+    nsCOMPtr<nsPIDOMWindow> window = do_QueryReferent(mOwner);
+    if (window) {
+      nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
+      if (doc) {
+        doc->RemoveSystemEventListener(NS_LITERAL_STRING("visibilitychange"),
+                                       this,
+                                       /* useCapture = */ true);
+      }
+    }
+  }
+
   if (mService) {
     mService->RemoveLocator(this);
     mService->UpdateAccuracy();

dom/geolocation/nsGeolocation.h

@@ -22,6 +22,7 @@
 #include "nsCycleCollectionParticipant.h"
 
 #include "nsGeoPosition.h"
+#include "nsIDOMEventListener.h"
 #include "nsIDOMGeoGeolocation.h"
 #include "nsIDOMGeoPosition.h"
 #include "nsIDOMGeoPositionError.h"
@@ -91,6 +92,7 @@ public:
 
   // create, or reinitalize the callback timer
   void     SetDisconnectTimer();
+  void     StopDisconnectTimer();
 
   // Update the accuracy and notify the provider if changed
   void     UpdateAccuracy(bool aForceHigh = false);
@@ -128,7 +130,8 @@ namespace dom {
  */
 class Geolocation final : public nsIDOMGeoGeolocation,
                           public nsIGeolocationUpdate,
-                          public nsWrapperCache
+                          public nsWrapperCache,
+                          public nsIDOMEventListener
 {
 public:
 
@@ -138,6 +141,8 @@ public:
   NS_DECL_NSIGEOLOCATIONUPDATE
   NS_DECL_NSIDOMGEOGEOLOCATION
 
+  NS_DECL_NSIDOMEVENTLISTENER
+
   Geolocation();
 
   nsresult Init(nsIDOMWindow* contentDom=nullptr);
@@ -154,6 +159,9 @@ public:
   // Register an allowed request
   void NotifyAllowedRequest(nsGeolocationRequest* aRequest);
 
+  // Check if callbacks arrays already contain this request
+  bool ContainsRequest(nsGeolocationRequest* aRequest);
+
   // Remove request from all callbacks arrays
   void RemoveRequest(nsGeolocationRequest* request);