Bug 734391 - coalesce the device motion events. r=jdm

dom/system/Makefile.in

@@ -87,6 +87,9 @@ EXPORTS     = \
   nsDeviceMotion.h \
   $(NULL)
 
+# We fire the nsDOMDeviceAcceleration
+LOCAL_INCLUDES += -I$(topsrcdir)/content/events/src
+
 include $(topsrcdir)/config/config.mk
 
 # we don't want the shared lib, but we want to force the creation of a static lib.

dom/system/android/Makefile.in

@@ -59,6 +59,7 @@ CPPSRCS     = \
         $(NULL)
 
 LOCAL_INCLUDES  += -I$(topsrcdir)/dom/src/geolocation \
+                     -I$(topsrcdir)/content/events/src
                      $(NULL)
 
 include $(topsrcdir)/config/rules.mk

dom/system/cocoa/Makefile.in

@@ -49,6 +49,9 @@ LIBXUL_LIBRARY   = 1
 FORCE_STATIC_LIB = 1
 EXPORT_LIBRARY = 1
 
+# We fire the nsDOMDeviceAcceleration
+LOCAL_INCLUDES += -I$(topsrcdir)/content/events/src
+
 include $(topsrcdir)/config/config.mk
 
 CMMSRCS     = \

dom/system/nsDeviceMotion.cpp

@@ -44,11 +44,11 @@
 #include "nsIDOMEventTarget.h"
 #include "nsIServiceManager.h"
 #include "nsIPrivateDOMEvent.h"
-#include "nsIDOMDeviceOrientationEvent.h"
-#include "nsIDOMDeviceMotionEvent.h"
 #include "nsIServiceManager.h"
 #include "nsIPrefService.h"
-#include "nsDOMDeviceMotionEvent.h"
+
+using mozilla::TimeStamp;
+using mozilla::TimeDuration;
 
 // also see sDefaultSensorHint in mobile/android/base/GeckoAppShell.java
 #define DEFAULT_SENSOR_POLL 100
@@ -361,45 +361,53 @@ nsDeviceMotion::FireDOMMotionEvent(nsIDOMDocument *domdoc,
                                    double x,
                                    double y,
                                    double z) {
+  // Attempt to coalesce events
+  bool fireEvent = TimeStamp::Now() > mLastDOMMotionEventTime + TimeDuration::FromMilliseconds(DEFAULT_SENSOR_POLL);
+
+  switch (type) {
+  case nsIDeviceMotionData::TYPE_LINEAR_ACCELERATION:
+      mLastAcceleration = new nsDOMDeviceAcceleration(x, y, z);
+      break;
+  case nsIDeviceMotionData::TYPE_ACCELERATION:
+      mLastAccelerationIncluduingGravity = new nsDOMDeviceAcceleration(x, y, z);
+      break;
+  case nsIDeviceMotionData::TYPE_GYROSCOPE:
+      mLastRotationRate = new nsDOMDeviceRotationRate(x, y, z);
+      break;
+  }
+
+  if (!fireEvent && (!mLastAcceleration || !mLastAccelerationIncluduingGravity || !mLastRotationRate)) {
+      return;
+  }
+
   nsCOMPtr<nsIDOMEvent> event;
-  bool defaultActionEnabled = true;
   domdoc->CreateEvent(NS_LITERAL_STRING("DeviceMotionEvent"), getter_AddRefs(event));
 
   nsCOMPtr<nsIDOMDeviceMotionEvent> me = do_QueryInterface(event);
 
   if (!me) {
     return;
-}
-
-  nsRefPtr<nsDOMDeviceAcceleration> acceleration;
-  nsRefPtr<nsDOMDeviceAcceleration> accelerationIncluduingGravity;
-  nsRefPtr<nsDOMDeviceRotationRate> rotationRate;
-
-  switch (type) {
-  case nsIDeviceMotionData::TYPE_LINEAR_ACCELERATION:
-      acceleration = new nsDOMDeviceAcceleration(x, y, z);
-      break;
-  case nsIDeviceMotionData::TYPE_ACCELERATION:
-      accelerationIncluduingGravity = new nsDOMDeviceAcceleration(x, y, z);
-      break;
-  case nsIDeviceMotionData::TYPE_GYROSCOPE:
-      rotationRate = new nsDOMDeviceRotationRate(x, y, z);
-      break;
   }
 
-
   me->InitDeviceMotionEvent(NS_LITERAL_STRING("devicemotion"),
                             true,
                             false,
-                            acceleration,
-                            accelerationIncluduingGravity,
-                            rotationRate,
+                            mLastAcceleration,
+                            mLastAccelerationIncluduingGravity,
+                            mLastRotationRate,
                             DEFAULT_SENSOR_POLL);
 
   nsCOMPtr<nsIPrivateDOMEvent> privateEvent = do_QueryInterface(event);
   if (privateEvent)
     privateEvent->SetTrusted(true);
   
+  bool defaultActionEnabled = true;
   target->DispatchEvent(event, &defaultActionEnabled);
+
+  mLastRotationRate = nsnull;
+  mLastAccelerationIncluduingGravity = nsnull;
+  mLastAcceleration = nsnull;
+  mLastDOMMotionEventTime = TimeStamp::Now();
+
 }
 

dom/system/nsDeviceMotion.h

@@ -43,6 +43,10 @@
 #include "nsTArray.h"
 #include "nsCOMPtr.h"
 #include "nsITimer.h"
+#include "nsIDOMDeviceOrientationEvent.h"
+#include "nsIDOMDeviceMotionEvent.h"
+#include "nsDOMDeviceMotionEvent.h"
+#include "mozilla/TimeStamp.h"
 
 #define NS_DEVICE_MOTION_CID \
 { 0xecba5203, 0x77da, 0x465a, \
@@ -91,10 +95,16 @@ private:
                           double x,
                           double y,
                           double z);
-  bool mEnabled;
 
   virtual void Startup()  = 0;
   virtual void Shutdown() = 0;
+
+  bool mEnabled;
+  mozilla::TimeStamp mLastDOMMotionEventTime;
+  nsRefPtr<nsDOMDeviceAcceleration> mLastAcceleration;
+  nsRefPtr<nsDOMDeviceAcceleration> mLastAccelerationIncluduingGravity;
+  nsRefPtr<nsDOMDeviceRotationRate> mLastRotationRate;
+
 };
 
 #endif

dom/system/unix/Makefile.in

@@ -82,4 +82,7 @@ LOCAL_INCLUDES  += $(MOZ_QT_CFLAGS) \
 endif
 endif
 
+# We fire the nsDOMDeviceAcceleration
+LOCAL_INCLUDES += -I$(topsrcdir)/content/events/src
+
 include $(topsrcdir)/config/rules.mk

dom/system/windows/Makefile.in

@@ -49,6 +49,9 @@ LIBXUL_LIBRARY   = 1
 FORCE_STATIC_LIB = 1
 EXPORT_LIBRARY = 1
 
+# We fire the nsDOMDeviceAcceleration
+LOCAL_INCLUDES += -I$(topsrcdir)/content/events/src
+
 include $(topsrcdir)/config/config.mk
 
 CPPSRCS     = \