Introduce PlatformEvent to handle Device events, Battery events and Gamepad events.

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 18 matching lines @@
  */
 
 #ifndef Platform_h
 #define Platform_h
 
 #ifdef WIN32
 #include <windows.h>
 #endif
 
 #include "WebAudioDevice.h"
+#include "WebBatteryStatusListener.h"
 #include "WebCommon.h"
 #include "WebData.h"
+#include "WebDeviceLightListener.h"
+#include "WebDeviceMotionListener.h"
+#include "WebDeviceOrientationListener.h"
 #include "WebGamepadListener.h"
 #include "WebGamepads.h"
 #include "WebGestureDevice.h"
 #include "WebGraphicsContext3D.h"
 #include "WebLocalizedString.h"
-#include "WebLockOrientationCallback.h"
+#include "WebPlatformEventType.h"
 #include "WebSpeechSynthesizer.h"
 #include "WebStorageQuotaCallbacks.h"
 #include "WebStorageQuotaType.h"
 #include "WebString.h"
 #include "WebURLError.h"
 #include "WebVector.h"
 
 class GrContext;
 
 namespace blink {
 
 class WebAudioBus;
-class WebBatteryStatusListener;
 class WebBlobRegistry;
 class WebContentDecryptionModule;
 class WebClipboard;
 class WebCompositorSupport;
 class WebConvertableToTraceFormat;
 class WebCookieJar;
 class WebCrypto;
 class WebDatabaseObserver;
-class WebDeviceLightListener;
-class WebDeviceMotionListener;
-class WebDeviceOrientationListener;
 class WebDiscardableMemory;
+class WebPlatformEventListener;
 class WebFallbackThemeEngine;
 class WebFileSystem;
 class WebFileUtilities;
 class WebFlingAnimator;
 class WebGestureCurveTarget;
 class WebGestureCurve;
 class WebGraphicsContext3DProvider;
 class WebIDBFactory;
 class WebMIDIAccessor;
 class WebMIDIAccessorClient;
@@ skipping 74 matching lines @@
     virtual WebAudioDevice* createAudioDevice(size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfChannels, double sampleRate, WebAudioDevice::RenderCallback*, const WebString& deviceId) { return 0; }
 
 
     // MIDI ----------------------------------------------------------------
 
     // Creates a platform dependent WebMIDIAccessor. MIDIAccessor under platform
     // creates and owns it.
     virtual WebMIDIAccessor* createMIDIAccessor(WebMIDIAccessorClient*) { return 0; }
 
 
-    // Battery -------------------------------------------------------------
-
-    // Sets the listener for watching battery status updates.
-    virtual void setBatteryStatusListener(blink::WebBatteryStatusListener*) { }
-
-
     // Blob ----------------------------------------------------------------
 
     // Must return non-null.
     virtual WebBlobRegistry* blobRegistry() { return 0; }
 
 
     // Database ------------------------------------------------------------
 
     // Opens a database file; dirHandle should be 0 if the caller does not need
     // a handle to the directory containing this file
@@ skipping 32 matching lines @@
     // IndexedDB ----------------------------------------------------------
 
     // Must return non-null.
     virtual WebIDBFactory* idbFactory() { return 0; }
 
 
     // Gamepad -------------------------------------------------------------
 
     virtual void sampleGamepads(WebGamepads& into) { into.length = 0; }
 
-    virtual void setGamepadListener(WebGamepadListener*) { }
-
 
     // History -------------------------------------------------------------
 
     // Returns the hash for the given canonicalized URL for use in visited
     // link coloring.
     virtual unsigned long long visitedLinkHash(
         const char* canonicalURL, size_t length) { return 0; }
 
     // Returns whether the given link hash is in the user's history. The
     // hash must have been generated by calling VisitedLinkHash().
@@ skipping 360 matching lines @@
 
     virtual void didStartWorkerRunLoop(const WebWorkerRunLoop&) { }
     virtual void didStopWorkerRunLoop(const WebWorkerRunLoop&) { }
 
 
     // WebCrypto ----------------------------------------------------------
 
     virtual WebCrypto* crypto() { return 0; }
 
 
-    // Device Motion / Orientation / Light ----------------------------------------
+    // Platform events -----------------------------------------------------
+    // Device Orientation, Device Motion, Device Light, Battery, Gamepad.
 
-    // Sets a Listener to listen for device motion data updates.
-    // If null, the platform stops providing device motion data to the current listener.
+    // Request the platform to start listening to the specified event and

[timvolodine, 2014/07/30 12:56:41]

nit: "to the specified event" -> "to events of specified type"?
also in stopListening()

[mlamouri (slow - plz ping), 2014/08/01 10:21:05]

Done.

+    // notify the given listener (if not null) when there is an update.
+    virtual void startListening(blink::WebPlatformEventType type, blink::WebPlatformEventListener* listener)

[abarth-chromium, 2014/07/29 22:24:38]

Why virtual?

It seems like we should implement this function in Source/platform rather than
in Platform.h.  The function here are mostly just stubs.

[mlamouri (slow - plz ping), 2014/07/29 22:27:54]

The only intent is to not break Chromium when this land. content/ would then
implement startListening() and stopListening() and we will be able to remove
those. If you prefer that temporary code to live in another place, I could do
that. What would be the best place?

+    {
+        switch (type) {
+        case blink::WebPlatformEventDeviceMotion:
+            setDeviceMotionListener(static_cast<blink::WebDeviceMotionListener*>(listener));
+            break;
+        case blink::WebPlatformEventDeviceOrientation:
+            setDeviceOrientationListener(static_cast<blink::WebDeviceOrientationListener*>(listener));
+            break;
+        case blink::WebPlatformEventDeviceLight:
+            setDeviceLightListener(static_cast<blink::WebDeviceLightListener*>(listener));
+            break;
+        case blink::WebPlatformEventBattery:
+            setBatteryStatusListener(static_cast<blink::WebBatteryStatusListener*>(listener));
+            break;
+        case blink::WebPlatformEventGamepad:
+            setGamepadListener(static_cast<blink::WebGamepadListener*>(listener));
+            break;
+        }
+    }
+
+    // Request the platform to stop listening to the specified event and no
+    // longer notify the listener, if any.
+    virtual void stopListening(blink::WebPlatformEventType type)
+    {
+        switch (type) {
+        case blink::WebPlatformEventDeviceMotion:
+            setDeviceMotionListener(0);
+            break;
+        case blink::WebPlatformEventDeviceOrientation:
+            setDeviceOrientationListener(0);
+            break;
+        case blink::WebPlatformEventDeviceLight:
+            setDeviceLightListener(0);
+            break;
+        case blink::WebPlatformEventBattery:
+            setBatteryStatusListener(0);
+            break;
+        case blink::WebPlatformEventGamepad:
+            setGamepadListener(0);
+            break;
+        }
+    }
+
+    // Deprecated: remove when content/ is updated.

[abarth-chromium, 2014/07/30 05:56:23]

I see, this comment was intended to communicate that information.

[mlamouri (slow - plz ping), 2014/08/01 10:21:05]

Yes. I've added a FIXME to make it clearer.

     virtual void setDeviceMotionListener(blink::WebDeviceMotionListener*) { }
-
-    // Sets a Listener to listen for device orientation data updates.
-    // If null, the platform stops providing device orientation data to the current listener.
     virtual void setDeviceOrientationListener(blink::WebDeviceOrientationListener*) { }
-
-    // Sets a Listener to listen for device light data updates.
-    // If null, the platform stops providing device light data to the current listener.
     virtual void setDeviceLightListener(blink::WebDeviceLightListener*) { }
+    virtual void setBatteryStatusListener(blink::WebBatteryStatusListener*) { }
+    virtual void setGamepadListener(blink::WebGamepadListener*) { }
 
 
     // Quota -----------------------------------------------------------
 
     // Queries the storage partition's storage usage and quota information.
     // WebStorageQuotaCallbacks::didQueryStorageUsageAndQuota will be called
     // with the current usage and quota information for the partition. When
     // an error occurs WebStorageQuotaCallbacks::didFail is called with an
     // error code.
     virtual void queryStorageUsageAndQuota(
@@ skipping 12 matching lines @@
     virtual WebNotificationPresenter* notificationPresenter() { return 0; }
 
 
 protected:
     virtual ~Platform() { }
 };
 
 } // namespace blink
 
 #endif