Index: chrome/browser/device_orientation/provider.h |
diff --git a/chrome/browser/device_orientation/provider.h b/chrome/browser/device_orientation/provider.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..aaa5106c95b290393f2dc3fbf390772337cf1256 |
--- /dev/null |
+++ b/chrome/browser/device_orientation/provider.h |
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+// Copyright (c) 2010 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#ifndef CHROME_BROWSER_DEVICE_ORIENTATION_PROVIDER_H_ |
+#define CHROME_BROWSER_DEVICE_ORIENTATION_PROVIDER_H_ |
+ |
+#include "base/logging.h" |
+#include "base/ref_counted.h" |
+ |
+namespace device_orientation { |
+ |
+class Orientation; |
+ |
+class Provider : public base::RefCounted<Provider> { |
+ public: |
+ class Observer { |
+ public: |
+ // Called when the orientation changes. |
+ // An Observer must not synchronously call Provider::RemoveObserver |
+ // or Provider::AddObserver when this is called. |
+ virtual void OnOrientationUpdate(const Orientation& orientation) = 0; |
+ }; |
+ |
+ // Returns a pointer to the singleton instance of this class. |
+ // The caller should store the returned pointer in a scoped_refptr. |
+ // The Provider instance is lazily constructed when GetInstance() is called, |
+ // and destructed when the last scoped_refptr referring to it is destructed. |
+ static Provider* GetInstance(); |
+ |
+ // Inject a mock Provider for testing. Only a weak pointer to the injected |
+ // object will be held by Provider, i.e. it does not itself contribute to the |
+ // injected object's reference count. |
+ static void SetInstanceForTests(Provider* provider); |
+ |
+ virtual void AddObserver(Observer* observer) {} |
+ virtual void RemoveObserver(Observer* observer) {} |
+ |
+ protected: |
+ Provider() {} |
+ virtual ~Provider() { |
+ DCHECK(instance_ == this); |
+ instance_ = NULL; |
+ } |
+ |
+ private: |
+ friend class base::RefCounted<Provider>; |
+ static Provider* instance_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(Provider); |
+}; |
+ |
+} // namespace device_orientation |
+ |
+#endif // CHROME_BROWSER_DEVICE_ORIENTATION_PROVIDER_H_ |