Index: content/browser/device_orientation/orientation.cc |
diff --git a/content/browser/device_orientation/orientation.cc b/content/browser/device_orientation/orientation.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..d6d630e5e23589b62700635b6bcb0d9f2e43b23d |
--- /dev/null |
+++ b/content/browser/device_orientation/orientation.cc |
@@ -0,0 +1,70 @@ |
+// Copyright (c) 2012 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. |
+ |
+#include "content/browser/device_orientation/orientation.h" |
+ |
+#include <cmath> |
+ |
+#include "content/common/device_orientation_messages.h" |
+ |
+namespace device_orientation { |
+ |
+Orientation::Orientation() |
+ : can_provide_alpha_(false), |
+ can_provide_beta_(false), |
+ can_provide_gamma_(false), |
+ can_provide_absolute_(false) { |
+} |
+ |
+Orientation::~Orientation() { |
+} |
+ |
+IPC::Message* Orientation::CreateIPCMessage(int render_view_id) const { |
+ DeviceOrientationMsg_Updated_Params params; |
+ params.can_provide_alpha = can_provide_alpha_; |
+ params.alpha = alpha_; |
+ params.can_provide_beta = can_provide_beta_; |
+ params.beta = beta_; |
+ params.can_provide_gamma = can_provide_gamma_; |
+ params.gamma = gamma_; |
+ params.can_provide_absolute = can_provide_absolute_; |
+ params.absolute = absolute_; |
+ |
+ return new DeviceOrientationMsg_Updated(render_view_id, params); |
+} |
+ |
+// Returns true if two orientations are considered different enough that |
+// observers should be notified of the new orientation. |
+bool Orientation::ShouldFireEvent(const DeviceData* old_data) const { |
+ scoped_refptr<const Orientation> old_orientation( |
+ static_cast<const Orientation*>(old_data)); |
+ |
+ return IsElementSignificantlyDifferent(can_provide_alpha_, |
+ old_orientation->can_provide_alpha(), |
+ alpha_, |
+ old_orientation->alpha()) || |
+ IsElementSignificantlyDifferent(can_provide_beta_, |
+ old_orientation->can_provide_beta(), |
+ beta_, |
+ old_orientation->beta()) || |
+ IsElementSignificantlyDifferent(can_provide_gamma_, |
+ old_orientation->can_provide_gamma(), |
+ gamma_, |
+ old_orientation->gamma()) || |
+ can_provide_absolute_ != old_orientation->can_provide_absolute() || |
+ absolute_ != old_orientation->absolute(); |
+} |
+ |
+bool Orientation::IsElementSignificantlyDifferent(bool can_provide_element1, |
+ bool can_provide_element2, double element1, double element2) { |
+ const double kThreshold = 0.1; |
+ |
+ if (can_provide_element1 != can_provide_element2) |
+ return true; |
+ if (can_provide_element1 && std::fabs(element1 - element2) >= kThreshold) |
+ return true; |
+ return false; |
+} |
+ |
+} // namespace device_orientation |