Extract touchscreen device management into a generic manager

ui/events/device_data_manager.cc

+// Copyright 2014 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 "ui/events/device_data_manager.h"
+
+#include "base/at_exit.h"
+#include "base/bind.h"
+#include "base/logging.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/geometry/point3_f.h"
+
+namespace ui {
+
+// static
+DeviceDataManager* DeviceDataManager::instance_ = NULL;
+
+DeviceDataManager::DeviceDataManager() {
+  CHECK(!instance_) << "Only one DeviceDataManager can be created.";
+  instance_ = this;
+  base::AtExitManager::RegisterTask(
+      base::Bind(&base::DeletePointer<DeviceDataManager>, this));
+
+  for (int i = 0; i < kMaxDeviceNum; ++i)
+    touch_device_to_display_map_[i] = gfx::Display::kInvalidDisplayID;
+}
+
+DeviceDataManager::~DeviceDataManager() {
+  CHECK_EQ(this, instance_);
+  instance_ = NULL;
+}
+
+// static
+DeviceDataManager* DeviceDataManager::GetInstance() {
+  CHECK(instance_) << "DeviceDataManager was not created.";
+  return instance_;
+}
+
+void DeviceDataManager::ClearTouchTransformerRecord() {
+  for (int i = 0; i < kMaxDeviceNum; i++) {
+    touch_device_transformer_map_[i] = gfx::Transform();
+    touch_device_to_display_map_[i] = gfx::Display::kInvalidDisplayID;
+  }
+}
+
+bool DeviceDataManager::IsTouchDeviceIdValid(int touch_device_id) const {
+  return (touch_device_id > 0 && touch_device_id < kMaxDeviceNum);
+}
+
+void DeviceDataManager::UpdateTouchInfoForDisplay(
+    int64_t display_id,
+    int touch_device_id,
+    const gfx::Transform& touch_transformer) {
+  if (IsTouchDeviceIdValid(touch_device_id)) {
+    touch_device_to_display_map_[touch_device_id] = display_id;
+    touch_device_transformer_map_[touch_device_id] = touch_transformer;
+  }
+}
+
+void DeviceDataManager::ApplyTouchTransformer(int touch_device_id,
+                                              float* x,
+                                              float* y) {
+  if (IsTouchDeviceIdValid(touch_device_id)) {
+    gfx::Point3F point(*x, *y, 0.0);
+    const gfx::Transform& trans =
+        touch_device_transformer_map_[touch_device_id];
+    trans.TransformPoint(&point);
+    *x = point.x();
+    *y = point.y();
+  }
+}
+
+int64_t DeviceDataManager::GetDisplayForTouchDevice(int touch_device_id) const {
+  if (IsTouchDeviceIdValid(touch_device_id))
+    return touch_device_to_display_map_[touch_device_id];
+  return gfx::Display::kInvalidDisplayID;
+}
+
+}  // namespace ui