Optimization: avoid making 4 JNI calls to get touch device attributes.

ui/base/touch/touch_device_win.cc

 // 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 "ui/base/touch/touch_device.h"
 #include "base/logging.h"
 #include "base/win/windows_version.h"
 #include <windows.h>
 
 namespace ui {
 
 namespace {
 
 bool IsTouchDevicePresent() {
   int value = GetSystemMetrics(SM_DIGITIZER);
   return (value & NID_READY) &&
       ((value & NID_INTEGRATED_TOUCH) || (value & NID_EXTERNAL_TOUCH));
 }
 
-}  // namespace
-
-TouchScreensAvailability GetTouchScreensAvailability() {
-  if (!IsTouchDevicePresent())
-    return TouchScreensAvailability::NONE;
-
-  return TouchScreensAvailability::ENABLED;
-}
-
-int MaxTouchPoints() {
-  if (!IsTouchDevicePresent())
-    return 0;
-
-  return GetSystemMetrics(SM_MAXIMUMTOUCHES);
-}
-
 int GetAvailablePointerTypes() {
   int available_pointer_types = 0;
   if (IsTouchDevicePresent())
     available_pointer_types |= POINTER_TYPE_COARSE;
   if (GetSystemMetrics(SM_MOUSEPRESENT) != 0 &&
       GetSystemMetrics(SM_CMOUSEBUTTONS) > 0)
     available_pointer_types |= POINTER_TYPE_FINE;
 
   if (available_pointer_types == 0)
     available_pointer_types = POINTER_TYPE_NONE;
 
   return available_pointer_types;
 }
 
-PointerType GetPrimaryPointerType() {
-  int available_pointer_types = GetAvailablePointerTypes();
-  if (available_pointer_types & POINTER_TYPE_FINE)
-    return POINTER_TYPE_FINE;
-  if (available_pointer_types & POINTER_TYPE_COARSE)
-    return POINTER_TYPE_COARSE;
-  DCHECK_EQ(available_pointer_types, POINTER_TYPE_NONE);
-  return POINTER_TYPE_NONE;
-}
-
 int GetAvailableHoverTypes() {
   int available_hover_types = 0;
   if (IsTouchDevicePresent())
     available_hover_types |= HOVER_TYPE_ON_DEMAND;
   if (GetSystemMetrics(SM_MOUSEPRESENT) != 0)
     available_hover_types |= HOVER_TYPE_HOVER;
 
   if (available_hover_types == 0)
     available_hover_types = HOVER_TYPE_NONE;
 
   return available_hover_types;
 }
 
-HoverType GetPrimaryHoverType() {
-  int available_hover_types = GetAvailableHoverTypes();
+}  // namespace
+
+TouchScreensAvailability GetTouchScreensAvailability() {
+  if (!IsTouchDevicePresent())
+    return TouchScreensAvailability::NONE;
+
+  return TouchScreensAvailability::ENABLED;
+}
+
+int MaxTouchPoints() {
+  if (!IsTouchDevicePresent())
+    return 0;
+
+  return GetSystemMetrics(SM_MAXIMUMTOUCHES);
+}
+
+PointerType GetPrimaryPointerType(int available_pointer_types) {
+  if (available_pointer_types & POINTER_TYPE_FINE)
+    return POINTER_TYPE_FINE;
+  if (available_pointer_types & POINTER_TYPE_COARSE)
+    return POINTER_TYPE_COARSE;
+  DCHECK_EQ(available_pointer_types, POINTER_TYPE_NONE);
+  return POINTER_TYPE_NONE;
+}
+
+HoverType GetPrimaryHoverType(int available_hover_types) {
   if (available_hover_types & HOVER_TYPE_HOVER)
     return HOVER_TYPE_HOVER;
   if (available_hover_types & HOVER_TYPE_ON_DEMAND)
     return HOVER_TYPE_ON_DEMAND;
   DCHECK_EQ(available_hover_types, HOVER_TYPE_NONE);
   return HOVER_TYPE_NONE;
 }
 
+std::pair<int, int> GetAvailablePointerAndHoverTypes() {
+  return std::make_pair(GetAvailablePointerTypes(), GetAvailableHoverTypes());
+}
+
 }  // namespace ui