Move DIP translation from ui/aura to ui/compositor

ui/gfx/compositor/dip_util.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/gfx/compositor/dip_util.h"
+
+#include "base/command_line.h"
+#include "ui/gfx/compositor/compositor.h"
+#include "ui/gfx/compositor/compositor_switches.h"
+#include "ui/gfx/compositor/layer.h"
+#include "ui/gfx/monitor.h"
+#include "ui/gfx/point.h"
+#include "ui/gfx/size.h"
+#include "ui/gfx/rect.h"
+
+namespace ui {
+
+bool IsDIPEnabled() {
+  static const bool dip_enabled =
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kUIEnableDIP);
+  return dip_enabled;
+}
+
+float GetDeviceScaleFactor(const Layer* layer) {
+  if (!IsDIPEnabled())
+    return 1.0f;
+  Layer* nonconst = const_cast<Layer*>(layer);

[piman, 2012/05/04 18:46:06]

We should add a const version of GetCompositor() instead.

+  Compositor* c = nonconst->GetCompositor();
+  return c ?
+      c->device_scale_factor() : gfx::Monitor::GetDefaultDeviceScaleFactor();
+}  // namespace
+
+gfx::Point ConvertPointToDIP(const Layer* layer,
+                             const gfx::Point& point_in_pixel) {
+  if (IsDIPEnabled())
+    return point_in_pixel.Scale(1.0f / GetDeviceScaleFactor(layer));
+  else
+    return point_in_pixel;
+}
+
+gfx::Size ConvertSizeToDIP(const Layer* layer,
+                           const gfx::Size& size_in_pixel) {
+  if (IsDIPEnabled())
+    return size_in_pixel.Scale(1.0f / GetDeviceScaleFactor(layer));
+  else
+    return size_in_pixel;
+}
+
+gfx::Rect ConvertRectToDIP(const Layer* layer,
+                           const gfx::Rect& rect_in_pixel) {
+  if (IsDIPEnabled()) {
+    float scale = 1.0f / GetDeviceScaleFactor(layer);
+    return gfx::Rect(rect_in_pixel.origin().Scale(scale),
+                     rect_in_pixel.size().Scale(scale));
+  } else {
+    return rect_in_pixel;
+  }
+}
+
+gfx::Point ConvertPointToPixel(const Layer* layer,
+                               const gfx::Point& point_in_dip) {
+  if (IsDIPEnabled()) {
+    return point_in_dip.Scale(GetDeviceScaleFactor(layer));
+  } else {
+    return point_in_dip;
+  }
+}
+
+gfx::Size ConvertSizeToPixel(const Layer* layer,
+                             const gfx::Size& size_in_dip) {
+  if (IsDIPEnabled()) {
+    return size_in_dip.Scale(GetDeviceScaleFactor(layer));
+  } else {
+    return size_in_dip;
+  }
+}
+
+gfx::Rect ConvertRectToPixel(const Layer* layer,
+                             const gfx::Rect& rect_in_dip) {
+  if (IsDIPEnabled()) {
+    float scale = GetDeviceScaleFactor(layer);
+    return gfx::Rect(rect_in_dip.origin().Scale(scale),
+                     rect_in_dip.size().Scale(scale));
+  } else {
+    return rect_in_dip;
+  }
+}
+}  // namespace aura