Multiple DPI Tracking for ScreenWin

ui/gfx/win/screen_win_display.cc

 // Copyright 2016 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/win/screen_win_display.h"
 
+#include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/win/display_info.h"
 #include "ui/gfx/win/dpi.h"
+#include "ui/gfx/win/rect_util.h"
 
 namespace {
 
 gfx::Display CreateDisplayFromDisplayInfo(
     const gfx::win::DisplayInfo& display_info) {
   gfx::Display display(display_info.id());
-  gfx::Rect dip_screen_bounds(
-      gfx::win::ScreenToDIPRect(display_info.screen_rect()));
-  display.set_bounds(dip_screen_bounds);
+  float scale_factor = display_info.device_scale_factor();
+  display.set_device_scale_factor(scale_factor);
   display.set_work_area(
-      gfx::win::ScreenToDIPRect(display_info.screen_work_rect()));
-  display.SetScaleAndBounds(display_info.device_scale_factor(),
-                            display_info.screen_rect());
+      gfx::ScaleToEnclosingRect(display_info.screen_work_rect(),
+                                1.0f / scale_factor));
+  display.set_bounds(gfx::ScaleToEnclosingRect(display_info.screen_rect(),
+                     1.0f / scale_factor));
   display.set_rotation(display_info.rotation());
   return display;
 }
+
+gfx::Display CreateDisplayWithReferenceFromDisplayInfo(
+    const gfx::win::ScreenWinDisplay& reference,
+    const gfx::win::DisplayInfo& display_info) {
+  gfx::Display display(display_info.id());
+  float scale_factor = display_info.device_scale_factor();
+  display.set_device_scale_factor(scale_factor);
+  const gfx::Insets pixel_insets =
+      display_info.screen_rect().InsetsFrom(display_info.screen_work_rect());
+  const gfx::Insets scaled_insets = pixel_insets.Scale(1.0f / scale_factor,
+                                                       1.0f / scale_factor);
+  const gfx::Rect scaled_bounds =
+      gfx::win::ScaleAndPositionRect(reference.display().bounds(),
+                                     reference.pixel_bounds(),
+                                     display_info.screen_rect(),
+                                     scale_factor);
+  display.set_bounds(scaled_bounds);
+  gfx::Rect scaled_work_area(scaled_bounds);
+  scaled_work_area.Inset(scaled_insets);
+  display.set_work_area(scaled_work_area);
+  display.set_rotation(display_info.rotation());
+  return display;
+}
 
 } // namespace
 
 namespace gfx {
 namespace win {
 
 ScreenWinDisplay::ScreenWinDisplay() = default;
 
 ScreenWinDisplay::ScreenWinDisplay(const DisplayInfo& display_info)
     : display_(CreateDisplayFromDisplayInfo(display_info)),
       pixel_bounds_(display_info.screen_rect()) {}
 
+ScreenWinDisplay::ScreenWinDisplay(const ScreenWinDisplay& reference,
+                                   const DisplayInfo& display_info)
+    : display_(CreateDisplayWithReferenceFromDisplayInfo(reference,
+                                                         display_info)),
+      pixel_bounds_(display_info.screen_rect()) {}
+
 }  // namespace win
 }  // namespace gfx