ScreenWin Testability and Restructuring

ui/gfx/screen_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/gfx/screen_win.h"
 
 #include <windows.h>
-#include <stdint.h>
 
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/hash.h"
-#include "base/logging.h"
-#include "base/strings/utf_string_conversions.h"
-#include "base/win/win_util.h"
 #include "ui/gfx/display.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/win/display_manager.h"
 #include "ui/gfx/win/dpi.h"
+#include "ui/gfx/win/screen_win_display.h"
 
 namespace {
 
-MONITORINFOEX GetMonitorInfoForMonitor(HMONITOR monitor) {
-  MONITORINFOEX monitor_info;
-  ZeroMemory(&monitor_info, sizeof(MONITORINFOEX));
-  monitor_info.cbSize = sizeof(monitor_info);
-  GetMonitorInfo(monitor, &monitor_info);
-  return monitor_info;
+std::vector<gfx::Display> ScreenWinDisplaysToDisplays(
+    const std::vector<gfx::win::ScreenWinDisplay>& screen_win_displays) {
+  std::vector<gfx::Display> displays;
+  for (const auto& screen_win_display : screen_win_displays)
+    displays.push_back(screen_win_display.display());
+
+  return displays;
 }
 
-gfx::Display GetDisplay(const MONITORINFOEX& monitor_info) {
-  int64_t id =
-      static_cast<int64_t>(base::Hash(base::WideToUTF8(monitor_info.szDevice)));
-  gfx::Rect bounds = gfx::Rect(monitor_info.rcMonitor);
-  gfx::Display display(id);
-  display.set_bounds(gfx::win::ScreenToDIPRect(bounds));
-  display.set_work_area(
-      gfx::win::ScreenToDIPRect(gfx::Rect(monitor_info.rcWork)));
-  display.SetScaleAndBounds(gfx::GetDPIScale(), bounds);
-
-  DEVMODE mode;
-  memset(&mode, 0, sizeof(DEVMODE));
-  mode.dmSize = sizeof(DEVMODE);
-  mode.dmDriverExtra = 0;
-  if (EnumDisplaySettings(monitor_info.szDevice,
-                          ENUM_CURRENT_SETTINGS,
-                          &mode)) {
-    switch (mode.dmDisplayOrientation) {
-    case DMDO_DEFAULT:
-      display.set_rotation(gfx::Display::ROTATE_0);
-      break;
-    case DMDO_90:
-      display.set_rotation(gfx::Display::ROTATE_90);
-      break;
-    case DMDO_180:
-      display.set_rotation(gfx::Display::ROTATE_180);
-      break;
-    case DMDO_270:
-      display.set_rotation(gfx::Display::ROTATE_270);
-      break;
-    default:
-      NOTREACHED();
-    }
-  }
-
-  return display;
-}
-
-BOOL CALLBACK EnumMonitorCallback(HMONITOR monitor,
-                                  HDC hdc,
-                                  LPRECT rect,
-                                  LPARAM data) {
-  std::vector<gfx::Display>* all_displays =
-      reinterpret_cast<std::vector<gfx::Display>*>(data);
-  DCHECK(all_displays);
-
-  MONITORINFOEX monitor_info = GetMonitorInfoForMonitor(monitor);
-  gfx::Display display = GetDisplay(monitor_info);
-  all_displays->push_back(display);
-  return TRUE;
-}
-
-std::vector<gfx::Display> GetDisplays() {
-  std::vector<gfx::Display> displays;
-  EnumDisplayMonitors(NULL, NULL, EnumMonitorCallback,
-                      reinterpret_cast<LPARAM>(&displays));
-  return displays;
+inline gfx::win::DisplayManager* GetDisplayManager() {
+  return gfx::win::DisplayManager::GetInstance();
 }
 
 }  // namespace
 
 namespace gfx {
 
-ScreenWin::ScreenWin()
-    : singleton_hwnd_observer_(new SingletonHwndObserver(
-          base::Bind(&ScreenWin::OnWndProc, base::Unretained(this)))),
-      displays_(GetDisplays()) {
+ScreenWin::ScreenWin() : display_manager_(GetDisplayManager()) {
+  display_manager_->AddObserver(this);
 }
 
-ScreenWin::~ScreenWin() {}
+ScreenWin::~ScreenWin() {
+  display_manager_->RemoveObserver(this);
+}
 
 HWND ScreenWin::GetHWNDFromNativeView(NativeView window) const {
   NOTREACHED();
   return NULL;
 }
 
 NativeWindow ScreenWin::GetNativeWindowFromHWND(HWND hwnd) const {
   NOTREACHED();
   return NULL;
 }
 
 gfx::Point ScreenWin::GetCursorScreenPoint() {
   POINT pt;
-  GetCursorPos(&pt);
+  ::GetCursorPos(&pt);
   gfx::Point cursor_pos_pixels(pt);
   return gfx::win::ScreenToDIPPoint(cursor_pos_pixels);
 }
 
 gfx::NativeWindow ScreenWin::GetWindowUnderCursor() {
   POINT cursor_loc;
-  HWND hwnd = GetCursorPos(&cursor_loc) ? WindowFromPoint(cursor_loc) : NULL;
+  HWND hwnd =
+      ::GetCursorPos(&cursor_loc) ? ::WindowFromPoint(cursor_loc) : NULL;
   return GetNativeWindowFromHWND(hwnd);
 }
 
 gfx::NativeWindow ScreenWin::GetWindowAtScreenPoint(const gfx::Point& point) {
   gfx::Point point_in_pixels = gfx::win::DIPToScreenPoint(point);
   return GetNativeWindowFromHWND(WindowFromPoint(point_in_pixels.ToPOINT()));
 }
 
 int ScreenWin::GetNumDisplays() const {
-  return GetSystemMetrics(SM_CMONITORS);
+  return static_cast<int>(display_manager_->GetScreenWinDisplays().size());
 }
 
 std::vector<gfx::Display> ScreenWin::GetAllDisplays() const {
-  return displays_;
+  return ScreenWinDisplaysToDisplays(display_manager_->GetScreenWinDisplays());
 }
 
 gfx::Display ScreenWin::GetDisplayNearestWindow(gfx::NativeView window) const {
   HWND window_hwnd = GetHWNDFromNativeView(window);
   if (!window_hwnd) {
     // When |window| isn't rooted to a display, we should just return the
     // default display so we get some correct display information like the
     // scaling factor.
     return GetPrimaryDisplay();
   }
-
-  MONITORINFOEX monitor_info;
-  monitor_info.cbSize = sizeof(monitor_info);
-  GetMonitorInfo(MonitorFromWindow(window_hwnd, MONITOR_DEFAULTTONEAREST),
-                 &monitor_info);
-  return GetDisplay(monitor_info);
+  gfx::win::ScreenWinDisplay screen_win_display =
+      display_manager_->GetScreenWinDisplayNearestHWND(window_hwnd);
+  return screen_win_display.display();
 }
 
 gfx::Display ScreenWin::GetDisplayNearestPoint(const gfx::Point& point) const {
-  gfx::Point point_in_pixels = gfx::win::DIPToScreenPoint(point);
-  POINT initial_loc = { point_in_pixels.x(), point_in_pixels.y() };
-  HMONITOR monitor = MonitorFromPoint(initial_loc, MONITOR_DEFAULTTONEAREST);
-  MONITORINFOEX mi;
-  ZeroMemory(&mi, sizeof(MONITORINFOEX));
-  mi.cbSize = sizeof(mi);
-  if (monitor && GetMonitorInfo(monitor, &mi)) {
-    return GetDisplay(mi);
-  }
-  return gfx::Display();
+  gfx::Point screen_point(gfx::win::DIPToScreenPoint(point));
+  gfx::win::ScreenWinDisplay screen_win_display =
+      display_manager_->GetScreenWinDisplayNearestScreenPoint(screen_point);
+  return screen_win_display.display();
 }
 
 gfx::Display ScreenWin::GetDisplayMatching(const gfx::Rect& match_rect) const {
-  RECT other_bounds_rect = match_rect.ToRECT();
-  MONITORINFOEX monitor_info = GetMonitorInfoForMonitor(MonitorFromRect(
-      &other_bounds_rect, MONITOR_DEFAULTTONEAREST));
-  return GetDisplay(monitor_info);
+  gfx::win::ScreenWinDisplay screen_win_display =
+      display_manager_->GetScreenWinDisplayNearestScreenRect(match_rect);
+  return screen_win_display.display();
 }
 
 gfx::Display ScreenWin::GetPrimaryDisplay() const {
-  MONITORINFOEX mi = GetMonitorInfoForMonitor(
-      MonitorFromWindow(NULL, MONITOR_DEFAULTTOPRIMARY));
-  gfx::Display display = GetDisplay(mi);
-  // TODO(kevers|girard): Test if these checks can be reintroduced for high-DIP
-  // once more of the app is DIP-aware.
-  if (GetDPIScale() == 1.0) {
-    DCHECK_EQ(GetSystemMetrics(SM_CXSCREEN), display.size().width());
-    DCHECK_EQ(GetSystemMetrics(SM_CYSCREEN), display.size().height());
-  }
-  return display;
+  return display_manager_->GetPrimaryScreenWinDisplay().display();
 }
 
 void ScreenWin::AddObserver(DisplayObserver* observer) {
   change_notifier_.AddObserver(observer);
 }
 
 void ScreenWin::RemoveObserver(DisplayObserver* observer) {
   change_notifier_.RemoveObserver(observer);
 }
 
-void ScreenWin::OnWndProc(HWND hwnd,
-                          UINT message,
-                          WPARAM wparam,
-                          LPARAM lparam) {
-  if (message != WM_DISPLAYCHANGE)
-    return;
-
-  std::vector<gfx::Display> old_displays = displays_;
-  displays_ = GetDisplays();
-
-  change_notifier_.NotifyDisplaysChanged(old_displays, displays_);
-}
-
-// static
-std::vector<gfx::Display> ScreenWin::GetDisplaysForMonitorInfos(
-    const std::vector<MONITORINFOEX>& monitor_infos) {
-  std::vector<gfx::Display> displays;
-  for (const MONITORINFOEX& monitor_info : monitor_infos)
-    displays.push_back(GetDisplay(monitor_info));
-
-  return displays;
+void ScreenWin::OnDisplaysChanged(
+    const std::vector<gfx::win::ScreenWinDisplay> old_screen_win_displays,
+    const std::vector<gfx::win::ScreenWinDisplay> new_screen_win_displays) {
+  std::vector<gfx::Display> old_displays =
+      ScreenWinDisplaysToDisplays(old_screen_win_displays);
+  std::vector<gfx::Display> new_displays =
+      ScreenWinDisplaysToDisplays(new_screen_win_displays);
+  change_notifier_.NotifyDisplaysChanged(old_displays, new_displays);
 }
 
 }  // namespace gfx