From fdc2e2bc57792f7faaf6c1ed6a2ff4e6f0fb0103 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Tue, 16 Mar 2021 02:41:59 -0700
Subject: [PATCH] fix: recalibrate simpleFullscreen when display metrics change
 (#28150)

* fix: recalibrate simpleFullscreen when display metrics change

* Address review feedback

* fix: compilation issues

* Address feedback from review
---
 shell/browser/native_window.h      |  1 +
 shell/browser/native_window_mac.h  | 10 +++++++++-
 shell/browser/native_window_mac.mm | 21 +++++++++++++++++++++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/shell/browser/native_window.h b/shell/browser/native_window.h
index 2bf22fc72c4e..0b1b8585e8f2 100644
--- a/shell/browser/native_window.h
+++ b/shell/browser/native_window.h
@@ -207,6 +207,7 @@ class NativeWindow : public base::SupportsUserData,
   virtual void SetTrafficLightPosition(base::Optional<gfx::Point> position) = 0;
   virtual base::Optional<gfx::Point> GetTrafficLightPosition() const = 0;
   virtual void RedrawTrafficLights() = 0;
+  virtual void UpdateFrame() = 0;
 #endif
 
   // Touchbar API
diff --git a/shell/browser/native_window_mac.h b/shell/browser/native_window_mac.h
index 45a7342dcc4b..88f65ea4201e 100644
--- a/shell/browser/native_window_mac.h
+++ b/shell/browser/native_window_mac.h
@@ -14,6 +14,7 @@
 
 #include "base/mac/scoped_nsobject.h"
 #include "shell/browser/native_window.h"
+#include "ui/display/display_observer.h"
 #include "ui/native_theme/native_theme_observer.h"
 #include "ui/views/controls/native/native_view_host.h"
 
@@ -27,7 +28,9 @@ namespace electron {
 
 class RootViewMac;
 
-class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
+class NativeWindowMac : public NativeWindow,
+                        public ui::NativeThemeObserver,
+                        public display::DisplayObserver {
  public:
   NativeWindowMac(const gin_helper::Dictionary& options, NativeWindow* parent);
   ~NativeWindowMac() override;
@@ -124,6 +127,7 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
   void SetTrafficLightPosition(base::Optional<gfx::Point> position) override;
   base::Optional<gfx::Point> GetTrafficLightPosition() const override;
   void RedrawTrafficLights() override;
+  void UpdateFrame() override;
   void SetTouchBar(
       std::vector<gin_helper::PersistentDictionary> items) override;
   void RefreshTouchBarItem(const std::string& item_id) override;
@@ -188,6 +192,10 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
   // ui::NativeThemeObserver:
   void OnNativeThemeUpdated(ui::NativeTheme* observed_theme) override;
 
+  // display::DisplayObserver:
+  void OnDisplayMetricsChanged(const display::Display& display,
+                               uint32_t changed_metrics) override;
+
  private:
   // Add custom layers to the content view.
   void AddContentViewLayers();
diff --git a/shell/browser/native_window_mac.mm b/shell/browser/native_window_mac.mm
index 21fff3e72474..618119a6eb48 100644
--- a/shell/browser/native_window_mac.mm
+++ b/shell/browser/native_window_mac.mm
@@ -39,6 +39,7 @@
 #include "shell/common/process_util.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "third_party/webrtc/modules/desktop_capture/mac/window_list_utils.h"
+#include "ui/display/screen.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gl/gpu_switching_manager.h"
 #include "ui/views/background.h"
@@ -258,6 +259,7 @@ NativeWindowMac::NativeWindowMac(const gin_helper::Dictionary& options,
                                  NativeWindow* parent)
     : NativeWindow(options, parent), root_view_(new RootViewMac(this)) {
   ui::NativeTheme::GetInstanceForNativeUi()->AddObserver(this);
+  display::Screen::GetScreen()->AddObserver(this);
 
   int width = 800, height = 600;
   options.Get(options::kWidth, &width);
@@ -882,6 +884,17 @@ void NativeWindowMac::SetExcludedFromShownWindowsMenu(bool excluded) {
   [window setExcludedFromWindowsMenu:excluded];
 }
 
+void NativeWindowMac::OnDisplayMetricsChanged(const display::Display& display,
+                                              uint32_t changed_metrics) {
+  // We only want to force screen recalibration if we're in simpleFullscreen
+  // mode.
+  if (!is_simple_fullscreen_)
+    return;
+
+  base::PostTask(FROM_HERE, {content::BrowserThread::UI},
+                 base::BindOnce(&NativeWindow::UpdateFrame, GetWeakPtr()));
+}
+
 void NativeWindowMac::SetSimpleFullScreen(bool simple_fullscreen) {
   NSWindow* window = GetNativeWindow().GetNativeNSWindow();
 
@@ -1396,6 +1409,13 @@ void NativeWindowMac::RedrawTrafficLights() {
     [buttons_view_ setNeedsDisplayForButtons];
 }
 
+// In simpleFullScreen mode, update the frame for new bounds.
+void NativeWindowMac::UpdateFrame() {
+  NSWindow* window = GetNativeWindow().GetNativeNSWindow();
+  NSRect fullscreenFrame = [window.screen frame];
+  [window setFrame:fullscreenFrame display:YES animate:YES];
+}
+
 void NativeWindowMac::SetTouchBar(
     std::vector<gin_helper::PersistentDictionary> items) {
   if (@available(macOS 10.12.2, *)) {
@@ -1551,6 +1571,7 @@ void NativeWindowMac::NotifyWindowWillLeaveFullScreen() {
 void NativeWindowMac::Cleanup() {
   DCHECK(!IsClosed());
   ui::NativeTheme::GetInstanceForNativeUi()->RemoveObserver(this);
+  display::Screen::GetScreen()->RemoveObserver(this);
   [NSEvent removeMonitor:wheel_event_monitor_];
 }