From 52529f589fa172b4209970f2b9d66f1bded04fe3 Mon Sep 17 00:00:00 2001
From: Brian Tsoi <btsoi@mozilla.com>
Date: Thu, 9 May 2024 14:37:04 +0000
Subject: [PATCH] Bug 1787382 - Remove resolutionchange events firing
 r=win-reviewers,cmartin

Differential Revision: https://phabricator.services.mozilla.com/D209883
---
 widget/cocoa/nsCocoaWindow.mm |  1 -
 widget/gtk/nsWindow.cpp       |  1 -
 widget/nsIWidgetListener.cpp  |  2 --
 widget/nsIWidgetListener.h    |  6 ------
 widget/windows/nsWindow.cpp   |  6 ------
 xpfe/appshell/AppWindow.cpp   | 14 --------------
 xpfe/appshell/AppWindow.h     |  3 ---
 7 files changed, 33 deletions(-)

diff --git a/widget/cocoa/nsCocoaWindow.mm b/widget/cocoa/nsCocoaWindow.mm
index d8f829971dba..5032f35fa17c 100644
--- a/widget/cocoa/nsCocoaWindow.mm
+++ b/widget/cocoa/nsCocoaWindow.mm
@@ -1971,7 +1971,6 @@ void nsCocoaWindow::BackingScaleFactorChanged() {
   if (PresShell* presShell = mWidgetListener->GetPresShell()) {
     presShell->BackingScaleFactorChanged();
   }
-  mWidgetListener->UIResolutionChanged();
 }
 
 int32_t nsCocoaWindow::RoundsWidgetCoordinatesTo() {
diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
index 47dec06e09e1..297149796986 100644
--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -5383,7 +5383,6 @@ void nsWindow::OnDPIChanged() {
     if (PresShell* presShell = mWidgetListener->GetPresShell()) {
       presShell->BackingScaleFactorChanged();
     }
-    mWidgetListener->UIResolutionChanged();
   }
   NotifyAPZOfDPIChange();
 }
diff --git a/widget/nsIWidgetListener.cpp b/widget/nsIWidgetListener.cpp
index b9f236f159fe..13eba4eeebf7 100644
--- a/widget/nsIWidgetListener.cpp
+++ b/widget/nsIWidgetListener.cpp
@@ -36,8 +36,6 @@ void nsIWidgetListener::SizeModeChanged(nsSizeMode aSizeMode) {}
 void nsIWidgetListener::SafeAreaInsetsChanged(const mozilla::ScreenIntMargin&) {
 }
 
-void nsIWidgetListener::UIResolutionChanged() {}
-
 #if defined(MOZ_WIDGET_ANDROID)
 void nsIWidgetListener::DynamicToolbarMaxHeightChanged(ScreenIntCoord aHeight) {
 }
diff --git a/widget/nsIWidgetListener.h b/widget/nsIWidgetListener.h
index aff753aaec64..950d4b46224c 100644
--- a/widget/nsIWidgetListener.h
+++ b/widget/nsIWidgetListener.h
@@ -81,12 +81,6 @@ class nsIWidgetListener {
    */
   virtual void SizeModeChanged(nsSizeMode aSizeMode);
 
-  /**
-   * Called when the DPI (device resolution scaling factor) is changed,
-   * such that UI elements may need to be rescaled.
-   */
-  virtual void UIResolutionChanged();
-
 #if defined(MOZ_WIDGET_ANDROID)
   virtual void DynamicToolbarMaxHeightChanged(mozilla::ScreenIntCoord aHeight);
   virtual void DynamicToolbarOffsetChanged(mozilla::ScreenIntCoord aOffset);
diff --git a/widget/windows/nsWindow.cpp b/widget/windows/nsWindow.cpp
index f5faba72556d..ac393e8b0932 100644
--- a/widget/windows/nsWindow.cpp
+++ b/widget/windows/nsWindow.cpp
@@ -5630,9 +5630,6 @@ bool nsWindow::ProcessMessageInternal(UINT msg, WPARAM& wParam, LPARAM& lParam,
         if (WinUtils::LogToPhysFactor(mWnd) != mDefaultScale) {
           ChangedDPI();
           ResetLayout();
-          if (mWidgetListener) {
-            mWidgetListener->UIResolutionChanged();
-          }
         }
       }
       break;
@@ -5670,9 +5667,6 @@ bool nsWindow::ProcessMessageInternal(UINT msg, WPARAM& wParam, LPARAM& lParam,
 
     case WM_DISPLAYCHANGE: {
       ScreenHelperWin::RefreshScreens();
-      if (mWidgetListener) {
-        mWidgetListener->UIResolutionChanged();
-      }
       break;
     }
 
diff --git a/xpfe/appshell/AppWindow.cpp b/xpfe/appshell/AppWindow.cpp
index b2979364cfbe..65c21e9579f5 100644
--- a/xpfe/appshell/AppWindow.cpp
+++ b/xpfe/appshell/AppWindow.cpp
@@ -2957,15 +2957,6 @@ void AppWindow::SizeModeChanged(nsSizeMode aSizeMode) {
   // then need to be different.
 }
 
-void AppWindow::UIResolutionChanged() {
-  nsCOMPtr<nsPIDOMWindowOuter> ourWindow =
-      mDocShell ? mDocShell->GetWindow() : nullptr;
-  if (ourWindow) {
-    ourWindow->DispatchCustomEvent(u"resolutionchange"_ns,
-                                   ChromeOnlyDispatch::eYes);
-  }
-}
-
 void AppWindow::FullscreenWillChange(bool aInFullscreen) {
   if (mDocShell) {
     if (nsCOMPtr<nsPIDOMWindowOuter> ourWindow = mDocShell->GetWindow()) {
@@ -3456,11 +3447,6 @@ void AppWindow::WidgetListenerDelegate::SizeModeChanged(nsSizeMode aSizeMode) {
   holder->SizeModeChanged(aSizeMode);
 }
 
-void AppWindow::WidgetListenerDelegate::UIResolutionChanged() {
-  RefPtr<AppWindow> holder = mAppWindow;
-  holder->UIResolutionChanged();
-}
-
 void AppWindow::WidgetListenerDelegate::MacFullscreenMenubarOverlapChanged(
     DesktopCoord aOverlapAmount) {
   RefPtr<AppWindow> holder = mAppWindow;
diff --git a/xpfe/appshell/AppWindow.h b/xpfe/appshell/AppWindow.h
index 4acee5dbfee3..d51c2c6aba2b 100644
--- a/xpfe/appshell/AppWindow.h
+++ b/xpfe/appshell/AppWindow.h
@@ -98,8 +98,6 @@ class AppWindow final : public nsIBaseWindow,
     MOZ_CAN_RUN_SCRIPT_BOUNDARY
     virtual void SizeModeChanged(nsSizeMode sizeMode) override;
     MOZ_CAN_RUN_SCRIPT_BOUNDARY
-    virtual void UIResolutionChanged() override;
-    MOZ_CAN_RUN_SCRIPT_BOUNDARY
     virtual void MacFullscreenMenubarOverlapChanged(
         mozilla::DesktopCoord aOverlapAmount) override;
     MOZ_CAN_RUN_SCRIPT_BOUNDARY
@@ -158,7 +156,6 @@ class AppWindow final : public nsIBaseWindow,
   bool WindowResized(nsIWidget* aWidget, int32_t aWidth, int32_t aHeight);
   MOZ_CAN_RUN_SCRIPT bool RequestWindowClose(nsIWidget* aWidget);
   MOZ_CAN_RUN_SCRIPT void SizeModeChanged(nsSizeMode aSizeMode);
-  MOZ_CAN_RUN_SCRIPT void UIResolutionChanged();
   MOZ_CAN_RUN_SCRIPT void FullscreenWillChange(bool aInFullscreen);
   MOZ_CAN_RUN_SCRIPT void FullscreenChanged(bool aInFullscreen);
   MOZ_CAN_RUN_SCRIPT void MacFullscreenMenubarOverlapChanged(