feat: default gtk darkTheme option to nativeTheme.shouldUseDarkColors for better platform support (#20138)

* feat: default gtk darkTheme option to nativeTheme.shouldUseDarkColors for better platform support

* chore: update syntax for PR feedback

* refactor: only define SetGTKDarkThemeEnabled when needed

Co-authored-by: Cheng Zhao <zcbenz@gmail.com>

docs/api/browser-window.md

@@ -207,7 +207,7 @@ It creates a new `BrowserWindow` with native properties as set by the `options`.
   * `opacity` Number (optional) - Set the initial opacity of the window, between 0.0 (fully
     transparent) and 1.0 (fully opaque). This is only implemented on Windows and macOS.
   * `darkTheme` Boolean (optional) - Forces using dark theme for the window, only works on
-    some GTK+3 desktop environments. Default is `false`.
+    some GTK+3 desktop environments. Default is [`nativeTheme.shouldUseDarkColors`](native-theme.md).
   * `transparent` Boolean (optional) - Makes the window [transparent](frameless-window.md#transparent-window).
     Default is `false`. On Windows, does not work unless the window is frameless.
   * `type` String (optional) - The type of window, default is normal window. See more about

shell/browser/api/electron_api_native_theme.cc

@@ -10,6 +10,8 @@
 #include "content/public/browser/browser_task_traits.h"
 #include "content/public/browser/browser_thread.h"
 #include "gin/handle.h"
+#include "shell/browser/native_window_views.h"
+#include "shell/browser/window_list.h"
 #include "shell/common/gin_converters/std_converter.h"
 #include "shell/common/gin_helper/dictionary.h"
 #include "shell/common/gin_helper/object_template_builder.h"
@@ -47,8 +49,13 @@ void NativeTheme::SetThemeSource(ui::NativeTheme::ThemeSource override) {
   // Update the macOS appearance setting for this new override value
   UpdateMacOSAppearanceForOverrideValue(override);
 #endif
-  // TODO(MarshallOfSound): Update all existing browsers windows to use GTK dark
+#if defined(USE_X11)
-  // theme
+  const bool dark_enabled = ShouldUseDarkColors();
+  for (auto* window : WindowList::GetWindows()) {
+    static_cast<NativeWindowViews*>(window)->SetGTKDarkThemeEnabled(
+        dark_enabled);
+  }
+#endif
 }
 
 ui::NativeTheme::ThemeSource NativeTheme::GetThemeSource() const {

shell/browser/api/electron_api_top_level_window.cc

@@ -906,10 +906,6 @@ void TopLevelWindow::CloseFilePreview() {
   window_->CloseFilePreview();
 }
 
-void TopLevelWindow::SetGTKDarkThemeEnabled(bool use_dark_theme) {
-  window_->SetGTKDarkThemeEnabled(use_dark_theme);
-}
-
 v8::Local<v8::Value> TopLevelWindow::GetContentView() const {
   if (content_view_.IsEmpty())
     return v8::Null(isolate());

shell/browser/api/electron_api_top_level_window.h

@@ -208,7 +208,6 @@ class TopLevelWindow : public gin_helper::TrackableObject<TopLevelWindow>,
   void SetAspectRatio(double aspect_ratio, gin_helper::Arguments* args);
   void PreviewFile(const std::string& path, gin_helper::Arguments* args);
   void CloseFilePreview();
-  void SetGTKDarkThemeEnabled(bool use_dark_theme);
 
   // Public getters of NativeWindow.
   v8::Local<v8::Value> GetContentView() const;

shell/browser/native_window.h

@@ -232,8 +232,6 @@ class NativeWindow : public base::SupportsUserData,
                            const std::string& display_name);
   virtual void CloseFilePreview();
 
-  virtual void SetGTKDarkThemeEnabled(bool use_dark_theme) = 0;
-
   // Converts between content bounds and window bounds.
   virtual gfx::Rect ContentBoundsToWindowBounds(
       const gfx::Rect& bounds) const = 0;

shell/browser/native_window_mac.h

@@ -137,7 +137,6 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
       std::vector<gin_helper::PersistentDictionary> items) override;
   void RefreshTouchBarItem(const std::string& item_id) override;
   void SetEscapeTouchBarItem(gin_helper::PersistentDictionary item) override;
-  void SetGTKDarkThemeEnabled(bool use_dark_theme) override {}
 
   gfx::Rect ContentBoundsToWindowBounds(const gfx::Rect& bounds) const override;
   gfx::Rect WindowBoundsToContentBounds(const gfx::Rect& bounds) const override;

shell/browser/native_window_views.cc

@@ -34,6 +34,7 @@
 #include "ui/base/hit_test.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/native_theme/native_theme.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/webview/unhandled_keyboard_event_handler.h"
 #include "ui/views/controls/webview/webview.h"
@@ -212,10 +213,10 @@ NativeWindowViews::NativeWindowViews(const gin_helper::Dictionary& options,
   window_state_watcher_ = std::make_unique<WindowStateWatcher>(this);
 
   // Set _GTK_THEME_VARIANT to dark if we have "dark-theme" option set.
-  bool use_dark_theme = false;
+  bool use_dark_theme =
-  if (options.Get(options::kDarkTheme, &use_dark_theme) && use_dark_theme) {
+      ui::NativeTheme::GetInstanceForNativeUi()->ShouldUseDarkColors();
-    SetGTKDarkThemeEnabled(use_dark_theme);
+  options.Get(options::kDarkTheme, &use_dark_theme);
-  }
+  SetGTKDarkThemeEnabled(use_dark_theme);
 
   // Before the window is mapped the SetWMSpecState can not work, so we have
   // to manually set the _NET_WM_STATE.
@@ -325,25 +326,6 @@ NativeWindowViews::~NativeWindowViews() {
 #endif
 }
 
-void NativeWindowViews::SetGTKDarkThemeEnabled(bool use_dark_theme) {
-#if defined(USE_X11)
-  XDisplay* xdisplay = gfx::GetXDisplay();
-  if (use_dark_theme) {
-    XChangeProperty(xdisplay, GetAcceleratedWidget(),
-                    XInternAtom(xdisplay, "_GTK_THEME_VARIANT", x11::False),
-                    XInternAtom(xdisplay, "UTF8_STRING", x11::False), 8,
-                    PropModeReplace,
-                    reinterpret_cast<const unsigned char*>("dark"), 4);
-  } else {
-    XChangeProperty(xdisplay, GetAcceleratedWidget(),
-                    XInternAtom(xdisplay, "_GTK_THEME_VARIANT", x11::False),
-                    XInternAtom(xdisplay, "UTF8_STRING", x11::False), 8,
-                    PropModeReplace,
-                    reinterpret_cast<const unsigned char*>("light"), 5);
-  }
-#endif
-}
-
 void NativeWindowViews::SetContentView(views::View* view) {
   if (content_view()) {
     root_view_->RemoveChildView(content_view());
@@ -1292,6 +1274,25 @@ void NativeWindowViews::SetIcon(const gfx::ImageSkia& icon) {
 }
 #endif
 
+#if defined(USE_X11)
+void NativeWindowViews::SetGTKDarkThemeEnabled(bool use_dark_theme) {
+  XDisplay* xdisplay = gfx::GetXDisplay();
+  if (use_dark_theme) {
+    XChangeProperty(xdisplay, GetAcceleratedWidget(),
+                    XInternAtom(xdisplay, "_GTK_THEME_VARIANT", x11::False),
+                    XInternAtom(xdisplay, "UTF8_STRING", x11::False), 8,
+                    PropModeReplace,
+                    reinterpret_cast<const unsigned char*>("dark"), 4);
+  } else {
+    XChangeProperty(xdisplay, GetAcceleratedWidget(),
+                    XInternAtom(xdisplay, "_GTK_THEME_VARIANT", x11::False),
+                    XInternAtom(xdisplay, "UTF8_STRING", x11::False), 8,
+                    PropModeReplace,
+                    reinterpret_cast<const unsigned char*>("light"), 5);
+  }
+}
+#endif
+
 void NativeWindowViews::OnWidgetActivationChanged(views::Widget* changed_widget,
                                                   bool active) {
   if (changed_widget != widget())

shell/browser/native_window_views.h

@@ -127,8 +127,6 @@ class NativeWindowViews : public NativeWindow,
 
   bool IsVisibleOnAllWorkspaces() override;
 
-  void SetGTKDarkThemeEnabled(bool use_dark_theme) override;
-
   content::DesktopMediaID GetDesktopMediaID() const override;
   gfx::AcceleratedWidget GetAcceleratedWidget() const override;
   NativeWindowHandle GetNativeWindowHandle() const override;
@@ -157,6 +155,10 @@ class NativeWindowViews : public NativeWindow,
   void SetIcon(const gfx::ImageSkia& icon);
 #endif
 
+#if defined(USE_X11)
+  void SetGTKDarkThemeEnabled(bool use_dark_theme);
+#endif
+
   SkRegion* draggable_region() const { return draggable_region_.get(); }
 
 #if defined(OS_WIN)