refactor: use WidgetDelegate's title property (#46849)

* refactor: use WidgetDelegate::SetTitle()

* Make NativeWindow::SetTitle() and NativeWindow::GetTitle() non-virtual.
  Use WidgetDelegate for their implementation.

* Add NativeWindow::OnTitleChanged(), a new protected virtual method to update
  subclasses (e.g. NativeWindowMac needs to redraw the button proxy).

* In NativeWindowMac, replace SetTitle() and GetTitle() with OnTitleChanged().

* In NativeWindowViews, replace SetTitle() and GetTitle() with OnTitleChanged().

* test: enable BrowserWindow.title tests on Linux

* test: add a test to confirm win.title changes when document.title is set in the renderer

shell/browser/native_window.cc

@@ -804,6 +804,18 @@ std::u16string NativeWindow::GetAccessibleWindowTitle() const {
   return accessible_title_;
 }
 
+std::string NativeWindow::GetTitle() const {
+  return base::UTF16ToUTF8(WidgetDelegate::GetWindowTitle());
+}
+
+void NativeWindow::SetTitle(const std::string_view title) {
+  if (title == GetTitle())
+    return;
+
+  WidgetDelegate::SetTitle(base::UTF8ToUTF16(title));
+  OnTitleChanged();
+}
+
 void NativeWindow::SetAccessibleTitle(const std::string& title) {
   accessible_title_ = base::UTF8ToUTF16(title);
 }

shell/browser/native_window.h

@@ -148,8 +148,6 @@ class NativeWindow : public base::SupportsUserData,
   virtual ui::ZOrderLevel GetZOrderLevel() const = 0;
   virtual void Center() = 0;
   virtual void Invalidate() = 0;
-  virtual void SetTitle(const std::string& title) = 0;
-  virtual std::string GetTitle() const = 0;
 #if BUILDFLAG(IS_MAC)
   virtual std::string GetAlwaysOnTopLevel() const = 0;
   virtual void SetActive(bool is_key) = 0;
@@ -160,6 +158,9 @@ class NativeWindow : public base::SupportsUserData,
   virtual void DetachChildren() = 0;
 #endif
 
+  void SetTitle(std::string_view title);
+  [[nodiscard]] std::string GetTitle() const;
+
   // Ability to augment the window title for the screen readers.
   void SetAccessibleTitle(const std::string& title);
   std::string GetAccessibleTitle();
@@ -437,6 +438,8 @@ class NativeWindow : public base::SupportsUserData,
 
   NativeWindow(const gin_helper::Dictionary& options, NativeWindow* parent);
 
+  virtual void OnTitleChanged() {}
+
   // views::WidgetDelegate:
   views::Widget* GetWidget() override;
   const views::Widget* GetWidget() const override;

shell/browser/native_window_mac.h

@@ -37,6 +37,7 @@ class NativeWindowMac : public NativeWindow,
   ~NativeWindowMac() override;
 
   // NativeWindow:
+  void OnTitleChanged() override;
   void SetContentView(views::View* view) override;
   void Close() override;
   void CloseImmediately() override;
@@ -85,8 +86,6 @@ class NativeWindowMac : public NativeWindow,
   ui::ZOrderLevel GetZOrderLevel() const override;
   void Center() override;
   void Invalidate() override;
-  void SetTitle(const std::string& title) override;
-  std::string GetTitle() const override;
   void FlashFrame(bool flash) override;
   void SetSkipTaskbar(bool skip) override;
   void SetExcludedFromShownWindowsMenu(bool excluded) override;

shell/browser/native_window_mac.mm

@@ -938,16 +938,13 @@ void NativeWindowMac::Invalidate() {
   [[window_ contentView] setNeedsDisplay:YES];
 }
 
-void NativeWindowMac::SetTitle(const std::string& title) {
+void NativeWindowMac::OnTitleChanged() {
-  [window_ setTitle:base::SysUTF8ToNSString(title)];
+  [window_ setTitle:base::SysUTF8ToNSString(GetTitle())];
+
   if (buttons_proxy_)
     [buttons_proxy_ redraw];
 }
 
-std::string NativeWindowMac::GetTitle() const {
-  return base::SysNSStringToUTF8([window_ title]);
-}
-
 void NativeWindowMac::FlashFrame(bool flash) {
   if (flash) {
     attention_request_id_ = [NSApp requestUserAttention:NSCriticalRequest];

shell/browser/native_window_views.cc

@@ -198,7 +198,8 @@ class NativeWindowClientView : public views::ClientView {
 NativeWindowViews::NativeWindowViews(const gin_helper::Dictionary& options,
                                      NativeWindow* parent)
     : NativeWindow(options, parent) {
-  options.Get(options::kTitle, &title_);
+  if (std::string val; options.Get(options::kTitle, &val))
+    SetTitle(val);
 
   bool menu_bar_autohide;
   if (options.Get(options::kAutoHideMenuBar, &menu_bar_autohide))
@@ -1160,15 +1161,6 @@ void NativeWindowViews::Invalidate() {
   widget()->SchedulePaintInRect(gfx::Rect(GetBounds().size()));
 }
 
-void NativeWindowViews::SetTitle(const std::string& title) {
-  title_ = title;
-  widget()->UpdateWindowTitle();
-}
-
-std::string NativeWindowViews::GetTitle() const {
-  return title_;
-}
-
 void NativeWindowViews::FlashFrame(bool flash) {
 #if BUILDFLAG(IS_WIN)
   // The Chromium's implementation has a bug stopping flash.
@@ -1750,10 +1742,6 @@ bool NativeWindowViews::CanMinimize() const {
 #endif
 }
 
-std::u16string NativeWindowViews::GetWindowTitle() const {
-  return base::UTF8ToUTF16(title_);
-}
-
 views::View* NativeWindowViews::GetContentsView() {
   return root_view_.GetMainView();
 }

shell/browser/native_window_views.h

@@ -98,8 +98,6 @@ class NativeWindowViews : public NativeWindow,
   ui::ZOrderLevel GetZOrderLevel() const override;
   void Center() override;
   void Invalidate() override;
-  void SetTitle(const std::string& title) override;
-  std::string GetTitle() const override;
   void FlashFrame(bool flash) override;
   void SetSkipTaskbar(bool skip) override;
   void SetExcludedFromShownWindowsMenu(bool excluded) override {}
@@ -191,7 +189,6 @@ class NativeWindowViews : public NativeWindow,
   views::View* GetInitiallyFocusedView() override;
   bool CanMaximize() const override;
   bool CanMinimize() const override;
-  std::u16string GetWindowTitle() const override;
   views::View* GetContentsView() override;
   bool ShouldDescendIntoChildForEventHandling(
       gfx::NativeView child,
@@ -327,7 +324,6 @@ class NativeWindowViews : public NativeWindow,
   bool maximizable_ = true;
   bool minimizable_ = true;
   bool fullscreenable_ = true;
-  std::string title_;
   gfx::Size widget_size_;
   double opacity_ = 1.0;
   bool widget_destroyed_ = false;

spec/api-browser-window-spec.ts

@@ -3888,8 +3888,14 @@ describe('BrowserWindow module', () => {
         });
         it('works for window events', async () => {
           const pageTitleUpdated = once(w, 'page-title-updated');
-          w.loadURL('data:text/html,<script>document.title = \'changed\'</script>');
+          const newTitle = 'changed';
+          w.loadURL(`data:text/html,<script>document.title = '${newTitle}'</script>`);
           await pageTitleUpdated;
+
+          // w.title should update after 'page-title-updated'.
+          // It happens right *after* the event fires though,
+          // so we have to waitUntil it changes
+          waitUntil(() => w.title === newTitle);
         });
 
         it('works for stop events', async () => {
@@ -5428,6 +5434,36 @@ describe('BrowserWindow module', () => {
         });
       });
     });
+
+    describe('native window title', () => {
+      describe('with properties', () => {
+        it('can be set with title constructor option', () => {
+          const w = new BrowserWindow({ show: false, title: 'mYtItLe' });
+          expect(w.title).to.eql('mYtItLe');
+        });
+
+        it('can be changed', () => {
+          const w = new BrowserWindow({ show: false });
+          expect(w.title).to.eql('Electron Test Main');
+          w.title = 'NEW TITLE';
+          expect(w.title).to.eql('NEW TITLE');
+        });
+      });
+
+      describe('with functions', () => {
+        it('can be set with minimizable constructor option', () => {
+          const w = new BrowserWindow({ show: false, title: 'mYtItLe' });
+          expect(w.getTitle()).to.eql('mYtItLe');
+        });
+
+        it('can be changed', () => {
+          const w = new BrowserWindow({ show: false });
+          expect(w.getTitle()).to.eql('Electron Test Main');
+          w.setTitle('NEW TITLE');
+          expect(w.getTitle()).to.eql('NEW TITLE');
+        });
+      });
+    });
   });
 
   ifdescribe(process.platform !== 'linux')('window states (excluding Linux)', () => {
@@ -5508,36 +5544,6 @@ describe('BrowserWindow module', () => {
       });
     });
 
-    describe('native window title', () => {
-      describe('with properties', () => {
-        it('can be set with title constructor option', () => {
-          const w = new BrowserWindow({ show: false, title: 'mYtItLe' });
-          expect(w.title).to.eql('mYtItLe');
-        });
-
-        it('can be changed', () => {
-          const w = new BrowserWindow({ show: false });
-          expect(w.title).to.eql('Electron Test Main');
-          w.title = 'NEW TITLE';
-          expect(w.title).to.eql('NEW TITLE');
-        });
-      });
-
-      describe('with functions', () => {
-        it('can be set with minimizable constructor option', () => {
-          const w = new BrowserWindow({ show: false, title: 'mYtItLe' });
-          expect(w.getTitle()).to.eql('mYtItLe');
-        });
-
-        it('can be changed', () => {
-          const w = new BrowserWindow({ show: false });
-          expect(w.getTitle()).to.eql('Electron Test Main');
-          w.setTitle('NEW TITLE');
-          expect(w.getTitle()).to.eql('NEW TITLE');
-        });
-      });
-    });
-
     describe('minimizable state', () => {
       describe('with properties', () => {
         it('can be set with minimizable constructor option', () => {