views: mac: Fix frameless window behavior (fixes issue #3189)

Frameless windows now display as expected. Default traffic light buttons can
optionally be shown at configurable vertical position. Layout respects text
direction.

libcef/browser/views/native_widget_mac.h

@@ -0,0 +1,37 @@
+// Copyright 2023 The Chromium Embedded Framework Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_
+#define CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_
+#pragma once
+
+#include "third_party/abseil-cpp/absl/types/optional.h"
+#include "ui/views/widget/native_widget_mac.h"
+
+class CefNativeWidgetMac : public views::NativeWidgetMac {
+ public:
+  CefNativeWidgetMac(views::internal::NativeWidgetDelegate* delegate,
+                     bool is_frameless,
+                     bool with_window_buttons,
+                     absl::optional<float> title_bar_height);
+  ~CefNativeWidgetMac() override = default;
+
+  CefNativeWidgetMac(const CefNativeWidgetMac&) = delete;
+  CefNativeWidgetMac& operator=(const CefNativeWidgetMac&) = delete;
+
+ protected:
+  // NativeWidgetMac:
+  NativeWidgetMacNSWindow* CreateNSWindow(
+      const remote_cocoa::mojom::CreateWindowParams* params) override;
+
+  void GetWindowFrameTitlebarHeight(bool* override_titlebar_height,
+                                    float* titlebar_height) override;
+
+ private:
+  const bool is_frameless_;
+  const bool with_window_buttons_;
+  const absl::optional<float> title_bar_height_;
+};
+
+#endif  // CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_

libcef/browser/views/native_widget_mac.mm

@@ -0,0 +1,52 @@
+// Copyright 2023 The Chromium Embedded Framework 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 "libcef/browser/views/native_widget_mac.h"
+
+#include "libcef/browser/views/ns_window.h"
+
+CefNativeWidgetMac::CefNativeWidgetMac(
+    views::internal::NativeWidgetDelegate* delegate,
+    bool is_frameless,
+    bool with_window_buttons,
+    absl::optional<float> title_bar_height)
+    : views::NativeWidgetMac(delegate),
+      is_frameless_(is_frameless),
+      with_window_buttons_(with_window_buttons),
+      title_bar_height_(title_bar_height) {}
+
+NativeWidgetMacNSWindow* CefNativeWidgetMac::CreateNSWindow(
+    const remote_cocoa::mojom::CreateWindowParams* params) {
+  NSUInteger style_mask =
+      NSWindowStyleMaskTitled | NSWindowStyleMaskMiniaturizable |
+      NSWindowStyleMaskClosable | NSWindowStyleMaskResizable |
+      NSWindowStyleMaskTexturedBackground;
+  auto window = [[CefNSWindow alloc] initWithStyle:style_mask
+                                       isFrameless:is_frameless_];
+
+  if (is_frameless_) {
+    [window setTitlebarAppearsTransparent:YES];
+    [window setTitleVisibility:NSWindowTitleHidden];
+  }
+
+  if (!with_window_buttons_) {
+    [[window standardWindowButton:NSWindowCloseButton] setHidden:YES];
+    [[window standardWindowButton:NSWindowMiniaturizeButton] setHidden:YES];
+    [[window standardWindowButton:NSWindowZoomButton] setHidden:YES];
+  }
+
+  return window;
+}
+
+void CefNativeWidgetMac::GetWindowFrameTitlebarHeight(
+    bool* override_titlebar_height,
+    float* titlebar_height) {
+  if (title_bar_height_) {
+    *override_titlebar_height = true;
+    *titlebar_height = title_bar_height_.value();
+  } else {
+    views::NativeWidgetMac::GetWindowFrameTitlebarHeight(
+        override_titlebar_height, titlebar_height);
+  }
+}

libcef/browser/views/ns_window.h

@@ -0,0 +1,20 @@
+// Copyright 2023 The Chromium Embedded Framework Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_VIEWS_NS_WINDOW_H_
+#define CEF_LIBCEF_BROWSER_VIEWS_NS_WINDOW_H_
+#pragma once
+
+#include "components/remote_cocoa/app_shim/native_widget_mac_nswindow.h"
+
+@interface CefNSWindow : NativeWidgetMacNSWindow {
+ @private
+  bool is_frameless_;
+}
+- (id)initWithStyle:(NSUInteger)style_mask isFrameless:(bool)is_frameless;
+
+- (BOOL)shouldCenterTrafficLights;
+@end
+
+#endif  // CEF_LIBCEF_BROWSER_VIEWS_NS_WINDOW_H_

libcef/browser/views/ns_window.mm

@@ -0,0 +1,104 @@
+// Copyright 2023 The Chromium Embedded Framework 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 "libcef/browser/views/ns_window.h"
+
+#include "base/i18n/rtl.h"
+#include "components/remote_cocoa/app_shim/native_widget_ns_window_bridge.h"
+#include "components/remote_cocoa/common/native_widget_ns_window_host.mojom.h"
+#include "ui/base/cocoa/window_size_constants.h"
+
+@interface CefThemeFrame : NativeWidgetMacNSWindowTitledFrame
+@end
+
+// NSThemeFrame (PrivateAPI) definitions.
+@interface NSThemeFrame (PrivateAPI)
+- (void)setStyleMask:(NSUInteger)styleMask;
+- (CGFloat)_titlebarHeight;
+- (BOOL)_shouldCenterTrafficLights;
+@end
+
+@implementation CefThemeFrame {
+  bool in_full_screen_;
+}
+
+// NSThemeFrame (PrivateAPI) overrides.
+- (void)setStyleMask:(NSUInteger)styleMask {
+  in_full_screen_ = (styleMask & NSWindowStyleMaskFullScreen) != 0;
+  [super setStyleMask:styleMask];
+}
+
+- (CGFloat)_titlebarHeight {
+  if (!in_full_screen_) {
+    bool override_titlebar_height = false;
+    float titlebar_height = 0;
+    auto* window = base::mac::ObjCCast<CefNSWindow>([self window]);
+    if (auto* bridge = [window bridge]) {
+      bridge->host()->GetWindowFrameTitlebarHeight(&override_titlebar_height,
+                                                   &titlebar_height);
+
+      if (override_titlebar_height)
+        return titlebar_height;
+    }
+  }
+
+  return [super _titlebarHeight];
+}
+
+- (BOOL)_shouldCenterTrafficLights {
+  auto* window = base::mac::ObjCCast<CefNSWindow>([self window]);
+  return [window shouldCenterTrafficLights];
+}
+
+- (BOOL)_shouldFlipTrafficLightsForRTL {
+  return base::i18n::IsRTL() ? YES : NO;
+}
+
+@end
+
+@interface NSWindow (PrivateAPI)
++ (Class)frameViewClassForStyleMask:(NSUInteger)windowStyle;
+@end
+
+@implementation CefNSWindow
+
+- (id)initWithStyle:(NSUInteger)style_mask isFrameless:(bool)is_frameless {
+  if ((self = [super initWithContentRect:ui::kWindowSizeDeterminedLater
+                               styleMask:style_mask
+                                 backing:NSBackingStoreBuffered
+                                   defer:NO])) {
+    is_frameless_ = is_frameless;
+  }
+  return self;
+}
+
+- (BOOL)shouldCenterTrafficLights {
+  return is_frameless_ ? YES : NO;
+}
+
+// NSWindow overrides.
+- (NSRect)contentRectForFrameRect:(NSRect)frameRect {
+  if (is_frameless_) {
+    return frameRect;
+  }
+  return [super contentRectForFrameRect:frameRect];
+}
+
+- (NSRect)frameRectForContentRect:(NSRect)contentRect {
+  if (is_frameless_) {
+    return contentRect;
+  }
+  return [super frameRectForContentRect:contentRect];
+}
+
+// NSWindow (PrivateAPI) overrides.
++ (Class)frameViewClassForStyleMask:(NSUInteger)windowStyle {
+  if (Class custom_frame = [CefThemeFrame class]) {
+    return custom_frame;
+  }
+
+  return [super frameViewClassForStyleMask:windowStyle];
+}
+
+@end

libcef/browser/views/view_util.h

@@ -9,6 +9,7 @@
 #include "include/views/cef_view.h"
 #include "include/views/cef_window.h"
 
+#include "third_party/abseil-cpp/absl/types/optional.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/views/view.h"
 
@@ -21,8 +22,12 @@ class Point;
 }
 
 namespace views {
+class NativeWidget;
 class Widget;
+namespace internal {
+class NativeWidgetDelegate;
 }
+}  // namespace views
 
 #define CEF_REQUIRE_VALID_RETURN(ret) \
   if (!ParentClass::IsValid())        \
@@ -141,6 +146,12 @@ CefWindowHandle GetWindowHandle(views::Widget* widget);
 // Returns the platform window handle for |window|. May return nullptr.
 CefWindowHandle GetWindowHandle(gfx::NativeWindow window);
 
+views::NativeWidget* CreateNativeWidget(
+    views::internal::NativeWidgetDelegate* delegate,
+    bool is_frameless,
+    bool with_window_buttons,
+    absl::optional<float> title_bar_height);
+
 }  // namespace view_util
 
 #endif  // CEF_LIBCEF_BROWSER_VIEWS_VIEW_UTIL_H_

libcef/browser/views/view_util_aura.cc

@@ -6,6 +6,8 @@
 
 #include "ui/aura/window.h"
 #include "ui/aura/window_tree_host.h"
+#include "ui/views/widget/native_widget.h"
+#include "ui/views/widget/native_widget_delegate.h"
 #include "ui/views/widget/widget.h"
 
 namespace view_util {
@@ -40,4 +42,12 @@ CefWindowHandle GetWindowHandle(gfx::NativeWindow window) {
   return kNullWindowHandle;
 }
 
+views::NativeWidget* CreateNativeWidget(
+    views::internal::NativeWidgetDelegate* delegate,
+    bool is_frameless,
+    bool with_window_buttons,
+    absl::optional<float> title_bar_height) {
+  return nullptr;
+}
+
 }  // namespace view_util

libcef/browser/views/view_util_mac.mm

@@ -7,6 +7,7 @@
 #import <Cocoa/Cocoa.h>
 
 #include "include/internal/cef_types_mac.h"
+#include "libcef/browser/views/native_widget_mac.h"
 
 #include "ui/views/widget/widget.h"
 
@@ -44,4 +45,12 @@ CefWindowHandle GetWindowHandle(gfx::NativeWindow window) {
   return kNullWindowHandle;
 }
 
+views::NativeWidget* CreateNativeWidget(
+    views::internal::NativeWidgetDelegate* delegate,
+    bool is_frameless,
+    bool with_window_buttons,
+    absl::optional<float> title_bar_height) {
+  return new CefNativeWidgetMac(delegate, is_frameless, with_window_buttons,
+                                title_bar_height);
+}
 }  // namespace view_util

libcef/browser/views/window_view.cc

@@ -312,6 +312,15 @@ void CefWindowView::CreateWidget(gfx::AcceleratedWidget parent_widget) {
       DCHECK(!params.bounds.IsEmpty());
     } else {
       is_frameless_ = cef_delegate()->IsFrameless(cef_window);
+
+      const bool with_standard_buttons =
+          cef_delegate()->WithStandardWindowButtons(cef_window);
+
+      const auto title_bar_height = GetTitlebarHeight(cef_window);
+
+      params.native_widget = view_util::CreateNativeWidget(
+          widget, is_frameless_, with_standard_buttons, title_bar_height);
+
       can_resize = cef_delegate()->CanResize(cef_window);
 
       const auto show_state = cef_delegate()->GetInitialShowState(cef_window);
@@ -657,3 +666,14 @@ views::NonClientFrameView* CefWindowView::GetNonClientFrameView() const {
   }
   return widget->non_client_view()->frame_view();
 }
+
+absl::optional<float> CefWindowView::GetTitlebarHeight(
+    const CefRefPtr<CefWindow>& window) const {
+  float title_bar_height = 0;
+  const bool has_title_bar_height =
+      cef_delegate()->GetTitlebarHeight(window, &title_bar_height);
+  if (has_title_bar_height) {
+    return title_bar_height;
+  }
+  return absl::nullopt;
+}

libcef/browser/views/window_view.h

@@ -14,6 +14,7 @@
 #include "libcef/browser/views/overlay_view_host.h"
 #include "libcef/browser/views/panel_view.h"
 
+#include "third_party/abseil-cpp/absl/types/optional.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/display/display.h"
 #include "ui/views/widget/widget_delegate.h"
@@ -119,6 +120,9 @@ class CefWindowView
 
   void MoveOverlaysIfNecessary();
 
+  absl::optional<float> GetTitlebarHeight(
+      const CefRefPtr<CefWindow>& window) const;
+
   // Not owned by this object.
   Delegate* window_delegate_;