fix: allow contextmenu event in draggable regions (#37386)

filenames.gni

@@ -153,7 +153,7 @@ filenames = {
     "shell/browser/notifications/mac/notification_presenter_mac.mm",
     "shell/browser/relauncher_mac.cc",
     "shell/browser/ui/certificate_trust_mac.mm",
-    "shell/browser/ui/cocoa/delayed_native_view_host.cc",
+    "shell/browser/ui/cocoa/delayed_native_view_host.mm",
     "shell/browser/ui/cocoa/delayed_native_view_host.h",
     "shell/browser/ui/cocoa/electron_bundle_mover.h",
     "shell/browser/ui/cocoa/electron_bundle_mover.mm",

shell/browser/api/electron_api_web_contents.h

@@ -442,7 +442,13 @@ class WebContents : public ExclusiveAccessContext,
   // content::RenderWidgetHost::InputEventObserver:
   void OnInputEvent(const blink::WebInputEvent& event) override;
 
-  SkRegion* draggable_region() { return draggable_region_.get(); }
+  SkRegion* draggable_region() {
+    return force_non_draggable_ ? nullptr : draggable_region_.get();
+  }
+
+  void SetForceNonDraggable(bool force_non_draggable) {
+    force_non_draggable_ = force_non_draggable;
+  }
 
   // disable copy
   WebContents(const WebContents&) = delete;
@@ -826,6 +832,8 @@ class WebContents : public ExclusiveAccessContext,
 
   std::unique_ptr<SkRegion> draggable_region_;
 
+  bool force_non_draggable_ = false;
+
   base::WeakPtrFactory<WebContents> weak_factory_{this};
 };
 

shell/browser/ui/cocoa/delayed_native_view_host.h

@@ -23,6 +23,7 @@ class DelayedNativeViewHost : public views::NativeViewHost {
   // views::View:
   void ViewHierarchyChanged(
       const views::ViewHierarchyChangedDetails& details) override;
+  bool OnMousePressed(const ui::MouseEvent& event) override;
 
  private:
   gfx::NativeView native_view_;

shell/browser/ui/cocoa/delayed_native_view_host.mm

@@ -0,0 +1,37 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "shell/browser/ui/cocoa/delayed_native_view_host.h"
+#include "shell/browser/ui/cocoa/electron_inspectable_web_contents_view.h"
+
+namespace electron {
+
+DelayedNativeViewHost::DelayedNativeViewHost(gfx::NativeView native_view)
+    : native_view_(native_view) {}
+
+DelayedNativeViewHost::~DelayedNativeViewHost() = default;
+
+void DelayedNativeViewHost::ViewHierarchyChanged(
+    const views::ViewHierarchyChangedDetails& details) {
+  NativeViewHost::ViewHierarchyChanged(details);
+  if (details.is_add && GetWidget())
+    Attach(native_view_);
+}
+
+bool DelayedNativeViewHost::OnMousePressed(const ui::MouseEvent& ui_event) {
+  // NativeViewHost::OnMousePressed normally isn't called, but
+  // NativeWidgetMacNSWindow specifically carves out an event here for
+  // right-mouse-button clicks. We want to forward them to the web content, so
+  // handle them here.
+  // See:
+  // https://source.chromium.org/chromium/chromium/src/+/main:components/remote_cocoa/app_shim/native_widget_mac_nswindow.mm;l=415-421;drc=a5af91924bafb85426e091c6035801990a6dc697
+  ElectronInspectableWebContentsView* inspectable_web_contents_view =
+      (ElectronInspectableWebContentsView*)native_view_.GetNativeNSView();
+  [inspectable_web_contents_view
+      redispatchContextMenuEvent:ui_event.native_event()];
+
+  return true;
+}
+
+}  // namespace electron

shell/browser/ui/cocoa/electron_inspectable_web_contents_view.h

@@ -46,6 +46,8 @@ using electron::InspectableWebContentsViewMac;
     (const DevToolsContentsResizingStrategy&)strategy;
 - (void)setTitle:(NSString*)title;
 
+- (void)redispatchContextMenuEvent:(NSEvent*)theEvent;
+
 @end
 
 #endif  // ELECTRON_SHELL_BROWSER_UI_COCOA_ELECTRON_INSPECTABLE_WEB_CONTENTS_VIEW_H_

shell/browser/ui/cocoa/electron_inspectable_web_contents_view.mm

@@ -5,10 +5,12 @@
 #include "shell/browser/ui/cocoa/electron_inspectable_web_contents_view.h"
 
 #include "content/public/browser/render_widget_host_view.h"
+#include "shell/browser/api/electron_api_web_contents.h"
 #include "shell/browser/ui/cocoa/event_dispatching_window.h"
 #include "shell/browser/ui/inspectable_web_contents.h"
 #include "shell/browser/ui/inspectable_web_contents_view_delegate.h"
 #include "shell/browser/ui/inspectable_web_contents_view_mac.h"
+#include "ui/base/cocoa/base_view.h"
 #include "ui/gfx/mac/scoped_cocoa_disable_screen_updates.h"
 
 @implementation ElectronInspectableWebContentsView
@@ -273,6 +275,27 @@ - (void)parentWindowBecameMain:(NSNotification*)notification {
     [self notifyDevToolsFocused];
 }
 
+- (void)redispatchContextMenuEvent:(NSEvent*)event {
+  DCHECK(event.type == NSEventTypeRightMouseDown ||
+         (event.type == NSEventTypeLeftMouseDown &&
+          (event.modifierFlags & NSEventModifierFlagControl)));
+  content::WebContents* contents =
+      inspectableWebContentsView_->inspectable_web_contents()->GetWebContents();
+  electron::api::WebContents* api_contents =
+      electron::api::WebContents::From(contents);
+  if (api_contents) {
+    // Temporarily pretend that the WebContents is fully non-draggable while we
+    // re-send the mouse event. This allows the re-dispatched event to "land"
+    // on the WebContents, instead of "falling through" back to the window.
+    api_contents->SetForceNonDraggable(true);
+    BaseView* contentsView = (BaseView*)contents->GetRenderWidgetHostView()
+                                 ->GetNativeView()
+                                 .GetNativeNSView();
+    [contentsView mouseEvent:event];
+    api_contents->SetForceNonDraggable(false);
+  }
+}
+
 #pragma mark - NSWindowDelegate
 
 - (void)windowWillClose:(NSNotification*)notification {