fix: Frameless window shows frame while opening (#35353)

* fix: Frameless window shows frame while opening

* Clarify comments

* Inline setter

* Edit comment

Co-authored-by: Raymond Zhao <[email protected]>

patches/chromium/.patches

@@ -116,3 +116,4 @@ chore_add_electron_deps_to_gitignores.patch
 chore_allow_chromium_to_handle_synthetic_mouse_events_for_touch.patch
 add_maximized_parameter_to_linuxui_getwindowframeprovider.patch
 add_electron_deps_to_license_credits_file.patch
+feat_add_set_can_resize_mutator.patch

patches/chromium/feat_add_set_can_resize_mutator.patch

@@ -0,0 +1,27 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Raymond Zhao <[email protected]>
+Date: Tue, 2 Aug 2022 09:30:36 -0700
+Subject: feat: Add set_can_resize mutator
+
+Adds a set_can_resize mutator to WidgetDelegate that
+doesn't emit the OnSizeConstraintsChanged event.
+This way, we can call set_can_resize from Electron before
+the widget is initialized to set the value earlier,
+and in turn, avoid showing a frame at startup
+for frameless applications.
+
+diff --git a/ui/views/widget/widget_delegate.h b/ui/views/widget/widget_delegate.h
+index 431d19f2543a9011de76b941982603ff98afa041..32e07e0c9686e6942a40c4d4775a03068cfd33b5 100644
+--- a/ui/views/widget/widget_delegate.h
++++ b/ui/views/widget/widget_delegate.h
+@@ -323,6 +323,10 @@ class VIEWS_EXPORT WidgetDelegate {
+   // be cycled through with keyboard focus.
+   virtual void GetAccessiblePanes(std::vector<View*>* panes) {}
+ 
++  // A setter for the can_resize parameter that doesn't
++  // emit any events.
++  void set_can_resize(bool can_resize) { params_.can_resize = can_resize; }
++
+   // Setters for data parameters of the WidgetDelegate. If you use these
+   // setters, there is no need to override the corresponding virtual getters.
+   void SetAccessibleRole(ax::mojom::Role role);

shell/browser/native_window_views.cc

@@ -281,7 +281,24 @@ NativeWindowViews::NativeWindowViews(const gin_helper::Dictionary& options,
       new ElectronDesktopWindowTreeHostLinux(this, native_widget);
 #endif
 
+  // Ref https://github.com/electron/electron/issues/30760
+  // Set the can_resize param before initializing the widget.
+  // When resizable_ is true, this causes the WS_THICKFRAME style
+  // to be passed into CreateWindowEx and SetWindowLong calls in
+  // WindowImpl::Init and HwndMessageHandler::SizeConstraintsChanged
+  // respectively. As a result, the Windows 7 frame doesn't show,
+  // but it isn't clear why this is the case.
+  // When resizable_ is false, WS_THICKFRAME is not passed into the
+  // SetWindowLong call, so the Windows 7 frame still shows.
+  // One workaround would be to call set_can_resize(true) here,
+  // and then move the SetCanResize(resizable_) call after the
+  // SetWindowLong call around line 365, but that's a much larger change.
+  set_can_resize(true);
   widget()->Init(std::move(params));
+
+  // When the workaround above is not needed anymore, only this
+  // call should be necessary.
+  // With the workaround in place, this call doesn't do anything.
   SetCanResize(resizable_);
 
   bool fullscreen = false;