fix: child window alwaysOnTop level persistence (#29813)

* fix: child window alwaysOnTop level

* chore: add undocumented getAlwaysOnTopLevel

* test: add test for level persistence

* Address feedback from review

shell/browser/api/electron_api_base_window.cc

@@ -882,6 +882,10 @@ void BaseWindow::SetVibrancy(v8::Isolate* isolate, v8::Local<v8::Value> value) {
 }
 
 #if defined(OS_MAC)
+std::string BaseWindow::GetAlwaysOnTopLevel() {
+  return window_->GetAlwaysOnTopLevel();
+}
+
 void BaseWindow::SetWindowButtonVisibility(bool visible) {
   window_->SetWindowButtonVisibility(visible);
 }
@@ -1271,6 +1275,7 @@ void BaseWindow::BuildPrototype(v8::Isolate* isolate,
       .SetMethod("isVisibleOnAllWorkspaces",
                  &BaseWindow::IsVisibleOnAllWorkspaces)
 #if defined(OS_MAC)
+      .SetMethod("_getAlwaysOnTopLevel", &BaseWindow::GetAlwaysOnTopLevel)
       .SetMethod("setAutoHideCursor", &BaseWindow::SetAutoHideCursor)
 #endif
       .SetMethod("setVibrancy", &BaseWindow::SetVibrancy)

shell/browser/api/electron_api_base_window.h

@@ -194,6 +194,7 @@ class BaseWindow : public gin_helper::TrackableObject<BaseWindow>,
   virtual void SetVibrancy(v8::Isolate* isolate, v8::Local<v8::Value> value);
 
 #if defined(OS_MAC)
+  std::string GetAlwaysOnTopLevel();
   void SetWindowButtonVisibility(bool visible);
   bool GetWindowButtonVisibility() const;
   void SetTrafficLightPosition(const gfx::Point& position);

shell/browser/native_window.h

@@ -135,6 +135,7 @@ class NativeWindow : public base::SupportsUserData,
   virtual void SetTitle(const std::string& title) = 0;
   virtual std::string GetTitle() = 0;
 #if defined(OS_MAC)
+  virtual std::string GetAlwaysOnTopLevel() = 0;
   virtual void SetActive(bool is_key) = 0;
   virtual bool IsActive() const = 0;
 #endif

shell/browser/native_window_mac.h

@@ -78,6 +78,7 @@ class NativeWindowMac : public NativeWindow,
   void SetAlwaysOnTop(ui::ZOrderLevel z_order,
                       const std::string& level,
                       int relative_level) override;
+  std::string GetAlwaysOnTopLevel() override;
   ui::ZOrderLevel GetZOrderLevel() override;
   void Center() override;
   void Invalidate() override;

shell/browser/native_window_mac.mm

@@ -869,6 +869,31 @@ void NativeWindowMac::SetAlwaysOnTop(ui::ZOrderLevel z_order,
   SetWindowLevel(level + relative_level);
 }
 
+std::string NativeWindowMac::GetAlwaysOnTopLevel() {
+  std::string level_name = "normal";
+
+  int level = [window_ level];
+  if (level == NSFloatingWindowLevel) {
+    level_name = "floating";
+  } else if (level == NSTornOffMenuWindowLevel) {
+    level_name = "torn-off-menu";
+  } else if (level == NSModalPanelWindowLevel) {
+    level_name = "modal-panel";
+  } else if (level == NSMainMenuWindowLevel) {
+    level_name = "main-menu";
+  } else if (level == NSStatusWindowLevel) {
+    level_name = "status";
+  } else if (level == NSPopUpMenuWindowLevel) {
+    level_name = "pop-up-menu";
+  } else if (level == NSScreenSaverWindowLevel) {
+    level_name = "screen-saver";
+  } else if (level == NSDockWindowLevel) {
+    level_name = "dock";
+  }
+
+  return level_name;
+}
+
 void NativeWindowMac::SetWindowLevel(int unbounded_level) {
   int level = std::min(
       std::max(unbounded_level, CGWindowLevelForKey(kCGMinimumWindowLevelKey)),
@@ -1805,10 +1830,15 @@ void NativeWindowMac::InternalSetParentWindow(NativeWindow* parent,
 
   // Set new parent window.
   // Note that this method will force the window to become visible.
-  if (parent && attach)
+  if (parent && attach) {
+    // Attaching a window as a child window resets its window level, so
+    // save and restore it afterwards.
+    NSInteger level = window_.level;
     [parent->GetNativeWindow().GetNativeNSWindow()
         addChildWindow:window_
                ordered:NSWindowAbove];
+    [window_ setLevel:level];
+  }
 }
 
 void NativeWindowMac::SetForwardMouseMessages(bool forward) {