...

6 files changed, 48 insertions, 26 deletions

diff --git a/demos/main/main.cpp b/demos/main/main.cpp
index dd3e31e9..2d5939f1 100644
--- a/demos/main/main.cpp
+++ b/demos/main/main.cpp
@@ -45,7 +45,7 @@ int main() {
   const auto text_box = TextBox::Create();
   flex_layout->AddChild(text_box, 2);
 
-  window->GetWindowHost()->GetNativeWindow()->SetVisible(true);
+  window->Show();
 
   return application->Run();
 }
diff --git a/include/cru/ui/controls/Window.hpp b/include/cru/ui/controls/Window.hpp
index 616e2ee7..996bc75e 100644
--- a/include/cru/ui/controls/Window.hpp
+++ b/include/cru/ui/controls/Window.hpp
@@ -24,13 +24,13 @@ class Window final : public LayoutControl {
 
   render::RenderObject* GetRenderObject() const override;
 
- protected:
-  void OnAddChild(Control* child, Index position) override;
-  void OnRemoveChild(Control* child, Index position) override;
+  // If create is false and native window is not create, it will not be created
+  // and shown.
+  void Show(bool create = true);
 
  private:
   std::unique_ptr<host::WindowHost> window_host_;
 
   std::unique_ptr<render::StackLayoutRenderObject> render_object_;
 };
-}  // namespace cru::ui
+}  // namespace cru::ui::controls
diff --git a/include/cru/ui/host/WindowHost.hpp b/include/cru/ui/host/WindowHost.hpp
index 6d338df1..9fc24eb2 100644
--- a/include/cru/ui/host/WindowHost.hpp
+++ b/include/cru/ui/host/WindowHost.hpp
@@ -28,8 +28,7 @@ class WindowHost : public Object {
   CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::host::WindowHost")
 
  public:
-  WindowHost(controls::Control* root_control,
-             CreateWindowParams create_window_params = {});
+  WindowHost(controls::Control* root_control);
 
   CRU_DELETE_COPY(WindowHost)
   CRU_DELETE_MOVE(WindowHost)
@@ -39,6 +38,10 @@ class WindowHost : public Object {
  public:
   platform::gui::INativeWindow* GetNativeWindow() { return native_window_; }
 
+  // Do nothing if native window is already created.
+  gsl::not_null<platform::gui::INativeWindow*> CreateNativeWindow(
+      CreateWindowParams create_window_params = {});
+
   // Mark the layout as invalid, and arrange a re-layout later.
   // This method could be called more than one times in a message cycle. But
   // layout only takes place once.
@@ -102,6 +105,10 @@ class WindowHost : public Object {
 
   void UpdateCursor();
 
+  IEvent<platform::gui::INativeWindow*>* NativeWindowChangeEvent() {
+    return &native_window_change_event_;
+  }
+
  private:
   //*************** region: native messages ***************
   void OnNativeDestroy(platform::gui::INativeWindow* window, std::nullptr_t);
@@ -152,5 +159,7 @@ class WindowHost : public Object {
   controls::Control* mouse_captured_control_ = nullptr;
 
   bool layout_prefer_to_fill_window_ = true;
+
+  Event<platform::gui::INativeWindow*> native_window_change_event_;
 };
 }  // namespace cru::ui::host
diff --git a/src/ui/controls/Popup.cpp b/src/ui/controls/Popup.cpp
index f51f2b3b..982aee38 100644
--- a/src/ui/controls/Popup.cpp
+++ b/src/ui/controls/Popup.cpp
@@ -9,11 +9,10 @@
 namespace cru::ui::controls {
 Popup::Popup(Control* attached_control) : attached_control_(attached_control) {
   render_object_ = std::make_unique<render::StackLayoutRenderObject>();
+  render_object_->SetAttachedControl(this);
   SetContainerRenderObject(render_object_.get());
 
-  window_host_ = std::make_unique<host::WindowHost>(
-      this, host::CreateWindowParams(
-                nullptr, platform::gui::CreateWindowFlags::NoCaptionAndBorder));
+  window_host_ = std::make_unique<host::WindowHost>(this);
 }
 
 Popup::~Popup() = default;
diff --git a/src/ui/controls/Window.cpp b/src/ui/controls/Window.cpp
index 7ce40dfe..b302cb62 100644
--- a/src/ui/controls/Window.cpp
+++ b/src/ui/controls/Window.cpp
@@ -1,6 +1,7 @@
 #include "cru/ui/controls/Window.hpp"
 
 #include "cru/common/Base.hpp"
+#include "cru/platform/gui/Base.hpp"
 #include "cru/ui/host/WindowHost.hpp"
 #include "cru/ui/render/Base.hpp"
 #include "cru/ui/render/StackLayoutRenderObject.hpp"
@@ -10,6 +11,7 @@ Window* Window::CreateOverlapped() { return new Window(); }
 
 Window::Window() : render_object_(new render::StackLayoutRenderObject()) {
   render_object_->SetAttachedControl(this);
+  SetContainerRenderObject(render_object_.get());
   window_host_ = std::make_unique<host::WindowHost>(this);
 }
 
@@ -21,12 +23,11 @@ render::RenderObject* Window::GetRenderObject() const {
   return render_object_.get();
 }
 
-void Window::OnAddChild(Control* child, Index position) {
-  render_object_->AddChild(child->GetRenderObject(), position);
-}
-
-void Window::OnRemoveChild(Control* child, Index position) {
-  CRU_UNUSED(child);
-  render_object_->RemoveChild(position);
+void Window::Show(bool create) {
+  platform::gui::INativeWindow* native_window =
+      create ? window_host_->CreateNativeWindow().get()
+             : window_host_->GetNativeWindow();
+  if (!native_window) return;
+  native_window->SetVisible(true);
 }
 }  // namespace cru::ui::controls
diff --git a/src/ui/host/WindowHost.cpp b/src/ui/host/WindowHost.cpp
index 95de51c2..4bd981c2 100644
--- a/src/ui/host/WindowHost.cpp
+++ b/src/ui/host/WindowHost.cpp
@@ -103,14 +103,8 @@ inline void BindNativeEvent(
 }
 }  // namespace
 
-WindowHost::WindowHost(controls::Control* root_control,
-                       CreateWindowParams create_window_params)
+WindowHost::WindowHost(controls::Control* root_control)
     : root_control_(root_control), focus_control_(root_control) {
-  const auto ui_application = IUiApplication::GetInstance();
-  auto native_window = ui_application->CreateWindow(create_window_params.parent,
-                                                    create_window_params.flag);
-  native_window_ = native_window;
-
   root_control_->TraverseDescendants([this](controls::Control* control) {
     control->window_host_ = this;
     control->OnAttachToHost(this);
@@ -120,6 +114,20 @@ WindowHost::WindowHost(controls::Control* root_control,
   root_render_object_->SetWindowHostRecursive(this);
 
   this->layout_paint_cycler_ = std::make_unique<LayoutPaintCycler>(this);
+}
+
+WindowHost::~WindowHost() {}
+
+gsl::not_null<platform::gui::INativeWindow*> WindowHost::CreateNativeWindow(
+    CreateWindowParams create_window_params) {
+  if (native_window_ != nullptr) return native_window_;
+
+  const auto ui_application = IUiApplication::GetInstance();
+
+  auto native_window = ui_application->CreateWindow(create_window_params.parent,
+                                                    create_window_params.flag);
+
+  native_window_ = native_window;
 
   BindNativeEvent(this, native_window, native_window->DestroyEvent(),
                   &WindowHost::OnNativeDestroy, event_revoker_guards_);
@@ -141,9 +149,11 @@ WindowHost::WindowHost(controls::Control* root_control,
                   &WindowHost::OnNativeKeyDown, event_revoker_guards_);
   BindNativeEvent(this, native_window, native_window->KeyUpEvent(),
                   &WindowHost::OnNativeKeyUp, event_revoker_guards_);
-}
 
-WindowHost::~WindowHost() {}
+  native_window_change_event_.Raise(native_window);
+
+  return native_window_;
+}
 
 void WindowHost::InvalidatePaint() { layout_paint_cycler_->InvalidatePaint(); }
 
@@ -254,6 +264,9 @@ void WindowHost::RunAfterLayoutStable(std::function<void()> action) {
 void WindowHost::OnNativeDestroy(INativeWindow* window, std::nullptr_t) {
   CRU_UNUSED(window)
   this->native_window_ = nullptr;
+  event_revoker_guards_.clear();
+
+  native_window_change_event_.Raise(nullptr);
 }
 
 void WindowHost::OnNativePaint(INativeWindow* window, std::nullptr_t) {