From b8863c403a44c1c7ac35f1a1da92bbf3c8858552 Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Wed, 9 Feb 2022 23:53:18 +0800
Subject: ...

---
 include/cru/ui/controls/SingleChildControl.h | 55 ++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 include/cru/ui/controls/SingleChildControl.h

(limited to 'include/cru/ui/controls/SingleChildControl.h')

diff --git a/include/cru/ui/controls/SingleChildControl.h b/include/cru/ui/controls/SingleChildControl.h
new file mode 100644
index 00000000..037d6dd3
--- /dev/null
+++ b/include/cru/ui/controls/SingleChildControl.h
@@ -0,0 +1,55 @@
+#pragma once
+#include "Control.h"
+
+namespace cru::ui::controls {
+template <typename TRenderObject>
+class CRU_UI_API SingleChildControl : public Control {
+ protected:
+  SingleChildControl() : container_render_object_(new TRenderObject()) {
+    container_render_object_->SetAttachedControl(this);
+  }
+
+ public:
+  CRU_DELETE_COPY(SingleChildControl)
+  CRU_DELETE_MOVE(SingleChildControl)
+
+  ~SingleChildControl() override {}
+
+  Control* GetChild() const { return child_; }
+  void SetChild(Control* child) {
+    if (child == child_) return;
+
+    assert(child == nullptr || child->GetParent() == nullptr);
+
+    if (child_) {
+      child_->SetParent(nullptr);
+    }
+
+    child_ = child;
+
+    if (child) {
+      child->SetParent(this);
+    }
+
+    container_render_object_->SetChild(child->GetRenderObject());
+  }
+
+  render::RenderObject* GetRenderObject() const override {
+    return container_render_object_.get();
+  }
+
+  TRenderObject* GetContainerRenderObject() const {
+    return container_render_object_.get();
+  }
+
+  void ForEachChild(const std::function<void(Control*)>& predicate) override {
+    if (child_) {
+      predicate(child_);
+    }
+  }
+
+ private:
+  Control* child_;
+  std::unique_ptr<TRenderObject> container_render_object_;
+};
+}  // namespace cru::ui::controls
-- 
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