4 files changed, 29 insertions, 13 deletions

diff --git a/src/ui/CMakeLists.txt b/src/ui/CMakeLists.txt
index a8fd46a5..777e4fbc 100644
--- a/src/ui/CMakeLists.txt
+++ b/src/ui/CMakeLists.txt
@@ -25,6 +25,7 @@ add_library(cru_ui STATIC
     render/flex_layout_render_object.cpp
     render/layout_utility.cpp
     render/render_object.cpp
+    render/scroll_render_object.cpp
     render/stack_layout_render_object.cpp
     render/text_render_object.cpp
     render/window_render_object.cpp
@@ -54,6 +55,7 @@ target_sources(cru_ui PUBLIC
 	${CRU_UI_INCLUDE_DIR}/render/layout_render_object.hpp
 	${CRU_UI_INCLUDE_DIR}/render/layout_utility.hpp
 	${CRU_UI_INCLUDE_DIR}/render/render_object.hpp
+    ${CRU_UI_INCLUDE_DIR}/render/scroll_render_object.hpp
     ${CRU_UI_INCLUDE_DIR}/render/stack_layout_render_object.hpp
 	${CRU_UI_INCLUDE_DIR}/render/text_render_object.hpp
 	${CRU_UI_INCLUDE_DIR}/render/window_render_object.hpp
diff --git a/src/ui/controls/text_box.cpp b/src/ui/controls/text_box.cpp
index 7b63eea1..8b7dc692 100644
--- a/src/ui/controls/text_box.cpp
+++ b/src/ui/controls/text_box.cpp
@@ -29,6 +29,7 @@ TextBox::TextBox() : border_render_object_(new BorderRenderObject()) {
 
   service_ = std::make_unique<TextControlService<TextBox>>(this);
   service_->SetEnabled(true);
+  service_->SetCaretVisible(true);
 
   GainFocusEvent()->Direct()->AddHandler([this](event::FocusChangeEventArgs&) {
     this->service_->SetEnabled(true);
@@ -43,6 +44,10 @@ TextBox::TextBox() : border_render_object_(new BorderRenderObject()) {
 
 TextBox::~TextBox() {}
 
+render::RenderObject* TextBox::GetRenderObject() const {
+  return border_render_object_.get();
+}
+
 render::TextRenderObject* TextBox::GetTextRenderObject() {
   return text_render_object_.get();
 }
diff --git a/src/ui/controls/text_control_service.hpp b/src/ui/controls/text_control_service.hpp
index 57a6efa7..626423bf 100644
--- a/src/ui/controls/text_control_service.hpp
+++ b/src/ui/controls/text_control_service.hpp
@@ -10,8 +10,7 @@
 #include "cru/ui/ui_event.hpp"
 
 namespace cru::ui::controls {
-constexpr float caret_width = 2;
-constexpr long long caret_blink_duration = 500;
+constexpr int k_default_caret_blink_duration = 500;
 
 // TControl should inherits `Control` and has following methods:
 // ```
@@ -31,14 +30,11 @@ class TextControlService : public Object {
   bool IsEnabled() { return enable_; }
   void SetEnabled(bool enable);
 
-  int GetCaretPosition() { return caret_position_; }
-  void SetCaretPosition(int position) { caret_position_ = position; }
-
   bool IsCaretVisible() { return caret_visible_; }
   void SetCaretVisible(bool visible);
 
-  // please set correct offset before calling this
-  void DrawCaret(platform::graph::IPainter* painter);
+  int GetCaretBlinkDuration() { return caret_blink_duration_; }
+  void SetCaretBlinkDuration(int milliseconds);
 
  private:
   void AbortSelection();
@@ -60,8 +56,8 @@ class TextControlService : public Object {
   bool enable_ = false;
 
   bool caret_visible_ = false;
-  int caret_position_ = 0;
   long long caret_timer_id_ = -1;
+  int caret_blink_duration_ = k_default_caret_blink_duration;
 
   // nullopt means not selecting
   std::optional<MouseButton> select_down_button_;
@@ -105,12 +101,22 @@ void TextControlService<TControl>::SetCaretVisible(bool visible) {
 
   if (this->enable_) {
     if (visible) {
-      this->SetupCaretTimer();
+      this->SetupCaret();
     } else {
-      this->TearDownCaretTimer();
+      this->TearDownCaret();
     }
   }
-}  // namespace cru::ui::controls
+}
+
+template <typename TControl>
+void TextControlService<TControl>::SetCaretBlinkDuration(int milliseconds) {
+  if (this->caret_blink_duration_ == milliseconds) return;
+
+  if (this->enable_ && this->caret_visible_) {
+    this->TearDownCaret();
+    this->SetupCaret();
+  }
+}
 
 template <typename TControl>
 void TextControlService<TControl>::AbortSelection() {
@@ -130,7 +136,7 @@ void TextControlService<TControl>::SetupCaret() {
 
   this->control_->GetTextRenderObject()->SetDrawCaret(true);
   this->caret_timer_id_ = application->SetInterval(
-      std::chrono::milliseconds(caret_blink_duration),
+      std::chrono::milliseconds(this->caret_blink_duration_),
       [this] { this->control_->GetTextRenderObject()->ToggleDrawCaret(); });
 }
 
@@ -169,7 +175,6 @@ void TextControlService<TControl>::MouseMoveHandler(
     const auto result = text_render_object->TextHitTest(
         text_render_object->FromRootToContent(args.GetPoint()));
     const auto position = result.position + (result.trailing ? 1 : 0);
-    this->caret_position_ = position;
     log::Debug(
         "TextControlService: Text selection changed on mouse move, range: {}, "
         "{}.",
@@ -178,6 +183,7 @@ void TextControlService<TControl>::MouseMoveHandler(
         TextRange::FromTwoSides(
             static_cast<unsigned>(position),
             static_cast<unsigned>(this->select_start_position_)));
+    text_render_object->SetCaretPosition(position);
   }
 }
 
@@ -194,6 +200,8 @@ void TextControlService<TControl>::MouseDownHandler(
     const auto result = text_render_object->TextHitTest(
         text_render_object->FromRootToContent(args.GetPoint()));
     const auto position = result.position + (result.trailing ? 1 : 0);
+    text_render_object->SetSelectionRange(std::nullopt);
+    text_render_object->SetCaretPosition(position);
     this->select_start_position_ = position;
     log::Debug("TextControlService: Begin to select text, start position: {}.",
                position);
diff --git a/src/ui/render/scroll_render_object.cpp b/src/ui/render/scroll_render_object.cpp
new file mode 100644
index 00000000..f77ee636
--- /dev/null
+++ b/src/ui/render/scroll_render_object.cpp
@@ -0,0 +1 @@
+#include "cru/ui/render/scroll_render_object.hpp"