Add mouse wheel support.

7 files changed, 99 insertions, 2 deletions

diff --git a/src/ui/control.cpp b/src/ui/control.cpp
index 32909c75..2a81427a 100644
--- a/src/ui/control.cpp
+++ b/src/ui/control.cpp
@@ -709,6 +709,16 @@ namespace cru::ui
 
     }
 
+    void Control::OnMouseWheel(events::MouseWheelEventArgs& args)
+    {
+
+    }
+
+    void Control::OnMouseWheelCore(events::MouseWheelEventArgs& args)
+    {
+
+    }
+
     void Control::RaiseMouseEnterEvent(MouseEventArgs& args)
     {
         OnMouseEnterCore(args);
@@ -751,6 +761,13 @@ namespace cru::ui
         mouse_click_event.Raise(args);
     }
 
+    void Control::RaiseMouseWheelEvent(MouseWheelEventArgs& args)
+    {
+        OnMouseWheelCore(args);
+        OnMouseWheel(args);
+        mouse_wheel_event.Raise(args);
+    }
+
     void Control::OnMouseClickBegin(MouseButton button)
     {
 
diff --git a/src/ui/control.hpp b/src/ui/control.hpp
index 5f5285b6..d6ad9f02 100644
--- a/src/ui/control.hpp
+++ b/src/ui/control.hpp
@@ -261,6 +261,8 @@ namespace cru::ui
         //Raised when a mouse button is pressed in the control and released in the control with mouse not leaving it between two operations.
         events::MouseButtonEvent mouse_click_event;
 
+        events::MouseWheelEvent mouse_wheel_event;
+
         events::KeyEvent key_down_event;
         events::KeyEvent key_up_event;
         events::CharEvent char_event;
@@ -334,6 +336,9 @@ namespace cru::ui
         virtual void OnMouseUpCore(events::MouseButtonEventArgs& args);
         virtual void OnMouseClickCore(events::MouseButtonEventArgs& args);
 
+        virtual void OnMouseWheel(events::MouseWheelEventArgs& args);
+        virtual void OnMouseWheelCore(events::MouseWheelEventArgs& args);
+
         void RaiseMouseEnterEvent(events::MouseEventArgs& args);
         void RaiseMouseLeaveEvent(events::MouseEventArgs& args);
         void RaiseMouseMoveEvent(events::MouseEventArgs& args);
@@ -341,6 +346,8 @@ namespace cru::ui
         void RaiseMouseUpEvent(events::MouseButtonEventArgs& args);
         void RaiseMouseClickEvent(events::MouseButtonEventArgs& args);
 
+        void RaiseMouseWheelEvent(events::MouseWheelEventArgs& args);
+
         virtual void OnMouseClickBegin(MouseButton button);
         virtual void OnMouseClickEnd(MouseButton button);
 
diff --git a/src/ui/controls/scroll_control.cpp b/src/ui/controls/scroll_control.cpp
index 103a5c20..aa5403d4 100644
--- a/src/ui/controls/scroll_control.cpp
+++ b/src/ui/controls/scroll_control.cpp
@@ -308,6 +308,29 @@ namespace cru::ui::controls
         }
     }
 
+    void ScrollControl::OnMouseWheelCore(events::MouseWheelEventArgs& args)
+    {
+        Control::OnMouseWheelCore(args);
+
+        constexpr const auto view_delta = 30.0f;
+
+        if (args.GetDelta() == 0.0f)
+            return;
+
+        const auto content_rect = GetRect(RectRange::Content);
+        if (IsVerticalScrollEnabled() && GetScrollOffsetY() != (args.GetDelta() > 0.0f ? 0.0f : AtLeast0(GetViewHeight() - content_rect.height)))
+        {
+            SetScrollOffset(std::nullopt, GetScrollOffsetY() - args.GetDelta() / WHEEL_DELTA * view_delta);
+            return;
+        }
+
+        if (IsHorizontalScrollEnabled() && GetScrollOffsetX() != (args.GetDelta() > 0.0f ? 0.0f : AtLeast0(GetViewWidth() - content_rect.width)))
+        {
+            SetScrollOffset(GetScrollOffsetX() - args.GetDelta() / WHEEL_DELTA * view_delta, std::nullopt);
+            return;
+        }
+    }
+
     void ScrollControl::CoerceAndSetOffsets(const float offset_x, const float offset_y, const bool update_children)
     {
         const auto old_offset_x = offset_x_;
diff --git a/src/ui/controls/scroll_control.hpp b/src/ui/controls/scroll_control.hpp
index 76762f21..0541a010 100644
--- a/src/ui/controls/scroll_control.hpp
+++ b/src/ui/controls/scroll_control.hpp
@@ -16,7 +16,7 @@ namespace cru::ui::controls
     // Done: Draw(no need)
     // Done: API
     // Done: ScrollBar
-    // TODO: MouseEvent
+    // Done: MouseEvent
     class ScrollControl : public Control
     {
     private:
@@ -128,6 +128,8 @@ namespace cru::ui::controls
         void OnMouseMoveCore(events::MouseEventArgs& args) override final;
         void OnMouseUpCore(events::MouseButtonEventArgs& args) override final;
 
+        void OnMouseWheelCore(events::MouseWheelEventArgs& args) override;
+
     private:
         void CoerceAndSetOffsets(float offset_x, float offset_y, bool update_children = true);
         void UpdateScrollBarVisibility();
diff --git a/src/ui/events/ui_event.hpp b/src/ui/events/ui_event.hpp
index cc651832..321e7135 100644
--- a/src/ui/events/ui_event.hpp
+++ b/src/ui/events/ui_event.hpp
@@ -88,6 +88,30 @@ namespace cru::ui::events
     };
 
 
+    class MouseWheelEventArgs : public MouseEventArgs
+    {
+    public:
+        MouseWheelEventArgs(Object* sender, Object* original_sender, const Point& point, const float delta)
+            : MouseEventArgs(sender, original_sender, point), delta_(delta)
+        {
+
+        }
+        MouseWheelEventArgs(const MouseWheelEventArgs& other) = default;
+        MouseWheelEventArgs(MouseWheelEventArgs&& other) = default;
+        MouseWheelEventArgs& operator=(const MouseWheelEventArgs& other) = default;
+        MouseWheelEventArgs& operator=(MouseWheelEventArgs&& other) = default;
+        ~MouseWheelEventArgs() override = default;
+
+        float GetDelta() const
+        {
+            return delta_;
+        }
+
+    private:
+        float delta_;
+    };
+
+
     class DrawEventArgs : public UiEventArgs
     {
     public:
@@ -307,6 +331,7 @@ namespace cru::ui::events
     using UiEvent = Event<UiEventArgs>;
     using MouseEvent = Event<MouseEventArgs>;
     using MouseButtonEvent = Event<MouseButtonEventArgs>;
+    using MouseWheelEvent = Event<MouseWheelEventArgs>;
     using DrawEvent = Event<DrawEventArgs>;
     using PositionChangedEvent = Event<PositionChangedEventArgs>;
     using SizeChangedEvent = Event<SizeChangedEventArgs>;
diff --git a/src/ui/window.cpp b/src/ui/window.cpp
index ceabddef..9352b747 100644
--- a/src/ui/window.cpp
+++ b/src/ui/window.cpp
@@ -412,6 +412,14 @@ namespace cru::ui
             result = 0;
             return true;
         }
+        case WM_MOUSEWHEEL:
+            POINT point;
+            point.x = GET_X_LPARAM(l_param);
+            point.y = GET_Y_LPARAM(l_param);
+            ScreenToClient(hwnd, &point);
+            OnMouseWheelInternal(GET_WHEEL_DELTA_WPARAM(w_param), point);
+            result = 0;
+            return true;
         case WM_KEYDOWN:
             OnKeyDownInternal(static_cast<int>(w_param));
             result = 0;
@@ -722,6 +730,20 @@ namespace cru::ui
         DispatchEvent(control, &Control::RaiseMouseUpEvent, nullptr, dip_point, button);
     }
 
+    void Window::OnMouseWheelInternal(short delta, POINT point)
+    {
+        const auto dip_point = PiToDip(point);
+
+        Control* control;
+
+        if (mouse_capture_control_)
+            control = mouse_capture_control_;
+        else
+            control = HitTest(dip_point);
+
+        DispatchEvent(control, &Control::RaiseMouseWheelEvent, nullptr, dip_point, static_cast<float>(delta));
+    }
+
     void Window::OnKeyDownInternal(int virtual_code)
     {
         DispatchEvent(focus_control_, &Control::RaiseKeyDownEvent, nullptr, virtual_code);
diff --git a/src/ui/window.hpp b/src/ui/window.hpp
index 7c82bf89..e82aa585 100644
--- a/src/ui/window.hpp
+++ b/src/ui/window.hpp
@@ -270,7 +270,8 @@ namespace cru::ui
         void OnMouseLeaveInternal();
         void OnMouseDownInternal(MouseButton button, POINT point);
         void OnMouseUpInternal(MouseButton button, POINT point);
- 
+
+        void OnMouseWheelInternal(short delta, POINT point);
         void OnKeyDownInternal(int virtual_code);
         void OnKeyUpInternal(int virtual_code);
         void OnCharInternal(wchar_t c);