//RadialPanel.cpp file

using namespace System;
using namespace System::Windows;
using namespace System::Windows::Controls;
using namespace System::Windows::Media;

namespace MyCustomPanels {

   public ref class RadialPanel : Panel {

   private: 
      double _maxChildHeight;
      double _perimeter;
      double _radius;
      double _adjustFactor;

   public:
      RadialPanel() : Panel(){};

   protected: 
      virtual System::Windows::Size MeasureOverride (System::Windows::Size availableSize) override 
      {
         _perimeter = 0;
         _maxChildHeight = 0;

         // Find the tallest child and determine the perimeter
         // based on the width of all of the children after
         // measuring all of the them and letting them size
         // to content by passing Double.PositiveInfinity as
         // the available size.

         for each (System::Windows::UIElement^ uie in Children)
         {
            uie->Measure(System::Windows::Size(Double::PositiveInfinity, Double::PositiveInfinity));
            _perimeter += uie->DesiredSize.Width;
            _maxChildHeight = Math::Max(_maxChildHeight, uie->DesiredSize.Height);
         }

         // If the marginal angle is not 0, 90 or 180
         // then the adjustFactor is needed.
         if (Children->Count > 2 && Children->Count != 4)
         {
            _adjustFactor = 10;
         }

         // Determine the radius of the circle layout and determine
         // the RadialPanel's DesiredSize.
         _radius = _perimeter / (2 * Math::PI) + _adjustFactor;
         double _squareSize = 2 * (_radius + _maxChildHeight);
         return System::Windows::Size(_squareSize, _squareSize);
      }
      ;

   protected: 
      // Perform arranging of children based on 
      // the final size.

      virtual System::Windows::Size ArrangeOverride (System::Windows::Size finalSize) override 
      {
         double _currentOriginX = 0,
            _currentOriginY = 0,
            _currentAngle = 0,
            _centerX = 0,
            _centerY = 0,
            _marginalAngle = 0;


         // During measure, an adjustFactor was added to the radius
         // to account for rotated children that might fall outside
         // of the desired size.  Now, during arrange, that extra
         // space isn't needed
         _radius -= _adjustFactor;

         // Find center of the circle based on arrange size.
         // DesiredSize is not used because the Panel
         // is potentially being arranged across a larger
         // area from the default alignment values.
         _centerX = finalSize.Width / 2;
         _centerY = finalSize.Height / 2;
         if (Children->Count != 0)
         {
            _marginalAngle = 360 / Children->Count;
         }
         for each (System::Windows::UIElement^ uie in Children)
         {
            // Find origin from which to arrange 
            // each child of the RadialPanel (its top
            // left corner.)
            _currentOriginX = _centerX - uie->DesiredSize.Width / 2;
            _currentOriginY = _centerY - _radius - uie->DesiredSize.Height;

            // Apply a rotation on each child around the center of the
            // RadialPanel.
            uie->RenderTransform = gcnew RotateTransform(_currentAngle);
            uie->Arrange(Rect(Point(_currentOriginX, _currentOriginY), Size(uie->DesiredSize.Width, uie->DesiredSize.Height)));

            // Increment the _currentAngle by the _marginalAngle
            // to advance the next child to the appropriate position.
            _currentAngle += _marginalAngle;
         }
         // In this case, the Panel is sizing to the space
         // given, so, return the finalSize which will be used
         // to set the ActualHeight & ActualWidth and for rendering.

         return finalSize;
      };
   };

   public ref class app : Application {

   private: 
      System::Windows::Window^ mainWindow;
      MyCustomPanels::RadialPanel^ radialPanel1;
      System::Windows::Controls::Button^ btn1;
      System::Windows::Controls::Button^ btn2;
      System::Windows::Controls::Button^ btn3;
      System::Windows::Controls::Button^ btn4;
      System::Windows::Controls::Button^ btn5;
      System::Windows::Controls::Border^ border1;

   protected: 
      virtual void OnStartup (System::Windows::StartupEventArgs^ e) override 
      {
         Application::OnStartup(e);
         CreateAndShowMainWindow();
      };

   private: 
      void CreateAndShowMainWindow () 
      {
         // Create the application's main Window and Border 
         // and instantiate a RadialPanel. RadialPanel is defined
         // below

         border1 = gcnew System::Windows::Controls::Border();
         border1->VerticalAlignment = VerticalAlignment::Top;
         border1->HorizontalAlignment = HorizontalAlignment::Left;
         border1->BorderThickness = System::Windows::Thickness(1);
         border1->BorderBrush = Brushes::Purple;

         radialPanel1 = gcnew MyCustomPanels::RadialPanel();
         radialPanel1->Width = 500;
         radialPanel1->Height = 500;
         radialPanel1->VerticalAlignment = VerticalAlignment::Stretch;
         radialPanel1->HorizontalAlignment = HorizontalAlignment::Stretch;

         // Add the Button Elements

         btn1 = gcnew System::Windows::Controls::Button();
         btn1->Background = Brushes::RoyalBlue;
         btn1->Content = "Button 1";
         btn1->BorderBrush = Brushes::Black;

         btn2 = gcnew System::Windows::Controls::Button();
         btn2->Background = Brushes::Red;
         btn2->Content = "Button 2";
         btn2->BorderBrush = Brushes::Black;

         btn3 = gcnew System::Windows::Controls::Button();
         btn3->Background = Brushes::Green;
         btn3->Content = "Button 3";
         btn3->BorderBrush = Brushes::Black;

         btn4 = gcnew System::Windows::Controls::Button();
         btn4->Background = Brushes::Purple;
         btn4->Content = "Button 4";
         btn4->BorderBrush = Brushes::Black;

         btn5 = gcnew System::Windows::Controls::Button();
         btn5->Background = Brushes::Yellow;
         btn5->Content = "Button 5";
         btn5->BorderBrush = Brushes::Black;

         // Add the button elements defined above as
         // children of the RadialPanel

         radialPanel1->Children->Add(btn1);
         radialPanel1->Children->Add(btn2);
         radialPanel1->Children->Add(btn3);
         radialPanel1->Children->Add(btn4);
         radialPanel1->Children->Add(btn5);

         // Add the RadialPanel to the Border

         border1->Child = radialPanel1;

         // Add the RadialPanel as a Child of the 
         // MainWindow and show the Window

         mainWindow = gcnew System::Windows::Window();
         mainWindow->Content = border1;
         mainWindow->Title = "Custom RadialPanel Sample";
         mainWindow->Show();
      };
   };

   private ref class EntryClass {

   public: 
      [System::STAThread()]
      static void Main () 
      {
         MyCustomPanels::app^ app = gcnew MyCustomPanels::app();
         app->Run();
      };
   };
}

//Entry Point:
[System::STAThreadAttribute()]
void main ()
{
   return MyCustomPanels::EntryClass::Main();
}