using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{
    /// <summary>
    /// MainWindow.xaml の相互作用ロジック
    /// </summary>
    public partial class MainWindow : Window
    {
        bool _leftIsDragging;
        bool _rightIsDragging;
        bool _middleIsDragging;
        Point _leftDragOffset;
        Point _rightDragOffset;
        Point _middleDragOffset;

        TranslateTransform _pan;
        ScaleTransform _zoom;
        RotateTransform _turn;

        public MainWindow()
        {
            InitializeComponent();

            _pan = new TranslateTransform();
            _zoom = new ScaleTransform(1.0,1.0,controlTarget.Height/2,controlTarget.Width/2);
            _turn = new RotateTransform();

            TransformGroup tGroup = new TransformGroup();
            tGroup.Children.Add(_zoom);
            tGroup.Children.Add(_turn);
            tGroup.Children.Add(_pan);
            controlTarget.RenderTransform = tGroup;

            controlTarget.MouseDown += new MouseButtonEventHandler(controlTarget_MouseDown);
            controlTarget.MouseMove += new MouseEventHandler(controlTarget_MouseMove);
            controlTarget.MouseUp += new MouseButtonEventHandler(controlTarget_MouseUp);

            this.KeyDown += new KeyEventHandler(MainWindow_KeyDown);
        }

        void MainWindow_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Escape)
            {
                _pan.X = 0;
                _pan.Y = 0;
                _zoom.ScaleX = 1;
                _zoom.ScaleY = 1;
                _zoom.CenterX = controlTarget.Height/2;
                _zoom.CenterY = controlTarget.Width / 2;
            }
        }

        void controlTarget_MouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.ChangedButton == MouseButton.Left)
            {
                var s = sender as UIElement;
                s.CaptureMouse();
                _leftDragOffset = e.GetPosition(this);
                _leftIsDragging = true;
            }
            else
            {
                if (e.ChangedButton == MouseButton.Right)
                {
                    var s = sender as UIElement;
                    s.CaptureMouse();
                    _rightDragOffset = e.GetPosition(this);
                    _rightIsDragging = true;
                    //Point center = e.GetPosition(s);
                    //_zoom.CenterX = center.X;
                    //_zoom.CenterY = center.Y;
                }
            }
        }

        void controlTarget_MouseMove(object sender, MouseEventArgs e)
        {
            if (_leftIsDragging)
            {
                var s = sender as UIElement;
                Point p = e.GetPosition(this);
                _pan.X += p.X - _leftDragOffset.X;
                _pan.Y += p.Y - _leftDragOffset.Y;
                _leftDragOffset = p;
            }
            else
            {
                if (_rightIsDragging)
                {
                    var s = sender as UIElement;
                    Point p = e.GetPosition(this);
                    double delta = (_rightDragOffset.Y - p.Y) * 0.01;
                    _zoom.ScaleX += delta;
                    _zoom.ScaleY += delta;
                    _rightDragOffset = p;
                }
            }
        }

        void controlTarget_MouseUp(object sender, MouseButtonEventArgs e)
        {
            if (e.ChangedButton == MouseButton.Left)
            {
                var s = sender as UIElement;
                s.ReleaseMouseCapture();
                _leftIsDragging = false;
            }
            if (e.ChangedButton == MouseButton.Right)
            {
                var s = sender as UIElement;
                s.ReleaseMouseCapture();
                _rightIsDragging = false;
            }
        }
    }
}