moved GUI project to a subdirectory.

GUI/DragScroll.cs

@@ -0,0 +1,166 @@
+//! \file       DragScroll.cs
+//! \date       Sun Jul 06 10:47:20 2014
+//! \brief      Scroll control contents by dragging.
+//
+// http://matthamilton.net/touchscrolling-for-scrollviewer
+
+using System.Collections.Generic;
+using System.Windows.Controls;
+using System.Windows;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Diagnostics;
+
+namespace GARbro.GUI
+{
+    public class TouchScrolling : DependencyObject
+    {
+        public static bool GetIsEnabled(DependencyObject obj)
+        {
+            return (bool)obj.GetValue(IsEnabledProperty);
+        }
+
+        public static void SetIsEnabled(DependencyObject obj, bool value)
+        {
+            obj.SetValue(IsEnabledProperty, value);
+        }
+
+        public bool IsEnabled
+        {
+            get { return (bool)GetValue(IsEnabledProperty); }
+            set { SetValue(IsEnabledProperty, value); }
+        }
+
+        public static readonly DependencyProperty IsEnabledProperty =
+            DependencyProperty.RegisterAttached("IsEnabled", typeof(bool), typeof(TouchScrolling), new UIPropertyMetadata(false, IsEnabledChanged));
+
+        static Dictionary<object, MouseCapture> _captures = new Dictionary<object, MouseCapture>();
+
+        static void IsEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            var target = d as FrameworkElement;
+            if (target == null) return;
+
+            if ((bool)e.NewValue)
+            {
+                target.Loaded += target_Loaded;
+            }
+            else
+            {
+                target_Unloaded(target, new RoutedEventArgs());
+            }
+        }
+
+        static void target_Unloaded(object sender, RoutedEventArgs e)
+        {
+            System.Diagnostics.Debug.WriteLine("Target Unloaded");
+
+            var target = sender as FrameworkElement;
+            if (null == target)
+                return;
+
+            _captures.Remove(sender);
+
+            target.Loaded -= target_Loaded;
+            target.Unloaded -= target_Unloaded;
+            target.PreviewMouseLeftButtonDown -= target_PreviewMouseLeftButtonDown;
+            target.PreviewMouseMove -= target_PreviewMouseMove;
+
+            target.PreviewMouseLeftButtonUp -= target_PreviewMouseLeftButtonUp;
+        }
+
+        static void target_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
+        {
+            var target = sender as FrameworkElement;
+            if (null == target)
+                return;
+            var scroller = FindVisualParent<ScrollViewer> (target);
+            if (null == scroller)
+            {
+                Trace.WriteLine ("Control should be placed inside ScrollViewer for drag scrolling to work");
+                return;
+            }
+
+            _captures[sender] = new MouseCapture
+            {
+                HorizontalOffset = scroller.HorizontalOffset,
+                VerticalOffset = scroller.VerticalOffset,
+                Point = e.GetPosition(scroller),
+            };
+        }
+
+        static void target_Loaded(object sender, RoutedEventArgs e)
+        {
+            var target = sender as FrameworkElement;
+            if (target == null) return;
+
+//            Debug.WriteLine("DragScroll target Loaded", sender);
+
+            target.Unloaded += target_Unloaded;
+            target.PreviewMouseLeftButtonDown += target_PreviewMouseLeftButtonDown;
+            target.PreviewMouseMove += target_PreviewMouseMove;
+
+            target.PreviewMouseLeftButtonUp += target_PreviewMouseLeftButtonUp;
+        }
+
+        static void target_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
+        {
+            var target = sender as FrameworkElement;
+            if (target == null) return;
+
+            target.ReleaseMouseCapture();
+            target.Cursor = Cursors.Arrow;
+        }
+
+        static void target_PreviewMouseMove(object sender, MouseEventArgs e)
+        {
+            if (!_captures.ContainsKey(sender)) return;
+
+            if (e.LeftButton != MouseButtonState.Pressed)
+            {
+                _captures.Remove(sender);
+                return;
+            }
+
+            var target = sender as FrameworkElement;
+            if (null == target)
+                return;
+            var scroller = FindVisualParent<ScrollViewer> (target);
+            if (null == scroller)
+                return;
+
+            var capture = _captures[sender];
+
+            var point = e.GetPosition (scroller);
+
+            var dx = point.X - capture.Point.X;
+            var dy = point.Y - capture.Point.Y;
+            if (System.Math.Abs(dy) > 5 || System.Math.Abs(dx) > 5)
+            {
+                target.CaptureMouse();
+                target.Cursor = Cursors.SizeAll;
+            }
+            scroller.ScrollToHorizontalOffset(capture.HorizontalOffset - dx);
+            scroller.ScrollToVerticalOffset(capture.VerticalOffset - dy);
+        }
+
+        static parentItem FindVisualParent<parentItem> (DependencyObject obj) where parentItem : DependencyObject
+        {
+            if (null == obj)
+                return null;
+            DependencyObject parent = VisualTreeHelper.GetParent (obj);
+            while (parent != null && !(parent is parentItem))
+            {
+                parent = VisualTreeHelper.GetParent (parent);
+            }
+            return parent as parentItem;
+        }
+
+        internal class MouseCapture
+        {
+            public double HorizontalOffset { get; set; }
+            public double VerticalOffset { get; set; }
+            public Point Point { get; set; }
+        }
+    }
+}