Initial Commit

Charts/Navigation/TouchPadScroll.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Windows;
+using System.Windows.Input;
+using System.Windows.Interop;
+
+
+namespace Microsoft.Research.DynamicDataDisplay.Navigation
+{
+    /// <summary>This class allows convenient navigation around viewport using touchpad on
+    /// some notebooks</summary>
+	public sealed class TouchpadScroll : NavigationBase {
+		public TouchpadScroll() {
+			Loaded += OnLoaded;
+		}
+
+		private void OnLoaded(object sender, RoutedEventArgs e) {
+			WindowInteropHelper helper = new WindowInteropHelper(Window.GetWindow(this));
+			HwndSource source = HwndSource.FromHwnd(helper.Handle);
+			source.AddHook(OnMessageAppeared);
+		}
+
+		private IntPtr OnMessageAppeared(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled) {
+			if (msg == WindowsMessages.WM_MOUSEWHEEL) {
+				Point mousePos = MessagesHelper.GetMousePosFromLParam(lParam);
+				mousePos = TranslatePoint(mousePos, this);
+
+				if (Viewport.Output.Contains(mousePos)) {
+					MouseWheelZoom(MessagesHelper.GetMousePosFromLParam(lParam), MessagesHelper.GetWheelDataFromWParam(wParam));
+					handled = true;
+				}
+			}
+			return IntPtr.Zero;
+		}
+
+		double wheelZoomSpeed = 1.2;
+		public double WheelZoomSpeed {
+			get { return wheelZoomSpeed; }
+			set { wheelZoomSpeed = value; }
+		}
+
+		private void MouseWheelZoom(Point mousePos, int wheelRotationDelta) {
+			Point zoomTo = mousePos.ScreenToData(Viewport.Transform);
+
+			double zoomSpeed = Math.Abs(wheelRotationDelta / Mouse.MouseWheelDeltaForOneLine);
+			zoomSpeed *= wheelZoomSpeed;
+			if (wheelRotationDelta < 0) {
+				zoomSpeed = 1 / zoomSpeed;
+			}
+			Viewport.Visible = Viewport.Visible.Zoom(zoomTo, zoomSpeed);
+		}
+	}
+}