diff --git a/NodeNetwork/ViewModels/NetworkViewModel.cs b/NodeNetwork/ViewModels/NetworkViewModel.cs
index a311b5a..e86a24b 100644
--- a/NodeNetwork/ViewModels/NetworkViewModel.cs
+++ b/NodeNetwork/ViewModels/NetworkViewModel.cs
@@ -148,7 +148,27 @@ public bool IsReadOnly
///
public CutLineViewModel CutLine { get; } = new CutLineViewModel();
#endregion
-
+
+ #region ZoomFactor
+ ///
+ /// Scale of the view. Larger means more zoomed in. Default value is 1. Must be greater than zero.
+ ///
+ public double ZoomFactor
+ {
+ get => _zoomFactor;
+ set
+ {
+ if (value <= 0)
+ {
+ throw new ArgumentException("ZoomFactor must be greater than zero");
+ }
+ this.RaiseAndSetIfChanged(ref _zoomFactor, value);
+ }
+ }
+
+ private double _zoomFactor = 1;
+ #endregion
+
#region SelectionRectangle
///
/// The viewmodel for the selection rectangle used in this network view.
diff --git a/NodeNetwork/Views/Controls/DragCanvas.cs b/NodeNetwork/Views/Controls/DragCanvas.cs
index 0bc2e07..f7e3c80 100644
--- a/NodeNetwork/Views/Controls/DragCanvas.cs
+++ b/NodeNetwork/Views/Controls/DragCanvas.cs
@@ -157,14 +157,32 @@ private void ApplyDragToChildren(DragMoveEventArgs drag)
#endregion
#region Zoom
- public delegate void ZoomEvent(object source, ZoomEventArgs args);
- public event ZoomEvent Zoom;
+ public event EventHandler Zoom;
private int _wheelOffset = 6;
private const int MinWheelOffset = 1;
private const int MaxWheelOffset = 15;
-
- private ScaleTransform _curScaleTransform = new ScaleTransform(1.0, 1.0);
+
+ #region ZoomFactor
+ public static readonly DependencyProperty ZoomFactorProperty = DependencyProperty.Register(nameof(ZoomFactor),
+ typeof(double), typeof(DragCanvas), new PropertyMetadata(1d, OnZoomFactorPropChanged));
+
+ public double ZoomFactor
+ {
+ get => (double)GetValue(ZoomFactorProperty);
+ set => SetValue(ZoomFactorProperty, value);
+ }
+ private bool isUpdatingZoomFactor;
+ #endregion
+
+ private static void OnZoomFactorPropChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+ {
+ DragCanvas dc = (DragCanvas)d;
+ if(!dc.isUpdatingZoomFactor)
+ {
+ dc.SetZoomImpl(new Point(dc.ActualWidth / 2, dc.ActualHeight / 2), (double)e.OldValue, (double)e.NewValue, null);
+ }
+ }
private Rect ZoomView(Rect curView, double curZoom, double newZoom, Point relZoomPoint) //curView in content space, relZoomPoint is relative to view space
{
@@ -199,9 +217,21 @@ protected override void OnMouseWheel(MouseWheelEventArgs e)
_wheelOffset = MaxWheelOffset;
}
- double oldScale = _curScaleTransform.ScaleX;
+ Point zoomCenter = e.GetPosition(this);
double newScale = Math.Log(1 + ((_wheelOffset) / 10d)) * 2d;
+ SetZoom(zoomCenter, newScale, e);
+ }
+
+ public void SetZoom(Point zoomCenter, double newScale, MouseEventArgs parentEvent)
+ {
+ SetZoomImpl(zoomCenter, ZoomFactor, newScale, parentEvent);
+ isUpdatingZoomFactor = true;
+ ZoomFactor = newScale;
+ isUpdatingZoomFactor = false;
+ }
+ private void SetZoomImpl(Point zoomCenter, double oldScale, double newScale, MouseEventArgs parentEvent)
+ {
//Calculate current viewing window onto the content
Point topLeftContentSpace = TranslatePoint(new Point(0, 0), Children[0]);
Point bottomRightContentSpace = TranslatePoint(new Point(ActualWidth, ActualHeight), Children[0]);
@@ -212,11 +242,10 @@ protected override void OnMouseWheel(MouseWheelEventArgs e)
};
//Mouse position as a fraction of the view size
- Point viewSpaceMousePos = e.GetPosition(this);
Point relZoomPoint = new Point
{
- X = viewSpaceMousePos.X / this.ActualWidth,
- Y = viewSpaceMousePos.Y / this.ActualHeight
+ X = zoomCenter.X / this.ActualWidth,
+ Y = zoomCenter.Y / this.ActualHeight
};
//Calculate new viewing window
@@ -232,12 +261,10 @@ protected override void OnMouseWheel(MouseWheelEventArgs e)
ScaleY = newScale
};
- var zoomEvent = new ZoomEventArgs(e, _curScaleTransform, newScaleTransform, newOffset);
+ var zoomEvent = new ZoomEventArgs(parentEvent, new ScaleTransform(oldScale, oldScale), newScaleTransform, newOffset);
Zoom?.Invoke(this, zoomEvent);
ApplyZoomToChildren(zoomEvent);
-
- _curScaleTransform = newScaleTransform;
}
private void ApplyZoomToChildren(ZoomEventArgs e)
diff --git a/NodeNetwork/Views/NetworkView.xaml.cs b/NodeNetwork/Views/NetworkView.xaml.cs
index 31c4524..8b82f28 100644
--- a/NodeNetwork/Views/NetworkView.xaml.cs
+++ b/NodeNetwork/Views/NetworkView.xaml.cs
@@ -257,6 +257,11 @@ private void SetupCutLine()
private void SetupViewportBinding()
{
+ this.WhenActivated(d =>
+ {
+ this.Bind(ViewModel, vm => vm.ZoomFactor, v => v.dragCanvas.ZoomFactor);
+ });
+
Binding binding = new Binding
{
Source = this,