/* Copyright © Northwoods Software Corporation, 2008-2010. All Rights Reserved. */
using System;
using System.Collections.ObjectModel;
using System.Globalization;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using Northwoods.GoXam;
using Northwoods.GoXam.Model;
namespace Zoom {
public partial class Zoom : UserControl {
public Zoom() {
InitializeComponent();
// create the diagram's data model
var model = new GraphLinksModel<State, String, String, Transition>();
model.NodesSource = new ObservableCollection<State>() {
new State() { Key="S1" },
new State() { Key="S2" },
new State() { Key="S3" },
};
model.LinksSource = new ObservableCollection<Transition>() {
new Transition() { From="S1", To="S2" },
new Transition() { From="S1", To="S3" },
};
model.Modifiable = true; // let the user modify the graph
model.HasUndoManager = true; // support undo/redo
myDiagram.Model = model;
// initialize the converter to know about the Diagram
var conv = Diagram.FindResource<SpacedLocationConverter>(this, "myDiagramSpacedLocationConverter");
if (conv != null) conv.Diagram = myDiagram;
}
}
// This redefines mouse wheel and keyboard zoom commands to change
// the SpacedLocationConverter.Space, rather than the DiagramPanel.Scale.
public class SpaceZoomCommandHandler : CommandHandler {
// This needs to be initialized!
public SpacedLocationConverter Conv { get; set; }
public override void DecreaseZoom(object param) {
this.Conv.Space = Math.Max(0.1, this.Conv.Space / 1.05);
}
public override void IncreaseZoom(object param) {
this.Conv.Space = Math.Min(10.0, this.Conv.Space * 1.05);
}
public override void Zoom(object param) {
this.Conv.Space = (param is double ? (double)param : 1.0);
}
}
// This is used in the Node.Location binding in the NodeTemplate.
// There has to be one of these for each Diagram –
// thus the NodeTemplate cannot be shared by different Diagrams.
#if !SILVERLIGHT
[ValueConversion(typeof(Point), typeof(Point))]
#endif
public class SpacedLocationConverter : DependencyObject, IValueConverter {
// This needs to be initialized!
public Diagram Diagram { get; set; }
static SpacedLocationConverter() {
SpaceProperty = DependencyProperty.Register("Space", typeof(double), typeof(SpacedLocationConverter),
new PropertyMetadata(1.0, OnSpaceChanged));
}
private static readonly DependencyProperty SpaceProperty;
public double Space {
get { return (double)GetValue(SpaceProperty); }
set { SetValue(SpaceProperty, value); }
}
private static void OnSpaceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) {
var conv = (SpacedLocationConverter)d;
if ((double)e.NewValue <= 0.01) { // don't allow negative or very small value
conv.Space = 1;
} else if (conv.Diagram != null) {
foreach (Node n in conv.Diagram.Nodes) {
// re-evaluate the binding to get the updated Location for the Node
FrameworkElement root = n.VisualElement;
if (root != null) {
BindingExpression expr = root.GetBindingExpression(Node.LocationProperty);
if (expr != null) root.SetBinding(Node.LocationProperty, expr.ParentBinding);
}
}
conv.Diagram.Panel.UpdateDiagramBounds();
}
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture) {
Point p = (Point)value;
return new Point(p.X*this.Space, -p.Y*this.Space);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) {
Point p = (Point)value;
return new Point(p.X/this.Space, -p.Y/this.Space);
}
}
// the data for each node; the predefined data class is enough for this sample
public class State : GraphLinksModelNodeData {
public State() {
this.Key = “State”;
}
}
// the data for each link
public class Transition : GraphLinksModelLinkData<String, String> { }
}