Hi all,
here I am with a couple of questions that came after I tried for a while to do what seems to be a trivial task and not succeding in it, anyway... here it goes:

I have a Diagram which should not be edited by the end user, but only viewed. The user cannot directly edit diagram items' text or layout (size, position etc.) properties. Instead the user should be able to select a node and execute some other actions which should actually drive to some modifications to the Diagram (e.g.: a node would change its color).
Besides, the user should be able to "select" the node by left-clicking on it.

I started by the most general requirement and I set the Diagram AllowInplaceEdit property to "false". But this prevents the user from even selecting the node, so the first question is: how to obtain node selection in a Diagram which does not allow inplace edit?

Then I tried and implement the second requirement, that is to say I've tried to change the color of a node programmatically, through this:

// from green to white
blockNode.Brush = new SolidColorBrush(Colors.White);

... but no, no way to make this thing happen. I only succedeed in changing the node border color by doing:
blockNode.Pen = new Pen(new SolidColorBrush(Colors.White));

or:

blockNode.Stroke = new SolidColorBrush(Colors.White);

And this is the second question, why the node background color does not change?

Thanks in advance,
baba.

Hi Stoyo,
yes you're right about the behavior being the point, not the AllowInplaceEdit property as I stated.
That said, I almost solved the first problem. I say "almost" because I've been following your directions and subscrived the modify validation events and called "e.CancelDrag()" inside them. Everything seems to work as expected BUT if I do the following:

- select a node (by the way: a simple class derived from ShapeNode, but setting node.Brush not working yet);
- left click on the inner-central selection handle;
- start to drag: in this case, in fact, the node is moved and, sometimes, even incoming links are.

Could you try and see if it's a bug or it's just me?

We're using v. 1.7 full here, no trial.

Cheers,
baba.

Hi Stoyo,
have you tried with more than just one diagram item?

Here's a MainPage for you to see, first the XAML:

<UserControl x:Class="CancelDragTest.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:my="clr-namespace:MindFusion.Diagramming.Silverlight;assembly=MindFusion.Diagramming.Silverlight"
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
    <Grid x:Name="LayoutRoot">

        <my:Diagram
            x:Name="diagramControl"
            Behavior="Modify"
            AllowInplaceEdit="False"
            DefaultShape="Rectangle"
            BackBrush="WhiteSmoke"
            LinkHeadShape="Triangle"
            LinkCrossings="Arcs" />

    </Grid>
</UserControl>
 

then the code-behind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using MindFusion.Diagramming.Silverlight;

namespace CancelDragTest
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            ShapeNode newNode = new ShapeNode(diagramControl);
            newNode.Bounds = new Rect(0, 0, 100, 100);

            ShapeNode destinationNode = new ShapeNode(diagramControl);

            destinationNode.Bounds = new Rect(newNode.Bounds.Right + 100, newNode.Bounds.Bottom + 100, 200, 200);

            diagramControl.Nodes.Add(newNode);
            diagramControl.Nodes.Add(destinationNode);
            DiagramLink connection = new DiagramLink(diagramControl);

            connection.Origin = newNode;
            connection.Destination = destinationNode;
            diagramControl.Links.Add(connection);

            diagramControl.NodeModifying += new NodeValidationEventHandler(diagramControl_NodeModifying);
            diagramControl.LinkModifying += new LinkValidationEventHandler(diagramControl_LinkModifying);
        }

        void diagramControl_LinkModifying(object sender, LinkValidationEventArgs e)
        {
            e.CancelDrag();
        }

        void diagramControl_NodeModifying(object sender, NodeValidationEventArgs e)
        {
            e.CancelDrag();
        }
    }
}

 

I've done the following tests:

1. select _only_ the first node, the small one, and try to drag it somewhere, starting the dragging action from some point inside the node but not a selection handle. Result: the node cannot be moved, the link stays in place, too. So far so good...

2. select _only_ the first node, the small one, and tried to drag it somewhere, starting the dragging action from one of the election handles. Result: the node cannot be moved, the link tail _moves_.

3. select the small node and the link or, as you prefer, both the nodes then start dragging a node from _any_ point inside it. Result: the node moves, the link too.

Can you reproduce this behavior?

Cheers,
baba.

Hi Stoyo,
  it seems to work now. Hope further tests will confirm this, thanks.

Cheers,
baba.