Disable Relations

[Nathan]

What's the best way of disabling the ability for viewers/users to add relations between tasks?

Is there a way of doing it similar to disabling drag-and-drop/resizing?  (over-wrote CanStartDrag, CanDrop, CanStartResize, CanResize, etc)

[Polya]

Hi Nathan,

In order to disable adding relations between GanttTasks you need a custom GanttDragDependenciesBehavior and override the CanStartLink/CanLink methods.

public class CustomDragDependenciesBehavior : GanttDragDependenciesBehavior
{
    protected override bool CanStartLink(SchedulingLinkState state)
    {
        return false;
    }

    protected override bool CanLink(SchedulingLinkState state)
    {
        return false;
    }
}

Then use this behavior in the RadGanttView as a DragDependenciesBehavior:

<telerik:RadGanttView TasksSource="{Binding GanttTasks}" VisibleRange="{Binding VisibleRange}">
    <telerik:RadGanttView.Columns>
        ...
    </telerik:RadGanttView.Columns>
    <telerik:RadGanttView.DragDependenciesBehavior>
        <local:CustomDragDependenciesBehavior/>
    </telerik:RadGanttView.DragDependenciesBehavior>
</telerik:RadGanttView>

Also you can take a look at our RadGanttView LockingFunctions example where we demonstrate how to disable adding relations, drag&drop and resizing GanttTasks. The examples can be downloaded from this link.

Hopefully this helps.

Regards,
Polya
Telerik

 

 

[Nathan]

I've figured out how to disable creating relations between tasks.  But the tooltip that says "Drag to create a relation" still appears.
Is it possible to disable this tooltip from appearing?

[Polya]

Hello Nathan,

In order to stop showing the "Drag to create a relation" we need to remove this ToolTip from the ControlTemplate of the DependencyIndicator. Then we need to use this new ControlTemplate in the Style of the DependencyIndicator and apply this style for the DependencyIndicators in the ControlTemplate of the EventDecoratorContainer.
Please find attached a sample project demonstrating this styling. Note that the project uses Implicit Styles.

Give it a try and let me know if it works for you.

Regards,
Polya
Telerik