DragStarted/DragStopped events

[hwsoderlund]

I'm having some problems detecting when the sliders thumb is dragged. What I'm trying to do is display a tooltip for each of the sliders ticks. I need to know when dragging starts and when it stops to show/hide the tooltip. Is this possible?

[hwsoderlund]

I solved this by extending RadSlider and adding the two events manually (see the code below). Please consider adding these two events to the component in a future version.

public class ExtendedRadSlider : RadSlider
    {
        /// <summary>
        /// Fired when the thumb has been clicked, and dragging is initiated
        /// </summary>
        public event EventHandler<EventArgs> ThumbDragStarted;

        /// <summary>
        /// Fired when the thumb has been released
        /// </summary>
        public event EventHandler<EventArgs> ThumbDragCompleted;

        public ExtendedRadSlider()
            : base()
        {
            DefaultStyleKey = typeof(RadSlider);
        }

        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();

            //Set up drag event handlers
            Thumb thumb = this.GetTemplateChild("HorizontalSingleThumb") as Thumb;
            if (thumb != null)
            {
                thumb.DragStarted += new DragStartedEventHandler(thumb_DragStarted);
                thumb.DragCompleted += new DragCompletedEventHandler(thumb_DragCompleted);
            }
        }

        void thumb_DragCompleted(object sender, DragCompletedEventArgs e)
        {
            OnThumbDragCompleted(this, new EventArgs());
        }

        void thumb_DragStarted(object sender, DragStartedEventArgs e)
        {
            OnThumbDragStarted(this, new EventArgs());
        }

        protected virtual void OnThumbDragStarted(object sender, EventArgs e)
        {
            if (ThumbDragStarted != null)
                ThumbDragStarted(sender, e);
        }

        protected virtual void OnThumbDragCompleted(object sender, EventArgs e)
        {
            if (ThumbDragCompleted != null)
                ThumbDragCompleted(sender, e);
        }

    }

[hwsoderlund]

I forgot to mention that the code above does not handle the vertical layout or the range selection mode. If someone needs help implementing support for that, I'll be happy to post a sample.

[Kiril Stanoev]

Hello Henrik,

Thank you very much for you interest in our controls suite. We will definitely consider implementing the events you mentioned for the next version of the controls. Your points have been updated as per our EAP Program.

Kind regards,
Kiril Stanoev
the Telerik team

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