Filter / Group Delay Animation

[ManniAT]

Hi,

I build an application where the user can change filtering / grouping.
It works very well, but when the user changes filter / group it takes some time (from half a second to about 3 seconds) till the UI is responsible again.
What I want to achieve is a kind of Hourglass reflecting that something lengthy is going on in the background.
I think about you BusyIndicator - but my problems are:
1.) I found no event for "filtering / grouping done"
2.) I'm not sure if changing the filter- / GroupDescriptors will freeze the UI
3.) I guess changing those descriptors must be done on the UI thread

So my questions - is something like this possible - or do you have any idea how this could be done.

Regards
Manfred

[Deyan]

Hi Manfred,

The data operations are done synchronously on the UI thread. Therefore, when you reset the data descriptors for your RadJumpList, you can be sure that they have completed after the code you are using to reset them. So, in this case, you can use the Busy Indicator in the following way:

this.radBusyIndicator.IsRunning = true;
this.Dispatcher.BeginInvoke(() =>
    {
        GenericGroupDescriptor<int, char> gd = new GenericGroupDescriptor<int, char>();
        gd.KeySelector = p => p.ToString()[p.ToString().Length - 1];
        this.radJumpList.BeginDataUpdate();
        this.radJumpList.GroupDescriptors.Clear();
        this.radJumpList.GroupDescriptors.Add(gd);
        this.radJumpList.EndDataUpdate();
        this.radBusyIndicator.IsRunning = false;
    });

As you can see, before calling the code that resets my group descriptors, I start the Busy Indicator. After that, in a Dispatcher, I am resetting the group descriptors and stop the busy indicator at the end.

This works as expected on my side.

I hope this helps.

Greetings,
Deyan
the Telerik team

[ManniAT]

Hi Deyan,

such a simple approach - I love this (should have found it myself) :)

Event though my solution is a bit more complex (My group / filter descriptors are bound to the view model)
it helps me to solve my problem.

Thanks a lot for the answer
Manfred

[Vitalii]

Hi,

is there a possibility to dynamically change grouping from viewmodel? Or should i just move this to codebehind?

[Deyan]

Hi Vitalii,

Thanks for writing.

Yes, it is possible to dynamically change the GroupDescriptors by binding them to an observable collection exposed by your ViewModel. You can read more about this here:

http://www.telerik.com/help/windows-phone/radjumplist-features-group-descriptors.html

Regards,
Deyan
Telerik

[Vitalii]

Thanks, guys, your support is awesome!

PS: in the sample, it is a List, not Observable. But i got the idea about GroupDescriptorsSource  :)

[Deyan]

Hi Vitalii,

Thanks for getting back to us.

We will make sure to update the examples accordingly.

We will consider this thread closed for now.

Let us know should you have further questions or need assistance.

Regards,
Deyan
Telerik