Some ListBox widget ideas and proposals:

See screenshot: https://lh6.googleusercontent.com/TAVZGw63BSVVT6Nh8hXbiHerZ3L0krBzboONI07PpFByROeqKPiFgrlaPnTMtIUZ94D8xRog=w1920-h960

1. Add two search fields, so it is possible to search within the left and right panes individually.
2. Add headers above the search fields. They can be configured via templates. Also add options for selecting/deselecting all items in the corresponding pane. Checkbox’s middle state should also be considered.
3. Add option (API) for enabling/disabling ListBox widget as a whole widget (similar to DropDownList, ComboBox, etc.), not only item by item.
4. Add support for data virtualization (similar to DropDownList, ComboBox and AutoComplete).
5. Add API (public methods or fields) for retrieving the current status of the items in the ListBox. For example:
- a method/property which returns the count of currently selected items
- a method/property which returns the count of currently showed items (if searching, not all items will be visible)
- a method/property which returns the count of total items
This information can be shown in the headers via template, for example.

The listview endless scrolling is a neat feature but it will be good if we could configure it to be in reverse. We are building chat system in our app and want to have the endless scrolling widget but need it to scroll in reverse.

It would be great to be able to sort the legends of a chart, without changing stack order.

Starting with Kendo-UI 2017, I've noticed that the row filter now shows two "x" buttons to clear the filter (one inside the text box and one to the right of the text box).  It's confusing having two of the exact same buttons next to each other, each doing a slightly different thing.  Please add option to remove either one of the two buttons without having to either do a dataBound or CSS trickery to hide them.

The interface for PromptOptions does not extend DialogOptions like it should. I added it into my definition file, and it compiles and works fine when testing.

    interface PromptOptions extends DialogOptions {
        name?: string;
        messages?: PromptMessages;
    }

R2 2017 release finally add a new KendoListBox component.

However, It lack some features, available in dropdownlist, like filter and item grouping who prevent me to use it for huge item list.

..,or make it at least optional when using grouped column headers. Scenarios with many or repeating column titles would extremely benefit from this. 

Other vendors offer visual representations and better access to what controls are available and how to quickly use them in different scenarios. I cannot find any visual such as http://www.oracle.com/webfolder/technetwork/jet/jetCookbook.html?component=home&demo=all which nicely highlights what each control looks like from an index perspective.
Furthermore, the code in a cookbook should be copy and paste and not have dependencies on hidden helper classes.

Kendo UI pivotgrid should have a way to customize the filters.  Specifically have a date picker for date fields and a date range.  But something so we can override what the default is.

It would be nice to apply known Excel formatting options to our export cells. For instance, we'd like to be able to rotate a cells content 90 degrees, which Excel allows, but we aren't allowed to add that custom formatting because Kendo's export doesn't handle it.

The option in the Kendo Spreadsheet to show the unmarked values when a filter is applied instead to reset it by pressing the Clear button

It would bei nice if the gantt would support Auto Height like Grid is doing and is only rendering the Height for the used elements, when you define no addiotional height property.

Splitter bar - animation when collapsing and expanding 
Would enhance a more graceful splitter widgets actions  

Since aggregation causes data to change when using a date axis (new minimums and maximums), provide a way to retrieve the new minimums and maximums for each series plotted on a graph.

Spreadsheet does not have a configuration option for maintaining the scroll position per sheet when scrolling horizontally. Currently spreadsheet maintains the common scrolling position whenever we move different sheets.

It would be nice if you could add a Legend to gauge control with multiple pointers, so it can be easier for users to determine which pointer stands for what. Something like the Legend control on RadHtlmChart, that allows for series to be toggled, except in this case it's the pointers that will need to be toggled.

All controls which work with Models (validation/grid etc) should recognize displayName instead of field name to allow localization.

Model.define({
     fields: {
              Description: { type: "string", displayName: "Beschreibung", validation: { required: true, maxlength: 200 } },
              Number: { type: "number", validation: { min: 0, max: 300 } }
     }
   });

Kendo map wraparound feature for geojson type

The wraparound feature in Kendo map doesnt work for GeoJso type, can we have this feature added.

Please consider to support grouped boxplot for Kendo UI. For example, we would like to compare the machine capacity within multiple parameters, like machine type, machine no, and employee. We need to group 2 or more parameters in x-axis. Many statistical package could generate this group boxplot and reach our request. But we need to developt a web application with this function.

The idea is to have demos of the different widgets made with Typescript. Nothing fancy just the simple demos so we can understand the different ways to create the objects and their interactions.