Proposal: Allow `ComboBox` `IsTextSearchEnabled` when `ItemTemplate` provided

Proposal: Allow ComboBox IsTextSearchEnabled when ItemTemplate provided

Summary

IsTextSearchEnabled allows users to type characters into a ComboBox and jump to the entry starting with that letter. However, this only works if the ItemsSource is a list of strings (understandably so). It would be nice to provide some kind of API to enable this feature when the ItemsSource is a custom object and the ComboBoxItems are presented as more complex views of the bound item.

Rationale

• Customizing the appearance of ComboBox items is not uncommon. In the example above, all I’ve added is an icon.
• TextSearch is a very useful feature. Users can get confused if some ComboBoxes have it enabled (because they are bound to strings) and others don’t.
• The developer could try to implement this manually, but then they are at risk of implementing it slightly differently. A first party solution would be preferred.

Scope

Capability	Priority
This proposal will allow developers to accomplish W	Must
This proposal will allow end users to accomplish X	Should
This proposal will allow developers to accomplish Y	Could
This proposal will allow end users to accomplish Z	Won’t

Important Notes

Example: Windows Terminal binds ComboBox.ItemsSource to the settings model as such:

                    <ComboBox x:Name="DefaultProfile"
                              ItemsSource="{x:Bind State.Settings.AllProfiles, Mode=OneWay}"
                              SelectedItem="{x:Bind CurrentDefaultProfile, Mode=TwoWay}"
                              Style="{StaticResource ComboBoxSettingStyle}">
                        <ComboBox.ItemTemplate>
                            <DataTemplate x:DataType="SettingsModel:Profile">
                                <Grid HorizontalAlignment="Stretch" ColumnSpacing="8">

                                    <Grid.ColumnDefinitions>
                                        <!-- icon -->
                                        <ColumnDefinition Width="16"/>
                                        <!-- profile name -->
                                        <ColumnDefinition Width="Auto"/>
                                    </Grid.ColumnDefinitions>

                                    <IconSourceElement
                                    Grid.Column="0"
                                    Width="16"
                                    Height="16"
                                    IconSource="{x:Bind Icon,
                                                        Mode=OneWay,
                                                        Converter={StaticResource IconSourceConverter}}"/>

                                    <TextBlock Grid.Column="1"
                                           Text="{x:Bind Name}"/>

                                </Grid>
                            </DataTemplate>
                        </ComboBox.ItemTemplate>
                    </ComboBox>

where State.Settings.AllProfiles is an observable vector of profile objects. All we’re doing in this template is adding an icon. Binding to Profile objects allows us to bind SelectedItem and have this work fairly straightforward with little modifications.

Open Questions

[carlos-zamora]

Aha! Turns out you need the Windows.Foundation.IStringable interface. Then it works!

I guess the only ask I have here is to please include this in the docs. Thanks for the quick response folks! Closing!

[carlos-zamora]

Yup. Dustin and I were chatting on teams haha