Closes: #40382
## To-do list
- [x] Add support for "single-select" filters to DynamicListPage
- [x] Filters can contain icons
- [x] Filter list can contain separators
- [x] Update Windows Services built-in extension to support filtering by
all, started, stopped, and pending services
- [x] Update SampleExtension dynamic list sample to filter.
## Example of filters in use
```C#
internal sealed partial class ServicesListPage : DynamicListPage
{
public ServicesListPage()
{
Icon = Icons.ServicesIcon;
Name = "Windows Services";
var filters = new ServiceFilters();
filters.PropChanged += Filters_PropChanged;
Filters = filters;
}
private void Filters_PropChanged(object sender, IPropChangedEventArgs args) => RaiseItemsChanged();
public override void UpdateSearchText(string oldSearch, string newSearch) => RaiseItemsChanged();
public override IListItem[] GetItems()
{
// ServiceHelper.Search knows how to filter based on the CurrentFilterIds provided
var items = ServiceHelper.Search(SearchText, Filters.CurrentFilterIds).ToArray();
return items;
}
}
public partial class ServiceFilters : Filters
{
public ServiceFilters()
{
// This would be a default selection. Not providing this will cause the filter
// control to display the "Filter" placeholder text.
CurrentFilterIds = ["all"];
}
public override IFilterItem[] GetFilters()
{
return [
new Filter() { Id = "all", Name = "All Services" },
new Separator(),
new Filter() { Id = "running", Name = "Running", Icon = Icons.GreenCircleIcon },
new Filter() { Id = "stopped", Name = "Stopped", Icon = Icons.RedCircleIcon },
new Filter() { Id = "paused", Name = "Paused", Icon = Icons.PauseIcon },
];
}
}
```
## Current example of behavior
https://github.com/user-attachments/assets/2e325763-ad3a-4445-bbe2-a840df08d0b3
---------
Co-authored-by: Mike Griese <migrie@microsoft.com>
_targets #40504_
Major refactoring for #40113
This moves a large swath of the codebase to a `.Core` project. "Core"
doesn't have any explicit dependencies on "extensions", settings or the
current `MainListPage`. It's just a filterable list of stuff. This
should let us make this component a bit more reusable.
This is half of a PR. As I did this, I noticed a particular bit of code
for TopLevelVViewModels and CommandPaletteHost that was _very rough_.
Solving it in this PR would make "move everything to a new project" much
harder to review. So I'm submitting two PRs simultaneously, so we can
see the changes separately, then merge together.
Refactored ContextMenu into it's own control to allow displaying in
CommandBar and in response to right click on list items.
- Adds "critical" styling to context menu items flagged as `IsCritical`.
This will use the theme to style with correct color.
- Added `SeparatorContextItem` and modified `MoreCommands` to allow for
both `CommandContextItem`s and `SeparatorContextItem`s.
- Right clicking a list item with a context menu will open the context
menu at the position of the click and position the filter box at the top
of the context menu.


This PR covers:
- closes#38308
- closes#39211
- closes#38307
- closes#38261