When I search I only get the trigger command that I search for shown, when I enter the exact CommandTrigger. But it should also show the items that contain that query
You should be able to call commands with a plugin, not just provide new commands. For example, if you build a custom keyboard, you could write a plugin that calls a command when you press a key.
To remove the flickering of the search while typing, we should not clear and add new items everytime the text changes, but rather get the existing items and change its propertys
The file search is a bit useless because the path is not displayed. You should be able to choose between certain actions for each file, for example: Copy path, Open file, Open file in Explorer, etc.
Create a property for every CommandCollector, that says, whether that command can handle drag dropped files or not. Just a bool.
Then when the user drops a file in, only show those items that allow drag drop.
When the searchbox is empty and you click on an item that does not directly open something, but needs further commands like e.g. RunCommand.
Maybe instead of doing nothing, put the trigger command into the searchbar?