## `ComboBox`
A button that, when clicked, opens a popup to select a value.
### Properties
- **`current-index`**: (_in-out_ _int_): The index of the selected value (-1 if no value is selected)
- **`current-value`**: (_in-out_ _string_): The currently selected text
- **`enabled`**: (_in_ _bool_): Defaults to true. When false, the combobox can't be interacted with
- **`has-focus`**: (_out_ _bool_): Set to true when the combobox has keyboard focus.
- **`model`** (_in_ _\[string\]_): The list of possible values
### Callbacks
- **`selected(string)`**: A value was selected from the combo box. The argument is the currently selected value.
### Example
```slint
import { ComboBox } from "std-widgets.slint";
export component Example inherits Window {
width: 200px;
height: 130px;
ComboBox {
y: 0px;
width: self.preferred-width;
height: self.preferred-height;
model: ["first", "second", "third"];
current-value: "first";
}
}
```