* **label** - _string_ - The label to display on the button
* **callback** - _function_ - The function to call when the button is pressed
* **\[tooltip\]** - _string_ - The tooltip to use on the new button
callback -
```
function(
event : string,
images : table oftypes.dt_lua_image_t
) : table oftypes.dt_lua_image_t
```
The function to call when the button is pressed
* **event** - _string_ - The name of the button that was pressed
* **images** - _table of [types.dt_lua_image_t](../../../types/dt_lua_image_t)_ - The images in the current collection. This is the same content asdarktable.collection
* **return** - _table of [types.dt_lua_image_t](../../../types/dt_lua_image_t)_ - The images to set the selection to