How to add your own function in ActionMode class in Android?

Question

I want to implement an ActionMode which acts as a selection mode . I want to add a function toggle() in my ActionMode which toggles the selection of my list.

my ActionMode code:

class Selection(/* some parameters */): ActionMode.Callback {
    private val selectedPositions = ArrayList<Int>()

    fun toggle(position: Int) {
        if (selectedPositions.contains(position)) {
            selectedPositions.remove(position)
        } else {
            selectedPositions.add(position)
        }
    }

    override fun onActionItemClicked(mode: ActionMode, item: MenuItem): Boolean { /* some code */ }
    override fun onCreateActionMode(mode: ActionMode, menu: Menu): Boolean { /* some code */ }
    override fun onPrepareActionMode(mode: ActionMode?, menu: Menu?): Boolean = false
    override fun onDestroyActionMode(mode: ActionMode?) { /* some code */ }
}

My problem is that I am not able to use the toggle() function from my calling activity/fragment. For example:

private var actionMode: ActionMode? = null

// initialising action mode
if (actionMode == null) {
    actionMode = activity!!.startActionMode(Selection(/* some parameters */))
}

// I am not able to do this
actionMode!!.toggle(position)

Answer 1

Because the function is on your Selection class, not the ActionMode class. Call it on the instnce of the Selection class