CODEWITHSUNDEEP
unity-game-engine
Kuroyuki Hikari
Kuroyuki Hikari

Reputation: 541

Disable an option(s) in a dropdown Unity

I need to disable 1(or 2) dropdown option from a dropdown menu in Unity. enter image description here The dropdown menu should not be repopulated.
There should not be any deletion/deactivated options from the dropdown menu

Anyone have any idea how to do this. ?

Upvotes: 5

Views: 9760

Answers (2)

derHugo
derHugo

Reputation: 90630

Similar to this answer but a slightly different approach.

The other answer uses a hardcoded toggle.name == "Item 1: Option B" to compare the buttons. I'd rather use a central and index-based system:

Put this component on the DropDown

[RequireComponent(typeof(Dropdown))]
[DisallowMultipleComponent]
public class DropDownController : MonoBehaviour, IPointerClickHandler
{
    [Tooltip("Indexes that should be ignored. Indexes are 0 based.")]
    public List<int> indexesToDisable = new List<int>();

    private Dropdown _dropdown;

    private void Awake()
    {
        _dropdown = GetComponent<Dropdown>();
    }

    public void OnPointerClick(PointerEventData eventData)
    {
        var dropDownList = GetComponentInChildren<Canvas>();
        if (!dropDownList) return;

        // If the dropdown was opened find the options toggles
        var toogles = dropDownList.GetComponentsInChildren<Toggle>(true);

        // the first item will always be a template item from the dropdown we have to ignore
        // so we start at one and all options indexes have to be 1 based
        for (var i = 1; i < toogles.Length; i++)
        {
            // disable buttons if their 0-based index is in indexesToDisable
            // the first item will always be a template item from the dropdown
            // so in order to still have 0 based indexes for the options here we use i-1
            toogles[i].interactable = !indexesToDisable.Contains(i - 1);
        }
    }

    // Anytime change a value by index
    public void EnableOption(int index, bool enable)
    {
        if (index < 1 || index > _dropdown.options.Count)
        {
            Debug.LogWarning("Index out of range -> ignored!", this);
            return;
        }

        if (enable)
        {
            // remove index from disabled list
            if (indexesToDisable.Contains(index)) indexesToDisable.Remove(index);
        }
        else
        {
            // add index to disabled list
            if (!indexesToDisable.Contains(index)) indexesToDisable.Add(index);
        }

        var dropDownList = GetComponentInChildren<Canvas>();

        // If this returns null than the Dropdown was closed
        if (!dropDownList) return;

        // If the dropdown was opened find the options toggles
        var toogles = dropDownList.GetComponentsInChildren<Toggle>(true);
        toogles[index].interactable = enable;
    }

    // Anytime change a value by string label
    public void EnableOption(string label, bool enable)
    {
        var index = _dropdown.options.FindIndex(o => string.Equals(o.text, label));

        // We need a 1-based index
        EnableOption(index + 1, enable);
    }
}

Configure in the Inspector

enter image description here

or via scripts e.g.

dropDownReference.GetComponent<DropDownController>().EnableOption("Option B", false);

enter image description here

Upvotes: 11

Ali Kanat
Ali Kanat

Reputation: 1889

You can achieve this using the Toggle component from DropDown->Template->ViewPort->Content->Item.

This script is creating items every time DropDown menu is selected. You can just access Toogle and disable interactable field like this:

void Start () 
{
    //This script should be attached to Item
    Toggle toggle = gameObject.GetComponent<Toggle>();
    Debug.Log(toggle);
    if (toggle != null && toggle.name == "Item 1: Option B")
    {
        toggle.interactable = false;
    }
}

You can also see a DropDown list is created every time arrow on DrowDown is clicked and destroyed when menu is closed.

Upvotes: 3

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