Simple drop-down menu script for Unity3d tutorial - Indie Devs

Since Unity3d doesn't have drop-down lists built in, here's a simple drop-down menu script heavily based on Eric Haines's PopupListUsageExample.js and Popup.cs from UnifyCommunity: Unifycommunity.com

Main differences:
- instead of mouseDown and mouseUp events it uses two mouseDown events (so you click to expand the list and then click the option to select)
- the C# part of it is completely converted to JavaScript
- in one single file instead of two

All in one JavaScript file, you just need to add it to your JavaScript file:

//global variables for settings
var showList 					: boolean 	= false;
static var listEntrySelected 	: int;
static var listEntry 			: int 		= 2;
static var defaultEntryNumber 	: int		= 0;
var generalListStyle 			: GUIStyle 	= new GUIStyle();

//dropdown menu content
var listColours : GUIContent[]; listColours = new GUIContent[5];
listColours[0] 	= new GUIContent("Blue");
listColours[1] 	= new GUIContent("White");
listColours[2] 	= new GUIContent("Red");
listColours[3] 	= new GUIContent("Green");
listColours[4] 	= new GUIContent("Purple");

generalListStyle.padding.left = generalListStyle.padding.right = generalListStyle.padding.top = generalListStyle.padding.bottom = 4;

var dropdownListHash : int = "DropdownList".GetHashCode();

//		List(Rect(0,0,100,100), 		false, 				0, 				GUIContent("Select Colour"), 	listColours				"button",				"box",			generalListStyle)
function List(position : Rect, expandList : boolean, listEntry : int, defaultListEntry : GUIContent, listToUse : GUIContent[], buttonStyle : GUIStyle, boxStyle : GUIStyle, listStyle : GUIStyle)
{
	
	controlID = GUIUtility.GetControlID(dropdownListHash, FocusType.Passive);
	var done : boolean = false;
	
	if(Event.current.GetTypeForControl(controlID) == EventType.mouseDown)
	{
	if (position.Contains(Event.current.mousePosition))
		{
        GUIUtility.hotControl = controlID;
       	showList = !showList;
		}
    }
    
   	if(Event.current.GetTypeForControl(controlID) == EventType.mouseDown && !position.Contains(Event.current.mousePosition))
	{
		GUIUtility.hotControl = controlID;
    }              
	
	GUI.Label(position, defaultListEntry, buttonStyle);
	
	if(expandList)
	{
	//list rectangle
	var listRect : Rect = new Rect(position.x, position.y+20, position.width, listStyle.CalcHeight(listToUse[0], 1.0f) * listToUse.Length);
	GUI.Box(listRect, "", boxStyle);
	
	listEntrySelected = GUI.SelectionGrid(listRect, listEntrySelected, listToUse, 1, listStyle);
	listEntry = listEntrySelected;
	
		if(listEntrySelected != defaultEntryNumber && !position.Contains(Event.current.mousePosition))
		{
		GUIUtility.hotControl = controlID;
       	showList = !showList;
       	defaultEntryNumber = listEntrySelected;
    	}    
	}
}

function OnGUI()
{
	GUI.Label(Rect(200,200, 100, 20), listColours[listEntrySelected].text);
	List(Rect(50, 100, 100, 20), showList, listEntry, GUIContent(listColours[listEntrySelected].text), listColours, "button", "box", generalListStyle);
}

Important note: you have to replace "& amp;& amp;" with two ampersands "&&" IndieDB/ModDB html editor converts them automatically to html code. Here's a clean script: Forum.unity3d.com

You can customise generalListStyle in the Unity3d editor and use List function to pass your list to the function.