Additional Button colour toggling for hover

Unity Courses Talk
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1

This is how did it - Po-tay-toe/Po-tah-toe.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class UnitButton_Script : MonoBehaviour {

	private SpriteRenderer rend;

	public GameObject defenderPrefab;
	public static GameObject selectedDefender;

	// Use this for initialization
	void Start () {
		rend = GetComponent<SpriteRenderer> ();
	}

    // If you move your mouse inside the button's collider, but DON'T click.
	void OnMouseEnter(){
		if (!defenderPrefab.Equals (selectedDefender)) {
			// Optional condition to check if there are enough resources.
			rend.color = Color.grey;
		}
	}

    // If you move your mouse outside the button's collider.
	void OnMouseExit(){
		if (!defenderPrefab.Equals (selectedDefender)) {
			rend.color = Color.black;
		}
	}

	void OnMouseDown(){
        // If the correct Defender is already selected, don't bother continuing.
		if (defenderPrefab.Equals (selectedDefender)) {
			return;
		} else {
            // transform.parent finds the parent of the current GameObject.
            // You can also loop through the transforms of any GameObject with 
            // children.
			foreach (Transform t in transform.parent) {
				SpriteRenderer sr = t.GetComponent<SpriteRenderer> ();
				if (sr) {
					sr.color = Color.black;
				}
			}
			selectedDefender = defenderPrefab;
			rend.color = Color.white;
		}
	}
}

Basically, I changed the script name (note that “Button” is the name of UnityEngine.UI Component, and will generate errors), and when I click on the buttons I loop through the parent’s transform to find any SpriteRenderers and change their colour (ignoring those without).
This works if the Buttons hierarchy is like this:

  • Buttons Container
    • Background
    • Buttons

OR

  • Buttons Container
    • Background
      • Buttons

BUT it’s easily defeated by having any Buttons outside this “Parent/Child Relationship”:

  • Buttons Container
    • Background
    • Buttons
  • Button that won’t work as intended

I also introduced hovering, such that if you enter the button without clicking it, it partially highlights the button, and changes back to normal when the mouse leaves (UNLESS you’re hovering over the currently selected defender, in which case both enter/exit methods are ignored.). This can be easily extended to, say, colour the defender red if there aren’t enough resources?

Finally, I also didn’t bother with the button array because…
I dunno. Laziness?

Thoughts?

2

I didn’t use the Array either… My solution to the challenge simply used OnMouseUp to change the colour back to black.

I’ll see if it hits any problems further down the line.

For your mouseover feature - I guess it depends on the platform that the game is intended for. This would only really be useful on PC/Mac. But I understand this one is aimed at mobile, where I guess hover probably isn’t really possible. Ultimately, It’s your choice :slight_smile:

Always good to experiment though, and extend your project above what the lectures contain! (but I think I’ll wait for the end on that because I’m never really sure if I’d end up conflicting with a later lecture)