GUI.tooltip

Description

The tooltip of the control the mouse is currently over, or which has keyboard focus. (Read Only).

When you create GUI controls, you can pass in a tooltip for them. This is done by changing the content parameter to take a custom-made GUIContent object, rather than just passing in a string to display.

When the mouse is over a control with a tooltip, it sets the global GUI.tooltip value to the tooltip you pass in. If the mouse is not hovering over any control, the value is set to the control which has keyboard focus. At the end of the OnGUI code, you can make a label showing the value of GUI.tooltip


GUI Tooltip on the Game view appears when the mouse is over the button.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    void OnGUI()
    {
        // Make a button using a custom GUIContent parameter to pass in the tooltip.
        GUI.Button(new Rect(10, 10, 100, 20), new GUIContent("Click me", "This is the tooltip"));

        // Display the tooltip from the element that has mouseover or keyboard focus
        GUI.Label(new Rect(10, 40, 100, 40), GUI.tooltip);
    }
}

You can use the ordering of elements to create 'hierarchical' tooltips:

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    void OnGUI()
    {
        // This box is larger than many elements following it, and it has a tooltip.
        GUI.Box(new Rect(5, 35, 110, 75), new GUIContent("Box", "this box has a tooltip"));

        // This button is inside the box, but has no tooltip so it does not
        // override the box's tooltip.
        GUI.Button(new Rect(10, 55, 100, 20), "No tooltip here");

        // This button is inside the box, and HAS a tooltip so it overrides
        // the tooltip from the box.
        GUI.Button(new Rect(10, 80, 100, 20), new GUIContent("I have a tooltip", "The button overrides the box"));

        // finally, display the tooltip from the element that has
        // mouseover or keyboard focus
        GUI.Label(new Rect(10, 40, 100, 40), GUI.tooltip);
    }
}

Tooltips can also be used to implement an OnMouseOver / OnMouseOut messaging system:

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    public string lastTooltip = " ";

    void OnGUI()
    {
        GUILayout.Button(new GUIContent("Play Game", "Button1"));
        GUILayout.Button(new GUIContent("Quit", "Button2"));

        if (Event.current.type == EventType.Repaint && GUI.tooltip != lastTooltip)
        {
            if (lastTooltip != "")
            {
                SendMessage(lastTooltip + "OnMouseOut", SendMessageOptions.DontRequireReceiver);
            }

            if (GUI.tooltip != "")
            {
                SendMessage(GUI.tooltip + "OnMouseOver", SendMessageOptions.DontRequireReceiver);
            }

            lastTooltip = GUI.tooltip;
        }
    }

    void Button1OnMouseOver()
    {
        Debug.Log("Play game got focus");
    }

    void Button2OnMouseOut()
    {
        Debug.Log("Quit lost focus");
    }
}