Unity EditorGuiLayout change slider properties depending on other values-CodePudding

I want to make a custom inspector script for my script. I need two gameobjects and a slider. However, the sliders max value is depending on the distance between the two gameobjects. I am using EditorGUILayout (Editor). Until now i tried to change it with an EditorGUI.BeginChangeCheck() and an if statement if (EditorGUI.EndChangeCheck()){...}. However, that doesn't really work and the slider does not show up. I am doing everything in the OnInspectorGUI() method. I am new to this, so I also don't really know what other things i can do.

Here is the code:

public override void OnInspectorGUI()
{
    UILineRenderer renderer = (UILineRenderer) target;
    EditorGUI.BeginChangeCheck();
    EditorGUILayout.BeginHorizontal();
    EditorGUILayout.LabelField("Points");
    renderer.startTR = (GameObject) EditorGUILayout.ObjectField(renderer.startTR, typeof(GameObject), true);
    renderer.endTR = (GameObject)EditorGUILayout.ObjectField(renderer.endTR, typeof(GameObject), true);
    EditorGUILayout.EndHorizontal();
    if (EditorGUI.EndChangeCheck())
    {
        if(renderer.startTR != null && renderer.endTR != null)
        {
            float val = Mathf.Abs(renderer.startTR.GetComponent<RectTransform>().anchoredPosition.x - renderer.endTR.GetComponent<RectTransform>().anchoredPosition.x);
            renderer.radius = EditorGUILayout.Slider("Radius", renderer.radius, 0, val);
        }
    }
}

Is there a way to save a createt EditorGUILayout element and change the properties of it afterwards? If not, how can I solve my problem? Thank you for your help in advance!

CodePudding user response：

You are making a huge but typical mistake ;)

You are accessing and setting values directly via the target. But this does not mark the object and changed fields as dirty which means

these values are not saved
the changes don't work with Undo/redo
prefabs will not be correctly overwritten

The most severe being of course already the first one ;)

Unless you know exactly what you are doing and mark the object manually as dirty you always rather want to go through the SerializedObject and SerializedPropertys.

This is a bit more effort to set it up but then it handles all the mentioned things automatically:

SerializedProperty startTr;
SerializedProperty endTr;
SerializedProperty radius;

private void OnEnable ()
{
    // Once link up the serialized properties whith their desired underlying fields
    startTr = serializedObject.FindPropery(nameof(UILimeRenderer.startTr));
    endTr = serializedObject.FindPropery(nameof(UILimeRenderer.endTr));
    radius = serializedObject.FindPropery(nameof(UILimeRenderer.radius));
}

public override void OnInspectorGUI()
{
    // Load current values into the serialized object
    serializedObject.Update();

    EditorGUILayout.BeginHorizontal();
    EditorGUILayout.LabelField("Points");

     // Use the default drawer for these properties
     // GUIContent.None for omitting the label
    EditorGUILayout.PropertyField(startTR, GUIContent.None, true);
    EditorGUILayout.PropertyField(endTR, GUIContent.None, true);
    
    EditorGUILayout.EndHorizontal();
    
    if(startTR.objectReferenceValue && endTR.objectReferenceValue)
    {
        var maxValue = Mathf.Abs(((GameObject)startTR.objectReferenceValue).GetComponent<RectTransform>().anchoredPosition.x - ((GameObject)endTR.objectReferenceValue).GetComponent<RectTransform>().anchoredPosition.x);
        radius.floatValue = EditorGUILayout.Slider("Radius", radius.floatValue, 0, maxValue);
    }

    // Write back changed values. This handles all the mentioned dirty marking
    serializedObject.ApplyModifiedProperties();
}

I would also suggest to use actually RectTransform fields instead of GameObject and then get rid of the GetComponent.