PropertyDrawer gives strange results about the position and width of rect.

Question

I cannot understand why this PropertyDrawer gives strange results about the position and width of rect.

 [CustomPropertyDrawer(typeof(MinMaxSliderAttribute))]
     public class MinMaxSliderPropertyDrawer : PropertyDrawer
     {
         public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
         {
             MinMaxSliderAttribute minMaxSliderAttribute = (MinMaxSliderAttribute)attribute;
 
             if (property.propertyType == SerializedPropertyType.Vector2)
             {
                 // Draw the label
                 Rect controlRect = EditorGUI.PrefixLabel(position, label);
                 float sliderPadding = 5f;
                 float floatFieldWidth = EditorGUIUtility.fieldWidth;
                 float sliderWidth = controlRect.width - 2f * (floatFieldWidth + sliderPadding);
 
                 Rect minFloatFieldRect = new Rect(
                     controlRect.x,
                     controlRect.y,
                     floatFieldWidth,
                     controlRect.height);
 
                 Rect sliderRect = new Rect(
                     controlRect.x + floatFieldWidth + sliderPadding,
                     controlRect.y,
                     sliderWidth,
                     controlRect.height);
 
                 Rect maxFloatFieldRect = new Rect(
                     controlRect.x + floatFieldWidth + sliderWidth + 2f * sliderPadding,
                     controlRect.y,
                     floatFieldWidth,
                     controlRect.height);
 
                 // Draw the slider
                 EditorGUI.BeginChangeCheck();
 
                 Vector2 sliderValue = property.vector2Value;
 
                 EditorGUI.MinMaxSlider(sliderRect, ref sliderValue.x, ref sliderValue.y, minMaxSliderAttribute.MinValue, minMaxSliderAttribute.MaxValue);
 
                 sliderValue.x = EditorGUI.FloatField(minFloatFieldRect, sliderValue.x);
                 sliderValue.x = Mathf.Clamp(sliderValue.x, minMaxSliderAttribute.MinValue, Mathf.Min(minMaxSliderAttribute.MaxValue, sliderValue.y));
 
                 sliderValue.y = EditorGUI.FloatField(maxFloatFieldRect, sliderValue.y);
                 sliderValue.y = Mathf.Clamp(sliderValue.y, Mathf.Max(minMaxSliderAttribute.MinValue, sliderValue.x), minMaxSliderAttribute.MaxValue);
 
                 if (EditorGUI.EndChangeCheck())
                 {
                     property.vector2Value = sliderValue;
                 }
             }
             else
             {
                 base.OnGUI(position, property, label);
             }
         }
     }

alt text

And after I add an offset range of 30f. Everything looks good.

    [CustomPropertyDrawer(typeof(MinMaxSliderAttribute))]
     public class MinMaxSliderPropertyDrawer : PropertyDrawer
     {
         public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
         {
             MinMaxSliderAttribute minMaxSliderAttribute = (MinMaxSliderAttribute)attribute;
 
             if (property.propertyType == SerializedPropertyType.Vector2)
             {
                 // Draw the label
                 Rect controlRect = EditorGUI.PrefixLabel(position, label);
                 controlRect.x -= 30f;
                 float sliderPadding = 5f;
                 float floatFieldWidth = EditorGUIUtility.fieldWidth + 30f;
                 float sliderWidth = controlRect.width - 2f * (floatFieldWidth + sliderPadding) + 90f;
 
                 Rect minFloatFieldRect = new Rect(
                     controlRect.x,
                     controlRect.y,
                     floatFieldWidth,
                     controlRect.height);
 
                 Rect sliderRect = new Rect(
                     controlRect.x + floatFieldWidth + sliderPadding - 30f,
                     controlRect.y,
                     sliderWidth,
                     controlRect.height);
 
                 Rect maxFloatFieldRect = new Rect(
                     controlRect.x + floatFieldWidth + sliderWidth + 2f * sliderPadding - 60f,
                     controlRect.y,
                     floatFieldWidth,
                     controlRect.height);
 
                 // Draw the slider
                 EditorGUI.BeginChangeCheck();
 
                 Vector2 sliderValue = property.vector2Value;
 
                 EditorGUI.MinMaxSlider(sliderRect, ref sliderValue.x, ref sliderValue.y, minMaxSliderAttribute.MinValue, minMaxSliderAttribute.MaxValue);

             sliderValue.x = EditorGUI.FloatField(minFloatFieldRect, sliderValue.x);
             sliderValue.x = Mathf.Clamp(sliderValue.x, minMaxSliderAttribute.MinValue, Mathf.Min(minMaxSliderAttribute.MaxValue, sliderValue.y));

             sliderValue.y = EditorGUI.FloatField(maxFloatFieldRect, sliderValue.y);
             sliderValue.y = Mathf.Clamp(sliderValue.y, Mathf.Max(minMaxSliderAttribute.MinValue, sliderValue.x), minMaxSliderAttribute.MaxValue);

             if (EditorGUI.EndChangeCheck())
             {
                 property.vector2Value = sliderValue;
             }
         }
         else
         {
             base.OnGUI(position, property, label);
         }
     }
 }

alt text

Can you tell me where I was wrong?

Answer 1

I guess this is related to the indent of the nested elements. For example the PrefixLabel method will add EditorGUI.indent to the x position. However the returned rect will always start at the same position.

Note that EditorGUI.indent is just a property which returns EditorGUI.indentLevel * 15f. The indentLevel is increased by the any code that displays nested elements. Most controls will use the indent level as well. The FloatField for example uses this internally:

 return EditorGUI.DoFloatField(EditorGUI.s_RecycledEditor, EditorGUI.IndentedRect(position), new Rect(0f, 0f, 0f, 0f), controlID, value, EditorGUI.kFloatFieldFormatString, style, false);

Note that the IndentedRect method just does add the indent value to the x value and subract it from the width:

 public static Rect IndentedRect(Rect source)
 {
     float indent = EditorGUI.indent;
     return new Rect(source.x + indent, source.y, source.width - indent, source.height);
 }

The FloatField that takes also a label does the splitting beforehand and calls the internal "DoFloatField" without the indent but with the calculated content rect.

The only proper way I know to "remove" any indent is to save the old indentLevel value in a local variable, set the indentLevel to 0, draw your content and restore the indentLevel to the old value.

PropertyDrawer gives strange results about the position and width of rect.

1 Reply

Welcome to Unity Answers

Follow this Question

Related Questions