Merge pull request #212 from Unity-Technologies/uniform-toggle-fix

Fixed categorical parameter uniform toggle issues in HDRP

com.unity.perception/CHANGELOG.md

 
 ### Fixed
 
+Fixed a null reference error that appeared when adding options to categorical parameters.
+
 Fixed ground truth not properly produced when there are other disabled PerceptionCameras present. Note: this does not yet add support for multiple enabled PerceptionCameras.
 
 ## [0.7.0-preview.2] - 2021-02-08

com.unity.perception/Editor/Randomization/Uss/Styles.uss

     flex-shrink: 0;
 }
 
+.parameter__categorical-option-property-field Label.unity-property-field__label {
+    display: none;
+}
+
 .parameter__categorical-options-list-button {
     align-self: flex-end;
     border-width: 0;

com.unity.perception/Editor/Randomization/VisualElements/Parameter/CategoricalOptionElement.cs

 {
     class CategoricalOptionElement : VisualElement
     {
-        SerializedProperty m_CategoryProperty;
+        SerializedProperty m_CategoryProperty;
         SerializedProperty m_ProbabilitiesProperty;
 
         internal CategoricalOptionElement(
             var optionProperty = m_CategoryProperty.GetArrayElementAtIndex(i);
             var option = this.Q<PropertyField>("option");
             option.BindProperty(optionProperty);
-
-            // Remove the redundant element label to save space
-            var label = option.Q<Label>();
-            label.parent.Remove(label);
 
             var probabilityProperty = m_ProbabilitiesProperty.GetArrayElementAtIndex(i);
             var probability = this.Q<FloatField>("probability");

com.unity.perception/Editor/Randomization/VisualElements/Parameter/ParameterElement.cs

             var uniformProperty = m_SerializedProperty.FindPropertyRelative("uniform");
             uniformToggle.BindProperty(uniformProperty);
 
-            if (uniformToggle.value)
-                listView.AddToClassList("collapsed");
-            else
-                listView.RemoveFromClassList("collapsed");
+            void ToggleUniform()
+            {
+                if (uniformToggle.value)
+                    listView.AddToClassList("collapsed");
+                else
+                    listView.RemoveFromClassList("collapsed");
+            }
+            ToggleUniform();
 
             if (Application.isPlaying)
                 uniformToggle.SetEnabled(false);
-                    listView.ToggleInClassList("collapsed");
+                    ToggleUniform();
                     if (!evt.newValue)
                         return;
                     var numOptions = optionsProperty.arraySize;