Aisv756 obj count bug (#84)

* Fixes for object count bug

* Updated change log

com.unity.perception/CHANGELOG.md

 
 ### Fixed
 
+Fixed visualization issue where object count and pixel count labelers were shown stale values
+Fixed visualization issue where HUD entry labels could be too long and take up the entire panel
+
 ## [0.4.0-preview.1] - 2020-08-07
 
 ### Added
 ### Removed
 
 ### Fixed
+
 Fixed 2d bounding boxes being reported for objects that do not match the label config.
 
 Fixed a categorical parameter UI error in which deleting an individual option would successfully remove the option from the UI but only serialize the option to null during serialization instead of removing it
 Changed minimum Unity Editor version to 2019.4
 
 ### Fixed
+
 Fixed compilation warnings with latest com.unity.simulation.core package.
 
 Fixed errors in example script when exiting play mode

com.unity.perception/Runtime/GroundTruth/Labelers/ObjectCountLabeler.cs

                 if (m_ClassCountValues == null || m_ClassCountValues.Length != entries.Count)
                     m_ClassCountValues = new ClassCountValue[entries.Count];
 
-                bool visualize = visualizationEnabled;
+                var visualize = visualizationEnabled;
+                if (visualize)
+                {
+                    // Clear out all of the old entries...
+                    hudPanel.RemoveEntries(this);
+                }
+                
                 for (var i = 0; i < entries.Count; i++)
                 {
                     m_ClassCountValues[i] = new ClassCountValue()
                         count = counts[i]
                     };
 
-                    if (visualize)
+                    // Only display entries with a count greater than 0
+                    if (visualize && counts[i] > 0)
-
-
                     }
                 }
 

com.unity.perception/Runtime/GroundTruth/Labelers/RenderedObjectInfoLabeler.cs

                 if (m_VisiblePixelsValues == null || m_VisiblePixelsValues.Length != renderedObjectInfos.Length)
                     m_VisiblePixelsValues = new RenderedObjectInfoValue[renderedObjectInfos.Length];
 
-                bool visualize = visualizationEnabled;
+                var visualize = visualizationEnabled;
+                if (visualize)
+                {
+                    // Clear out all of the old entries...
+                    hudPanel.RemoveEntries(this);
+                }
+                
                 for (var i = 0; i < renderedObjectInfos.Length; i++)
                 {
                     var objectInfo = renderedObjectInfos[i];

com.unity.perception/Runtime/GroundTruth/Labelers/Visualization/HUDPanel.cs

 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using UnityEngine;
 using UnityEngine.UI;
 
         const int k_YPadding = 10;
         const int k_BoxWidth = 200;
         const int k_YLineSpacing = 4;
-
+        const int k_MaxKeyLength = 20;
 
         /// <summary>
         /// The number of labelers currently displaying real-time information on the visualization HUD
             GUI.skin.label.font = Resources.Load<Font>("Inter-Light");
             GUI.skin.label.padding = new RectOffset(0, 0, 1, 1);
             GUI.skin.label.margin = new RectOffset(0, 0, 1, 1);
+            GUI.skin.label.wordWrap = false;
+            GUI.skin.label.clipping = TextClipping.Clip;
             GUI.skin.box.padding = new RectOffset(5, 5, 5, 5);
             GUI.skin.toggle.margin = new RectOffset(0, 0, 0, 0);
             GUI.skin.horizontalSlider.margin = new RectOffset(0, 0, 0, 0);
                 {
                     GUILayout.BeginHorizontal();
                     GUILayout.Space(5);
-                    GUILayout.Label(entry.Key);
+                    var k = new StringBuilder(entry.Key.Substring(0, Math.Min(entry.Key.Length, k_MaxKeyLength)));
+                    if (k.Length != entry.Key.Length) 
+                        k.Append("...");
+                    GUILayout.Label(k.ToString());
                     GUILayout.FlexibleSpace();
                     GUILayout.Label(entry.Value);
                     GUILayout.EndHorizontal();