More stable size calculations

Author: vanifatovvlad

Editor.Samples/TriSamplesWindow.cs

@@ -106,8 +106,7 @@ private void DrawElement()
                     using (TriGuiHelper.PushEditorTarget(_current))
                     using (new GUILayout.VerticalScope(SampleWindowStyles.BoxWithPadding))
                     {
-                        var viewWidth = GUILayoutUtility.GetRect(0, 10000, 0, 0).width;
-                        _currentPropertyTree.Draw(viewWidth);
+                        _currentPropertyTree.Draw();
                     }
 
                     if (_currentSerializedObject.ApplyModifiedProperties())

Editor/TriPropertyTree.cs

@@ -8,6 +8,7 @@ namespace TriInspector
     public abstract class TriPropertyTree
     {
         private TriPropertyElement _rootPropertyElement;
+        private Rect _cachedOuterRect = new Rect(0, 0, 0, 0);
 
         public TriPropertyDefinition RootPropertyDefinition { get; protected set; }
         public TriProperty RootProperty { get; protected set; }
@@ -48,7 +49,7 @@ public void RunValidation()
             RequestRepaint();
         }
 
-        public virtual void Draw(float? viewWidth = null)
+        public virtual void Draw()
         {
             RepaintRequired = false;
 
@@ -62,19 +63,19 @@ public virtual void Draw(float? viewWidth = null)
             }
 
             _rootPropertyElement.Update();
-            var width = viewWidth ?? GUILayoutUtility.GetRect(0, 9999, 0, 0).width;
-            var height = _rootPropertyElement.GetHeight(width);
-            var rect = GUILayoutUtility.GetRect(width, height);
 
-            if (viewWidth == null)
-            {
-                rect.xMin += 3;
-            }
+            var rectOuter = GUILayoutUtility.GetRect(0, 9999, 0, 0);
+            _cachedOuterRect = Event.current.type == EventType.Layout ? _cachedOuterRect : rectOuter;
 
+            var rect = new Rect(_cachedOuterRect);
             rect = EditorGUI.IndentedRect(rect);
+            rect.height = _rootPropertyElement.GetHeight(rect.width);
+
             var oldIndent = EditorGUI.indentLevel;
             EditorGUI.indentLevel = 0;
 
+            GUILayoutUtility.GetRect(_cachedOuterRect.width, rect.height);
+
             _rootPropertyElement.OnGUI(rect);
 
             EditorGUI.indentLevel = oldIndent;

Editor/TriPropertyTreeForSerializedObject.cs

@@ -56,11 +56,11 @@ public override void Update(bool forceUpdate = false)
             base.Update(forceUpdate);
         }
 
-        public override void Draw(float? viewWidth = null)
+        public override void Draw()
         {
             DrawMonoScriptProperty();
 
-            base.Draw(viewWidth);
+            base.Draw();
         }
 
         public override bool ApplyChanges()