Merge branch 'Swiggies-control-child-size-update'

Source/Engine/UI/GUI/Panels/HorizontalPanel.cs

@@ -44,6 +44,15 @@ namespace FlaxEngine.GUI
             float h = Height - _margin.Height;
             float maxHeight = h;
             bool hasAnyLeft = false, hasAnyRight = false;
+
+            float itemWidth = 0;
+            if (_children.Count > 0)
+            {
+                float totalGaps = (_children.Count - 1) * Spacing;
+                float availableWidth = Width - totalGaps - _margin.Width;
+                itemWidth = availableWidth / _children.Count;
+            }
+
             for (int i = 0; i < _children.Count; i++)
             {
                 Control c = _children[i];
@@ -64,6 +73,11 @@ namespace FlaxEngine.GUI
                         hasAnyRight = true;
                     }
                     maxHeight = Mathf.Max(maxHeight, ch);
+
+                    if (ExpandChildSize && !AutoSize)
+                    {
+                        c.Width = itemWidth;
+                    }
                 }
             }
             if (hasAnyLeft)

Source/Engine/UI/GUI/Panels/PanelWithMargins.cs

@@ -36,6 +36,7 @@ namespace FlaxEngine.GUI
         protected TextAlignment _alignment = TextAlignment.Near;
 
         private bool _controlChildSize = true;
+        private bool _expandChildSize = false;
 
         /// <summary>
         /// Gets or sets the left margin.
@@ -173,6 +174,23 @@ namespace FlaxEngine.GUI
             }
         }
 
+        /// <summary>
+        /// If checked, the panel will expand all children in the relevant direction with even spacing and size (horizontally for Horizontal Panel, vertically for Vertical Panel).
+        /// </summary>
+        [EditorOrder(36), DefaultValue(false), VisibleIf(nameof(AutoSize), true)]
+        public bool ExpandChildSize
+        {
+            get => _expandChildSize;
+            set
+            {
+                if (_expandChildSize != value)
+                {
+                    _expandChildSize = value;
+                    PerformLayout();
+                }
+            }
+        }
+
         /// <summary>
         /// Gets or sets the panel area margin.
         /// </summary>

Source/Engine/UI/GUI/Panels/VerticalPanel.cs

@@ -44,6 +44,15 @@ namespace FlaxEngine.GUI
             float w = Width - _margin.Width;
             float maxWidth = w;
             bool hasAnyTop = false, hasAnyBottom = false;
+
+            float itemHeight = 0;
+            if (_children.Count > 0)
+            {
+                float totalGaps = (_children.Count - 1) * Spacing;
+                float availableHeight = Height - totalGaps - _margin.Height;
+                itemHeight = availableHeight / _children.Count;
+            }
+
             for (int i = 0; i < _children.Count; i++)
             {
                 Control c = _children[i];
@@ -64,6 +73,11 @@ namespace FlaxEngine.GUI
                         hasAnyBottom = true;
                     }
                     maxWidth = Mathf.Max(maxWidth, cw);
+
+                    if (ExpandChildSize && !AutoSize)
+                    {
+                        c.Height = itemHeight;
+                    }
                 }
             }
             if (hasAnyTop)