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

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+using System;
+
+namespace FlaxEngine.GUI
+{
+    /// <summary>
+    /// A panel that divides up available space between all of its children.
+    /// </summary>
+    /// <seealso cref="FlaxEngine.GUI.ContainerControl" />
+    public class GridPanel : ContainerControl
+    {
+        private Margin _slotPadding;
+        private float[] _cellsV;
+        private float[] _cellsH;
+
+        /// <summary>
+        /// Gets or sets the padding applied to each item slot.
+        /// </summary>
+        [EditorOrder(0), Tooltip("The padding margin applied to each item slot.")]
+        public Margin SlotPadding
+        {
+            get => _slotPadding;
+            set
+            {
+                if (_slotPadding != value)
+                {
+                    _slotPadding = value;
+                    PerformLayout();
+                }
+            }
+        }
+
+        /// <summary>
+        /// The cells heights in container height percentage (from top to bottom). Use negative values to set fixed widths for the cells.
+        /// </summary>
+        [EditorOrder(10), Tooltip("The cells heights in container height percentage (from top to bottom). Use negative values to set fixed height for the cells.")]
+        public float[] RowFill
+        {
+            get => _cellsV;
+            set
+            {
+                if (value == null)
+                    throw new ArgumentNullException();
+                _cellsV = value;
+                PerformLayout();
+            }
+        }
+
+        /// <summary>
+        /// The cells heights in container width percentage (from left to right). Use negative values to set fixed heights for the cells.
+        /// </summary>
+        [EditorOrder(20), Tooltip("The cells heights in container width percentage (from left to right). Use negative values to set fixed width for the cells.")]
+        public float[] ColumnFill
+        {
+            get => _cellsH;
+            set
+            {
+                if (value == null)
+                    throw new ArgumentNullException();
+                _cellsH = value;
+                PerformLayout();
+            }
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GridPanel"/> class.
+        /// </summary>
+        public GridPanel()
+        : this(2)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GridPanel"/> class.
+        /// </summary>
+        /// <param name="slotPadding">The slot padding.</param>
+        public GridPanel(float slotPadding)
+        {
+            SlotPadding = new Margin(slotPadding);
+            _cellsH = new[]
+            {
+                0.5f,
+                0.5f
+            };
+            _cellsV = new[]
+            {
+                0.5f,
+                0.5f
+            };
+        }
+
+        /// <inheritdoc />
+        protected override void PerformLayoutBeforeChildren()
+        {
+            base.PerformLayoutBeforeChildren();
+
+            int i = 0;
+            Vector2 upperLeft = Vector2.Zero;
+            float reamingHeight = Height;
+            for (int rowIndex = 0; rowIndex < _cellsV.Length; rowIndex++)
+            {
+                upperLeft.X = 0;
+                float cellHeight = _cellsV[rowIndex] * reamingHeight;
+                if (_cellsV[rowIndex] < 0)
+                {
+                    cellHeight = -_cellsV[rowIndex];
+                    reamingHeight -= cellHeight;
+                }
+
+                float reamingWidth = Width;
+                for (int columnIndex = 0; columnIndex < _cellsH.Length; columnIndex++)
+                {
+                    if (i >= ChildrenCount)
+                        break;
+
+                    float cellWidth = _cellsH[columnIndex] * reamingWidth;
+                    if (_cellsH[columnIndex] < 0)
+                    {
+                        cellWidth = -_cellsH[columnIndex];
+                        reamingWidth -= cellWidth;
+                    }
+
+                    var slotBounds = new Rectangle(upperLeft, cellWidth, cellHeight);
+                    _slotPadding.ShrinkRectangle(ref slotBounds);
+
+                    var c = _children[i++];
+                    c.Bounds = slotBounds;
+
+                    upperLeft.X += cellWidth;
+                }
+                upperLeft.Y += cellHeight;
+            }
+        }
+    }
+}