Layout changes to support Vertical Flow

Scripts/Layout/FlowLayoutGroup.cs

@@ -3,50 +3,64 @@
 /// Example http://forum.unity3d.com/threads/flowlayoutgroup.296709/
 /// Update by Martin Sharkbomb - http://forum.unity3d.com/threads/flowlayoutgroup.296709/#post-1977028
 /// Last item alignment fix by Vicente Russo - https://bitbucket.org/ddreaper/unity-ui-extensions/issues/22/flow-layout-group-align
+/// Vertical Flow by Ramon Molossi 
 
 using System.Collections.Generic;
 
 namespace UnityEngine.UI.Extensions
 {
 	/// <summary>
-    /// Layout Group controller that arranges children in rows, fitting as many on a line until total width exceeds parent bounds
+	/// Layout Group controller that arranges children in bars, fitting as many on a line until total size exceeds parent bounds
 	/// </summary>
 	[AddComponentMenu("Layout/Extensions/Flow Layout Group")]
 	public class FlowLayoutGroup : LayoutGroup
 	{
+		public enum Axis { Horizontal = 0, Vertical = 1 }
+
 		public float SpacingX = 0f;
 		public float SpacingY = 0f;
 		public bool ExpandHorizontalSpacing = false;
 
 		public bool ChildForceExpandWidth = false;
 		public bool ChildForceExpandHeight = false;
-		
+		public bool invertOrder = false;
 		private float _layoutHeight;
+		private float _layoutWidth;
+
+		[SerializeField] protected Axis m_StartAxis = Axis.Horizontal;
+		public Axis startAxis { get { return m_StartAxis; } set { SetProperty(ref m_StartAxis, value); } }
 
 		public override void CalculateLayoutInputHorizontal()
 		{
-			
+			if (startAxis == Axis.Horizontal) {
-			base.CalculateLayoutInputHorizontal();
+				base.CalculateLayoutInputHorizontal ();
-			
+				var minWidth = GetGreatestMinimumChildWidth () + padding.left + padding.right;
-			var minWidth = GetGreatestMinimumChildWidth() + padding.left + padding.right;
+				SetLayoutInputForAxis (minWidth, -1, -1, 0);
-			
+			} else {
-			SetLayoutInputForAxis(minWidth, -1, -1, 0);
+				_layoutWidth = SetLayout (0, true);
+			}
 
 		}
 
 		public override void SetLayoutHorizontal()
 		{
-			SetLayout(rectTransform.rect.width, 0, false);
+			SetLayout(0, false);
 		}
 
 		public override void SetLayoutVertical()
 		{
-			SetLayout(rectTransform.rect.width, 1, false);
+			SetLayout(1, false);
 		}
 
 		public override void CalculateLayoutInputVertical()
 		{
-			_layoutHeight = SetLayout(rectTransform.rect.width, 1, true);
+			if (startAxis == Axis.Horizontal) {
+				_layoutHeight = SetLayout (1, true);
+			} else {
+				base.CalculateLayoutInputHorizontal ();
+				var minHeight = GetGreatestMinimumChildHeigth () + padding.bottom + padding.top;
+				SetLayoutInputForAxis (minHeight, -1, -1, 1);
+			}
 		}
 
 		protected bool IsCenterAlign
@@ -86,9 +100,9 @@ namespace UnityEngine.UI.Extensions
 		}
 
 		/// <summary>
-		/// Holds the rects that will make up the current row being processed
+		/// Holds the rects that will make up the current bar being processed
 		/// </summary>
-		private readonly IList<RectTransform> _rowList = new List<RectTransform>(); 
+		private readonly IList<RectTransform> _itemList = new List<RectTransform>(); 
 
 		/// <summary>
 		/// Main layout method
@@ -96,138 +110,197 @@ namespace UnityEngine.UI.Extensions
 		/// <param name="width">Width to calculate the layout with</param>
 		/// <param name="axis">0 for horizontal axis, 1 for vertical</param>
 		/// <param name="layoutInput">If true, sets the layout input for the axis. If false, sets child position for axis</param>
-		public float SetLayout(float width, int axis, bool layoutInput)
+		public float SetLayout(int axis, bool layoutInput)
 		{
+			//container height and width
 			var groupHeight = rectTransform.rect.height;
+			var groupWidth = rectTransform.rect.width;
 
-			// Width that is available after padding is subtracted
+			float spacingBetweenBars = 0;
-			var workingWidth = rectTransform.rect.width - padding.left - padding.right;
+			float spacingBetweenElements = 0;
+			float offset = 0;
+			float counterOffset = 0;
+			float groupSize = 0;
+			float workingSize = 0;
+			if (startAxis == Axis.Horizontal) {
+				groupSize = groupHeight;
+				workingSize = groupWidth - padding.left - padding.right;
+				if (IsLowerAlign) {
+					offset = (float)padding.bottom;
+					counterOffset = (float)padding.top;
+				} else {
+					offset = (float)padding.top;
+					counterOffset = (float)padding.bottom;
+				}
+				spacingBetweenBars = SpacingY;
+				spacingBetweenElements = SpacingX;
+			} else if (startAxis == Axis.Vertical) {
+				groupSize = groupWidth;
+				workingSize = groupHeight - padding.top - padding.bottom;
+				if (IsRightAlign) {
+					offset = (float)padding.right;
+					counterOffset = (float)padding.left;
+				} else {
+					offset = (float)padding.left;
+					counterOffset = (float)padding.right;
+				}
+				spacingBetweenBars = SpacingX;
+				spacingBetweenElements = SpacingY;
+			}
 
-			// Accumulates the total height of the rows, including spacing and padding.
+			var currentBarSize = 0f;
-			var yOffset = IsLowerAlign ? (float)padding.bottom : (float)padding.top;
+			var currentBarSpace = 0f;
-			
-			var currentRowWidth = 0f;
-			var currentRowHeight = 0f;
 
 			for (var i = 0; i < rectChildren.Count; i++) {
 
-				// LowerAlign works from back to front
+				int index = i;
-				var index = IsLowerAlign ? rectChildren.Count - 1 - i : i;
+				var child = rectChildren [index];
+				float childSize = 0;
+				float childOtherSize = 0;
+				//get height and width of elements.
+				if (startAxis == Axis.Horizontal) {
+					if (invertOrder) {
+						index = IsLowerAlign ? rectChildren.Count - 1 - i : i;	
+					}
+					child = rectChildren [index];
+					childSize = LayoutUtility.GetPreferredSize (child, 0);
+					childSize = Mathf.Min (childSize, workingSize);
+					childOtherSize = LayoutUtility.GetPreferredSize (child, 1);
+					childOtherSize = Mathf.Min (childOtherSize, workingSize);
+				} else if (startAxis == Axis.Vertical) {
+					if (invertOrder) {
+						index = IsRightAlign ? rectChildren.Count - 1 - i : i;
+					}
+					child = rectChildren [index];
+					childSize = LayoutUtility.GetPreferredSize (child, 1);
+					childSize = Mathf.Min (childSize, workingSize);
+					childOtherSize = LayoutUtility.GetPreferredSize (child, 0);
+					childOtherSize = Mathf.Min (childOtherSize, workingSize);
+				}
 
-				var child = rectChildren[index];
+				// If adding this element would exceed the bounds of the container,
+				// go to a new bar after processing the current bar
+				if (currentBarSize + childSize > workingSize) {
 
-				var childWidth = LayoutUtility.GetPreferredSize(child, 0);
+					currentBarSize -= spacingBetweenElements;
-				var childHeight = LayoutUtility.GetPreferredSize(child, 1);
 
-				// Max child width is layout group width - padding
+					// Process current bar elements positioning
-				childWidth = Mathf.Min(childWidth, workingWidth);
-				
-				// If adding this element would exceed the bounds of the row,
-				// go to a new line after processing the current row
-				if (currentRowWidth + childWidth > workingWidth) {
-					
-					currentRowWidth -= SpacingX;
-					
-					// Process current row elements positioning
 					if (!layoutInput) {
+						if (startAxis == Axis.Horizontal) {
+							float newOffset = CalculateRowVerticalOffset (groupSize, offset, currentBarSpace);
+							LayoutRow (_itemList, currentBarSize, currentBarSpace, workingSize, padding.left, newOffset, axis);
+						} else if (startAxis == Axis.Vertical) {
+							float newOffset = CalculateColHorizontalOffset (groupSize, offset, currentBarSpace);
+							LayoutCol (_itemList, currentBarSpace, currentBarSize, workingSize, newOffset, padding.top, axis);
+						}
+					}
 
-						var h = CalculateRowVerticalOffset(groupHeight, yOffset, currentRowHeight);
+					// Clear existing bar
-						LayoutRow(_rowList, currentRowWidth, currentRowHeight, workingWidth, padding.left, h, axis);
+					_itemList.Clear ();
+
+					// Add the current bar space to total barSpace accumulator, and reset to 0 for the next row
+					offset += currentBarSpace;
+					offset += spacingBetweenBars;
+
+					currentBarSpace = 0;
+					currentBarSize = 0;
 
 				}
 
-					// Clear existing row
+				currentBarSize += childSize;
-					_rowList.Clear();
+				_itemList.Add (child);
-					
-					// Add the current row height to total height accumulator, and reset to 0 for the next row
-					yOffset += currentRowHeight;
-					yOffset += SpacingY;
-					
-					currentRowHeight = 0;
-					currentRowWidth = 0;
-					
-				}
-				
-				currentRowWidth += childWidth;
-				_rowList.Add(child);
 
 				// We need the largest element height to determine the starting position of the next line
-				if (childHeight > currentRowHeight) {
+				if (childOtherSize > currentBarSpace) {
-					currentRowHeight = childHeight;
+					currentBarSpace = childOtherSize;
 				}
 
 				// Don't do this for the last one
-				if (i < rectChildren.Count - 1 ) 
+				if (i < rectChildren.Count - 1){
-					currentRowWidth += SpacingX;
+					currentBarSize += spacingBetweenElements;
 				}
 				
+			}
+
+			// Layout the final bar
 			if (!layoutInput) {
-				var h = CalculateRowVerticalOffset(groupHeight, yOffset, currentRowHeight);
+				if (startAxis == Axis.Horizontal) {
-				currentRowWidth -= SpacingX;
+					float newOffset = CalculateRowVerticalOffset (groupHeight, offset, currentBarSpace);
-				// Layout the final row
+					currentBarSize -= spacingBetweenElements;
-				LayoutRow(_rowList, currentRowWidth, currentRowHeight, workingWidth - (_rowList.Count > 1 ? SpacingX : 0), padding.left, h, axis);
+					LayoutRow (_itemList, currentBarSize, currentBarSpace, workingSize - (ChildForceExpandWidth ? 0 : spacingBetweenElements), padding.left, newOffset, axis);
+				}else if (startAxis == Axis.Vertical) {
+					float newOffset = CalculateColHorizontalOffset(groupWidth, offset, currentBarSpace);
+					currentBarSize -= spacingBetweenElements;
+					LayoutCol(_itemList, currentBarSpace, currentBarSize, workingSize - (ChildForceExpandHeight ? 0 : spacingBetweenElements), newOffset, padding.top, axis);
+				}
 			}
 
-			_rowList.Clear();
+			_itemList.Clear();
 
-			// Add the last rows height to the height accumulator
+			// Add the last bar space to the barSpace accumulator
-			yOffset += currentRowHeight;
+			offset += currentBarSpace;
-			yOffset += IsLowerAlign ? padding.top : padding.bottom;
+			offset += counterOffset;
 
 			if (layoutInput) {
-				
+				SetLayoutInputForAxis(offset, offset, -1, axis);
-				if(axis == 1)
-					SetLayoutInputForAxis(yOffset, yOffset, -1, axis);
-				
 			}
-			
+			return offset;
-			return yOffset;
 		}
 
 		private float CalculateRowVerticalOffset(float groupHeight, float yOffset, float currentRowHeight)
 		{
-			float h;
-			
 			if (IsLowerAlign) {
-				h = groupHeight - yOffset - currentRowHeight;
+				return groupHeight - yOffset - currentRowHeight;
 			} else if (IsMiddleAlign) {
-				h = groupHeight*0.5f - _layoutHeight * 0.5f + yOffset;
+				return groupHeight * 0.5f - _layoutHeight * 0.5f + yOffset;
 			} else {
-				h = yOffset;
+				return yOffset;
+			}
+		}
+
+		private float CalculateColHorizontalOffset(float groupWidth, float xOffset, float currentColWidth)
+		{
+			if (IsRightAlign) {
+				return groupWidth - xOffset - currentColWidth;
+			} else if (IsCenterAlign) {
+				return groupWidth * 0.5f - _layoutWidth * 0.5f + xOffset;
+			} else {
+				return xOffset;
 			}
-			return h;
 		}
 
 		protected void LayoutRow(IList<RectTransform> contents, float rowWidth, float rowHeight, float maxWidth, float xOffset, float yOffset, int axis)
 		{
 			var xPos = xOffset;
 
-			if (!ChildForceExpandWidth && IsCenterAlign)
+			if (!ChildForceExpandWidth && IsCenterAlign) {
 				xPos += (maxWidth - rowWidth) * 0.5f;
-			else if (!ChildForceExpandWidth && IsRightAlign)
+			} else if (!ChildForceExpandWidth && IsRightAlign) {
 				xPos += (maxWidth - rowWidth);
+			}
 
 			var extraWidth = 0f;
 			var extraSpacing = 0f;
 
 			if (ChildForceExpandWidth) {
-				extraWidth = (maxWidth - rowWidth)/_rowList.Count;
+				extraWidth = (maxWidth - rowWidth)/_itemList.Count;
 			}
 			else if (ExpandHorizontalSpacing) {
-				extraSpacing = (maxWidth - rowWidth)/(_rowList.Count - 1);
+				extraSpacing = (maxWidth - rowWidth)/(_itemList.Count - 1);
-				if (_rowList.Count > 1) {
+				if (_itemList.Count > 1) {
-					if (IsCenterAlign)
+					if (IsCenterAlign) {
-						xPos -= extraSpacing * 0.5f * (_rowList.Count - 1);
+						xPos -= extraSpacing * 0.5f * (_itemList.Count - 1);
-					else if (IsRightAlign)
+					} else if (IsRightAlign) {
-						xPos -= extraSpacing * (_rowList.Count - 1);
+						xPos -= extraSpacing * (_itemList.Count - 1);
+					}
 				}
 			}
 
-			for (var j = 0; j < _rowList.Count; j++) {
+			for (var j = 0; j < _itemList.Count; j++) {
 
-				var index = IsLowerAlign ? _rowList.Count - 1 - j : j;
+				var index = IsLowerAlign ? _itemList.Count - 1 - j : j;
 
-				var rowChild = _rowList[index];
+				var rowChild = _itemList[index];
 
 				var rowChildWidth = LayoutUtility.GetPreferredSize(rowChild, 0) + extraWidth;
 				var rowChildHeight = LayoutUtility.GetPreferredSize(rowChild, 1);
@@ -239,36 +312,116 @@ namespace UnityEngine.UI.Extensions
 
 				var yPos = yOffset;
 
-				if (IsMiddleAlign)
+				if (IsMiddleAlign) {
 					yPos += (rowHeight - rowChildHeight) * 0.5f;
-				else if (IsLowerAlign)
+				} else if (IsLowerAlign) {
 					yPos += (rowHeight - rowChildHeight);
+				}
 
-				// 
+				if (ExpandHorizontalSpacing && j > 0) {
-				if (ExpandHorizontalSpacing && j > 0)
 					xPos += extraSpacing;
+				}
 
-				if (axis == 0)
+				if (axis == 0) {
-					SetChildAlongAxis(rowChild, 0, xPos, rowChildWidth);
+					SetChildAlongAxis (rowChild, 0, xPos, rowChildWidth);
-				else
+				} else {
-					SetChildAlongAxis(rowChild, 1, yPos, rowChildHeight);
+					SetChildAlongAxis (rowChild, 1, yPos, rowChildHeight);
+				}
 
 				// Don't do horizontal spacing for the last one
-				if (j < _rowList.Count - 1 ) 
+				if (j < _itemList.Count - 1) {
 					xPos += rowChildWidth + SpacingX;
 				}
 			}
+		}
+
+		protected void LayoutCol(IList<RectTransform> contents, float colWidth, float colHeight, float maxHeight, float xOffset, float yOffset, int axis)
+		{
+			var yPos = yOffset;
+
+			if (!ChildForceExpandHeight && IsMiddleAlign) {
+				yPos += (maxHeight - colHeight) * 0.5f;
+			} else if (!ChildForceExpandHeight && IsLowerAlign) {
+				yPos += (maxHeight - colHeight);
+			}
+
+			var extraHeight = 0f;
+			var extraSpacing = 0f;
+
+			if (ChildForceExpandHeight) {
+				extraHeight = (maxHeight - colHeight)/_itemList.Count;
+			}
+			else if (ExpandHorizontalSpacing) {
+				extraSpacing = (maxHeight - colHeight)/(_itemList.Count - 1);
+				if (_itemList.Count > 1) {
+					if (IsMiddleAlign) {
+						yPos -= extraSpacing * 0.5f * (_itemList.Count - 1);
+					} else if (IsLowerAlign) {
+						yPos -= extraSpacing * (_itemList.Count - 1);
+					}
+				}
+			}
+
+			for (var j = 0; j < _itemList.Count; j++) {
+
+				var index = IsRightAlign ? _itemList.Count - 1 - j : j;
+
+				var rowChild = _itemList[index];
+
+				var rowChildWidth = LayoutUtility.GetPreferredSize(rowChild, 0) ;
+				var rowChildHeight = LayoutUtility.GetPreferredSize(rowChild, 1) + extraHeight;
+
+				if (ChildForceExpandWidth) {
+					rowChildWidth = colWidth;
+				}
+
+				rowChildHeight = Mathf.Min(rowChildHeight, maxHeight);
+
+				var xPos = xOffset;
+
+				if (IsCenterAlign) {
+					xPos += (colWidth - rowChildWidth) * 0.5f;
+				} else if (IsRightAlign) {
+					xPos += (colWidth - rowChildWidth);
+				}
+
+				// 
+				if (ExpandHorizontalSpacing && j > 0) {
+					yPos += extraSpacing;
+				}
+
+				if (axis == 0) {
+					SetChildAlongAxis (rowChild, 0, xPos, rowChildWidth);
+				} else {
+					SetChildAlongAxis (rowChild, 1, yPos, rowChildHeight);
+				}
+
+				// Don't do vertical spacing for the last one
+				if (j < _itemList.Count - 1) {
+					yPos += rowChildHeight + SpacingY;
+				}
+			}
+		}
 
 		public float GetGreatestMinimumChildWidth()
 		{
 			var max = 0f;
-			
 			for (var i = 0; i < rectChildren.Count; i++) {
 				var w = LayoutUtility.GetMinWidth(rectChildren[i]);
 
 				max = Mathf.Max(w, max);
 			}
+			return max;
+		}
 
+		public float GetGreatestMinimumChildHeigth()
+		{
+			var max = 0f;
+			for (var i = 0; i < rectChildren.Count; i++) {
+				var w = LayoutUtility.GetMinHeight(rectChildren[i]);
+
+				max = Mathf.Max(w, max);
+			}
 			return max;
 		}
 	}