[Mac] Cache cell width to improve size calculations

Xwt.XamMac/Xwt.Mac.CellViews/CellViewBackend.cs

@@ -90,7 +90,7 @@ public void QueueDraw ()
 		public void QueueResize ()
 		{
 			CurrentCellView.NeedsDisplay = true;
-			((ICellRenderer)CurrentCellView).CellContainer.InvalidateRowHeight ();
+			((ICellRenderer)CurrentCellView).CellContainer.QueueResize ();
 		}
 
 		public Rectangle CellBounds {

Xwt.XamMac/Xwt.Mac.CellViews/CompositeCell.cs

@@ -89,11 +89,11 @@ public void SetCurrentEventRow ()
 		}
 
 		bool recalculatingHeight = false;
-		public void InvalidateRowHeight ()
+		public void QueueResize ()
 		{
 			if (tablePosition != null && !recalculatingHeight) {
 				recalculatingHeight = true;
-				source.InvalidateRowHeight (tablePosition.Position);
+				source.QueueResizeRow (tablePosition.Position);
 				recalculatingHeight = false;
 			}
 		}
@@ -193,7 +193,7 @@ public override CGRect Frame {
 						height = Math.Max (height, c.Frame.Height);
 					}
 					if (Math.Abs(value.Height - height) > double.Epsilon)
-						InvalidateRowHeight ();
+						QueueResize ();
 
 				}
 			}

Xwt.XamMac/Xwt.Mac.CellViews/ICellSource.cs

@@ -35,7 +35,7 @@ interface ICellSource
 		object GetValue (object pos, int nField);
 		void SetValue (object pos, int nField, object value);
 		void SetCurrentEventRow (object pos);
-		void InvalidateRowHeight (object pos);
+		void QueueResizeRow (object pos);
 		List<NSTableColumn> Columns { get; }
 		NSTableView TableView { get; }
 	}

Xwt.XamMac/Xwt.Mac/ListViewBackend.cs

@@ -72,16 +72,25 @@ public override nfloat GetSizeToFitColumnWidth (NSTableView tableView, nint colu
 			{
 				var tableColumn = Backend.Columns[(int)column] as TableColumn;
 				var width = tableColumn.HeaderCell.CellSize.Width;
+				var rowWidths = Backend.ColumnRowWidths[(int)column];
 
 				CompositeCell templateCell = null;
 				for (int i = 0; i < tableView.RowCount; i++) {
+					if (rowWidths[i] > -1)
+						width = (nfloat)Math.Max (width, rowWidths[i]);
+					else {
 					var cellView = tableView.GetView (column, i, false) as CompositeCell;
-					if (cellView == null) { // use template for invisible rows
-						cellView = templateCell ?? (templateCell = (tableColumn as TableColumn)?.DataView?.Copy () as CompositeCell);
-						if (cellView != null)
-							cellView.ObjectValue = NSNumber.FromInt32 (i);
+						if (cellView == null) { // use template for invisible rows
+							cellView = templateCell ?? (templateCell = (tableColumn as TableColumn)?.DataView as CompositeCell);
+							if (cellView != null)
+								cellView.ObjectValue = NSNumber.FromInt32 (i);
+						}
+						if (cellView != null) {
+							var size = cellView.FittingSize;
+							rowWidths[i] = size.Width;
+							width = (nfloat)Math.Max (width, size.Width);
+						}
 					}
-					width = (nfloat)Math.Max (width, cellView.FittingSize.Width);
 				}
 				return width;
 			}
@@ -95,6 +104,9 @@ public override NSIndexSet GetSelectionIndexes(NSTableView tableView, NSIndexSet
 		IListDataSource source;
 		ListSource tsource;
 
+		List<List<nfloat>> ColumnRowWidths = new List<List<nfloat>> ();
+		List<nfloat> RowHeights = new List<nfloat> ();
+
 		protected override NSTableView CreateView ()
 		{
 			var listView = new NSTableViewBackend (this);
@@ -140,14 +152,40 @@ void HandleDoubleClick (object sender, EventArgs e)
 				});
 			}
 		}
-
+
+		public override NSTableColumn AddColumn (ListViewColumn col)
+		{
+			NSTableColumn tcol = base.AddColumn (col);
+			List<nfloat> widths;
+			var rows = (int)Table.RowCount;
+			if (rows > 0) {
+				widths = new List<nfloat> (rows);
+				for (int i = 0; i < rows; ++i) widths.Add (-1f);
+			} else
+				widths = new List<nfloat> ();
+			ColumnRowWidths.Add (widths);
+			return tcol;
+		}
+
+		public override void RemoveColumn (ListViewColumn col, object handle)
+		{
+			var tcol = (NSTableColumn)handle;
+			var index = Columns.IndexOf (tcol);
+			ColumnRowWidths.RemoveAt (index);
+			base.RemoveColumn (col, handle);
+		}
+
 		public virtual void SetSource (IListDataSource source, IBackend sourceBackend)
 		{
 			this.source = source;
 
 			RowHeights = new List<nfloat> ();
 			for (int i = 0; i < source.RowCount; i++)
 				RowHeights.Add (-1);
+			foreach (var colWidths in ColumnRowWidths) {
+				colWidths.Clear ();
+				for (int i = 0; i < source.RowCount; ++i) colWidths.Add (-1f);
+			}
 
 			tsource = new ListSource (source);
 			Table.DataSource = tsource;
@@ -157,30 +195,43 @@ public virtual void SetSource (IListDataSource source, IBackend sourceBackend)
 			//      only the visible rows are reloaded.
 			source.RowInserted += (sender, e) => {
 				RowHeights.Insert (e.Row, -1);
+				foreach (var colWidths in ColumnRowWidths)
+					colWidths.Insert (e.Row, -1);
 				Table.ReloadData ();
 			};
 			source.RowDeleted += (sender, e) => {
 				RowHeights.RemoveAt (e.Row);
+				foreach (var colWidths in ColumnRowWidths)
+					colWidths.RemoveAt (e.Row);
 				Table.ReloadData ();
 			};
 			source.RowChanged += (sender, e) => {
 				UpdateRowHeight (e.Row);
 				Table.ReloadData (NSIndexSet.FromIndex (e.Row), NSIndexSet.FromNSRange (new NSRange (0, Table.ColumnCount)));
 			};
-			source.RowsReordered += (sender, e) => { RowHeights.Clear (); Table.ReloadData (); };
+			source.RowsReordered += (sender, e) => {
+				RowHeights.Clear ();
+				foreach (var colWidths in ColumnRowWidths)
+					colWidths.Clear ();
+				Table.ReloadData ();
+			};
 		}
 
-		public override void InvalidateRowHeight (object pos)
+		public override void QueueResizeRow (object pos)
 		{
 			UpdateRowHeight((int)pos);
 		}
-
-		List<nfloat> RowHeights = new List<nfloat> ();
+
 		bool updatingRowHeight;
 		public void UpdateRowHeight (nint row)
 		{
 			if (updatingRowHeight)
 				return;
+
+			// FIXME: this won't resize the columns, which might be needed for custom cells
+			// In order to resize horizontally we'll need trigger column autosizing.
+			foreach (var colWidths in ColumnRowWidths) // invalidate widths for full recalculation
+				colWidths[(int)row] = -1;
 			RowHeights[(int)row] = CalcRowHeight (row);
 			Table.NoteHeightOfRowsWithIndexesChanged (NSIndexSet.FromIndex (row));
 		}

Xwt.XamMac/Xwt.Mac/TableViewBackend.cs

@@ -205,7 +205,7 @@ object IColumnContainerBackend.AddColumn (ListViewColumn col)
 			return AddColumn (col);
 		}
 
-		public void RemoveColumn (ListViewColumn col, object handle)
+		public virtual void RemoveColumn (ListViewColumn col, object handle)
 		{
 			var tcol = (NSTableColumn)handle;
 			cols.Remove (tcol);
@@ -271,7 +271,7 @@ public void StartEditingCell (int row, CellView cell)
 
 		public abstract void SetCurrentEventRow (object pos);
 
-		public abstract void InvalidateRowHeight (object pos);
+		public abstract void QueueResizeRow (object pos);
 
 		public bool BorderVisible {
 			get { return scroll.BorderType == NSBorderType.BezelBorder;}

Xwt.XamMac/Xwt.Mac/TreeViewBackend.cs

@@ -38,6 +38,9 @@ public class TreeViewBackend: TableViewBackend<NSOutlineView,ITreeViewEventSink>
 		ITreeDataSource source;
 		TreeSource tsource;
 
+		List<Dictionary<TreePosition, nfloat>> ColumnRowWidths = new List<Dictionary<TreePosition, nfloat>> ();
+		Dictionary<TreeItem, nfloat> RowHeights = new Dictionary<TreeItem, nfloat> ();
+
 		class TreeDelegate: NSOutlineViewDelegate
 		{
 			public TreeViewBackend Backend;
@@ -95,17 +98,23 @@ public override nfloat GetSizeToFitColumnWidth (NSOutlineView outlineView, nint
 
 				CompositeCell templateCell = null;
 				for (int i = 0; i < outlineView.RowCount; i++) {
-					var cellView = outlineView.GetView (column, i, false) as CompositeCell;
-					if (cellView == null) { // use template for invisible rows
-						cellView = templateCell ?? (templateCell = (tableColumn as TableColumn)?.DataView?.Copy () as CompositeCell);
-						if (cellView != null)
-							cellView.ObjectValue = outlineView.ItemAtRow (i);
-					}
-					if (cellView != null) {
-						if (column == 0) // first column contains expanders
-							width = (nfloat)Math.Max (width, cellView.Frame.X + cellView.FittingSize.Width);
-						else
-							width = (nfloat)Math.Max (width, cellView.FittingSize.Width);
+					nfloat cellWidth;
+					var item = (TreeItem)outlineView.ItemAtRow (i);
+					if (Backend.ColumnRowWidths[(int)column].TryGetValue (item.Position, out cellWidth) && cellWidth > -1)
+						width = (nfloat)Math.Max (width, cellWidth);
+					else {
+						var cellView = outlineView.GetView (column, i, false) as CompositeCell;
+						if (cellView == null) { // use template for invisible rows
+							cellView = templateCell ?? (templateCell = (tableColumn as TableColumn)?.DataView as CompositeCell);
+							if (cellView != null)
+								cellView.ObjectValue = item;
+						}
+						if (cellView != null) {
+							// first column contains expanders
+							cellWidth = column == 0 ? cellView.Frame.X + cellView.FittingSize.Width : cellView.FittingSize.Width;
+							Backend.ColumnRowWidths[(int)column][item.Position] = cellWidth;
+							width = (nfloat)Math.Max (width, cellWidth);
+						}
 					}
 				}
 				return width;
@@ -148,8 +157,17 @@ public override NSTableColumn AddColumn (ListViewColumn col)
 			NSTableColumn tcol = base.AddColumn (col);
 			if (Tree.OutlineTableColumn == null)
 				Tree.OutlineTableColumn = tcol;
+			ColumnRowWidths.Add (new Dictionary<TreePosition, nfloat> ());
 			return tcol;
 		}
+
+		public override void RemoveColumn (ListViewColumn col, object handle)
+		{
+			var tcol = (NSTableColumn)handle;
+			var index = Columns.IndexOf (tcol);
+			ColumnRowWidths.RemoveAt (index);
+			base.RemoveColumn (col, handle);
+		}
 
 		public void SetSource (ITreeDataSource source, IBackend sourceBackend)
 		{
@@ -163,6 +181,8 @@ public void SetSource (ITreeDataSource source, IBackend sourceBackend)
 				Tree.ReloadItem (parent, parent == null || Tree.IsItemExpanded (parent));
 			};
 			source.NodeDeleted += (sender, e) => {
+				foreach (var colWidths in ColumnRowWidths)
+					colWidths.Remove (e.Child);
 				var parent = tsource.GetItem (e.Node);
 				var item = tsource.GetItem(e.Child);
 				if (item != null)
@@ -173,17 +193,24 @@ public void SetSource (ITreeDataSource source, IBackend sourceBackend)
 				var item = tsource.GetItem (e.Node);
 				if (item != null) {
 					Tree.ReloadItem (item, false);
+					foreach (var colWidths in ColumnRowWidths)
+						colWidths [e.Node] = -1;
 					UpdateRowHeight (item);
 				}
 			};
 			source.NodesReordered += (sender, e) => {
 				var parent = tsource.GetItem (e.Node);
+				foreach (var colWidths in ColumnRowWidths)
+					for (int i = 0; i < source.GetChildrenCount (e.Node); i++)
+						colWidths [source.GetChild (e.Node, i)] = -1;
 				Tree.ReloadItem (parent, parent == null || Tree.IsItemExpanded (parent));
 			};
 			source.Cleared += (sender, e) =>
 			{
 				Tree.ReloadData ();
 				RowHeights.Clear ();
+				foreach (var colWidths in ColumnRowWidths)
+					colWidths.Clear ();
 			};
 		}
 
@@ -197,12 +224,11 @@ public override void SetValue (object pos, int nField, object value)
 			source.SetValue ((TreePosition)pos, nField, value);
 		}
 
-		public override void InvalidateRowHeight (object pos)
+		public override void QueueResizeRow (object pos)
 		{
 			UpdateRowHeight (tsource.GetItem((TreePosition)pos));
 		}
 
-		Dictionary<TreeItem, nfloat> RowHeights = new Dictionary<TreeItem, nfloat> ();
 		bool updatingRowHeight;
 
 		void UpdateRowHeight (TreeItem pos)
@@ -211,8 +237,12 @@ void UpdateRowHeight (TreeItem pos)
 				return;
 			var row = Tree.RowForItem (pos);
 			if (row >= 0) {
-				// calculate new height now by reusing the visible cell to avoid using the template cell with unnecessary data reloads
+				// calculate new size now by reusing the visible cell to avoid using the template cell with unnecessary data reloads
 				// NOTE: cell reusing is not supported in Delegate.GetRowHeight and would require an other data reload to the template cell
+				// FIXME: this won't resize the columns, which might be needed for custom cells
+				// In order to resize horizontally we'll need trigger column autosizing.
+				foreach (var colWidths in ColumnRowWidths) // invalidate widths for full recalculation
+					colWidths [pos.Position] = -1;
 				RowHeights[pos] = CalcRowHeight (pos);
 				Table.NoteHeightOfRowsWithIndexesChanged (NSIndexSet.FromIndex (row));
 			} else // Invalidate the height, to force recalculation in Delegate.GetRowHeight
@@ -226,13 +256,21 @@ nfloat CalcRowHeight (TreeItem pos, bool tryReuse = true)
 			var row = Tree.RowForItem (pos);
 
 			for (int i = 0; i < Columns.Count; i++) {
+				var col = (TableColumn)Columns [i];
 				CompositeCell cell = tryReuse && row >= 0 ? Tree.GetView (i, row, false) as CompositeCell : null;
 				if (cell == null) {
-					cell = (Columns [i] as TableColumn)?.DataView as CompositeCell;
+					cell = col.DataView;
 					cell.ObjectValue = pos;
 					height = (nfloat)Math.Max (height, cell.FittingSize.Height);
 				} else {
-					height = (nfloat)Math.Max (height, cell.GetRequiredHeightForWidth (cell.Frame.Width));
+					nfloat cellWidth = -1;
+					ColumnRowWidths [i].TryGetValue (pos.Position, out cellWidth);
+					if (cellWidth <= 0)
+						cellWidth = cell.Frame.Width;
+					if (cellWidth <= 0)
+						height = (nfloat)Math.Max (height, cell.FittingSize.Height);
+					else
+						height = (nfloat)Math.Max (height, cell.GetRequiredHeightForWidth (cellWidth));
 				}
 			}
 			updatingRowHeight = false;