Improve WPF auto-filter UI and filter logic

Enhanced the WPF filter dropdown UI with a custom ContextMenu, improved selection logic for 'Select All' and partial selections, and unified filter state handling. Added a new funnel icon for filtered columns, fixed DPI scaling in PointToScreen, and made filter logic more robust for both WinForm and WPF platforms.

Author: yepeng2002

DemoWPF/MainWindow.xaml.cs

@@ -96,7 +96,9 @@ private void AddDemoSheet2()
 					{"Total", 25, 28, 28, 27, 27},
 			};
 
-			worksheet.AddOutline(RowOrColumn.Row, 3, 4);
+      var filter = worksheet.CreateColumnFilter(new RangePosition("A1:F7"));
+
+      worksheet.AddOutline(RowOrColumn.Row, 3, 4);
 
 			var range = worksheet.Ranges["B3:F6"];
 			worksheet.AddHighlightRange(range);

ReoGrid/CellTypes/DropdownCell.cs

@@ -663,8 +663,8 @@ public virtual void PushDown()
 
         dropdownPanel.Width = Math.Max(Bounds.Width, MinimumDropdownWidth);
         dropdownPanel.Height = DropdownPanelHeight;
-
-        dropdownPanel.Show(sheet.workbook.ControlInstance, new System.Windows.Point(p.X, p.Y + Bounds.Height));
+        var sp = sheet.ControlAdapter.PointToScreen(p);
+        dropdownPanel.Show(sheet.workbook.ControlInstance, new System.Windows.Point(sp.X, sp.Y + Bounds.Height));
         DropdownControl.Focus();
         isDropdown = true;
       }

ReoGrid/Common/GraphicsToolkit.cs

@@ -130,7 +130,7 @@ public static Point PointAtArc(Rectangle rect, RGFloat angle)
 		#endregion // Calculation
 
 		#region Drawing
-		public enum TriangleDirection { Left, Up, Right, Down, }
+		public enum TriangleDirection { Left, Up, Right, Down, DownFilter, }
 
 		public static void FillTriangle(PlatformGraphics g, RGFloat size, Point loc, TriangleDirection dir = TriangleDirection.Down)
 		{
@@ -154,63 +154,110 @@ public static void FillTriangle(PlatformGraphics g, RGFloat size, Point loc, Tri
 			RGFloat x = loc.X;
 			RGFloat y = loc.Y;
 
-			switch (dir)
-			{
-				case TriangleDirection.Up:
-					loc.X -= size / 2;
-					for (x = 0; x < size / 2; x++)
-					{
+      switch (dir)
+      {
+        case TriangleDirection.Up:
+          loc.X -= size / 2;
+          for (x = 0; x < size / 2; x++)
+          {
 #if WINFORM || WPF
-						g.DrawLine(p, new Point(loc.X + x, y), new Point(loc.X + size - x - 1, y));
+            g.DrawLine(p, new Point(loc.X + x, y), new Point(loc.X + size - x - 1, y));
 #elif ANDROID
 						g.DrawLine(loc.X + x, y, loc.X + size - x - 1, y, p);
 #endif
-						y--;
-					}
-					break;
-
-				case TriangleDirection.Down:
-					loc.X -= size / 2 - 1;
-					y--;
-					for (x = 0; x < size / 2; x++)
-					{
+            y--;
+          }
+          break;
+
+        case TriangleDirection.Down:
+          loc.X -= size / 2 - 1;
+          y--;
+          for (x = 0; x < size / 2; x++)
+          {
 #if WINFORM || WPF
-						g.DrawLine(p, new Point(loc.X + x, y), new Point(loc.X + size - x, y));
+            g.DrawLine(p, new Point(loc.X + x, y), new Point(loc.X + size - x, y));
 #elif ANDROID
 						g.DrawLine(loc.X + x, y, loc.X + size - x, y, p);
 #endif
-						y++;
-					}
-					break;
+            y++;
+          }
+          break;
 
-				case TriangleDirection.Left:
-					loc.Y -= size / 2;
-					for (y = 0; y < size / 2; y++)
-					{
+        case TriangleDirection.DownFilter:
+          loc.X -= size / 2;
+          loc.Y -= size / 2;
+
+          // Draw the outline of the funnel
+          // Upper wide opening
+          int topWidth = (int)size;
+          int bottomWidth = (int)(size / 4);
+          int funnelHeight = (int)(size / 2);
+          int neckHeight = (int)(size / 2 + 1); // Extended funnel neck
+
+#if WINFORM || WPF
+          // Draw four side lines of the funnel to create a hollow effect
+          // Top left to bottom left
+          g.DrawLine(p, new Point(loc.X, loc.Y), new Point(loc.X + (topWidth - bottomWidth) / 2, loc.Y + funnelHeight));
+          // Top right to bottom right
+          g.DrawLine(p, new Point(loc.X + topWidth, loc.Y), new Point(loc.X + (topWidth + bottomWidth) / 2, loc.Y + funnelHeight));
+          // Bottom connecting line
+          g.DrawLine(p, new Point(loc.X + (topWidth - bottomWidth) / 2, loc.Y + funnelHeight),
+                     new Point(loc.X + (topWidth + bottomWidth) / 2, loc.Y + funnelHeight));
+          // Top connecting line (optional, for closing the top)
+          g.DrawLine(p, new Point(loc.X, loc.Y), new Point(loc.X + topWidth, loc.Y));
+
+          // Draw extended neck lines
+          Point neckTopLeft = new Point(loc.X + (topWidth - bottomWidth) / 2, loc.Y + funnelHeight);
+          Point neckTopRight = new Point(loc.X + (topWidth + bottomWidth) / 2, loc.Y + funnelHeight);
+          Point neckBottomLeft = new Point(neckTopLeft.X, neckTopLeft.Y + neckHeight);
+          Point neckBottomRight = new Point(neckTopRight.X, neckTopRight.Y + neckHeight);
+
+          // Left neck line
+          g.DrawLine(p, neckTopLeft, neckBottomLeft);
+          // Right neck line
+          g.DrawLine(p, neckTopRight, neckBottomRight);
+
+          // Draw square dot (1x1 pixel) at bottom left corner
+          Point dotPosition = new Point(neckBottomLeft.X - 3, neckBottomLeft.Y - 1);
+#endif
+
+#if WPF
+          // Keep original for WPF platform
+          g.DrawRectangle(RGBrushes.Black, p, new Rectangle(dotPosition.X, dotPosition.Y, 1, 1));
+#elif WINFORM
+          g.DrawRectangle(p, dotPosition.X, dotPosition.Y, 1, 1);
+#elif ANDROID        
+
+#endif
+          break;  
+        case TriangleDirection.Left:
+          loc.Y -= size / 2;
+          for (y = 0; y < size / 2; y++)
+          {
 #if WINFORM || WPF
-						g.DrawLine(p, new Point(x, loc.Y + y), new Point(x, loc.Y + size - y - 1));
+            g.DrawLine(p, new Point(x, loc.Y + y), new Point(x, loc.Y + size - y - 1));
 #elif ANDROID
 						g.DrawLine(x, loc.Y + y, x, loc.Y + size - y - 1, p);
 #endif
-						x--;
-					}
-					break;
-
-				case TriangleDirection.Right:
-					loc.Y -= size / 2;
-					for (y = 0; y < size / 2; y++)
-					{
+            x--;
+          }
+          break;
+
+        case TriangleDirection.Right:
+          loc.Y -= size / 2;
+          for (y = 0; y < size / 2; y++)
+          {
 #if WINFORM || WPF
-						g.DrawLine(p, new Point(x, loc.Y + y), new Point(x, loc.Y + size - y - 1));
+            g.DrawLine(p, new Point(x, loc.Y + y), new Point(x, loc.Y + size - y - 1));
 #elif ANDROID
 						g.DrawLine(x, loc.Y + y, x, loc.Y + size - y - 1, p);
 #endif
-						x++;
-					}
-					break;
+            x++;
+          }
+          break;
 
-			}
-		}
+      }
+    }
 
 #endregion
 

ReoGrid/Data/AutoFilter.cs

@@ -21,8 +21,11 @@
 
 #if WINFORM || ANDROID
 using RGFloat = System.Single;
+using RGPoint = unvell.ReoGrid.Graphics.Point;
 #elif WPF
 using RGFloat = System.Double;
+using RGPoint = unvell.ReoGrid.Graphics.Point;
+using System.Windows.Controls;
 #elif iOS
 using RGFloat = System.Double;
 #endif // WINFORM
@@ -110,25 +113,25 @@ public void Apply()
 					if (columnHeader == null) { c++; continue; }
 
 					var columnFilterBody = columnHeader.Body as AutoColumnFilterBody;
-					if (columnFilterBody == null || columnFilterBody.IsSelectAll)
+					if (columnFilterBody == null || columnFilterBody.IsSelectAll == true)
 					{
 						c++; continue;
 					}
 
 					var cell = this.Worksheet.GetCell(r, c);
-					if (cell == null) { c++; continue; }
+          //if (cell == null) { c++; continue; }
 
-					var text = cell.DisplayText;
-					if (string.IsNullOrEmpty(text)) text = LanguageResource.Filter_Blanks;
+          var text = cell == null ? string.Empty : cell.DisplayText;
+          if (string.IsNullOrEmpty(text)) text = LanguageResource.Filter_Blanks;
 
 					if (!columnFilterBody.SelectedTextItems.Contains(text))
 					{
 						// hide the row
 						return false;
 					}
 
-					c += cell.Colspan;
-				}
+          c += cell == null ? 1 : cell.Colspan;
+        }
 
 				// show the row
 				return true;
@@ -245,23 +248,29 @@ public void OnPaint(CellDrawingContext dc, Size headerSize)
 				{
 					Rectangle bounds = GetColumnFilterButtonRect(headerSize);
 
-					SolidColor color1 = controlStyle.GetColHeadStartColor(isHover: false, isInvalid: false,
-						isSelected: IsDropdown, isFullSelected: false);
+          SolidColor color1 = controlStyle.GetColHeadStartColor(isHover: false, isInvalid: false,
+            isSelected: IsDropdown, isFullSelected: !(IsSelectAll == true));
 
-					SolidColor color2 = controlStyle.GetColHeadEndColor(isHover: false, isInvalid: false,
-						isSelected: IsDropdown, isFullSelected: false);
+          SolidColor color2 = controlStyle.GetColHeadEndColor(isHover: false, isInvalid: false,
+            isSelected: IsDropdown, isFullSelected: !(IsSelectAll == true));
 
-					var g = dc.Graphics;
+          var g = dc.Graphics;
 
 					g.FillRectangleLinear(color1, color2, 90f, bounds);
 
 					g.DrawRectangle(bounds, unvell.ReoGrid.Rendering.StaticResources.SystemColor_ControlDark);
 
-					unvell.Common.GraphicsToolkit.FillTriangle(dc.Graphics.PlatformGraphics, 
-						Math.Min(7 * dc.Worksheet.renderScaleFactor, 7.0f),
-						new Point(bounds.X + bounds.Width / 2, bounds.Y + bounds.Height / 2), 
-						unvell.Common.GraphicsToolkit.TriangleDirection.Down);
-				}
+          if (IsSelectAll == true)
+            Common.GraphicsToolkit.FillTriangle(dc.Graphics.PlatformGraphics,
+              Math.Min(7 * dc.Worksheet.renderScaleFactor, 7.0f),
+              new Point(bounds.X + bounds.Width / 2, bounds.Y + bounds.Height / 2),
+              Common.GraphicsToolkit.TriangleDirection.Down);
+          else
+            Common.GraphicsToolkit.FillTriangle(dc.Graphics.PlatformGraphics,
+              Math.Min(7 * dc.Worksheet.renderScaleFactor, 7.0f),
+              new Point(bounds.X + bounds.Width / 2, bounds.Y + bounds.Height / 2),
+              Common.GraphicsToolkit.TriangleDirection.DownFilter);
+        }
 			}
 
 			/// <summary>
@@ -332,16 +341,19 @@ internal Rectangle GetColumnFilterButtonRect(Size size)
 			/// </summary>
 			public System.Windows.Forms.ContextMenuStrip ContextMenuStrip { get; set; }
 #elif WPF
-
+      /// <summary>
+      /// Get or set the context menu of column filter.
+      /// </summary>
+      public ContextMenu ContextMenuStrip { get; set; }
 #endif
 
-			internal List<string> selectedTextItems = new List<string>();
+      internal List<string> selectedTextItems = new List<string>();
 
 			/// <summary>
 			/// Get or set whether or not this column is marked as SelectAll.
 			/// The column is marked as SelectAll will be ignored during filter.
 			/// </summary>
-			public bool IsSelectAll { get; set; }
+			public bool? IsSelectAll { get; set; }
 
 			private TextFilterCollection textItemsCollection;
 
@@ -421,7 +433,7 @@ public void Add(string item)
 					if (!this.columnFilter.selectedTextItems.Contains(item))
 					{
 						this.columnFilter.selectedTextItems.Add(item);
-						this.columnFilter.IsSelectAll = false;
+						//this.columnFilter.IsSelectAll = false;
 					}
 				}
 
@@ -431,7 +443,7 @@ public void Add(string item)
 				public void Clear()
 				{
 					this.columnFilter.selectedTextItems.Clear();
-					columnFilter.IsSelectAll = false;
+					//columnFilter.IsSelectAll = false;
 				}
 
 				/// <summary>
@@ -477,7 +489,7 @@ public bool IsReadOnly
 				/// <returns>true if item exist and has been removed successfully</returns>
 				public bool Remove(string item)
 				{
-					this.columnFilter.IsSelectAll = false;
+					//this.columnFilter.IsSelectAll = false;
 					return this.columnFilter.selectedTextItems.Remove(item);
 				}
 
@@ -488,7 +500,7 @@ public bool Remove(string item)
 				public void AddRange(IEnumerable<string> items)
 				{
 					this.columnFilter.selectedTextItems.AddRange(items);
-					this.columnFilter.IsSelectAll = false;
+					//this.columnFilter.IsSelectAll = false;
 				}
 			}
 			#endregion // TextFilterCollection
@@ -506,11 +518,11 @@ public List<string> GetDistinctItems()
 				int maxRow = this.ColumnHeader.Worksheet.MaxContentRow;
 
 				this.ColumnHeader.Worksheet.IterateCells(this.autoFilter.ApplyRange.Row,
-					this.ColumnHeader.Index, this.autoFilter.ApplyRange.Rows, 1, true,
+					this.ColumnHeader.Index, this.autoFilter.ApplyRange.Rows, 1, false,
 					(r, c, cell) =>
-					{
-						var str = cell.DisplayText;
-						if (string.IsNullOrEmpty(str)) str = LanguageResource.Filter_Blanks;
+          {
+            var str = cell == null ? string.Empty : cell.DisplayText;
+            if (string.IsNullOrEmpty(str)) str = LanguageResource.Filter_Blanks;
 
 						if (!items.Contains(str))
 						{
@@ -544,7 +556,7 @@ public void OnDataChange(int startRow, int endRow)
 		/// </summary>
 		public event EventHandler FilterButtonPressed;
 
-		internal bool RaiseFilterButtonPress(AutoColumnFilterBody headerBody, Point point)
+		internal bool RaiseFilterButtonPress(AutoColumnFilterBody headerBody, RGPoint point)
 		{
 			if (headerBody.ColumnHeader == null) return false;
 
@@ -562,11 +574,9 @@ internal bool RaiseFilterButtonPress(AutoColumnFilterBody headerBody, Point poin
 #if WINFORM
 				unvell.ReoGrid.WinForm.ColumnFilterContextMenu.ShowFilterPanel(headerBody, (System.Drawing.Point)point);
 #elif WPF
-				var ctx = new System.Windows.Controls.ContextMenu();
-				ctx.Items.Add(new System.Windows.Controls.MenuItem() { Header = "Item" });
-				ctx.IsOpen = true;
+        unvell.ReoGrid.WPF.ColumnFilterContextMenu.ShowFilterPanel(headerBody, point);
 #endif // WPF
-				return true;
+        return true;
 			}
 
 			return false;