DataGridViewTopLeftHeaderCell.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / whidbey / netfxsp / ndp / fx / src / WinForms / Managed / System / WinForms / DataGridViewTopLeftHeaderCell.cs / 1 / DataGridViewTopLeftHeaderCell.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Windows.Forms 
{ 
    using System;
    using System.Diagnostics; 
    using System.Drawing;
    using System.Windows.Forms.VisualStyles;
    using System.ComponentModel;
    using System.Windows.Forms.Internal; 
    using System.Security.Permissions;
 
    ///  
    /// 
    ///     
    /// 
    public class DataGridViewTopLeftHeaderCell : DataGridViewColumnHeaderCell
    {
        private static readonly VisualStyleElement HeaderElement = VisualStyleElement.Header.Item.Normal; 

        private const byte DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginLeft = 1; 
        private const byte DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginRight = 2; 
        private const byte DATAGRIDVIEWTOPLEFTHEADERCELL_verticalTextMargin = 1;
 
        /// 
        public DataGridViewTopLeftHeaderCell()
        {
        } 

        ///  
        protected override AccessibleObject CreateAccessibilityInstance() 
        {
            return new DataGridViewTopLeftHeaderCellAccessibleObject(this); 
        }

        /// 
        protected override Rectangle GetContentBounds(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex) 
        {
            if (cellStyle == null) 
            { 
                throw new ArgumentNullException("cellStyle");
            } 

            if (rowIndex != -1)
            {
                throw new ArgumentOutOfRangeException("rowIndex"); 
            }
 
            if (this.DataGridView == null) 
            {
                return Rectangle.Empty; 
            }

            object value = GetValue(rowIndex);
 
            // Intentionally not using GetFormattedValue because header cells don't typically perform formatting.
            // the content bounds are computed on demand 
            // we mimic a lot of the painting code 

            // get the borders 
            DataGridViewAdvancedBorderStyle dgvabsEffective;
            DataGridViewElementStates cellState;
            Rectangle cellBounds;
 
            ComputeBorderStyleCellStateAndCellBounds(rowIndex, out dgvabsEffective, out cellState, out cellBounds);
 
            Rectangle contentBounds = PaintPrivate(graphics, 
                cellBounds,
                cellBounds, 
                rowIndex,
                cellState,
                value,
                null /*errorText*/,                 // contentBounds is independent of errorText 
                cellStyle,
                dgvabsEffective, 
                DataGridViewPaintParts.ContentForeground, 
                true /*computeContentBounds*/,
                false /*computeErrorIconBounds*/, 
                false /*paint*/);

#if DEBUG
            Rectangle contentBoundsDebug = PaintPrivate(graphics, 
                cellBounds,
                cellBounds, 
                rowIndex, 
                cellState,
                value, 
                GetErrorText(rowIndex),
                cellStyle,
                dgvabsEffective,
                DataGridViewPaintParts.ContentForeground, 
                true /*computeContentBounds*/,
                false /*computeErrorIconBounds*/, 
                false /*paint*/); 
            Debug.Assert(contentBoundsDebug.Equals(contentBounds));
#endif 

            return contentBounds;
        }
 
        /// 
        protected override Rectangle GetErrorIconBounds(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex) 
        { 
            if (rowIndex != -1)
            { 
                throw new ArgumentOutOfRangeException("rowIndex");
            }

            if (this.DataGridView == null) 
            {
                return Rectangle.Empty; 
            } 

            if (cellStyle == null) 
            {
                throw new ArgumentNullException("cellStyle");
            }
 
            DataGridViewAdvancedBorderStyle dgvabsEffective;
            DataGridViewElementStates cellState; 
            Rectangle cellBounds; 

            ComputeBorderStyleCellStateAndCellBounds(rowIndex, out dgvabsEffective, out cellState, out cellBounds); 

            Rectangle errorBounds = PaintPrivate(graphics,
                cellBounds,
                cellBounds, 
                rowIndex,
                cellState, 
                null /*formattedValue*/,            // errorIconBounds is independent of formattedValue 
                GetErrorText(rowIndex),
                cellStyle, 
                dgvabsEffective,
                DataGridViewPaintParts.ContentForeground,
                false /*computeContentBounds*/,
                true /*computeErrorIconBounds*/, 
                false /*paint*/);
 
#if DEBUG 
            object value = GetValue(rowIndex);
 
            Rectangle errorBoundsDebug = PaintPrivate(graphics,
                cellBounds,
                cellBounds,
                rowIndex, 
                cellState,
                value, 
                GetErrorText(rowIndex), 
                cellStyle,
                dgvabsEffective, 
                DataGridViewPaintParts.ContentForeground,
                false /*computeContentBounds*/,
                true /*computeErrorIconBounds*/,
                false /*paint*/); 
            Debug.Assert(errorBoundsDebug.Equals(errorBounds));
#endif 
 
            return errorBounds;
        } 

        /// 
        protected override Size GetPreferredSize(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex, Size constraintSize)
        { 
            if (rowIndex != -1)
            { 
                throw new ArgumentOutOfRangeException("rowIndex"); 
            }
 
            if (this.DataGridView == null)
            {
                return new Size(-1, -1);
            } 

            if (cellStyle == null) 
            { 
                throw new ArgumentNullException("cellStyle");
            } 

            Rectangle borderWidthsRect = BorderWidths(this.DataGridView.AdjustedTopLeftHeaderBorderStyle);
            int borderAndPaddingWidths = borderWidthsRect.Left + borderWidthsRect.Width + cellStyle.Padding.Horizontal;
            int borderAndPaddingHeights = borderWidthsRect.Top + borderWidthsRect.Height + cellStyle.Padding.Vertical; 
            TextFormatFlags flags = DataGridViewUtilities.ComputeTextFormatFlagsForCellStyleAlignment(this.DataGridView.RightToLeftInternal, cellStyle.Alignment, cellStyle.WrapMode);
 
            // Intentionally not using GetFormattedValue because header cells don't typically perform formatting. 
            object val = GetValue(rowIndex);
            if (!(val is string)) 
            {
                val = null;
            }
            return DataGridViewUtilities.GetPreferredRowHeaderSize(graphics, 
                                                                   (string) val,
                                                                   cellStyle, 
                                                                   borderAndPaddingWidths, 
                                                                   borderAndPaddingHeights,
                                                                   this.DataGridView.ShowCellErrors, 
                                                                   false /*showGlyph*/,
                                                                   constraintSize,
                                                                   flags);
        } 

        ///  
        protected override void Paint(Graphics graphics, 
            Rectangle clipBounds,
            Rectangle cellBounds, 
            int rowIndex,
            DataGridViewElementStates cellState,
            object value,
            object formattedValue, 
            string errorText,
            DataGridViewCellStyle cellStyle, 
            DataGridViewAdvancedBorderStyle advancedBorderStyle, 
            DataGridViewPaintParts paintParts)
        { 
            if (cellStyle == null)
            {
                throw new ArgumentNullException("cellStyle");
            } 

            PaintPrivate(graphics, 
                clipBounds, 
                cellBounds,
                rowIndex, 
                cellState,
                formattedValue,
                errorText,
                cellStyle, 
                advancedBorderStyle,
                paintParts, 
                false /*computeContentBounds*/, 
                false /*computeErrorIconBounds*/,
                true /*paint*/); 
        }

        // PaintPrivate is used in three places that need to duplicate the paint code:
        // 1. DataGridViewCell::Paint method 
        // 2. DataGridViewCell::GetContentBounds
        // 3. DataGridViewCell::GetErrorIconBounds 
        // 
        // if computeContentBounds is true then PaintPrivate returns the contentBounds
        // else if computeErrorIconBounds is true then PaintPrivate returns the errorIconBounds 
        // else it returns Rectangle.Empty;
        private Rectangle PaintPrivate(Graphics graphics,
            Rectangle clipBounds,
            Rectangle cellBounds, 
            int rowIndex,
            DataGridViewElementStates cellState, 
            object formattedValue, 
            string errorText,
            DataGridViewCellStyle cellStyle, 
            DataGridViewAdvancedBorderStyle advancedBorderStyle,
            DataGridViewPaintParts paintParts,
            bool computeContentBounds,
            bool computeErrorIconBounds, 
            bool paint)
        { 
            // Parameter checking. 
            // One bit and one bit only should be turned on
            Debug.Assert(paint || computeContentBounds || computeErrorIconBounds); 
            Debug.Assert(!paint || !computeContentBounds || !computeErrorIconBounds);
            Debug.Assert(!computeContentBounds || !computeErrorIconBounds || !paint);
            Debug.Assert(!computeErrorIconBounds || !paint || !computeContentBounds);
            Debug.Assert(cellStyle != null); 

            // If computeContentBounds == TRUE then resultBounds will be the contentBounds. 
            // If computeErrorIconBounds == TRUE then resultBounds will be the error icon bounds. 
            // Else resultBounds will be Rectangle.Empty;
            Rectangle resultBounds = Rectangle.Empty; 

            Rectangle valBounds = cellBounds;
            Rectangle borderWidths = BorderWidths(advancedBorderStyle);
 
            valBounds.Offset(borderWidths.X, borderWidths.Y);
            valBounds.Width -= borderWidths.Right; 
            valBounds.Height -= borderWidths.Bottom; 

            bool cellSelected = (cellState & DataGridViewElementStates.Selected) != 0; 

            if (paint && DataGridViewCell.PaintBackground(paintParts))
            {
                if (this.DataGridView.ApplyVisualStylesToHeaderCells) 
                {
                    // XP Theming 
                    int state = (int)HeaderItemState.Normal; 

                    if (this.ButtonState != ButtonState.Normal) 
                    {
                        Debug.Assert(this.ButtonState == ButtonState.Pushed);
                        state = (int)HeaderItemState.Pressed;
                    } 
                    else if (this.DataGridView.MouseEnteredCellAddress.Y == rowIndex && this.DataGridView.MouseEnteredCellAddress.X == this.ColumnIndex)
                    { 
                        state = (int)HeaderItemState.Hot; 
                    }
 
                    valBounds.Inflate(16, 16);
                    DataGridViewTopLeftHeaderCellRenderer.DrawHeader(graphics, valBounds, state);
                    valBounds.Inflate(-16, -16);
                } 
                else
                { 
                    SolidBrush br = this.DataGridView.GetCachedBrush((DataGridViewCell.PaintSelectionBackground(paintParts) && cellSelected) ? cellStyle.SelectionBackColor : cellStyle.BackColor); 
                    if (br.Color.A == 255)
                    { 
                        graphics.FillRectangle(br, valBounds);
                    }
                }
            } 

            if (paint && DataGridViewCell.PaintBorder(paintParts)) 
            { 
                PaintBorder(graphics, clipBounds, cellBounds, cellStyle, advancedBorderStyle);
            } 

            if (cellStyle.Padding != Padding.Empty)
            {
                if (this.DataGridView.RightToLeftInternal) 
                {
                    valBounds.Offset(cellStyle.Padding.Right, cellStyle.Padding.Top); 
                } 
                else
                { 
                    valBounds.Offset(cellStyle.Padding.Left, cellStyle.Padding.Top);
                }
                valBounds.Width -= cellStyle.Padding.Horizontal;
                valBounds.Height -= cellStyle.Padding.Vertical; 
            }
 
            Rectangle errorBounds = valBounds; 
            string formattedValueStr = formattedValue as string;
 
            // Font independent margins
            valBounds.Offset(DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginLeft, DATAGRIDVIEWTOPLEFTHEADERCELL_verticalTextMargin);
            valBounds.Width -= DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginLeft + DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginRight;
            valBounds.Height -= 2 * DATAGRIDVIEWTOPLEFTHEADERCELL_verticalTextMargin; 
            if (valBounds.Width > 0 &&
                valBounds.Height > 0 && 
                !String.IsNullOrEmpty(formattedValueStr) && 
                (paint || computeContentBounds))
            { 
                Color textColor;
                if (this.DataGridView.ApplyVisualStylesToHeaderCells)
                {
                    textColor = DataGridViewTopLeftHeaderCellRenderer.VisualStyleRenderer.GetColor(ColorProperty.TextColor); 
                }
                else 
                { 
                    textColor = cellSelected ? cellStyle.SelectionForeColor : cellStyle.ForeColor;
                } 
                TextFormatFlags flags = DataGridViewUtilities.ComputeTextFormatFlagsForCellStyleAlignment(this.DataGridView.RightToLeftInternal, cellStyle.Alignment, cellStyle.WrapMode);
                if (paint)
                {
                    if (DataGridViewCell.PaintContentForeground(paintParts)) 
                    {
                        if ((flags & TextFormatFlags.SingleLine) != 0) 
                        { 
                            flags |= TextFormatFlags.EndEllipsis;
                        } 
                        TextRenderer.DrawText(graphics,
                                              formattedValueStr,
                                              cellStyle.Font,
                                              valBounds, 
                                              textColor,
                                              flags); 
                    } 
                }
                else 
                {
                    Debug.Assert(computeContentBounds);
                    resultBounds = DataGridViewUtilities.GetTextBounds(valBounds, formattedValueStr, flags, cellStyle);
                } 
            }
            else if (computeErrorIconBounds && !String.IsNullOrEmpty(errorText)) 
            { 
                resultBounds = ComputeErrorIconBounds(errorBounds);
            } 

            if (this.DataGridView.ShowCellErrors && paint && DataGridViewCell.PaintErrorIcon(paintParts))
            {
                PaintErrorIcon(graphics, cellStyle, rowIndex, cellBounds, errorBounds, errorText); 
            }
 
            return resultBounds; 
        }
 
        /// 
        protected override void PaintBorder(Graphics graphics,
            Rectangle clipBounds,
            Rectangle bounds, 
            DataGridViewCellStyle cellStyle,
            DataGridViewAdvancedBorderStyle advancedBorderStyle) 
        { 
            if (this.DataGridView == null)
            { 
                return;
            }

            base.PaintBorder(graphics, clipBounds, bounds, cellStyle, advancedBorderStyle); 

            if (!this.DataGridView.RightToLeftInternal && 
                this.DataGridView.ApplyVisualStylesToHeaderCells) 
            {
                if (this.DataGridView.AdvancedColumnHeadersBorderStyle.All == DataGridViewAdvancedCellBorderStyle.Inset) 
                {
                    Pen penControlDark = null, penControlLightLight = null;
                    GetContrastedPens(cellStyle.BackColor, ref penControlDark, ref penControlLightLight);
                    graphics.DrawLine(penControlDark, bounds.X, bounds.Y, bounds.X, bounds.Bottom - 1); 
                    graphics.DrawLine(penControlDark, bounds.X, bounds.Y, bounds.Right - 1, bounds.Y);
                } 
                else if (this.DataGridView.AdvancedColumnHeadersBorderStyle.All == DataGridViewAdvancedCellBorderStyle.Outset) 
                {
                    Pen penControlDark = null, penControlLightLight = null; 
                    GetContrastedPens(cellStyle.BackColor, ref penControlDark, ref penControlLightLight);
                    graphics.DrawLine(penControlLightLight, bounds.X, bounds.Y, bounds.X, bounds.Bottom - 1);
                    graphics.DrawLine(penControlLightLight, bounds.X, bounds.Y, bounds.Right - 1, bounds.Y);
                } 
                else if (this.DataGridView.AdvancedColumnHeadersBorderStyle.All == DataGridViewAdvancedCellBorderStyle.InsetDouble)
                { 
                    Pen penControlDark = null, penControlLightLight = null; 
                    GetContrastedPens(cellStyle.BackColor, ref penControlDark, ref penControlLightLight);
                    graphics.DrawLine(penControlDark, bounds.X + 1, bounds.Y + 1, bounds.X + 1, bounds.Bottom - 1); 
                    graphics.DrawLine(penControlDark, bounds.X + 1, bounds.Y + 1, bounds.Right - 1, bounds.Y + 1);
                }
            }
        } 

        ///  
        ///  
        ///    
        ///  
        public override string ToString()
        {
            return "DataGridViewTopLeftHeaderCell";
        } 

        private class DataGridViewTopLeftHeaderCellRenderer 
        { 
            private static VisualStyleRenderer visualStyleRenderer;
 
            private DataGridViewTopLeftHeaderCellRenderer()
            {
            }
 
            public static VisualStyleRenderer VisualStyleRenderer
            { 
                get 
                {
                    if (visualStyleRenderer == null) 
                    {
                        visualStyleRenderer = new VisualStyleRenderer(HeaderElement);
                    }
 
                    return visualStyleRenderer;
                } 
            } 

            public static void DrawHeader(Graphics g, Rectangle bounds, int headerState) 
            {
                VisualStyleRenderer.SetParameters(HeaderElement.ClassName, HeaderElement.Part, headerState);
                VisualStyleRenderer.DrawBackground(g, bounds, Rectangle.Truncate(g.ClipBounds));
            } 
        }
 
        ///  
        protected class DataGridViewTopLeftHeaderCellAccessibleObject : DataGridViewColumnHeaderCellAccessibleObject
        { 
            /// 
            public DataGridViewTopLeftHeaderCellAccessibleObject(DataGridViewTopLeftHeaderCell owner) : base (owner)
            {
            } 

            ///  
            public override Rectangle Bounds 
            {
                get 
                {
                    Rectangle cellRect = this.Owner.DataGridView.GetCellDisplayRectangle(-1, -1, false /*cutOverflow*/);
                    return this.Owner.DataGridView.RectangleToScreen(cellRect);
                } 
            }
 
            ///  
            public override string DefaultAction
            { 
                get
                {
                    if (this.Owner.DataGridView.MultiSelect)
                    { 
                        return SR.GetString(SR.DataGridView_AccTopLeftColumnHeaderCellDefaultAction);
                    } 
                    else 
                    {
                        return String.Empty; 
                    }
                }
            }
 

            ///  
            public override string Name 
            {
                get 
                {
                    object value = this.Owner.Value;
                    if (value != null && !(value is String))
                    { 
                        // The user set the Value on the DataGridViewTopLeftHeaderCell and it did not set it to a string.
                        // Then the name of the DataGridViewTopLeftHeaderAccessibleObject is String.Empty; 
                        // 
                        return String.Empty;
                    } 
                    string strValue = value as string;
                    if (String.IsNullOrEmpty(strValue))
                    {
                        if (this.Owner.DataGridView != null) 
                        {
                            if (this.Owner.DataGridView.RightToLeft == RightToLeft.No) 
                            { 
                                return SR.GetString(SR.DataGridView_AccTopLeftColumnHeaderCellName);
                            } 
                            else
                            {
                                return SR.GetString(SR.DataGridView_AccTopLeftColumnHeaderCellNameRTL);
                            } 
                        }
                        else 
                        { 
                            return String.Empty;
                        } 
                    }
                    else
                    {
                        return String.Empty; 
                    }
                } 
            } 

            ///  
            public override AccessibleStates State
            {
                get
                { 
                    AccessibleStates resultState = AccessibleStates.Selectable;
 
                    // get the Offscreen state from the base method. 
                    AccessibleStates state = base.State;
                    if ((state & AccessibleStates.Offscreen) == AccessibleStates.Offscreen) 
                    {
                        resultState |= AccessibleStates.Offscreen;
                    }
 
                    // If all the cells are selected, then the top left header cell accessible object is considered to be selected as well.
                    if (this.Owner.DataGridView.AreAllCellsSelected(false /*includeInvisibleCells*/)) 
                    { 
                        resultState |= AccessibleStates.Selected;
                    } 

                    return resultState;
                }
            } 

            ///  
            public override string Value 
            {
                [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)] 
                get
                {
                    // We changed DataGridViewTopLeftHeaderCellAccessibleObject::Name to return a string : vsw 393122
                    // However, DataGridViewTopLeftHeaderCellAccessibleObject::Value should still return String.Empty. 
                    return String.Empty;
                } 
            } 

            ///  
            [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
            public override void DoDefaultAction()
            {
                this.Owner.DataGridView.SelectAll(); 
            }
 
            ///  
            [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
            public override AccessibleObject Navigate(AccessibleNavigation navigationDirection) 
            {
                Debug.Assert(this.Owner.DataGridView.RowHeadersVisible, "if the row headers are not visible how did you get the top left header cell acc object?");
                switch (navigationDirection)
                { 
                    case AccessibleNavigation.Previous:
                        return null; 
                    case AccessibleNavigation.Left: 
                        if (this.Owner.DataGridView.RightToLeft == RightToLeft.No)
                        { 
                            return null;
                        }
                        else
                        { 
                            return NavigateForward();
                        } 
                    case AccessibleNavigation.Next: 
                        return NavigateForward();
                    case AccessibleNavigation.Right: 
                        if (this.Owner.DataGridView.RightToLeft == RightToLeft.No)
                        {
                            return NavigateForward();
                        } 
                        else
                        { 
                            return null; 
                        }
                    default: 
                        return null;
                }
            }
 
            private AccessibleObject NavigateForward()
            { 
                if (this.Owner.DataGridView.Columns.GetColumnCount(DataGridViewElementStates.Visible) == 0) 
                {
                    return null; 
                }

                // return the acc object for the first visible column
                return this.Owner.DataGridView.AccessibilityObject.GetChild(0).GetChild(1); 
            }
 
            ///  
            [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
            public override void Select(AccessibleSelection flags) 
            {
                if (this.Owner == null)
                {
                    throw new InvalidOperationException(SR.GetString(SR.DataGridViewCellAccessibleObject_OwnerNotSet)); 
                }
 
                // AccessibleSelection.TakeFocus should focus the grid and then focus the first data grid view data cell 
                if ((flags & AccessibleSelection.TakeFocus) == AccessibleSelection.TakeFocus)
                { 
                    // Focus the grid
                    this.Owner.DataGridView.FocusInternal();
                    if (this.Owner.DataGridView.Columns.GetColumnCount(DataGridViewElementStates.Visible) > 0 &&
                        this.Owner.DataGridView.Rows.GetRowCount(DataGridViewElementStates.Visible) > 0) 
                    {
                        // This means that there are visible rows and columns. 
                        // Focus the first data cell. 
                        DataGridViewRow row = this.Owner.DataGridView.Rows[this.Owner.DataGridView.Rows.GetFirstRow(DataGridViewElementStates.Visible)];
                        DataGridViewColumn col = this.Owner.DataGridView.Columns.GetFirstColumn(DataGridViewElementStates.Visible); 

                        // DataGridView::set_CurrentCell clears the previous selection.
                        // So use SetCurrenCellAddressCore directly.
                        this.Owner.DataGridView.SetCurrentCellAddressCoreInternal(col.Index, row.Index, false /*setAnchorCellAddress*/, true /*validateCurrentCell*/, false /*thoughMouseClick*/); 
                    }
                } 
 
                // AddSelection selects the entire grid.
                if ((flags & AccessibleSelection.AddSelection) == AccessibleSelection.AddSelection) 
                {
                    if (this.Owner.DataGridView.MultiSelect)
                    {
                        this.Owner.DataGridView.SelectAll(); 
                    }
                } 
 
                // RemoveSelection clears the selection on the entire grid.
                // But only if AddSelection is not set. 
                if ((flags & AccessibleSelection.RemoveSelection) == AccessibleSelection.RemoveSelection &&
                    (flags & AccessibleSelection.AddSelection) == 0)
                {
                    this.Owner.DataGridView.ClearSelection(); 
                }
            } 
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Windows.Forms 
{ 
    using System;
    using System.Diagnostics; 
    using System.Drawing;
    using System.Windows.Forms.VisualStyles;
    using System.ComponentModel;
    using System.Windows.Forms.Internal; 
    using System.Security.Permissions;
 
    ///  
    /// 
    ///     
    /// 
    public class DataGridViewTopLeftHeaderCell : DataGridViewColumnHeaderCell
    {
        private static readonly VisualStyleElement HeaderElement = VisualStyleElement.Header.Item.Normal; 

        private const byte DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginLeft = 1; 
        private const byte DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginRight = 2; 
        private const byte DATAGRIDVIEWTOPLEFTHEADERCELL_verticalTextMargin = 1;
 
        /// 
        public DataGridViewTopLeftHeaderCell()
        {
        } 

        ///  
        protected override AccessibleObject CreateAccessibilityInstance() 
        {
            return new DataGridViewTopLeftHeaderCellAccessibleObject(this); 
        }

        /// 
        protected override Rectangle GetContentBounds(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex) 
        {
            if (cellStyle == null) 
            { 
                throw new ArgumentNullException("cellStyle");
            } 

            if (rowIndex != -1)
            {
                throw new ArgumentOutOfRangeException("rowIndex"); 
            }
 
            if (this.DataGridView == null) 
            {
                return Rectangle.Empty; 
            }

            object value = GetValue(rowIndex);
 
            // Intentionally not using GetFormattedValue because header cells don't typically perform formatting.
            // the content bounds are computed on demand 
            // we mimic a lot of the painting code 

            // get the borders 
            DataGridViewAdvancedBorderStyle dgvabsEffective;
            DataGridViewElementStates cellState;
            Rectangle cellBounds;
 
            ComputeBorderStyleCellStateAndCellBounds(rowIndex, out dgvabsEffective, out cellState, out cellBounds);
 
            Rectangle contentBounds = PaintPrivate(graphics, 
                cellBounds,
                cellBounds, 
                rowIndex,
                cellState,
                value,
                null /*errorText*/,                 // contentBounds is independent of errorText 
                cellStyle,
                dgvabsEffective, 
                DataGridViewPaintParts.ContentForeground, 
                true /*computeContentBounds*/,
                false /*computeErrorIconBounds*/, 
                false /*paint*/);

#if DEBUG
            Rectangle contentBoundsDebug = PaintPrivate(graphics, 
                cellBounds,
                cellBounds, 
                rowIndex, 
                cellState,
                value, 
                GetErrorText(rowIndex),
                cellStyle,
                dgvabsEffective,
                DataGridViewPaintParts.ContentForeground, 
                true /*computeContentBounds*/,
                false /*computeErrorIconBounds*/, 
                false /*paint*/); 
            Debug.Assert(contentBoundsDebug.Equals(contentBounds));
#endif 

            return contentBounds;
        }
 
        /// 
        protected override Rectangle GetErrorIconBounds(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex) 
        { 
            if (rowIndex != -1)
            { 
                throw new ArgumentOutOfRangeException("rowIndex");
            }

            if (this.DataGridView == null) 
            {
                return Rectangle.Empty; 
            } 

            if (cellStyle == null) 
            {
                throw new ArgumentNullException("cellStyle");
            }
 
            DataGridViewAdvancedBorderStyle dgvabsEffective;
            DataGridViewElementStates cellState; 
            Rectangle cellBounds; 

            ComputeBorderStyleCellStateAndCellBounds(rowIndex, out dgvabsEffective, out cellState, out cellBounds); 

            Rectangle errorBounds = PaintPrivate(graphics,
                cellBounds,
                cellBounds, 
                rowIndex,
                cellState, 
                null /*formattedValue*/,            // errorIconBounds is independent of formattedValue 
                GetErrorText(rowIndex),
                cellStyle, 
                dgvabsEffective,
                DataGridViewPaintParts.ContentForeground,
                false /*computeContentBounds*/,
                true /*computeErrorIconBounds*/, 
                false /*paint*/);
 
#if DEBUG 
            object value = GetValue(rowIndex);
 
            Rectangle errorBoundsDebug = PaintPrivate(graphics,
                cellBounds,
                cellBounds,
                rowIndex, 
                cellState,
                value, 
                GetErrorText(rowIndex), 
                cellStyle,
                dgvabsEffective, 
                DataGridViewPaintParts.ContentForeground,
                false /*computeContentBounds*/,
                true /*computeErrorIconBounds*/,
                false /*paint*/); 
            Debug.Assert(errorBoundsDebug.Equals(errorBounds));
#endif 
 
            return errorBounds;
        } 

        /// 
        protected override Size GetPreferredSize(Graphics graphics, DataGridViewCellStyle cellStyle, int rowIndex, Size constraintSize)
        { 
            if (rowIndex != -1)
            { 
                throw new ArgumentOutOfRangeException("rowIndex"); 
            }
 
            if (this.DataGridView == null)
            {
                return new Size(-1, -1);
            } 

            if (cellStyle == null) 
            { 
                throw new ArgumentNullException("cellStyle");
            } 

            Rectangle borderWidthsRect = BorderWidths(this.DataGridView.AdjustedTopLeftHeaderBorderStyle);
            int borderAndPaddingWidths = borderWidthsRect.Left + borderWidthsRect.Width + cellStyle.Padding.Horizontal;
            int borderAndPaddingHeights = borderWidthsRect.Top + borderWidthsRect.Height + cellStyle.Padding.Vertical; 
            TextFormatFlags flags = DataGridViewUtilities.ComputeTextFormatFlagsForCellStyleAlignment(this.DataGridView.RightToLeftInternal, cellStyle.Alignment, cellStyle.WrapMode);
 
            // Intentionally not using GetFormattedValue because header cells don't typically perform formatting. 
            object val = GetValue(rowIndex);
            if (!(val is string)) 
            {
                val = null;
            }
            return DataGridViewUtilities.GetPreferredRowHeaderSize(graphics, 
                                                                   (string) val,
                                                                   cellStyle, 
                                                                   borderAndPaddingWidths, 
                                                                   borderAndPaddingHeights,
                                                                   this.DataGridView.ShowCellErrors, 
                                                                   false /*showGlyph*/,
                                                                   constraintSize,
                                                                   flags);
        } 

        ///  
        protected override void Paint(Graphics graphics, 
            Rectangle clipBounds,
            Rectangle cellBounds, 
            int rowIndex,
            DataGridViewElementStates cellState,
            object value,
            object formattedValue, 
            string errorText,
            DataGridViewCellStyle cellStyle, 
            DataGridViewAdvancedBorderStyle advancedBorderStyle, 
            DataGridViewPaintParts paintParts)
        { 
            if (cellStyle == null)
            {
                throw new ArgumentNullException("cellStyle");
            } 

            PaintPrivate(graphics, 
                clipBounds, 
                cellBounds,
                rowIndex, 
                cellState,
                formattedValue,
                errorText,
                cellStyle, 
                advancedBorderStyle,
                paintParts, 
                false /*computeContentBounds*/, 
                false /*computeErrorIconBounds*/,
                true /*paint*/); 
        }

        // PaintPrivate is used in three places that need to duplicate the paint code:
        // 1. DataGridViewCell::Paint method 
        // 2. DataGridViewCell::GetContentBounds
        // 3. DataGridViewCell::GetErrorIconBounds 
        // 
        // if computeContentBounds is true then PaintPrivate returns the contentBounds
        // else if computeErrorIconBounds is true then PaintPrivate returns the errorIconBounds 
        // else it returns Rectangle.Empty;
        private Rectangle PaintPrivate(Graphics graphics,
            Rectangle clipBounds,
            Rectangle cellBounds, 
            int rowIndex,
            DataGridViewElementStates cellState, 
            object formattedValue, 
            string errorText,
            DataGridViewCellStyle cellStyle, 
            DataGridViewAdvancedBorderStyle advancedBorderStyle,
            DataGridViewPaintParts paintParts,
            bool computeContentBounds,
            bool computeErrorIconBounds, 
            bool paint)
        { 
            // Parameter checking. 
            // One bit and one bit only should be turned on
            Debug.Assert(paint || computeContentBounds || computeErrorIconBounds); 
            Debug.Assert(!paint || !computeContentBounds || !computeErrorIconBounds);
            Debug.Assert(!computeContentBounds || !computeErrorIconBounds || !paint);
            Debug.Assert(!computeErrorIconBounds || !paint || !computeContentBounds);
            Debug.Assert(cellStyle != null); 

            // If computeContentBounds == TRUE then resultBounds will be the contentBounds. 
            // If computeErrorIconBounds == TRUE then resultBounds will be the error icon bounds. 
            // Else resultBounds will be Rectangle.Empty;
            Rectangle resultBounds = Rectangle.Empty; 

            Rectangle valBounds = cellBounds;
            Rectangle borderWidths = BorderWidths(advancedBorderStyle);
 
            valBounds.Offset(borderWidths.X, borderWidths.Y);
            valBounds.Width -= borderWidths.Right; 
            valBounds.Height -= borderWidths.Bottom; 

            bool cellSelected = (cellState & DataGridViewElementStates.Selected) != 0; 

            if (paint && DataGridViewCell.PaintBackground(paintParts))
            {
                if (this.DataGridView.ApplyVisualStylesToHeaderCells) 
                {
                    // XP Theming 
                    int state = (int)HeaderItemState.Normal; 

                    if (this.ButtonState != ButtonState.Normal) 
                    {
                        Debug.Assert(this.ButtonState == ButtonState.Pushed);
                        state = (int)HeaderItemState.Pressed;
                    } 
                    else if (this.DataGridView.MouseEnteredCellAddress.Y == rowIndex && this.DataGridView.MouseEnteredCellAddress.X == this.ColumnIndex)
                    { 
                        state = (int)HeaderItemState.Hot; 
                    }
 
                    valBounds.Inflate(16, 16);
                    DataGridViewTopLeftHeaderCellRenderer.DrawHeader(graphics, valBounds, state);
                    valBounds.Inflate(-16, -16);
                } 
                else
                { 
                    SolidBrush br = this.DataGridView.GetCachedBrush((DataGridViewCell.PaintSelectionBackground(paintParts) && cellSelected) ? cellStyle.SelectionBackColor : cellStyle.BackColor); 
                    if (br.Color.A == 255)
                    { 
                        graphics.FillRectangle(br, valBounds);
                    }
                }
            } 

            if (paint && DataGridViewCell.PaintBorder(paintParts)) 
            { 
                PaintBorder(graphics, clipBounds, cellBounds, cellStyle, advancedBorderStyle);
            } 

            if (cellStyle.Padding != Padding.Empty)
            {
                if (this.DataGridView.RightToLeftInternal) 
                {
                    valBounds.Offset(cellStyle.Padding.Right, cellStyle.Padding.Top); 
                } 
                else
                { 
                    valBounds.Offset(cellStyle.Padding.Left, cellStyle.Padding.Top);
                }
                valBounds.Width -= cellStyle.Padding.Horizontal;
                valBounds.Height -= cellStyle.Padding.Vertical; 
            }
 
            Rectangle errorBounds = valBounds; 
            string formattedValueStr = formattedValue as string;
 
            // Font independent margins
            valBounds.Offset(DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginLeft, DATAGRIDVIEWTOPLEFTHEADERCELL_verticalTextMargin);
            valBounds.Width -= DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginLeft + DATAGRIDVIEWTOPLEFTHEADERCELL_horizontalTextMarginRight;
            valBounds.Height -= 2 * DATAGRIDVIEWTOPLEFTHEADERCELL_verticalTextMargin; 
            if (valBounds.Width > 0 &&
                valBounds.Height > 0 && 
                !String.IsNullOrEmpty(formattedValueStr) && 
                (paint || computeContentBounds))
            { 
                Color textColor;
                if (this.DataGridView.ApplyVisualStylesToHeaderCells)
                {
                    textColor = DataGridViewTopLeftHeaderCellRenderer.VisualStyleRenderer.GetColor(ColorProperty.TextColor); 
                }
                else 
                { 
                    textColor = cellSelected ? cellStyle.SelectionForeColor : cellStyle.ForeColor;
                } 
                TextFormatFlags flags = DataGridViewUtilities.ComputeTextFormatFlagsForCellStyleAlignment(this.DataGridView.RightToLeftInternal, cellStyle.Alignment, cellStyle.WrapMode);
                if (paint)
                {
                    if (DataGridViewCell.PaintContentForeground(paintParts)) 
                    {
                        if ((flags & TextFormatFlags.SingleLine) != 0) 
                        { 
                            flags |= TextFormatFlags.EndEllipsis;
                        } 
                        TextRenderer.DrawText(graphics,
                                              formattedValueStr,
                                              cellStyle.Font,
                                              valBounds, 
                                              textColor,
                                              flags); 
                    } 
                }
                else 
                {
                    Debug.Assert(computeContentBounds);
                    resultBounds = DataGridViewUtilities.GetTextBounds(valBounds, formattedValueStr, flags, cellStyle);
                } 
            }
            else if (computeErrorIconBounds && !String.IsNullOrEmpty(errorText)) 
            { 
                resultBounds = ComputeErrorIconBounds(errorBounds);
            } 

            if (this.DataGridView.ShowCellErrors && paint && DataGridViewCell.PaintErrorIcon(paintParts))
            {
                PaintErrorIcon(graphics, cellStyle, rowIndex, cellBounds, errorBounds, errorText); 
            }
 
            return resultBounds; 
        }
 
        /// 
        protected override void PaintBorder(Graphics graphics,
            Rectangle clipBounds,
            Rectangle bounds, 
            DataGridViewCellStyle cellStyle,
            DataGridViewAdvancedBorderStyle advancedBorderStyle) 
        { 
            if (this.DataGridView == null)
            { 
                return;
            }

            base.PaintBorder(graphics, clipBounds, bounds, cellStyle, advancedBorderStyle); 

            if (!this.DataGridView.RightToLeftInternal && 
                this.DataGridView.ApplyVisualStylesToHeaderCells) 
            {
                if (this.DataGridView.AdvancedColumnHeadersBorderStyle.All == DataGridViewAdvancedCellBorderStyle.Inset) 
                {
                    Pen penControlDark = null, penControlLightLight = null;
                    GetContrastedPens(cellStyle.BackColor, ref penControlDark, ref penControlLightLight);
                    graphics.DrawLine(penControlDark, bounds.X, bounds.Y, bounds.X, bounds.Bottom - 1); 
                    graphics.DrawLine(penControlDark, bounds.X, bounds.Y, bounds.Right - 1, bounds.Y);
                } 
                else if (this.DataGridView.AdvancedColumnHeadersBorderStyle.All == DataGridViewAdvancedCellBorderStyle.Outset) 
                {
                    Pen penControlDark = null, penControlLightLight = null; 
                    GetContrastedPens(cellStyle.BackColor, ref penControlDark, ref penControlLightLight);
                    graphics.DrawLine(penControlLightLight, bounds.X, bounds.Y, bounds.X, bounds.Bottom - 1);
                    graphics.DrawLine(penControlLightLight, bounds.X, bounds.Y, bounds.Right - 1, bounds.Y);
                } 
                else if (this.DataGridView.AdvancedColumnHeadersBorderStyle.All == DataGridViewAdvancedCellBorderStyle.InsetDouble)
                { 
                    Pen penControlDark = null, penControlLightLight = null; 
                    GetContrastedPens(cellStyle.BackColor, ref penControlDark, ref penControlLightLight);
                    graphics.DrawLine(penControlDark, bounds.X + 1, bounds.Y + 1, bounds.X + 1, bounds.Bottom - 1); 
                    graphics.DrawLine(penControlDark, bounds.X + 1, bounds.Y + 1, bounds.Right - 1, bounds.Y + 1);
                }
            }
        } 

        ///  
        ///  
        ///    
        ///  
        public override string ToString()
        {
            return "DataGridViewTopLeftHeaderCell";
        } 

        private class DataGridViewTopLeftHeaderCellRenderer 
        { 
            private static VisualStyleRenderer visualStyleRenderer;
 
            private DataGridViewTopLeftHeaderCellRenderer()
            {
            }
 
            public static VisualStyleRenderer VisualStyleRenderer
            { 
                get 
                {
                    if (visualStyleRenderer == null) 
                    {
                        visualStyleRenderer = new VisualStyleRenderer(HeaderElement);
                    }
 
                    return visualStyleRenderer;
                } 
            } 

            public static void DrawHeader(Graphics g, Rectangle bounds, int headerState) 
            {
                VisualStyleRenderer.SetParameters(HeaderElement.ClassName, HeaderElement.Part, headerState);
                VisualStyleRenderer.DrawBackground(g, bounds, Rectangle.Truncate(g.ClipBounds));
            } 
        }
 
        ///  
        protected class DataGridViewTopLeftHeaderCellAccessibleObject : DataGridViewColumnHeaderCellAccessibleObject
        { 
            /// 
            public DataGridViewTopLeftHeaderCellAccessibleObject(DataGridViewTopLeftHeaderCell owner) : base (owner)
            {
            } 

            ///  
            public override Rectangle Bounds 
            {
                get 
                {
                    Rectangle cellRect = this.Owner.DataGridView.GetCellDisplayRectangle(-1, -1, false /*cutOverflow*/);
                    return this.Owner.DataGridView.RectangleToScreen(cellRect);
                } 
            }
 
            ///  
            public override string DefaultAction
            { 
                get
                {
                    if (this.Owner.DataGridView.MultiSelect)
                    { 
                        return SR.GetString(SR.DataGridView_AccTopLeftColumnHeaderCellDefaultAction);
                    } 
                    else 
                    {
                        return String.Empty; 
                    }
                }
            }
 

            ///  
            public override string Name 
            {
                get 
                {
                    object value = this.Owner.Value;
                    if (value != null && !(value is String))
                    { 
                        // The user set the Value on the DataGridViewTopLeftHeaderCell and it did not set it to a string.
                        // Then the name of the DataGridViewTopLeftHeaderAccessibleObject is String.Empty; 
                        // 
                        return String.Empty;
                    } 
                    string strValue = value as string;
                    if (String.IsNullOrEmpty(strValue))
                    {
                        if (this.Owner.DataGridView != null) 
                        {
                            if (this.Owner.DataGridView.RightToLeft == RightToLeft.No) 
                            { 
                                return SR.GetString(SR.DataGridView_AccTopLeftColumnHeaderCellName);
                            } 
                            else
                            {
                                return SR.GetString(SR.DataGridView_AccTopLeftColumnHeaderCellNameRTL);
                            } 
                        }
                        else 
                        { 
                            return String.Empty;
                        } 
                    }
                    else
                    {
                        return String.Empty; 
                    }
                } 
            } 

            ///  
            public override AccessibleStates State
            {
                get
                { 
                    AccessibleStates resultState = AccessibleStates.Selectable;
 
                    // get the Offscreen state from the base method. 
                    AccessibleStates state = base.State;
                    if ((state & AccessibleStates.Offscreen) == AccessibleStates.Offscreen) 
                    {
                        resultState |= AccessibleStates.Offscreen;
                    }
 
                    // If all the cells are selected, then the top left header cell accessible object is considered to be selected as well.
                    if (this.Owner.DataGridView.AreAllCellsSelected(false /*includeInvisibleCells*/)) 
                    { 
                        resultState |= AccessibleStates.Selected;
                    } 

                    return resultState;
                }
            } 

            ///  
            public override string Value 
            {
                [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)] 
                get
                {
                    // We changed DataGridViewTopLeftHeaderCellAccessibleObject::Name to return a string : vsw 393122
                    // However, DataGridViewTopLeftHeaderCellAccessibleObject::Value should still return String.Empty. 
                    return String.Empty;
                } 
            } 

            ///  
            [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
            public override void DoDefaultAction()
            {
                this.Owner.DataGridView.SelectAll(); 
            }
 
            ///  
            [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
            public override AccessibleObject Navigate(AccessibleNavigation navigationDirection) 
            {
                Debug.Assert(this.Owner.DataGridView.RowHeadersVisible, "if the row headers are not visible how did you get the top left header cell acc object?");
                switch (navigationDirection)
                { 
                    case AccessibleNavigation.Previous:
                        return null; 
                    case AccessibleNavigation.Left: 
                        if (this.Owner.DataGridView.RightToLeft == RightToLeft.No)
                        { 
                            return null;
                        }
                        else
                        { 
                            return NavigateForward();
                        } 
                    case AccessibleNavigation.Next: 
                        return NavigateForward();
                    case AccessibleNavigation.Right: 
                        if (this.Owner.DataGridView.RightToLeft == RightToLeft.No)
                        {
                            return NavigateForward();
                        } 
                        else
                        { 
                            return null; 
                        }
                    default: 
                        return null;
                }
            }
 
            private AccessibleObject NavigateForward()
            { 
                if (this.Owner.DataGridView.Columns.GetColumnCount(DataGridViewElementStates.Visible) == 0) 
                {
                    return null; 
                }

                // return the acc object for the first visible column
                return this.Owner.DataGridView.AccessibilityObject.GetChild(0).GetChild(1); 
            }
 
            ///  
            [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
            public override void Select(AccessibleSelection flags) 
            {
                if (this.Owner == null)
                {
                    throw new InvalidOperationException(SR.GetString(SR.DataGridViewCellAccessibleObject_OwnerNotSet)); 
                }
 
                // AccessibleSelection.TakeFocus should focus the grid and then focus the first data grid view data cell 
                if ((flags & AccessibleSelection.TakeFocus) == AccessibleSelection.TakeFocus)
                { 
                    // Focus the grid
                    this.Owner.DataGridView.FocusInternal();
                    if (this.Owner.DataGridView.Columns.GetColumnCount(DataGridViewElementStates.Visible) > 0 &&
                        this.Owner.DataGridView.Rows.GetRowCount(DataGridViewElementStates.Visible) > 0) 
                    {
                        // This means that there are visible rows and columns. 
                        // Focus the first data cell. 
                        DataGridViewRow row = this.Owner.DataGridView.Rows[this.Owner.DataGridView.Rows.GetFirstRow(DataGridViewElementStates.Visible)];
                        DataGridViewColumn col = this.Owner.DataGridView.Columns.GetFirstColumn(DataGridViewElementStates.Visible); 

                        // DataGridView::set_CurrentCell clears the previous selection.
                        // So use SetCurrenCellAddressCore directly.
                        this.Owner.DataGridView.SetCurrentCellAddressCoreInternal(col.Index, row.Index, false /*setAnchorCellAddress*/, true /*validateCurrentCell*/, false /*thoughMouseClick*/); 
                    }
                } 
 
                // AddSelection selects the entire grid.
                if ((flags & AccessibleSelection.AddSelection) == AccessibleSelection.AddSelection) 
                {
                    if (this.Owner.DataGridView.MultiSelect)
                    {
                        this.Owner.DataGridView.SelectAll(); 
                    }
                } 
 
                // RemoveSelection clears the selection on the entire grid.
                // But only if AddSelection is not set. 
                if ((flags & AccessibleSelection.RemoveSelection) == AccessibleSelection.RemoveSelection &&
                    (flags & AccessibleSelection.AddSelection) == 0)
                {
                    this.Owner.DataGridView.ClearSelection(); 
                }
            } 
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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