KryptonFontDialog

Overview

The KryptonFontDialog class provides a Krypton-themed wrapper around the standard Windows font selection dialog. It inherits from System.Windows.Forms.FontDialog and enhances it with Krypton styling, custom icons, titles, high-DPI support, and optional extended color selection capabilities for font styling.

Class Hierarchy

System.Object
└── System.ComponentModel.Component
    └── System.Windows.Forms.CommonDialog
        └── System.Windows.Forms.FontDialog
            └── Krypton.Toolkit.KryptonFontDialog

Constructor and Initialization

public KryptonFontDialog()

The constructor initializes the enhanced features:

• CommonDialogHandler: Manages Krypton theming and window behavior
• Default Icon: Uses DialogImageResources.font
• Default Icon Display: ShowIcon = false
• Click Callback: Handles dialog-specific button interactions

Key Properties

Title Property

public string Title { get; set; }

• Purpose: Sets the caption text shown in the dialog's title bar
• Category: Appearance
• Default Value: Empty string (uses system default)
• Designer Visible: Yes

Usage Example:

var dialog = new KryptonFontDialog
{
    Title = "Choose Document Font"
};

Icon Property

public Icon Icon { get; set; }

• Purpose: Sets a custom icon displayed in the dialog's title bar
• Category: Appearance
• Default Value: DialogImageResources.font
• Designer Visible: Yes

Usage Example:

var dialog = new KryptonFontDialog
{
    Icon = MyApplicationIcon,
    ShowIcon = true
};

ShowIcon Property

[DefaultValue(false)]
public bool ShowIcon { get; set; }

• Purpose: Controls whether the dialog displays an icon in the title bar
• Category: Appearance
• Default Value: false

DisplayExtendedColorsButton Property

public bool DisplayExtendedColorsButton { get; set; }

• Purpose: Shows an enhanced color selection interface instead of the basic color dropdown
• Category: Appearance
• Default Value: false
• Side Effects: Automatically enables ShowColor when set to true

Enhanced Color Selection: When enabled, replaces the standard color combobox with:

• KryptonColorButton: Full-featured color selection
• Scheme Support: Office themes and basic 16-color schemes
• Enhanced UX: Better visual feedback and color preview
• Custom Color Support: Selection beyond basic palette

Usage Example:

var dialog = new KryptonFontDialog
{
    DisplayExtendedColorsButton = true,
    ShowColor = true,  // Automatically enabled
    Title = "Font & Color Selection"
};

DisplayIsPrinterFontDescription Property

public bool DisplayIsPrinterFontDescription { get; set; }

Purpose: Shows informational text about printer compatibility

• Category: Behavior
• Implementation: Uses internal Win32 dialog options
• Use Case: Warns users when selected fonts may not print correctly

Internal Implementation:

• Accesses private GetOption and SetOption methods via reflection
• Controls bit 0x02 in internal dialog options
• Provides printer compatibility warnings

Usage Example:

var dialog = new KryptonFontDialog
{
    DisplayIsPrinterFontDescription = true,
    Title = "Font Selection (Printer Compatible)"
};

Standard FontDialog Properties

The dialog inherits all standard FontDialog properties with full compatibility:

• AllowSimulations: Allows font simulation options
• AllowVectorFonts: Permits vector font selection
• AllowVerticalFonts: Enables vertical font selection
• Color: Font color selection
• FixedPitchOnly: Restricts to fixed-width fonts only
• Font: Selected font object
• MaxSize: Maximum font size allowed
• MinSize: Minimum font size allowed
• ScriptsOnly: Restricts to specific script subsets
• ShowApply: Shows Apply button
• ShowColor: Enables color selection
• ShowEffects: Displays strikethrough and underline options
• ShowHelp: Shows Help button

Enhanced Features

Custom Color Button Integration

When DisplayExtendedColorsButton is enabled:

public void ConfigureRichTextFont()
{
    var dialog = new KryptonFontDialog
    {
        Title = "Rich Text Font Selection",
        DisplayExtendedColorsButton = true,
        ShowEffects = true,
        AllowVectorFonts = true,
        MaxSize = 24,
        MinSize = 8
    };

    if (dialog.ShowDialog() == DialogResult.OK)
    {
        RichTextBox richTextBox = GetActiveRichTextBox();
        richTextBox.SelectionFont = dialog.Font;
        richTextBox.SelectionColor = dialog.Color;
    }
}

Theme Integration

The dialog automatically applies Krypton theming:

• CommonDialogHandler: Provides consistent window styling
• DPI Scaling: Automatic scaling for high-DPI displays
• Palette Awareness: Respects global Krypton palette settings
• Consistent UI: Matches other Krypton-themed dialogs

Native Integration

Special considerations for font dialog behavior:

• Limited Embedding: Avoids breaking modal loops
• Control Substitution: Seamlessly replaces color combobox
• Event Handling: Proper message routing and button states
• Print Awareness: Printer compatibility information

Advanced Usage Patterns

Font Family Management

public class FontManager
{
    private Font _defaultFont = new Font("Segoe UI", 12F);
    private Color _defaultColor = Color.Black;

    public FontInfo SelectFont(FontInfo currentFont)
    {
        var dialog = new KryptonFontDialog
        {
            Title = "Font Configuration",
            ShowIcon = true,
            Icon = SystemIcons.Information,
            DisplayExtendedColorsButton = true,
            Font = currentFont?.Font ?? _defaultFont,
            Color = currentFont?.Color ?? _defaultColor,
            ShowEffects = true,
            AllowVectorFonts = true
        };

        if (dialog.ShowDialog() == DialogResult.OK)
        {
            return new FontInfo
            {
                Font = dialog.Font,
                Color = dialog.Color,
                IsPrinterCompatible = IsPrinterFont(dialog.Font)
            };
        }

        return currentFont;
    }

    private static bool IsPrinterFont(Font font)
    {
        // Check if font has printer-compatible alternatives
        return !font.GdiVerticalFont && !font.GdiCharSet.Equals(1);
    }
}

Document Formatting Application

public class DocumentFormatter
{
    public void ApplyFontToSelection()
    {
        var currentSelection = GetSelectedTextProperties();
        
        var dialog = new KryptonFontDialog
        {
            Title = "Font Properties",
            DisplayExtendedColorsButton = true,
            Font = currentSelection.Font,
            Color = currentSelection.Color,
            ShowEffects = true,
            ShowApply = true,  // Allows preview without closing dialog
            AllowVectorFonts = true
        };

        // Handle Apply button for live preview
        dialog.Apply += (sender, e) => 
        {
            PreviewFontChange(dialog.Font, dialog.Color);
        };

        if (dialog.ShowDialog() == DialogResult.OK)
        {
            ApplyFontChange(dialog.Font, dialog.Color);
        }
    }

    private void PreviewFontChange(Font font, Color color)
    {
        // Temporarily apply changes for preview
        SetSelectionProperties(font, color);
    }

    private void ApplyFontChange(Font font, Color color)
    {
        // Apply final changes
        SetSelectionProperties(font, color);
        SaveDocument();
    }
}

Multi-Language Font Selection

public class LocalizationFontSelector
{
    public FontInfo SelectLocalizedFont(LanguageInfo language)
    {
        var dialog = new KryptonFontDialog
        {
            Title = $"Font for {language.DisplayName}",
            DisplayIsPrinterFontDescription = true,
            DisplayExtendedColorsButton = true,
            ScriptsOnly = GetScriptCode(language),
            AllowVectorFonts = language.SupportsVectorFonts,
            MinSize = language.MinimumFontSize,
            MaxSize = language.MaximumFontSize
        };

        if (dialog.ShowDialog() == DialogResult.OK)
        {
            return new FontInfo
            {
                Font = dialog.Font,
                Color = dialog.Color,
                Language = language,
                SupportsUnicode = CheckUnicodeSupport(dialog.Font)
            };
        }

        return null;
    }

    private UInt32 GetScriptCode(LanguageInfo language)
    {
        return language.ScriptCode switch
        {
            "Latin" => 0x0001,      // ANSI_CHARSET
            "Arabic" => 0x0002,     // SYMBOL_CHARSET  
            "Cyrillic" => 0x0004,   // SHIFTJIS_CHARSET
            "Chinese" => 0x0005,     // HANGEUL_CHARSET
            _ => 0x0000             // DEFAULT_CHARSET
        };
    };
}

Design-Time Integration

Visual Studio Designer

• Toolbox Integration: Available with custom bitmap representation
• Property Window: All properties properly categorized and exposed
• Custom Editors: Specialized editors for font and color properties
• Serialization: Design-time settings saved to designer files

Property Categories

• Data: Core font selection properties (Font, Color)
• Behavior: Control behavior (ShowColor, ShowEffects, ShowApply)
• Appearance: Visual customization (Title, Icon, ShowIcon, DisplayExtendedColorsButton)

Performance Considerations

• Lazy Color Button: Enhanced color button created only when needed
• Memory Management: Proper cleanup of embedded controls
• Event Handling: Optimized message routing for responsive UI
• DPI Scaling: Automatic scaling prevents layout issues

Common Issues and Solutions

Color Button Not Appearing

Issue: Extended color button not visible despite enabling DisplayExtendedColorsButton
Solution: Ensures ShowColor is enabled (automatically handled by setter)

Font Compatibility Warnings

Issue: Printer compatibility information not showing
Solution: Enable DisplayIsPrinterFontDescription and ensure printer fonts are available

Performance with Many Fonts

Issue: Slow font enumeration on systems with many fonts
Solution: Font dialog handles this internally; consider caching common fonts

Theme Inconsistencies

Issue: Dialog doesn't match application theme
Solution: Ensure global Krypton palette is properly initialized

Migration from Standard FontDialog

Direct Replacement

// Old code
using FontDialog = System.Windows.Forms.FontDialog;
var dialog = new FontDialog();

// New code
var dialog = new KryptonFontDialog();

Enhanced Features

// Standard FontDialog (basic)
var standardDialog = new FontDialog();

// KryptonFontDialog (enhanced)
var kryptonDialog = new KryptonFontDialog
{
    Title = "Enhanced Font Selection",
    Icon = applicationIcon,
    ShowIcon = true,
    DisplayExtendedColorsButton = true,  // Enhanced color selection
    DisplayIsPrinterFontDescription = true  // Printer compatibility info
};

Real-World Integration Examples

Text Editor Font Panel

public partial class TextEditorForm : Form
{
    private void ShowFontDialog()
    {
        var dialog = new KryptonFontDialog
        {
            Title = "Font Settings",
            Font = textEditor.SelectionFont ?? textEditor.Font,
            Color = textEditor.SelectionColor,
            DisplayExtendedColorsButton = true,
            ShowEffects = true,
            ShowApply = true
        };

        // Live preview on Apply
        dialog.Apply += (sender, e) =>
        {
            PreviewFont(dialog.Font, dialog.Color);
        };

        if (dialog.ShowDialog() == DialogResult.OK)
        {
            ApplyFont(dialog.Font, dialog.Color);
        }
    }

    private void PreviewFont(Font font, Color color)
    {
        textEditor.SelectionFont = font;
        textEditor.SelectionColor = color;
        
        // Highlight preview
        var oldBackColor = textEditor.SelectionBackColor;
        textEditor.SelectionBackColor = Color.LightYellow;
        
        // Restore after short delay
        var timer = new System.Windows.Forms.Timer { Interval = 2000 };
        timer.Tick += (s, e) =>
        {
            textEditor.SelectionBackColor = oldBackColor;
            timer.Stop();
            timer.Dispose();
        };
        timer.Start();
    }
}

Document Template Designer

public class DocumentTemplateDesigner : Form
{
    public void ConfigureStyles()
    {
        var styles = new[]
        {
            ("Heading", FontStyle.Bold),
            ("Subheading", FontStyle.Regular),
            ("Body", FontStyle.Regular),
            ("Caption", FontStyle.Italic)
        };

        foreach (var (styleName, defaultStyle) in styles)
        {
            ConfigureStyle(styleName, defaultStyle);
        }
    }

    private void ConfigureStyle(string styleName, FontStyle defaultStyle)
    {
        var dialog = new KryptonFontDialog
        {
            Title = $"Configure {styleName} Style",
            Style = defaultStyle,
            DisplayIsPrinterFontDescription = true,
            DisplayExtendedColorsButton = true,
            ShowIcon = true,
            Icon = GetStyleIcon(styleName)
        };

        if (dialog.ShowDialog() == DialogResult.OK)
        {
            UpdateStyleTemplate(styleName, dialog.Font, dialog.Color);
        }
    }
}