How to Customize the RichTextEditor's Context Menu items

Environment

Product Version	Product	Author
2022.2.622	RadRichTextEditor for WinForms	Desislava Yordanova

Description

RadRichTextEditor internally uses a ContextMenuContentBuilder which is responsible for populating the menu items according to the currently selected element in the document.

The following article demonstrates a sample approach how to eliminate the last two groups of context menu items for a selected image, e.g. Edit Image, Insert Caption, Text Wrapping:

Default context menu for an image element

Solution

Create a custom ContextMenuContentBuilder. It allows overriding multiple methods that are responsible for creating and populating the different groups of items according to the document element they are related to:

• CreateImageCommands - Creates the image commands menu items.
• CreateListCommands - Creates the list commands menu items.
• CreateFloatingBlockCommands - Creates the floating block commands menu items.
• CreateFieldCommands - Creates the field commands menu items.
• CreateTableCommands - Creates the table commands menu items.
• CreateTextEditCommands - Creates the text edit commands menu items.
• CreateHyperlinkCommands - Creates the hyperlink commands menu items.
• CreateSpellCheckingSuggestions - Creates the spell checking suggestions menu items.
• CreateClipboardCommands - Creates the clipboard commands menu items (cut, copy, paste, etc.).
• CreateHeaderFooterCommands - Creates the headers/footers commands.
• CreateTrackChangesCommands - Creates the track changes commands menu items (accept, reject, etc.).
• CreateCodeBlockCommands - Creates the code block commands menu items.

For the image element example, we will override the CreateImageCommands and CreateFloatingBlockCommands methods

• C#
• VB.NET

public RadForm1()
{
    InitializeComponent();

    Telerik.WinControls.RichTextEditor.UI.ContextMenu contextMenu = (Telerik.WinControls.RichTextEditor.UI.ContextMenu)this.radRichTextEditor1.RichTextBoxElement.ContextMenu;
    contextMenu.ContentBuilder = new CustomContextMenuContentBuilder();
} 

public class CustomContextMenuContentBuilder : ContextMenuContentBuilder
{
    protected override ContextMenuGroup CreateImageCommands()
    {
        //return base.CreateImageCommands();
        return null;
    }

    protected override ContextMenuGroup CreateFloatingBlockCommands()
    {
        //return base.CreateFloatingBlockCommands();
        return null;
    }
}

Public Sub New()
    InitializeComponent()
    Dim contextMenu As Telerik.WinControls.RichTextEditor.UI.ContextMenu = CType(Me.RadRichTextEditor1.RichTextBoxElement.ContextMenu, Telerik.WinControls.RichTextEditor.UI.ContextMenu)
    contextMenu.ContentBuilder = New CustomContextMenuContentBuilder()
End Sub

Public Class CustomContextMenuContentBuilder
    Inherits Telerik.WinForms.RichTextEditor.RichTextBoxUI.Menus.ContextMenuContentBuilder

    Protected Overrides Function CreateImageCommands() As ContextMenuGroup
        Return Nothing
    End Function

    Protected Overrides Function CreateFloatingBlockCommands() As ContextMenuGroup
        Return Nothing
    End Function
End Class

Make sure that you added using for C# and imports for VB Telerik.WinForms.RichTextEditor.RichTextBoxUI.Menus.